HISTOLOGY OF THE URETHRA AND ACCESSORY SEX GLANDS OF THE DOMESTIC ANIMALS AND OBSERVATIONS ON THE SURGICAL INSERTION OF THE URINARY BLADDER-NECK INTO THE DESCENDING COLON IN THE DOG Thesis Ior TI'IO Dogru oI DII. D. MICHIGAN STATE UNIVERSITY Madan B. Bharadwa j 1960 This is to certify that the thesis entitled HISTOLOGY OF THE URETHRA AND ACCESSORY SEX GLANDS OF THE DOMESTIC ANIMALS AND OBSERVATIONS ON THE SURGICAL INSERTION OF THE URINARY BLADDER-NECK INTO THE DESCENDING COLON IN THE DOG presented by MADAN B. BHARADWAJ has been accepted towards fulfillment of the requirements for Eh.D. degree in Anatomy [\0/ ’ I I I ' ' ‘ . / / A ' \ l . Major professor Date_AUQUSt I7 . I 960 0-169 L I B R A R Y Michigan State University A — HISTOLOGY OF THE URETHRA AND ACCESSORY SEX GLANDS OF THE DOHESTIC ANIMALS AND OBSERVATIONS ON THE SURGICAL INSEHTION OF THE URINARY BLADDER-NECK INTO THE DESCENDING COLON IN THE DOG BY MADAN B. BHARADWAJ A THESIS Submitted to the School for Advanced Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirement for the degree of DOCTOR OF PHILOSOPHY Department of Anatomy 1960 :n I J. ,1: N U fl/’ .1, fr, ABSTRACT Comparative histological studies of the urethrae and accessory sex glands were made on fifty-two domestic animals of seven species. The surgical insertion of the bladder into the intestine was done in three female dogs and one male dog. The pelvic urethra of the ruminants and the boar contains a pars disseminate. The boar has the most exten- sive disseminate prostate while the buck and the ram con- tain large cavernous spaces within the prostatic lobules. These cavernous spaces are especially large in the buck. The horse has 'Glands of Littre' in the fibromuscular sub— mucosa. The dog presents a prostatic and a membranous part of the pelvic urethra while the cat has preprostatic, prostatic and post prostatic portions. Variations are marked in the penile urethra of the domestic animals. The bulbocavernous muscle is present ventrolaterally in the urethra of the horse and the cat, while in the ruminants and the boar, the white fibrous tunic derived from the corpus cavernosum penis surrounds the urethra. in the dog, the urethra is lodged in the ventrally grooved os penis. The size of the cavernous spaces and the distribution of the elastic tissue in the trabeculae are most extensive in the buck. In all animals ii the cavernous spaces increase in size peripherally, and in the boar the urethra is contained inside a peripherally placed cavernous sinus. The processus urethrae of the bull and the horse contain erectile tissue, while in the buck and the ram the urethral lumen of the process is flanked by fibrocartilagencus cords. Specialized nerve endings are seen in the processus urethrae of the buck. In the female animals the cavernous spaces are most marked in the carnivores. The submucosa of the mare's urethra is rich in longitudinally placed smooth muscle bundles. The cow presents cavernous Spaces in the tunica prOpria in addition to the cavernous spaces seen in the submucosa of all the animals. Lamellated corpuscles are frequently seen in the urethral wall of the cat. The seminal vesicle is a true vesicular structure in the horse. It is glandular in ruminants and is struc— turally intermediate to the above two groups in the boar. The gland is compound tubular in the horse and the boar and is tubulo-alveolar in ruminants. The lining epithelium is simple columnar in the horse and boar, and it is pseudo— stratified columnar in ruminants. The ducts have an epi- thelial lining similar to the glands. In the mature bull, the basal epithelial cells contain fat. The ram lamb ex- hibits fat in these cells but fat is absent in the basal cells in the adult ram. The secretion is mainly serous in all species. Spermatozoa are frequently seen in the iii gland of the buck and the ram. The prostate gland is present in all domestic animals, but the location and distribution varies in most species. The gland is compound tubule-alveolar in rumi— nants and compound tubular in the remainder of the animals. The epithelial lining is simple columnar in all species. The secretion is serous in the horse, dog and cat, sero— mucous in ruminants, and mainly serous secretion with only traces of mucus in the boar. Concretions in the bull and corpora amylacea in the dog are occasionally seen. The bulbo-urethral glands are absent in the dog. The gland is compound tubular in all species except in the horse and the boar. In the two latter species it is compound tubulo-alveolar. The tubules and the ducts are lined by simple columnar epithelium in all animals. The secretion is mainly serous in the horse, while the other animals have a mucous secretion with traces of serous se- cretion. The insertion of the bladder to the descending colon in the dogs revealed that the Operation has no visible adverse effects in the adult females. It does not inter- fere with the normal gestation period or the prenatal de- velopment of the fetuses carried by pregnant experimental animals. The condition is disadvantageous in the male dog, and in addition to the surgical risks, leads to the regres— sion of the prostate gland in the recovered animal. iv .mpnmnwadn SH BSHSOHpHo>H© HmhnpoHSDSm m mo monommam on» mopocov mafia coupon on» cam mnemm> one ovum mnflnomo suspend one mqfisonm Eopmhm Ahmcfihs camaom on» Mo scab ofipmaamnmmwn .mmnnpohs mammooonm one canons maenmam ammom on» mnweonm soaaampm one no mason macaw onp nmsounp soapoom HmGHUSpHmnoq mow 039 .m anon one .m ash one .c pmo Sov one .0 Hana one .9 nomaampm one .m lumo mccmam Xom Ahommooom cam mason .mhnpohz .Houumam WUMHmmHHZOma .mpcmcanaa 2a m a; mocmmmna ox» mmpozvn seas oucfi TCHCmao weapons can . .. .. NV A. it“ 12.5....“ 3.3 we 3mH> ofipmahmmfiq .mmhnpoas ..nraz ammom one mafiaozm :oaaampm :g- n.aoamp :oapoom HmcfluapfimCOQ um .v Ema one .u .i 232a? may 3% shim ......fi..&.mt.3 .medem .mu ACKNOWLEDGMENTS The author wishes to eXpress his sincere appre— ciation to Dr. M. Lois Calhoun, Professor and Head of the Department of Anatomy for her inspirational guidance in this investigation and for her constant help in the prepa- ration of this manuscript. He is also grateful to Dr. W. O. Brinker, Professor and Head of the Department of Surgery and Medicine for his unfailing interest and constant assis- tance in the surgical work involved in this investigation. The author is also indebted to Dr. J. F. Smithcors, Dr. C. W. Titkemeyer, Dr. J. T. Bell, Jr., Dr. T. W. Jenkins, and Dr. E. M. Smith, all of the Department of Anatomy, for making valuable suggestions during the preparation of the manuscript. Appreciation is also eXpressed to the remainder of the staff of the Department of Anatomy for their help 'in various ways. Thanks are also extended to Mr. James H. Tucker, student in the department of Zoology, for his help in the preparation of the photographs, and to Dr. Robert R. Filkins, then a senior veterinary student, for his assis- tance in the surgical work. To his family members, for their unlimited pa— tience and cooperation, the author expresses his profound gratitude. vii VITA Madan B. Bharadwaj candidate for the degree of Doctor of Philosophy Final examination: 9:30 a.m., June 17, 1960, Room 101, Giltner Hall. Dissertation: Histology of the Urethra and Accessory Sex Glands of the Domestic Animals; and Observations on the Surgical Insertion of the Urinary Bladder- neck into the Descending Colon in the Dog. Outline of Studies: Major subject: Anatomy. Minor subjects: Surgery and Medicine. Biographical items: Born: August 2, 1927. Lucknow, India. Undergraduate Studies: Bihar Veterinary College, India; G.B.V.C., 1949. U.P. College of Veterinary Science & Animal Husbandry, India; B.V.Sc. & A.H., 1954. Graduate Studies: Michigan State University; M.S., 1958. Experience: Veterinary Assistant Surgeon, U.P., India, 1949-1950; Demonstrator in Anatomy, U.P. College of Veterinary Science and Animal Husbandry, India, 1950-1957; Graduate Teach- ing Assistant in Anatomy, Michigan State University, 1957-1960. Member: Phi Zeta; Sigma Xi. viii TABLE OF CONTENTS INTRODUCTION. . . . . . . . . . . . . . . . . . . . . 2 hEVIEW OF LITERATURE. . . . . . . . . . . . . . . . . 3 The urethra. . . . . . . . . . . . . . . . . . . 3 The seminal vesicle. . . . . . . . . . . . . . . 10 The prostate gland . . . . . . . . . . . . . . . 16 The bulbo-urethral gland . . . . . . . . . . . . 20 MATERIALS AND METHODS . . . . . . . . . . . . . . . . 24 RESULTS AND DISCUSSION. . . . . . . . . . . . . . . . 26 The urethra. . . . . . . . . . . . . . . . . . . 26 General description . . . . . . . . . . . . 26 The urethra of the male domestic animals. . 27 The stallion . . . . . . . . . . . . . 27 The bull . . . . . . . . . . . . . . . 29 The buck . . . . . . . . . . . . . . . 30 The ram. . . . . . . . . . . . . . . . 33 The boar . . . . . . . . . . . . . . . 34 The dog. . . . . . . . . . . . . . . . 36 The cat. . . . . . . . . . . . . . . . 39 The urethra of the female domestic animals. 42 The mare . . . . . . . . . . . . . . . 42 The cow. . . . . . . . . . . . . . . . 42 The doe. O O O O O O O O O O O O I O O 43 ix The ewe. . . The sow. . . The bitch. . The cat. . . The seminal vesicle. . General description The stallion. . . The bull. . . . . The buck. . . . . The ram . . . . . The boar. . . . . The prostate gland . . General description The stallion. . . The bull. . . . . The buck. . . . . The ram . . . . . The boar. . . . . The dog . The cat . . . . . The bulbo-urethral gland General description The stallion. . . The bull. . . . . The buck. . . . . The ram . . . . . 44 45 46 47 127 127 128 129 130 131 132 159 159 159 160 162 163 164 166 168 195 195 195 196 197 198 lib—I The boar. . . . . The cat 0 O O O 0 SUMMARY AND CONCLUSIONS for Part I. PART INTRODUCTION. . . . . . . . REVIEW OF LITERATURE. . . . MATERIALS AND METHODS . . . RESULTS AND DISCUSSION. . . Dog no. 1. Dog no. 2. Dog no. 3. Dog no. 4. SUMMARY AND CONCLUSIONS for Part II LITERATURE CITED. . . . . . xi II (mature male). . (non-pregnant female). (non-pregnant female). (female at mid-gestation 199 200 222 Table I. II. III. LIST OF TABLES Page The seminal vesicle of the domestic animals . . 134 The prostate gland of the domestic animals. . . 170 The bulbo-urethral gland of the domestic ani- mals. O O O O O O O O O O O 0 O O O O O I O O O 20]- xii LIST OF PLATES Plate page 1. Duct of prostate gland entering the horse urethra SO 2. Penile urethra of the horse. . . . . . . . . . . 52 3. Processus urethrae of the horse. . . . . . . . . 54 4. Fossa glandis of the horse . . . . . . . . . . . 56 5. Urethra of the mare. . . . . . . . . . . . . . . 58 6. Corpus prostatae and urethra of the bull . . . . 6O 7. Penile urethra of the bull . . . . . . . . . . . 62 8. Urethra of the cow . . . . . . . . . . . . . . . 64 9. Suburethral diverticulum of the cow. . . . . . . 66 10. Disseminate prostate and urethra of the buck . . 68 ll. Penile urethra of the buck . . . . . . . . . . . 7O 12. Processus urethrae of the buck . . . . . . . . . 72 13. Processus urethrae of the buck . . . . . . . . . 74 14. Processus urethrae of the buck . . . . . . . . . 76 15. Urethra of the doe . . . . . . . . . . . . . . . 78 16. Seminal vesicles, deferential canals, uterus mas- culinus and the pelvic urethra of the ram lamb . 8O 17. Disseminate prostate in the urethra of the ram . 82 18. Disseminate prostate in the urethra of the ram lamb I O O O O O O O O O O O O O I I O O O O 0 0 84 19. Penile urethra of the ram. . . . . . . . . . . . 86 20. Urethra in the glans of the ram lamb .'. . . . . 88 21. Processus urethrae of the ram lamb . . . . . . . 9O 22. Urethra of the ewe . . . . . . . . . . . . . xiii 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. Disseminate prostate in the urethra of the immature boar. . . . . . . . . . . . . . . . . Penile urethra of the boar . . . . . . . . . . Penile urethra of the immature boar. . . . . . Preputial cul-de-sac of an immature boar . . . Urethra of the sow . . . . . . . . . . . . . . Prostatic urethra of the dog . . . . . . . . . Penile urethra of the puppy. . . . . . . . . . Urethra of the bitch . . Contracted preprostatic urethra of tom Distended preprostatic urethra of the tom cat. Prostatic urethra of the tom cat . . Postprostatic urethra of the tom cat . . . . . Urethra of the tom cat near the bulbo-urethral glands . . . Penile urethra of the tom cat. . . . . . . . . Urethra at the penile tip of the tom cat . . . Urethra Urethra near the vagina of the female cat. . . Seminal vesicle of the horse . . . . . . . . . Seminal vesicle of the horse . . . . . . . . . Seminal vesicle of the bull. . . . . . . . . . Seminal vesicle of the bull. . . . . . . . . . Seminal vesicle of the buck. . . . Seminal vesicle of the buck. . . . . . . . . . Seminal vesicle of the ram . . . . . . . . . . Seminal vesicle of the ram . . . . . xiv near the bladder neck of the female cat. 94 96 98 100 102 104 106 108 110 112 114 116 118 120 122 124 126 136 138 140 142 144 146 148 150 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. Seminal vesicle of the ram . . . . . . . . Seminal vesicle of the ram lamb. . . . . . Seminal vesicle of the boar. . . . . . . . Seminal vesicle of the boar. . . . . . . . Prostate gland Prostate gland Prostate gland Prostate gland Prostate gland Prostate gland Prostate gland Prostate gland immature boar. Prostate gland Prostate gland Prostate gland Prostate gland Bulbo—urethral Bulbo-urethral Bulbo-urethral Bulbo-urethral Cul-de-sac of the urethral valve Bulbo—urethral Bulbo-urethral of the horse. . . . . . . . of the horse. . . . . . . . of the horse. . . . . . . . of the castrated horse. . . of the bull . . . . . . . . of the bull . . . . . . . . of the buck . . . . . . . . and bulbo—urethral gland of of the boar . . . . . . . . of the boar . . . . . . . . of the dog. . . . . . . . . of the puppy. . . . . . . . gland of the horse. . . . . gland of the horse. . . . . gland of the bull . . . . . gland of the bull . . . . . gland of the buck . . . . . gland of the ram. . . . . . Bulbo-urethral gland of the ram. . . . . . Bulbo-urethral gland of the boar . . . . . Bulbo—urethral gland of the tom cat. . . . XV of the bull . 186 188 190 192 194 203 205 207 209 211 213 215 217 219 221 ‘1_ _____ 74. 75. 76. 77c 78. 79. 80. 81. 82. 83. 84. The viscera of the experimental female dog . . . The internal view of the vesico-colic union of the eXperimental female dog. . . . . . . . . . . The dysfunctional urethra of the experimental female dog 0 O O O O O O O O O O O O O O O O O O Desquamation of the dysfunctional urethral epi- theliwnO O O O O 0 O O O O O O O O O O O O O O 0 Healing in the vesico-colic union of the eXperi- mental female dog. . . . . . . . . . . . . . . . Mucosal changes in the urinary bladder of the experimental female dog. . . . . . . . . . . . . Plasma cell infiltration in the bladder tunica propriao I O O O O O O O O O O O O O O O O O O O Descending colon of the experimental female. . . Viscera of the experimental male dog . . . . . . The internal view of the vesico—colic union of the experimental male dog. . . . . . . . . . . . The dysfunctional penile urethra of the experi- mental male dog. . . . . . . . . . . . . . . . . The dysfunctional prostate gland of the experi- mental male dog. . . . . . . . . . . . . . . . . xvi 240 242 244 246 248 250 252 254 256 258 260 262 PART I. THE URETHRA AND ACCESSORY SEX GLANDS INTRODUCTION The comparative histology of the urethra of the domestic animals is a part of a continuing study involving the entire urinary tract. The notable species differences in the urethral epithelium and its changes at different levels in the same species of animal, have already been studied (Bharadwaj and Calhoun, 1959). The present work deals with the other layers of the urethra. Considering the intimacy of the accessory sex glands to the urethra and their functional importance, it is appropriate to include them. Further, the lack of availability of the older French and German works on this subject, necessitates such studies. It is believed that the present study will be helpful in the fields of Anatomy, Pathology, Endocrinology and Animal Breeding. Some authors include the ampulla of the ductus deferens with the accessory sex glands; however, this has not been included in the present work. REVIEW OF LITERATURE THE URETHRA THE HORSE The Stallion. Sisson and Grossman (1953) stated that cephalically near the bladder neck, the urethral mucosa is covered by a layer of circular unstriped muscle. Caudal to this, it is enclosed by a layer of erectile tissue with trabeculae containing elastic and smooth muscle fibers. An intrinsic unstriped muscular coat having an outer and inner longitudinal and a middle circular layer, surrounds the corpus cavernosum urethrae. The striped urethral muscle of the pelvic region and the bulbocavernous muscle of the extrapelvic region cover the urethra. In the penile region the bulbocavernous muscle is not complete dorsally where it blends with the tunica albuginea of the corpus caverno- sum of the penis. The mucous membrane is rich in fine elastic fibers and presents tubulo-alveolar glands in the pelvic part (Lesbouyries, 1949, Sisson and Grossman, 1953, Trautmann and Fiebiger, 1957). The pelvic urethra has a transitional epithelial lining while the penile urethra bears an admixture of stratified columnar and transitional epithelium (Bharadwaj and Calhoun, 1959). The processus urethrae is covered by a delicate integument, under which is a thin ring of 'lympho-reticu- 1949, Sisson and Gross— lar' erectile tissue (Lesbouyries, man, 1933). The Rare. The mucosa is non-glandular, erectile and rich in elastic fibers (Sisson and Grossman, 1953. Trautmann and Fiebiger, 1957). It is lined by transitional epithelium (Bharaiwaj and Calhoun, 1959) which shows tubular evaginations (Trautmann and Fiebiger). Sisson and Grossman (1933) stated that the intrin31c smooth muscular coat has a heavy external longitudinal layer and an inner circular layer. This intrinsic muscle is absent where the urethra is attached to the vagina. Trautmann and Fiebiger (1957) mentioned an additional inner longitudinal muscle layer in the mare. Latenal and ventral to the intrinsic smooth muscle lies the striated urethral muscle which is covered by a fibroelastic membrane. The urethral muscle is con- tinuous posteriorly with the constrictor vestibulae (Sisson and Grossman, 1933, Trautmann and Fiebiger, 1957). CATTLE The Bull. The urethral wall in the pelvic region is much thicker than in the horse (Lesbouyries, 1949). Dorsally the aponeurosis is thick and the urethral muscle is absent (Lesbouyries, 1949, Sisson and Grossman, 1953). he pars disseminata surrounds the urethra to the level The T of the bulbo-urethral glands (Sisson and Grossman). mucosa bears transitional epithelium and consists of a fairly loose vascular connective tissue of an erectile nature (Lesbouyries, 1949, Trotter, 1959). In the penile part the cavernous tissue surround- ing the urethra is composed of connective tissue trabeculae which are continuous peripherally with the tunica albuginea (Trautmann and Fiebiger, 1937, Trotter, 1959). In addition to the fibre-elastic tissue, the trabeculae contain longi- tudinal smooth muscle fibers (Trautmann and Fiebiger). The cavernous spaces increase in size toward the albuginea L6 (frautmann and Piebiger, 1957, Trotter, 1959). The tunica prOpria has the character of lymphatic tissue (Trautmann and Fiebiger). The epithelial lining is transitional in both the pelvic and the extra pelvic parts (Bharadwaj and cal‘IAC'drl, 1959). In the processus urethrae the erectile tissue surrounding the urethra is poorly deveIOped (Trotter, 1959). The Cow. The urethra is narrow and much less dilatable than in the mare and a suburethral diverticulum is seen close to the external urinary meatus (Sisson and Grossman, 1933). The lining epithelium is transitional and single branched tubular glands are present in the tunica prOpria. The muscular lining differs from that of the CK mare by the absence of the inner longitudinal smooth muscle layer (Trautmann and Fiebiger, 1957). $3? GOAT The Buck. In the pelvic urethra the pars dis— serinata is dispersed within the corpus cavernosum urethrae (Lesbouyries, 1949). According to Yao and Eaton (1954), in the penile part the extensive corpus cavernosum urethrae is closely united with the dense fibro-elastic connective tissue of the corpus cavernosum penis. The urethral canal is surrounded by dense fibro—elastic tissue with longitudi- nal fibers. The terminal part of the goat's penis has a urethral process (Yao and Eaton, 1954). An admixture of stratified columnar and transitional epithelium is present throughout the entire length of the urethra (Bharadwaj and Calhoun, 1959). The Doe. A very small suburethral diverticulum is seen close to the external urinary meatus (Sisson and Grossman, 1953). An admixture of stratified columnar and transitional epithelium lines the urethral mucosa. THE SHEEP The Ram. The pelvic urethra is circular in out- line and contains large venous spaces (Strickland-Goodall, 1949, 1902) and disseminate prostatic tissue (Lesbouyries, Sisson and Grossm n, 1953). The penile urethra lies in a groove on the ventral surface of the corpus cavernosum penis (Sisson and Gross- man). The corpus cavernosum urethrae in the penile portion 1 )5 is enclosed by .n extension of the tunica albuginea of the corpus cavernosum penis. 8 ”he terminal part of the urethra is continued a .L the processus urethrae which is supported by two 'fibro— Spongy' cords (Lesbouyries, 1949). The urethral epithelium varies with the age of the animal. In the ram lamb the pelvic urethra bears an 'dmixture of stratified squamous and transitional epithelium while the penile part is lined mostly by stratified squamous epithelium. In the adult animal the entire urethra is lined by transitional epithelium (Bharadwaj and Calhoun, 1959). The Ewe. A very small suburethral diverticulum, similar to that of the doe, is present (Sisson and Gross— man, 1955). The epithelial lining is similar to that of the doe. THE PIG The Boar. The pelvic urethra is very long and is covered by a urethral sphincter which is aponeurotic on the superior aSpect (Lesbouyries, 1949). The tunica- propria contains disseminate prostate and cavernous spaces (fichenzie et al., 1938, Lesbouyries, 1949, Sisson and Gross- man, 1953). The penile urethra is completely enclosed by the large furrow of the corpus cavernosum and is entirely covered by the tunica albuginea (Lesbouyries, 1949). The small, ventrally located corpus cavernosum urethrae con- tinues throughout the length of the entire urethra (McKen- zie et al., 1938). Both the pelvic and the penile parts bear a transitional epithelial lining (Bharadwaj and Calhoun, 1959) and the tunica prOpria contains scattered 'Glands of Littre' (Trautmann and Fiebiger, 1957). The Sow. The urethra is about 5" long, fused with the vagina, and produces a corresponding elevation of the floor of the latter (Sisson and Grossman, 1955). The lining epithelium is transitional (Bharadwaj and Cal- houn, 1959) and shows tubular evaginations (Trautmann and Fiebiger, 1957). THE DOG The Male Dog. The pelvic portion contains a prostatic and a membranous part (Lesbouyries, 1949, Miller, 1952, Sisson and Grossman, 1953). In the penile part the bulbus glandis, a cavernous Jlla—L—f; ,, eXpansion of the corpus cavernosum urethrae, surrounds the proximal part of the os penis. The trabeculae in the bulbus glandis are rich in elastic tissue (Christensen, 1954). The epithelial lining consists of an admixture of stratified columnar and transitional. The Bitch. miller (1952) found that the urethra is 7 cm. long and 0.5 cm. wide. It is covered by the urethral muscle and has a very vascular submucosa. The epithelial lining resembles that of the male dog. Tfli CAT Schmaltz (1911) described a thin preprostatic urethra and Trautmann and Fiebiger (1937) The Tomcat. mentioned the absence of cavernous tissue in the same region. The lining of both the pelvic and extra pelvic parts is an admixture of stratified columnar and transi- tional epithelium. The Female Cat. The lining epithelium is an admixture of stratified squamous and stratified cuboidal which becomes transitional near the bladder (Bharadwaj and Calhoun, 1959). 10 THJ SEMINAL VESICLE The Stallion. The gland has a true vesicular Lesbouyries, 1949, 1957)- nature like that of man (Elias, 1944, disso" and Grossman, 1953, Trautmann and Fiebiger, The duct system is very well developed at the expense of the glandular mass, which results in the formation of pyriform pouches (Lesbouyries). The gland is branched tubular (Trautmann and Fiebiger) and consists of a mucous membrane, muscularis and adventitia (Lesbouyries, and Sisson and drossman). The epithelial lining of the secre- tory tubules and the intraglandular ducts is simple colum— nar but the main excretory duct has a ’stratified' epi- thelium (Sisson and Grossman, Trautmann and Fiebiger). The capsule and the septa are very rich in smooth muscle (Trautmann and Fiebiger) and the capsular muscle is ar- ranged into three rows with the outer and inner longitudi— nal layers and a middle circular layer (Sisson and Gross- man). The Bull. It is typical glandular organ with lobulated surface (Lesbouyries, 1949, Sisson and Grossman, 1953). The latter authors describe the gland very appro— priately by saying that "Each gland may be regarded as consisting of a very thick walled sacculated tube bent on itself...". The structure of the vesicle is masked 11 by a thick capsule of fibrous tissue and non-striated which maintains its bent condition and also sends Mann et a1. (1949) de— muscle, trabeculae between the alveoli. scribed the seminal vesicle of a fully mature bull as a lobulated, tubulo-alveolar orean, somewhat resemblin O the human pancreas. Sisson and Grossman (1953) also men— tioned the tubulovalveolar nature. The large lobules eparated by connective tissue septa are rich in smooth muscle fibers (Lesbouyries, 1949, Trautmann and Fiebiger, 1957). Sisson and Grossman (1953) and Trotter (1959) described numerous folds in the mucous membrane which leave no distinct outline of the lumina of the glands. The epithelial lining is described as pseudostratified columnar by Lesbouyries (1949) and Trotter (1959) and as simple columnar by Sisson and Grossman (1953). Trautmann and Fiebiger mentioned that the epithelium of the glands and the intra—glandular excretory ducts is always simple columnar varying with the functional state. They also described peculiar fat cells between the epithelium and the basement membrane. A more complete description of the tubular lining was given by Mann et a1. (1949). They found that in the bull the tubules measure 500 p in diameter and are lined by three distinct types of cells, designated as 'A', 'B' and 'C'. The most numerous type ’A' is a tall columnar cell 25-50 F high and is the main cell of the inner row. The free surface of this cell diSplays a brush border at most places and occasionally blebs and streamers project into the lumen. The type 'B' cells are placed basally and are the main component of the outer epithelial row and contain lipid. The type 'C' cells are tall, thin and dark staining dispersed in between the type 'A' cells. (1957) agreed with the description given 'C' Cons by mann et a1. (1949) but suggested that the type cells are not Special cells but are only a developmental stage of all the cells lining the inner wall of the tubules. Further, he stated that in the calf and the bullock the whole gland has a much less differentiated appearance, but 'A’ and 'B' type cells show up clearly. The type 'A' cells appear shorter and show no secretory activity. The lobules Opening centrally into the sacculated but narrower excretory ducts give rise to the main excre- tory duct (Trautmann and Fiebiger, 1957). The primary duct is lined by 'stratified' epithelium (Trotter, 1959). The common canals join with the extremity of the ampullae of the ductus deferens to form a very short ejaculatory canal (Lesbouyries, 1949). According to Trotter (1959), the secretion in an active gland appears as a slightly eosinOphilic mass, partially or completely filling the lumen of the secretory The secretory mass is not homogenous and exhibits areas . many irregular densely packed globules. Occasionally, l3 calcified concretions are seen in the lumina of the glands of the mature animals. Yao and Eaton (1954) described the "J seminal vesicle as a multilobulated sac enclosed in a fibrcmuscular sheath. Each sac is divided into a number of compartments by a thick layer of dense fibro-elastic connective tissue. Each compartment contains branching tortuous tubules. The epithelium is pseudostratified the cells show changes in size with increasing 55v columnar and age. In the 50-day-old kid, most of the tubules are closed with cells 36‘» tall and 8 p wide. The spherical nucleus is situated at the distal part of the cell. The cytoplasm between the nucleus and the distal border of the cell is granular and stains more deeply than the cytoplasm between the nucleus and the basal border of the cell. At 60 days, the epithelial cells are lé‘y tall and 6 P wide and thus are lower than those at 30 days. However, some tubules have cells 30.” tall but only 4 p wide. The nucleus is oblong or elliptical and is situated at the middle or the base of the cell. The distal part of the cell is granular and more deeply stained. At 70 days, drops of secretion are seen and at 120 days most tubules are wide Open. The Ram. Aitken (1955) described the gland as compound tubular. The tubules which are separated from each other by thin trabeculae of connective tissue Show a 14 marked variation in the diameter. The pseudostratified epithelium lining the tubules is 29 p high. The wider tubules generally have a low epithelium. The two cell types of the epithelium are described as (1) tall columnar Cells extending from the thin basement membrane to the free surface (comparable to the type 'A' mentioned for the bull), and (2) angular or rounded cells placed between the bases of the columnar cells. The few basal cells are scattered singly among the columnar cells (comparable to type 'B' in the bull); however, these do not show any lipid. Aitken (1955) further stated that in the seminal vesicle of the castrated sheep, the tubules are markedly reduced in diameter with a noticeable increase of inter- tubular connective tissue. The epithelium is reduced in height, aVeraging only 17 p. The free surface of the epithelium is eVen and sharply defined without cytoplasmic projections. The vacuolation of the basal cells due to lipid inclusions is much more pronounced than in the normal adult male. The Boar. The seminal vesicle of the boar is voluminous. Structurally it is intermediate between that of the equine and of the ruminants, is distinctly lobulated and is branched tubular (Lesbouyries, 1949, Sisson and Grossman, 1995, Trautmann and Fiebiger, 1957). McKenzie et al. (1938) stated that the mucous membrane forms an elaborate system of thin high primary folds which branch into secondary and tertiary folds. These project far into the lumen anastomosing frequently with one another forming irregular cavities of different sizes. The epi- thelium is described as simple columnar (McKenzie et al., Sisson and Grossman, Trautman and Fiebiger) or at times as pseudostratified columnar, and it rests on a vascularized fine connective tissue, supported by muscle strands. The nuclei are rounded or oval and are located at or near the base. The ducts have a similar lining to the body of the gland (Mohenzie et al., 1938). The secretion granules are present above the nuclei and on the free surface drops of bleb—like forma- tions appear which are cast into the lumen forming the secretion (McKenzie et al., 1958). The secretion is thick and turbid (Sisson and Grossman, 1953) and concretions are found in the duct (McKenzie et al.). The Dog. The gland is absent. Bullon and Lopez (1959) considered the ampullae of the ductus deferens as homologue to the seminal vesicle. The authors further described a chain of ganglia running along the length of the ampullae in the dog and the seminal vesicle in man. The Cat. The gland is absent. THE PROSTATE GLAND The Stallion. The lobulated gland has lateral lobes and a connecting isthmus and is structurally branched tubulo-alveolar (Sisson and Grossman, 1953). The volume of the gland varies with age and each lobule has a large collecting sinus which is larger in the donkey (Lesbouyries, 1949). The latter author described the epithelial lining as 'double layered', while Sisson and Grossman (1953) and Trautmann and Fiebiger (1957) found that the ducts and tubules are lined with cuboidal or columnar epithelium. According to Sisson and Grossman, amyloid bodies and cal- carieous concretions may be found in the prostate. The gland is enclosed in a capsule of fibrous tissue with an admixture of smooth muscle fibers (Lesbouyries, 1949, Sisson and Grossman, 1953). Trautmann and Fiebiger de- scribed lamellated corpuscles in the capsule. Elias (1944) and Sisson and Grossman mentioned that the trabeculae dividing the glandular tissue are rich in non-striated muscle. The Bull. The gland has two parts, a corpus prostatae and a pars disseminata (Lesbouyries, 1949, Sis- son and Grossman, 1953, Trautmann and Fiebiger, 1957). . . 3 ‘ ar In general the gland is described as branched tubul (Sisson and Grossman), and the pars disseminata is radially diapersed in relation to the urethral lumen (Lesbouyries). \] 17 According to the latter, the glandular epithelium is simple columnar with flattened or rounded free borders. The epithelium gradually becomes similar to the urethral epi— thelium toward the terminal part of the excretory canals. The Buck. The prostate is only disseminate in the tuck and is continued into the corpus spongiosum of the urethra (Lesbouyries, l949). According to Yao and Qaton (1954) the tubules show many convoluted folds which are formed by a 32 tall and 4’» wide pseudostratified epithelium, supported by a thin layer of loose fibro-elastic connective tissue. In both young and old goats the tubules are filled with secretion. Thick layers of loose fibro- elastic connective tissue separate the lobules. The ham. The prostate gland is entirely dis- seminate (Lesbouyries, 1949, Sisson and Grossman, 1953). The Boar. The gland has two parts, a corpus prostatae and a pars disseminata (Lesbouyries, 1949, Sis— son and Grossman, 1953, Trautmann and Fiebiger, 1957). According to McKenzie g£_§l. (1938) the body and the an- terior part of the disseminate prostate are compound tubulo-alveolar, while the glandular tissue in the pos- terior part, around the urethra, is compound tubular in nature. These authors further stated that the lining epithelium varies from simple columnar to cuboidal or even siuamous, Ind numerous secretion and cytoplasmic drOplets appear to be attached to the free end of the epithelial cells. Lesbouyries (1949) noted that the duct epithelium is like that of the tubules but gradually be- comes similar to that of the urethra. Concretions are freauently seen in the ducts of old boars. The gland is covered by the urethral muscle (Lesbouyries) and there is an abundance of interstitial tissue which contains a dense fibre—elastic network and many smooth muscle fibers arranged in strands of varying thickness (McKenzie et al., 193d). in addition to the smooth muscle fibers observed by most investigators, Elias (1944) described a rudimentary corpus cavernosum in the interstitial tissue. The Dog. Lesbouyries (1949) and Sisson and Grossman (1953) described a slight amount of disseminate prostate in addition to the main body of the prostate gland in the dog. Berg (1958) called these 'periurethral' glands and noted their morphological similarity to the glands of the peripheral parenchyma of the prostate gland. He also stated that these 'periurethral' glands are absent up to 4 months of age and become visible at 6 to 9 months of age. According to Lesbouyries (1949), the tubular dimensions differ. Their lumina are larger and the glandu- lar element predominates peripherally. Elias (1944) de- scribed columnar epithelium lining the narrow tubules and L.) 1\ low cuboidal in the larger cavities. Berg (1958) made similar observations in the adult dogs. The latter studied age changes in the prostatic parenchyma of the dog. In newborn puppies the prostatic parenchyma is recognizable but the stroma predominates. Berg further stated that "The epithelium at this stage is cuboidal and no squamous metaplasia is present as observed in newborn boys." In the adult, however, the parenchyma prevails but it is unequally distributed. Centrally, the stroma still pre- dominates, eSpecially dorsal to the urethra. The epithelium is cuboidal or columnar with distinct signs of secretory activity. According to Lesbouyries (1949) the relatively spacious excretory canals are formed in the middle of the lobules, and their epithelium gradually becomes like that of the prostatic urethra. Elias (1944), and Sisson and drossman (1953) mentioned that the capsule and the stroma contain large amounts of unstriped muscle. Berg (1958) stated that in very young animals a thin external capsule is recognizable, and smooth muscle cells may be seen in the connective tissue. Lesbouyries (1949) and Berg (1958) described the predominant fibro—muscular tissue in the center of the prostate. Berg (1958) also mentioned the presence of cavernous-like tissue in the colliculus area but did not observe corpora amylacea in dogs of any age. The Cat. Elias (1944) described an alveolar prostate gland in the young cat and a tubular structure in the old cat. The secreting epithelium is low columnar. The capsule contains lamellated corpuscles (Lesbouyries, 1949, Trautmann and Fiebiger, 1957) and the interstitial tissue presents many smooth muscle and elastic fibers (Elias). Ganglia could be seen throughout the entire supporting tissue in the cat (Trautmann and Fiebiger). THE BULBO-URETHRAL GLAND The Stallion. The lobular disposition of the gland is not pronounced (Lesbouyries, 1949, Trautmann and Fiebiger, 1957). Each lobule contains a central collecting sinus from which narrow, coiled and ramifying branches radiate in all directions (Trautmann and Fiebiger). Struc- turally the gland resembles the prostate, and the tubules are lined by cuboidal epithelium (Sisson and Grossman, 1953). The excretory canals possess secretion 'vacuoles’ (Lesbouyries). The striated muscle covering the gland sends off bundles into the larger trabeculae of the gland, and inter—lobular connective tissue septa also contain smooth muscle fibers (Lesbouyries, 1949, Sisson and Gross- man, 1953, Trautmann and Fiebiger, 1957). The Bull. The columnar epithelial lining of the gland is especially high in the bull (Trautmann and Fiebiger, 1957), and fat cells are seen under the epithelium in the lamina propria (Lesbouyries, 1949). The latter mentioned that the two excretory canals Open under the 'urethral valve' of the ischial region. The gland is covered by the striated urethral muscle but the surrounding capsule is distinctly fibrous (Iesbouyries, 1949, Sisson and Grossman, 1953, Trautmann and Fiebiger, 1957). The Buck. According to Yao and Eaton (1954), the numerous acini of the gland are enclosed in a thin layer of fibrous connective tissue which is surrounded by a thick layer of mixed smooth and striated muscle. The epithelium is tall columnar with a height of 28 u, and the small nuclei are basally located. The cytoplasm is highly ranular and fibrillar. The acini are OO‘u in diameter 0‘4 and most of these are closed at all ages. A secretion is present in those that are Open. The Ram. The bulbo—urethral gland resembles that of the bull and is relatively larger (Lesbouyries, 1949, Sisson and Grossman, 1953). The Boar. Lesbouyries (1949) mentioned the gland is similar to that of ruminants. Sisson and Gross- man (1953) described a lobulated surface. According to McKenzie gg_§1. (1938) the gland is compound tubulo-alveo— lar and resembles mucous glands. The epithelium is simple columnar or cuboidal with small basal nuclei and rests on a basement membrane. Blob—like drOplets are present on the free end of the cells. The epithelium of the larger ducts is somewhat flattened but remains typically cuboidal. The excretory canals present secretion 'vacuoles' (Les- bouyries) and open dorsally in the urethra at the ischial arch under a fold of urethral mucosa (Lesbouyries, 1949, Sisson and Gr ssman, 195$). McKenzie et al. described the thick and waxy, which becomes more secretion as white, viscous when cool. 'ouyries (1949) described certain age changes the young animal the lobules are rounded tissue is made up of ramifying tubules and the glandular separated by large septa. 1n the adult, the tubular nature of the gland is changed to that of a vesicular structure by the accumulation of the secreting material. Trautmann and Fiebiger (1957) also described a similar distortion of the tubular structure. The gland is partially covered by a layer of striated muscle (McKenzie et al., 1938, Lesbouyries, 1949, Sisson and Grossman, 1953). McKenzie et al. suggested that the heavy muscular arrangement plays some role in forcing the waxy secretion through the excretory duct into the urethra during ejaculation. Also they described fibro-elastic septa containing striated and smooth muscle strands separating the lobules. The Dog. The gland is absent in the dog (Les- bouyries, 1949, Sisson and Grossman, 1953). The Cat. The glands are relatively large (dchmaltz, 1911, Lesbouyries, 1949). The glandular cavi- ties are vast and structurally resemble the prostate (Les- bouyries). The excretory canals open under a fold of the urethral mucosa in the region of the root of the penis (dchmaltz, 1911, Lesbouyries, 1949). Each gland is covered by muscle fibers derived from the neighboring bulbo—cavern— cus muscle (heighard and Jennings, 1940), and the capsule is rich in connective tissue (Lesbouyries). MATEnIALS AND METHODS For the study of the urethrae and accessory sex glands, a total of fifty—two animals was used. These included seven male and three female horses; sheep and swine; four four males and three females each from cattle, male and two female goats; five male and four female dogs; and three male and three female cats. The entire urethra and the accessory sex glands from the freshly killed .nimals were fixed in F.A.A. (Lav- dowsxy's mixture of formalin, alcohol and acetic acid, Guver, 1949). Following fixation tissues were taken from J J three to five levels in the females and eight to sixteen levels in the males, depending upon the length of the urethra and the presence of bone, flexures, processes, and diverticulae of the urethrae in different species. Two or three additional sections were taken from each of the accessory sex glands in the male animals. Dehydration and infiltrating methods of Johnson et al. (1943) were followed using Tissuemat* for embedding. Several staining techniques were employed: (1) hematoxylin and eosin; (2) Weigert's and Van Gieson's for connective tissue; (5) 0.5 per cent toluidine blue *Fisher Scientific Company, Pittsburgh, Pennsylvania. 24 for determining the mucoid material; and (4) Mallory's .5 trichrome stain (Crossman's modification, 1937) as an additional aid for routine study of the sections. the heights Usinw a “alibrated ocular micrometer O 9 of the glandular epithelial cell were measured at the highest and lowest areas in the epithelium, irrespective to secretion in the lumen or the cyclic h b 0 0‘ . F} o toning due d I‘ (T O u, tate of the cells. The number of the epithelial layers (0 was counted at the typical lowest and highest areas of the epithelium. | . a. . Y ~ ;“ ‘ ‘N \ AEJJ US AND DISCUSJIUH TH? URETHHA H General Description. The urethra in the male animals is a common urogenital canal which presents a pelvic part and an extra—pelvic part. In the domestic animals, the presence of a disseminate prostate in some species and an erectile envelOpe in most species renders the customary the prostatic and membranous parts insignifi- division of cant. The length of the penile urethra varies in different ‘pecies. It presents a sigmoid flexure in ruminants and the boar. An os-penis is located dorsally to the urethra of the dog and ne tom cat. Except the boar, dog and cat, the remainder of the domestic animals possess a processus urethrae of varying length. In the horse, the fossa glandis surrounds the processus urethrae at the level of the glans penis (plate 4), while in the boar, a cul-de-sac is present dorsally in the preputial cavity near the external urinary orifice (plate 26). The urethra in the female domestic animals pre- sents no Special features except that in ruminants a sub- urethral diverticulum is seen at the external urinary orifice (plate 9). 26 I")? L. The crethra of th Male Domestic Animals i The Stallion The Pelvic Urethra. At its origin, the pelvic urethra is surrounded by a dense fibrous adventitia which is rich in fat cells, blood vessels and nerves. The non-striated muscularis consists of three layerS--an outer thick longi- tudinal, a middle circular and an inner longitudinal. The scattered, longitudinally arranged bundles of the inner smooth muscle coat extend into the dense collagenous sub- mucosa. The submucosa contains a few blood vessels but no distinct cavernous Spaces. A fine collagenous tunica prepria supports the transitional epithelial lining. Distally, toward the ischial arch, the outer layer of the muscularis gradually changes to thick, inter— mixing circular and longitudinal bundles of striated ureth- ral muscle. The inner coat contains longitudinally arranged smooth muscle bundles. The submucosa contains extensive cavernous Spaces separated by fibro-elastic trabeculae including longitudinally placed smooth muscle bundles. The tunica prOpria presents occasional'Glands of Littre'. The ducts of the accessory glands open into the urethral lumen at their Specific levels (plate 1). The Penile Urethra. In the penile region, he urethra is incompletely surrounded by the striated bulbocavernous (\J U.) muscle. It is present mainly on the ventro-lateral aspect of the urethra. The continuity of thick striated muscle is interrupted ventrally by the bundles of the retractor ‘niS muscle at the level of the glans. The tunica al- 'r‘, (1 5:1 3 (T i .ea of the corpus cavernosum penis orms the dorsal ' covering of the urethra and displays a distinct increase in elastic fibers on its urethral aspect. The cavernous Spaces are distinct and the fibro—elastic trabeculae are 3 the scattered longitudinally arranged smooth muscle PJ- 5 ’ rickx bundl (plate 2). Fine fibre-elastic tunica propria (1 0) supports an admixture of stratified columnar and transi- tional epithelium. The processus urethrae is covered by a thick layer of stratified squamous epithelium which has a thin stratum corneum and presents marked rete pegs. The tunica prepria is composed primarily of fine collagenous fibers with a few elastic fibers, blood vessels, nerves and co- casional lymph nodules. ”he connective tissue core between the outer integumentary covering and the urethral epithelium contains distinct cavernous spaces. The trabeculae inter- secting the cavernous Spaces are rich in elastic fibers but lack muscle cells (plate 3). Lesbouyries (1949), and Sisson and Grossman (1953) mentioned a Similar erectile tissue in the processus urethrae of the horses. \L.) R) The Bull The Pelvic Urethra. At its origin, the pelvic urethra L lacks cavernous spaces in the submucosa. The non-striated ‘ muscular coat conSists of irregularly arranged muscle : bundles. in the remainder of the pelvic urethra, the cir— cularly arranged striated urethral muscle covers the urcti- \ ra on its ventrolateral aspect. The dorsal part of the urethra is covered by a thick collagenous tunic. The submucosa contains the disseminate prostate, cavernous Spaces and scattered smooth muscle cells (plates 6 and 56). Lesbouyries (1949), and Sisson and Grossman (1953) made similar observations in the pelvic urethra of the bull. In the ischial region the urethra is completely surrounded by white fibrous tissue. The cavernous spaces are extensive and a fibrous median raphe more or less divides the corpus caVernosum urethrae into two lateral groups. A fine fibro-elastic tunica propria supports the transitional epithelium in the entire pelvic urethra. The Penile Urethra. The urethra is lodged in a ventral groove of the corpus cavernosum penis. A dense fibrous tunic derived from the tunica albuginea of the corpus cavernosum penis completely encircles the urethra. Under this collagenous covering the urethral canal is eccentrical— ly located, and dorsally the lumen is closer to the corpus cavernosum penis. The submucosa presents concentrically k4 C) placed cavernous Spaces which are more extensive and numer- ous on the ventral aspect of the urethral lumen. The caVernous spaces increase in size toward the periphery (plate 7). Trautmann and Fiebiger (1957), and Trotter (1959) mentioned a similar Size increase in the cavernous spaces. The processus ureth as is fused to the glans penis. On its lateral surface it is covered by a thick layer of stratified squamous epithelium which has a thin stratum corneum but does not Show marked rete pegs as in the horse. On its medial aspect the processus urethrae is related to the corpus cavernosum of the glans to which it is united by thick, coarse longitudinal bundles of white fibrous tissue. A rudimentary erectile envelope surrounds the urethral canal as mentioned by Trautmann and Fiebiger (1957). The connective tissue trabeculae between the integumentary covering and the urethral epi- thelium are especially rich in elastic fibers. Lymph nodules are frequently present in the tunica prOpria sup- porting the transitional epithelium of the urethra. The tunica prOpria of the integumentary covering contains small cavernous Spaces. The Buck The Pelvic Urethra. At its origin the urethral canal is surrounded mainly by a thick muscular wall wnicn conSists of lonéitudinally placed smooth muscle bundles. These bundles diminish in size toward the urethral lumen. A narrow zone of fibrous submucosa blends with the collage- nous tunica propria which supports the transitional epi— thelium. The remainder of the pelvic urethra presents an outer fibre-elastic adventitia which contains fat, blood vessels, nerves, ganglia and scattered smooth muscle bundles. The muscularis is composed of the circularly arranged striated urethral muscle which completely encircles the urethral canal. The fibre-elastic submucosa is rich in cavernous Spaces and contains the lobulated disseminate prostate (see description under 'The Prostate Gland'). ollagenous tunica propria supports the strati— C The dense fied columnar epithelium of the urethra. At the level of the bulbo-urethral glands, the striated urethral muscle is present on the ventro-lateral aspect of the urethra. Dorsally, it is replaced by a thick collagenous tunic, which serves as a partition be- tween the urethra and the medial aspect of the bulbo-ureth- ral glands. The submucosa presents two distinct zones—- an outer half containing the wedge-shaped lobules of the . . y . a p . . fl 've disseminate prostate and an inner half containinO extenSi cavernous spaces (plate 10). In the ischial region the urethra is completely surrounded by a collagenous tunic. The cavernous spaces l are extensive in the non-glandular suomucosa. Near the urethral lumen, the submucosa presents a distinct increase in elastic fibers. The fibro-elastic propria supports the stratified columnar epithelium of the urethra. The Penile Urethra. The urethra is lodged in the ventral groove of the corpus cavernosum penis. It is completely surrounded by white fibrous tissue derived from the tunica albuginea. The urethral aspect of the tunica albuginea presents a distinct increase in elastic fibers. It serves as a partition between the corpus cavernosum penis and the urethra. The submucosal connective tissue is more or less replaced by extensive cavernous spaces. The urethral canal is connected by fibro—elastic trabeculae to the peripheral tunic and appears to hang in the center of the large cavernous spaces (plate 11). The fine fibro-elastic tunica propria presents a few small cavernous Spaces and supports an admixture of stratified columnar and transi— tional epithelium. There is no evidence of muscular tissue in the penile urethra. 1n the processus urethrae, the urethral lumen bearing transitional epithelium is flanked by two fibro- cartilagenous cords (plate 12). The connective tissue the bulk of the processus urethrae is non-muscular, A forming; non-glandular and contains small cavernous spaces. ' ' ' “ ' m " ‘ ‘ rneum stratified squamous epithelium witn thin stratum co \JJ \N covers the urethral process. Unier this covering, there I 40*. f‘ ‘. fl$,u__‘e fl. '5‘ - . is a distinct increase in the eiicularly arranged elastic Atle fibers. Specialized nerve endir's are frequently present (plates 13 and 14). O \ ‘f‘Y .ne ”1.11 _ The Lelvic Urethra. At the junction of the bladder and the urethra, -he aTVentitia is rich in blood vessels, (1. nerVes, fat c lls and ganglia. The fat cells occasionally extend between the muscle bundles. The non-striated mus- cularis consists of three layers--an outer thick longi- tudinal, a middle circular and an inner longitudinal layer with scattered bundles. The fibrous submucosa does not contain caVernous spaces (plate 16). in the remainder of the pelvic urethra the ad- ventitia remains the same, but the muscularis and the sub- mucosa present changes similar to those mentioned in the buck. The muscularis consists of striated muscle which encircles the urethra completely except at the level of the bulbo-urethral glands. The submucosa contains the dis— seminate prostate and cavernous spaces similar to those in the buck but these cavernous spaces are relatively less develOped in the ram (plate 17). The fibro-elastic tunica propria supports transitional epithelium. in the ischial region the urethra resembles that of the buck. However, the trabeculae intersecting the cavernous Spaces are thicker and occasionally contain fat cells. The lining epithelium is transitional in con- trast to the stratified columnar epithelium in the buck. The Penile Urethra. In general it resembles that of the buck. The cavernous spaces are relatively less extensive and there is an overall decrease in the elastic fibers as compared to that in the buck (plate 19). At the level of the origin of the processus urethrae in the glans, the cavernous spaces are poorly develOped in the thin urethral wall on the lateral aspect of the processus urethrae. However, these spaces are well marked medially toward the bulk of the penis (plate 20). The processus urethrae is morphologically simi- t lar to that of the buck. The Ram Lamb. The stratified squamous epithelium of the urethra, less develOped cavernous spaces and prostatic parenchyma are distinctive features of the urethra of the ram lambs (compare plate 17 of the adult animal with the plate 18 of the ram lambs). The Boar The Pelvic Urethra. At its origin the urethra is covered by a fibro-elastic adventitia which is rich in fat cells and contains blood vessels, nerves and ganglia. The smooth muscular coat consists of an outer longitudinal layer and an inner circular layer with slight intermixing of the bundles. The fibrous submucosa contains smooth muscle cells and blood vessels, but cavernous spaces are lacking. in the remainder of the pelvic urethra, the smooth muscle coat is replaced by the striated urethral muscle which is dorsally incomplete as it is in the bull. ihe submucosa is more or less completely occupied by the radially arranged disseminate prostate (plates 23 and 59). The extensive glandular parenchyma leaves a central core of submucosal connective tissue around the urethral lumen. This stroma contains cavernous spaces and smooth muscle cells. In the ischial region the urethra presents the same features as mentioned in the buck and the ram. How- ever, the cavernous spaces are interrupted by ill defined median fibromuscular septa. The fine collagenous tunica propria supports transitional epithelium throughout the entire pelvic urethra. The Penile Urethra. The urethra is lodged in a ventral groove of the corpus cavernosum penis and is covered by a fibrous tunic as it is in ruminants. The cavernous spaces are extensive and a more or less well defined peri- pheral cavernous sinus surrounds the urethral canal (plates 24 and 25). fine corpus cavernosum urethrae resembles, U! C“ in general, that of the buck, but an overall increase in elastic tissue in the latter animal is distinctive. The fibre-elastic tunica propria supports a transitional epithelium. ’Glands of Littre', mentioned by Trautmann and Fiebiger, 1957, were not observed in the penile urethra of the boar in the present study. Near the external urinary orifice, the boar possesses a preputial cul-de-sac. It contains a highly folded mucosa bearing a thick, keratinized, stratified squamous epithelium which rests on loose fibro-elastic tissue. Ventrally, the wall of the cul-de—sac contains fibro-elastic tissue while dorsally it is rich in striated muscle bundles derived from the abdominal muscles. The lumen of the cul—de-sac contains decaying cell debris mixed with urine (plate 26). The DOg The Pelvic Urethra. Between the prostate gland and the bladder, the urethra is covered by a fibro-elastic adven— titia rich in fat cells. On its ventrolateral aspect the muscular coat consists of three smooth muscle layers--an outer longitudinal, a middle circular and an inner longi— tudinal layer with scattered bundles. On the dorsal as- pect, the thin non-striated muscularis contains an outer longitudinal and an inner circular layer. These layers intervene between the deferential canals and the urethra. )7 The submucosa has dense fibrous connective tissue and contains longitudinally placed smooth muscle bundles that are more numerous on the dorsal aspect of the lumen. No cavernous spaces are seen in the submucosa. The dense collagenous tunica propria supports the transitional epi— thelium. r“he remainder of the pelvic urethra is distinctly divided into a prostatic part and a membranous part. Lesbouyries, 1949, and Sisson and Grossman, 1953. described similar division in the urethra of the dog. The Lrostatic fart. For a description of the urethral wall refer to ’The Prostate Gland'. The fibro-elastic tunica prOpria contains oc- casional lymph nodules and supports the transitional epi- thelium. The Membranous Part. The adventitia is rich in fat, blood vessels and nerves. The striated muscularis encircles the urethra, and contains intermingled longitudinal and circular muscle bundles. The fibro-elastic submucosa contains scattered smooth muscle bundles which are especi- ally numerous peripherally near the muscularis. The cavern- ous Spaces are present in the submucosa and they increase in size in the ischial region. The fine fibro-elastic tunica prepria supports an admixture of stratified columnar and transitional epithelium. The Penile Urethra. Proximal to the os penis, the urethra is lodged in the ventral groove of the corpus cavernosum penis. The dense collagenous tissue derived from the tunica albuginea surrounds the urethra on its ventral aspect and contains occasional smooth muscle bundles. The fibre-elastic submucosa contains cavernous spaces which increase in size peripherally. in the middle of the penis, the urethra is covered by an os penis on its dorsolateral aspect (plates 29 and d4). A thick collagenous tunic covers the urethra ven— trally and blends with the periosteum of the os penis. The submucosa contains extensive cavernous Spaces which increase in size away from the urethral lumen. The inter- secting trabeculae are mainly dense collagenous with a few elastic fibers. The compact collagenous tunica propria supports the stratified columnar epithelium. The bone-free penile tip is covered by stratified squamous epithelium characterized by extensive branching epidermal pegs. On the ventral aSpect a frenulum can be seen. A distinct erectile envelOpe with marked cavernous spaces surrounds the urethral lumen. The cavernous spaces are larger on the dorsal part of the urethral lumen. Ventrally, the small cavernous spaces are separated from the integumentary tunica prOpria by a condensation of collagenous tissue rich in elastic fibers. The integumentary tunica propria contains poorly developed cavernous spaces 59 which extend into the base of the frenulum. The urethral epithelium is supported by a fine fibro-elastic tunica prepria. The Cat The Pelvic Urethra. The middle position of the prostate gland in the cat divides the pelvic urethra into three distinct portions, namely preprostatic, prostatic and postprostatic. rreprostatic Tart. The fibro-elastic adventitia contains nerve fibers, ganglia and occasional lamellated corpuscles (plates 31 and 32). The non-striated muscularis consists of two layers-~an outer thick longitudinal and an inner thin circular layer. The bundles are widely separated by fibre—elastic connective tissue. Schmaltz (1911) men- tioned that the preprostatic urethra is thin, and Traut- mann and Fiebiger (1957) stated that it lacks cavernous tissue. however, a few cavernous spaces were seen in the collagenous submucosa, in the present study. The dense fibrous tunica prepria supports the transitional epithelium. The Prostatic Tart. The middle part of the pelvic urethra is related dorso-laterally to the prostate gland (see description of the gland under 'The Prostate Gland'). Ventrolaterally the urethra has an outer fibre-elastic coat which contains fat, blood vessels, lymphatics and I». 40 nerves. The muscularis consists of three layers—~an outer thick longitudinal and a middle circular layer of striated muscle, and an inner smooth muscle layer of intermixing circular and longitudinal bundles. The submucosa contains cavernous Spaces which extend to some extent into the inner muscle coat. The fibre-elastic trabeculae contain smooth muscle cells which are especially numerous in the urethral crest. Mucous secreting glands are frequently present (plate 33). The dense collagenous propria sup— ports an admixture of stratified columnar and transitional epithelium. The rostprostatic Part. The fibrosa is rich in large blood vessels, lymphatics, nerve fibers and lamellated corpuscles. The muscularis completely surrounds the urethra and the arrangement of the layers is Similar to the one described on the ventro-lateral aspect of the prostatic part. However, the outer two striated muscle layers are intermixed and the inner smooth muscle layer is thickened. The cavernous spaces are extensive. The submucosa contains mucous glands (plate 34). The tunica propria and the epithelial lining are similar to that in the prostatic part. At the level of the bulbo—urethral glands, the arrangement of the outer striated muscle layers remains unaltered on the ventrolateral aSpect. However, on the 41 dorsal aSpect, the smooth muscle layer is thickened under the paired glands. The extensive cavernous spaces of the submucosa occasionally extend into the glands (plate 35). The submucosa contains mucous glands and the excretory ducts of the bulbo-urethral glands. The compact tunica prepria supports the stratified columnar epithelium of the urethra. The Penile Urethra. Ventrolaterally, the urethra is cov- ered by the thick longitudinal bundles of the striated bulbocavernous muscle. The dorsal aspect of the urethra is covered by the tunica albuginea of the corpus cavernosum penis, into which the bulbocavernous muscle is inserted. The submucosa is more or less completely replaced by the cavernous spaces which are separated by thin fibrous trabeculae containing a few smooth muscle cells. The urethral canal appears to float in the extensive cavernous spaces (plate 36). The tunica propria is dense collagenous and supports an admixture of stratified columnar and transi- tional epithelium. In the region of the glans penis, the cavernous Spaces are less developed, the submucosa is thick and an 08 penis is placed dorsally to the urethral lumen (plate 37). Occasionally mucous secreting glands are seen open— ing into the lumen of the urethra. 42 The Urethra of the Female Domestic Animals The hare. The urethra is very Short. The fibre-elastic adventitia contains fat cells, blood vessels, nerves and occasional ganglia. The muscularis varies structurally in the proximal and distal parts of the urethra. In the proximal part the muscularis consists of three smooth muscle layers--an outer and inner longitudinal and a middle thick circular layer. Distally, the outer layer of the muscularis is changed to the thick striated urethral muscle arranged circularly. An inner smooth muscle coat consists of intermixing circular and longitudinal bundles. The loosely organized fibre—elastic submucosa contains cavernous Spaces and a few smooth muscle bundles (plate 5). The cavernous Spaces increase in size and number toward the external urethral orifice. The tunica prepria is dense collagenous with few elastic fibers and supports the transitional epithelium. Tubular evaginations of the urethral epithelium mentioned by Trautmann and Fiebiger (1957) were not seen in the present study. The Cow. The loosely arranged fibre-elastic adventitia fat cells, blood vessels, nerves and occaSional the thick contains ganglia. In the proximal part of the urethra, . . . r .' . non-striated muscularis conSistS mainly oi longitudinally placed bundles with a few intermixing circular bundles on its inner aspect. Listally, the muscularis consists of the outer thick, circular, striated urethral muscle and ’J. an nner thin longitudinal smooth muscle layer. Occasion- ally, near the external urinary orifice, an additional longitudinal layer of smooth muscle may be seen lateral to the striated urethral muscle. The dense collagenous submucosa contains few cavernous Spaces at the origin of the urethra. These spaces, however, increase in size and number distally toward the external urinary orifice. The fine fibro-elastic tunica prepria presents cavernous spaces and supports the transitional epithelium (plate 8). The branched tubular glands mentioned by Traut- mann and Fiebiger (1957) were not seen in the present study. The suburethral diverticulum is located near the external urinary orifice. The connective tissue core between the urethral epithelium and that of the suburethral diverticulum is mainly collagenous and non—muscular with numerous cavernous Spaces. The tunica propria supporting the transitional epithelium of the diverticulum is fine collagenous and contains blood capillaries and occaSional lymph nodules (plate 9). The Doe. At its origin, the urethra is covered by a fibro- elastic adventitia rich in blood vessels and nerves. The | r thick non-striated muscularis contains intermixing circular and longitudinal nuscle bundles. The dense collagenous submucosa contains few elastic fibers, nerves and blood v ssels but no cavernous Spaces are seen. The collagenous (1) tunica prepria supports an admixture of stratified columnar and transitional epithelium. Under the epithelium a dis- tinct capillary bed is seen. The distal part of the urethra is related to the ventral aspect Oi the vagina (plate 15). The adventitia preSents an increase in fat cells. On the ventrolateral aspect of the urethra the muscularis consists of an outer circular striated muscle laver and an inner longitudina smooth muscle coat, which more or less completely surrounds the urethral lumen. however, dorsally, under the vagina, the irregularly arranged muscularis contains a mixture of longitudinal and circular non-striated muscle bundles with few striated fibers. The collagenous submucosa Shows an increase in caVernouS spaces toward the external urinary orifice and the trabeculae contain scattered smooth muscle cells. A small suburethral diverticulum is present at the external urinary orifice which presents morphological similarities to that of the cow. The Ewe. The urethra is morphologically similar to that of the doe; however, fat cells are frequently seen between ,_’ Iv- the muscle bundles (plate 22). *3 he Sow. At its origin the urethra is covered by a dense fibro-elastic adventitia containing blood vessels, nerves, ganglia and fat cells. The thick non—striated muscularis contains intermixing circular and longitudinal bundles. The submucosa is dense collagenous with few elastic fibers and contains blood vessels but no cavernous Spaces. The collagenous tunica prOpria under the transitional epi- thelium occasionally contains lymph nodules. Distally, the urethra is intimately connected to the ventral aSpect of the vagina. Sisson and Grossman (1393) mentioned a similar fusion of the urethra to the vagina in the sow. The adventitia presents an increase in fat cells. Occasionally ganglia are present between the vagina and the urethra. The muscularis is thickened and is represented by a thick outer circular layer of striated urethral muscle. It mainly covers the ventro— lateral aspect of the urethra and is confluent with the constrictor vestibulae. An inner muscle coat presents an intermixing of circular and longitudinal bundles of smooth muscle. This muscle layer completely encircles the urethra . . 4. and serves as a muscular partition between the urethra ' T' a " ' 6 us and and the vagina. The submucosa lS mostly collaoeno contains the eccentrically located urethral lumen. Dor- sally, the lumen is nearer to the vagina. The thin dorsal 46 zone of the submucosa between the urethral lumen and the vagina contains few caVernous Spaces. Ventrally, the wider zone of the submucosa contains well marked cavernous spaces which increase in size peripherally. The tunica propria and the epithelium remain the same as at the ureth— ral origin. Trautmann and Fiebiger (1957) mentioned tubu— lar evaginations from the epithelium, but these could not be seen in the present work. The bitch. Proximally the urethra is covered by the fibro- elastic adventitia which contains blood vessels, nerves, ganglia and occasionally lamellated corpuscles. The non- striated muscularis consists of two layers-~an outer layer of scattered longitudinal bundles and an inner circular layer. The fibro-elastic submucosa contains longitudinally placed scattered smooth muscle bundles and presents ex— tensive cavernous spaces. The fibro-elastic tunica prOpria is rich in capillaries and supports the transitional epi- thelium. bistally, the urethra is related to the ventral aSpect of the vagina. ln this part the muscularis presents a distinct change. The unstriated muscularis is gradually replaced by a striated muscularis, consisting of three layers--an outer scattered longitudinal layer, a middle thick circular layer and an inner longitudinal layer of scattered small bundles. The submucosa, tunica prOpria and the epithelial lining present little change in the entire urethra. The cavernous spaces (plate 30), however, greatly increase in size toward the external urinary ori- fice and may even extend between the muscle bundles. Miller (1952) also described a highly vascular submucosa in the bitch. The Female Cat. The proximal part of the urethra is cov- ered by a fibro—elastic adventitia which is rich in blood vessels and nerves, and contains occasional ganglia and lamellated corpuscles. The non-striated muscularis con- sists of two layers--an outer longitudinal and an inner circular layer. The fibro-elastic submucosa is rich in blood Vessels but no distinct cavernous spaces are seen at the origin of the urethra. The compact collagenous tunica propria supports transitional epithelium. In the distal part of the urethra, the adventitia remains the same as in the proximal part. However, a few venous Spaces are seen, and the lamellated corpuscles occur with greater frequency. As in the bitch, the mus- cularis presents a distinct change in the region where the urethra is related to the vagina. The smooth muscle is replaced by circularly arranged striated muscle bundles with few intermixed longitudinal fibers. ln addition, on the inner aspect of the striated muscle bundles, thin ' ' r . le are seen. bundles of Circularly arranged smooth musc L. (L. Venous spaces are present between the striated muscle bundles (plate 39). The fibro-elastic submucosa contains a few smooth muscle bundles arranged longitudinally. A well deVeloped corpus cavernosum urethrae is present. The tunica propria and the epithelial lining are the same as in the proximal part of the urethra. ll- I ' E x. \D J FLA Cross section through the mucos of the stallion showing the pro the urethral lumen. *1 H t o ta a f the pelvic urethra s t 10 duct opening into w. o. PLATE 1 ELATE 2 Cross section through the penile urethra of the stal- lion. Neigert & Van Gieson; X50 1. Smooth muscle bundles in the fibro-elastlc submucosa. Cavernous spaces. '5. Elastic fiber layer on the urethral aspect of the tunica al osum penis. buéinea of the corpus cavern- PLATE 2 Longitudinal section of stallion. ELAJE 3 the processus urethrae of the Toluidine blue; X50 Stratified squam ous epithelium containing marked rete pegs. Cavernous spaces. Urethral lumen. . {K3 If I: , ' ., f " ' W. A , J; I .r (I ,‘V: / 2’5: 32;?“ 3 .,4 ”I 57 ELAIS 4 Cross section through the glans penis of the foal- ‘ dd: L; 1139 l. Urethral lumen. 2. Corpus cavernosum of the processus urethrae- 3. Corpus cavernosum of the glans penis- 4. fartially opened deVEIOping fossa glandis- 5 '1 . . . mused epithelial layers of the visceral and parietal Preputial coverings prior to the formation of ‘ e Preputial cavity. “6 , xx“ . .. JV»? Ks“: ... .. ,., .. “3.3.. ...... 57‘. . . . ... ... . v .... .Ntxwa....._..i.. W fiwmfifi ,. as.» ...... ....)fiWr. Longitudina section C -e orcximal urethra of the mare. ‘f‘ 3‘ . ‘\v"\ “Lila-” Transitional epit 2. Smooth muscle bundles in the submucosa. 3. Cavernous Spaces. PLATE 5 ' . ‘ ‘ ' "n r P 4"‘x ‘ . Cross section through the peivm urethra c the bull .L l. Urethral lumen with trar u nsitional Epithelial lining. 2. Cavernous spaces in the submucosa. 3. Disseminate prostate. 4. Corpus prostatae. 5. Deferential canal. 6. Seminal vesicle duct. GO ELATE 7 \ , ‘ . ‘A bull. Cross section through the penile urethra oi the H 5: 3; K50 l. 'l‘unica albuginea of the corpus cavernosum penis. 2. Cavernous spaces increasing in size peri- pherally. 3. Urethral lumen. k q‘fl‘fl'r' FLAT: 5 Cross section through the urethra of the cow showing cavernous spaces under the transitional epithelial lining. 61+ PL ATE 8 ’5 a'Y‘" rLALL 9 ' ‘ lum longitudinal section of the suburethral diverticu of the cow. Neigert & Va" "' l. Folded urethral mucosa. 2. less folded mucosa of the diverticulum- }. Cavernous spaces. 4. lymphoid nodules. k. 66 Cross section through ILATS 13 *i‘n the pelvic urethra of the .MM V H8: :3; x23 O . . . ,l ‘ e i- Urethral lumen with stratified colu...ner P thelial lining. Cavernous spaces. Disseminate prostate. Bulbo-urethral gland. Fibrous covering on the dorso-lateral Hop 0f the urethra. ' w - reth- Striated compressor muscle of the bulb0 u ral gland. Fat cells. 68 . s «z, . . .“~As$ , v 0.. \. . 'S‘v‘nllflth .. . .. .t. .. \ [J ..a d ...x... .3 ...: .u I . \ /e..(:{ l , PLATE 1O Cross section through the l. PLATE 1 Penile ur et‘n ra of the buck. Weigert & Van Gie Urethral lumen lined with an admixture 0f stratified columnar and transitional epi- thelium. . son; X55 Cavernous spaces, Highly elastic trabeculae in the submuCOSI'iI 7O PLATE 11 ~J 'J PLATE l2 ‘ ~ + of the Cross section through tne processus ure thrae buck. Ioluidine blue; X75 1. Urethral lumen lined with transitional epi- thelium. 2. Fibro-cartilagenous unnsses. 3. Cavernous spaces. 4. lntegumentary covering. 72 ..\ .‘ o.- fixc‘? "\ .n.'... I. Ir“ \‘1‘ ‘ '32:. PLATE 12 PLATE 13 . . , d w" the Cross section through the processus urethrae of buck. Neigert.& Van Gieson; X100 1. Urethral lumen LA. 2. Edbro-cartilagenous mass. 3. Ihuuease in elastic fibers. 4. lntegumentary cov g’ : T ering. 71+ PLATE 13 \jl FLAT [1) 14 Cross section through the processus urethrae 0f the buck showmg specialized nerve ending (x) in the in- tegumentary covering. Trichrome; X320 xO PLATE 1% PLATE 15 Cross section through the uretnzea H dc E; 2:25 - ' of l. Urethral lumen lined with an admixture ‘. . e i... stratified columnar and trennxitional P thelium. 2. Cavernous spaces. 3. Vaginal mucosa. 78 PLATE 1 5 “J \..,1 PLATE 16 Cross section through the a. pelvic urethra of the ram lamb near the bladder neck, Trichrome; X25 Urethra with transitional epithelial lining. 2. Seminal vesicle. 3. Ductus deferens. Uterus masculinus. 80 PLATE 16 PLATE 1? Cross section through the pelvic urethra of the ram. Trichrome; X20 1. Urethral lumen with transitional epithelial lining. 2. Disseminate prostate. 3. Cavernous spaces. 4. Smooth muscle bundles. 5. Striated urethral muscle. .lllllll--—————~ anTE 17 — —vv——q. Cross section throu lamb. PLATE 18 gh the pelvic urethra of the ram E{<&.E; X30 Urethral lumen with stratified squamous epi- thelial lining. Disseminate prostate. Prostatic ducts. Striated urethral muscle. Fat cells. rm 4: PLATE 18 i. -uu-.-.‘3_. _ - 85 PLATE i9 Cross section through the penile urethra of the ram, H & E; X60 1. Urethral lumen with transitional epithelial lining. 3. Cavernous spaces. Integumentary covering of the penis. 87 PLATE 20 Cross section through the penile urethra of the ram lamb at the level of the origin of the processus urethrae. H & E; X65 1. Urethral lumen. 2. Cavernous spaces in the urethral wall toward the bulk of the penis. 3. Fused epithelial lin parietal layers of t formation of the pre ings of the visceral and he Prepuce prior to the Putial cavity. r L, C) PLATE 21 p (floss section through the processus urethrae oi the ram lamb. H & E; X75 1” Urethral lumen with transitional epithelial lining. 2. Fused epithelial linings of the visceral and Parietal layers of the prepuce prior to the formation of the preputial cavity. ‘— . ' . p‘o‘ ’ .. ‘ ' 5:2: .t-'I ' O . n ' ‘ .“ J‘ o . . _. ’ ‘0 "C -‘-“ F" - ' .' -‘ . f: “2;, +~m' 0‘; . M‘s ‘ _ .‘ ' .- '4-'_3' . 3 .‘ - J .1‘. ‘3 .:.a_' .. I ‘ I ‘1‘??- s s “-.u'ar-e ..A ~“ y. 22 t1] PLAT Cross section through the urethra oiTtxue ewe. H & E; X45 1. Urethral lumen with transitional epithelial lining. 2. Fat cells distributed in muscle bundles. a Puff... .. ... .4 . . an... «new .taaav .«u:.. v.J £3. 92 PLATE 22 \i) \21 PLATE 23 Cross section through the pelVic urethra of the im— mature boar. H &:13;.XSO l. Lhethral lumen with transitional epithelial lining. Radially arranged disseminate prostate. 3. Striated urethral muscle. 9L. .fi’ . 3 PLATE 23 V 3. en ‘0‘\ I. ‘ . .- .. 1.,” ..wd?)1.’b".. .’ r v/ ,. .... , .. t. . . .... ..\ ..M ‘ . . .n - ‘o%\s‘.c..‘ .. .... 0' . _ .. ...e . to? diff... » ... paw ... .. . .. ‘ ... . 0.. .‘ .fir _ H. . a .z #1 auntie o. PLATE 24 Cross section through the penis of the boalu Toluidine blue; X35 1. Urethral lumen with transitional epithelial lining. 2. Metachromatically stained corpus cavernosum penis. 3. Peripheral cavernous sinus around the urethra- ¥ '.¢ 4) 1. \‘i I I“ Fl ‘ ‘ a x}, f \ '- 'u .v pLiTE 24 Cross section through the penis of the «J Ki) PLATE 25 immature boar. Toluidine blue; X45 Urethral lumen with tr ansitional epithelial lining. Detachromatically stained corpus cavernosum penis. Peripheral cavernous sinus around the urethra. Fused epithelial linings of the visceral and Parietal layers of the prepuce prior to the formation of the preputial cavity; I J ‘ v... . .‘ ‘ ‘1 'v \ l i “13' fi“ '7 . ‘./v\ D .5 l . o t v ‘-—: - ' PLATE 25 any Hit-:1 \L k0 PLATE 26 Cross section through the penis and the preputial cul-de-sac of the immature boar. Toluidine blue; X40 Urethral lumen with transitional epithelial lining. Corpus cavernosum penis. Highly keratinized e pithelial lining of the Preputial cul-de-sac Lumen of the preputial cul-de-sac. Fused epithelial linings of the visceral and parietal layers of . the prepuce prior to the formation of the preputial cavity. r 100 / 2o 7‘ u u PLLT p4 (3' F4 Cr oss sec ti on * ohI‘ K ough PLAT? the u u 27 ret hr a of th e sow H & E; X3 5 PLATE 27 Cross section throu \3‘3 }.J PLATE 28 gh the prostatic urethra of the dog. H & E; Xl0 l. Urethral lumen. 2. Central zone of stroma containing cavernous spaces. 3. Prostatic parenchyma. 4. Crista urethralis. 5. Prostate duct Opening into the urethral lumen. 6. Dorsal median septum. 7. Ventral median septum. 8. Dorso~lateral septum. 9. Fibro—muscular capsule. - 1 C}? I r a 4 '0' 1f?" 4" 9 fr" ’31" Q .5 ’ ”H. may! DTP/{4 u -' w! ' I.\ ' t l . . t . ‘ . - . u ‘6“ . "‘ ‘!..V ' nn‘ 64. 3M k .l. Ql. . .},, I; PLATE 29 Cross section through the penis of the puPpy- Trichrome; X55 1. Urethral lumen wit h transitional epithelial lining. Developing os penis. Fused epithelial linings of the visceral and parietal layers of the prepuce prior to the formation of the preputial cavity. —_ —-— ...—...— -——————- —— .— . . —-——s- FLATE 29 PLATE 30 Cross section through the middle portion of the Eriigé‘a of the bitch showing extensive cavernous spaces 1 with blood. Hdc E; X40 10C ’5‘. u K... PLATE 3O I. PLAT DJ 31 Cross section through the contracted preprostatic urethra near the bladder of the tom cat. Trichrome; X50 1” Urethral lumen with transitional epithelial lining. 2. Dense collagenous submucosa. Lamellated corpuscle. 4. Ductus deferens. ’4 PLATE 32 (Jess section through the distended preprostatic urethra of the tom cat showing cavernous spaces in the submucosa. 112 PLATE 32 -—__§__ _ ___..__.-_ ‘ __ _ --- _.... -..- — _—— §—_ _ ——_~_ __ —_.______ .‘ ’4 H \N) PLATE 33 Cross section through the prostatic urethra of the tom cat. Trichrome; X25 Urethral lumen with transitional epithelial lining. 2. Prostate gland. Median muscular septum in the prostate gland. Mucous glands in the submucosa. ° AdiPose tissue. M 41"?” Jr? \‘ "NT" PLATE 33 PLATE 34 Cross section through the postprostatic urethra of the tom cat. Toluidine blue; X75 Urethral lumen with transitional epithelial lining. Extensive cavernous spaces in the submucosa. Mucous glands. Striated muscularis. Cavernous spaces extending into the muscularis. PLATE 31+ 117 PLATE 35 Cross section through the postprostatic urethra of d the tom cat at the level of the bulbo-urethral glan s. H & E; X60 1. Urethral lumen with transitional epithelial lining. 2. Striated urethral muscle. 3. Fibrous partition between the urethra and the bulbo-urethral gland. 4O Cavernous spaces extending toward the bulbo- urethral gland. I 116 I I PLATE 35 PLATE 36 ‘ ‘ ' a 1 tom Cross section through the penile urethra of'tne cat. H & E; X25 Urethral lumen lined with an’admixture of stratified columnar and transitional 8P1- thelium. Corpus cavernosum urethrae. Corpus cavernosum penis. Bulbo-cavernous muscle. Tunica albuginea. PLATE 36 p.) I #4 PLATE 37 Cross section through the penile tip of the tom cat. Trichrome; X90 1. Urethral lumen. 2. Us penis. Cavernous spaces. Horny papillae on the glans. . Preputial cavity. “‘5 ‘P‘rw i’ PLATE 37 PLATE 38 Cross section through the urethra of the female cat near the bladder neck showing a few small cavernous spaces. H& E; X65 1. Outer longitudinal smooth muscle coat. 2. inner circular smooth muscle coat. 121. a.» Jr...— 1\ fl 9%... PLATE 38 [\J l 5 PLATE 39 Cross section through the urethra of the female cat. H d E; X45 1. Urethral lumen with transitional epithelial lining. 2. Vaginal lumen. 3. Cavernous spaces in the submucosa. 4. Cavernous Spaces in the muscularis and ad- ventitia. 5. Lamellated corpuscle. 126 II II, PLATE 39 we; SiMINAL VJSICLE *aired seminal vesicles are present in all domestic animals except in the dog and the cat. They are situated in the pelvic cavity between the rectum and tne bladder on each side of the dorso-lateral aSpect ladder-neck. in th’ horse each gland is a true vesicle, as in man. Ihe ruminant seminal vesicle is glandular while the boar's Seminal vesicle presents an intermediate struc- f the horse and of the ruminant. CV‘ ture ‘etween (he wall of the seminal vesicle is composed of mucosa, muscularis and adventitia. Each of these three layers can be easily seen in the horse (plate 40). The fibro-elastic adventitia is rich in blood vessels, nerves and fat. The muscular coat varies in thickness in differ- ent Species. It consists of an outer longitudinal and n inner circular layer of smooth muscle bundles which present freguent intermixing. The fibro-elastic septa dividing the gland into lobes contain smooth muscle fibers The inter~lobular connective tissue 0 in vary ng amounts. is mainly fibro-elastic but occasionally scattered smooth muscle cells are seen. The gland is branched tubular. The epithelial lining of the tubules and the ducts is either simple columnar or pseudostratified columnar. The glandular secretion contains eosinophilic granules and "i .2 x. {J appears to be serous in nature. The *tallion. Fine fibre-elastic adventitia . 0 covers the muscular wall of the pear shaped seminal ves- icle. The muscularis is well developed and consists of an outer thick longitudinal smooth muscle layer and an inner thin circular smooth muscle layer with some inter- mixing of the bundles. The inner muscular coat sends muscle strands into the fibrous septa supporting the mu— s. The author is in agreement with the descrip- CL cosal fol tion given by Lesbouyries (1949). that the duct system cf is Very well develOped a the eXpense of the glandular mass. Conseguently, the glandular parenchyma is relatively thin and is confined to the inner aspect of the wall of the pyrifcrm pouch. The gland is compound tubular in nature. The simple columnar cells lining the tubules (I are 9-22 m tall and 5-9 m wide. The spherical nuclei of the cells contain coarse chromatin granules and are basally located (plate 41). The supra-nuclear zone of the cell is rich in eosinOphilic granules. The fibrous interstitial connective tissue contains irregularly ar- ranged smooth muscle cells. The intraglandular ducts are lined by simple columnar cells similar to those found in the tubules. The main ducts are lined by stratified columnar epithelium. This is in agreement with the find- ings of Sisson and Jrossman (1953) and Trautmann and 129 Fiebiger (1937). The secretion of the gland consists of eosinopnilic granules and globules and appears to be serous in nature. The Bull. She loosely arranged fibrosa is rich in blood vessels, nerves and fat cells and covers the muscular coat of the lobulated gland. The smooth muscular coat has irregularly arranged bundles. The septa contain— ntities of smooth muscle cells divide the $0 in; ,7 J gland into distinct lobes. The interlobular connective large qu tissue is fibre-elastic and contains discrete smooth muscle 051.130 Each lobule diSplays the tubule—alveolar nature of th gland (plate 4;), as has been described by Mann et al. (1949). [he glandular epithelium is pseudostrati- fied columnar. This agrees with the findings of Lesbouyries (1949) and Jrotter (1359). The three types of 'A', 'B' and 'C’ cells, mentioned by Mann et al. (1949), are clearly seen (plate 43). However, the author is in agreement with Cons (1997) in not considering the type 'C' cells as special cells. The tall columnar cells, comparable to the type 'A' cells of mann ct al., are 23-30 p tall and 4-6 p wide. The basally located spherical or oval nuclei present two to six large chromatin masses. The supra—nuclear zone of the cell is rich in dense staining fine eosinophilic granules. .ne free surface of the cell displays a brush streamers project into the lumen (plate 43). The basally located fat containing cells, comparable to the type 'B' cells of Mann et al., are 10-16 y in diameter. These cells contain large ves- icular, oval or crescentic nuclei that are much lighter stained than the nuclei of typ 'A' cells, and contain fine evenly dispersed chromatin. The interlobular and ary ducts bear an epithelial lining similar to c? the excre that present in the tubules. However, in the excretory ducts the ty"e 'B' cells are comparatively less in number. Glandular outpocketings are seen. The finely granular ' b eosinOpnilic Secretion appears mainly serous but a few granules show a faint mucin reaction with toluidine blue. No mucous secreting cells could be seen in the epithelium of the tubules and the ducts. The Buck. The loosely arranged fibrosa is very rich in fat cells and contains many nerve fibers and fre- quently occurring ganglia. Bullon and Lopez (1959) also mention a similar ganglionic chain in the human seminal vesicle. The unstriped muscular coat, as in the bull, The septa are highly muscular The is irregularly arranged. and divide the gland inta distinct lobes (plate 44). interlobular connective tissue is similar to that in the bull. The gland is tubulo—alveolar in nature and the tubules bear a pseilcstrat‘fied columnar epithelium. This is in agreement with the epithelial lining described The columnar cells extending to The by Yao and saton (1954). the free surface are 12-35 P tall and 4-9 p wide. dense staining nuclei of these cells are spherical or The infranuclear oval and divide the cell into two zones. one-fourth part of the total cell is lightly stained and contains ver" few granules. The supranuclear one—half dense staining and contains eosino- of th total cell is (L 110 granules. The free surface of the cells presents '\‘ J ..J. ‘1‘; blebs and streamers. Occasionally a brush border is seen The ‘asally located small cells of the pseudo— (plate 45). stratified epithelium contain a lightly stained cytople m and a dense staining ro‘nd nucleus. The ducts bear an epithelial lining similar to the one mentioned in the tubules. The glandular secretion is eosinophilic, granu— lar and appears to be serous. Spermatozoa are frequently encountered in the lumina of the tubules. The Ram. The gland in general resembles that of the buck. The epithelium is pseudostratified columnar and rests on a basement membrane. This is in agreement with the description given by Aitken (1955). The columnar cells extending to the free surface show variations in size. In the distended tubules they are 10-13 P tall and 4-6 p wide, while in the contracted tubules they are 132 ll-BO/p tall and e—io,u wide. These columnar cells are comparable to the type 'A' cells of the bull's seminal vesicle as has been suggested previously by Aitken (1955). The small basal cells, as in the buck, are lightly stained and contain dense staining spherical nuclei. Aitken (1955) compared these cells to the type 'B' cells of the bull's seminal vesicle. The basal cells do not show any fat in the adult animal but in the immature animal they contain fat and distinctly resemble the type 'B' cells described in the bull (plate 49). The lumina of the tubules and the ducts contain granular eosinophilic secretion and occasional Spermatozoa, as in the buck (plates 46, 47 and 48). The Boar. The distinctly lobulated gland is structurally intermediate to the equine and ruminant seminal vesicle. The adventitia contains loose fibro-elastic connective tissue with blood vessels, nerves and fat. The smooth muscular coat is much thinner than in the other animals and extends into the septa dividing the gland into The lobular disposition of the gland is small lobes. like that of the ruminant seminal vesicle. The central wide lumen and branching peripheral mucosal folds of each lobe present in miniature a structural similarity to the seminal vesicle of the horse. The compound tubular gland is lined by simple 133 columnar cells 13-33 p tall and 4-6 p wide. The nuclei are round or oval and are basally located. The evenly distributed fine chromatin shows two or three nucleoli. The cytOplasm of the cells contains an abundance of eosino- philic granules. The free surface of the cells is irregu- lar and appears foamy with secretion globules and stream- ers. Occasionally a brush border is seen. The ducts are lined by an epithelium similar to that found in the tubules. The secretion is granular, eosinophilic and appears to be serous in nature (plates 50 and 51). .HHSQ map ma comm maamo .m. make way manammmh and paw campaoo moHSLSp one mo ESHHmSpfiam uchSHoo umfimwpmnpmocdmma any mo maamo Amman map Dada awn map :H a: .pwo and mad on» ma Pcmwnm ma ccwdm one * muoamm .Hoo .aaflm 1 one 1 mmlma Hoo.mawm Hmadpsa.maoo pmom mmHSLSp any mo mcflESH A muv k MHIOH .4 any Cw Comm mapcmsc .ndp omoEmpmHQ 7; -mpw was mONOmeAmam 1 oauw 1 omlaa .H00 1. mSOAmm .Hoo .pum .mm .929 cmpomupsoo .Hpm.mm .>awloasDSB **adm mwfiSQSP on» mo mcflESH omu cfl comm meCmSG Imam mum wouOPwEmmam .Hoo msopmm .Hoo .ppm .mm 1 one 1 mmlma .upm.mm .>Hmu0H:psa xosm .amS 5 1313 unmmmpa maamo .m. adoss mo mmocpu 1 mnv 1 OmIOm .Hoo asp msopmm macflmz .Hoo .ppm .mm maamo .4. .hum.mm .>Hmuoadnda aadm whopmm .Hoo .ppm mo .Hoo .Hmafim A mem 1 mmum Hoo.mawm Haasnsa .oaaoo omuom spew; unmamm .npamm :oflpoaomm mpozo any mo mafiaflq mccwam mm» mo mcwzfiq ncmHm Ho mama adaacd .mgasz< oHemmzom may mo onHmm> HH< H3938 @800 an; mucosa acnom mH COHpmnomm one mwceHc Happens: no aansc esp Hmcz a; msopmm 1i MHchE one mchmh: one go pace Has a. o o - J- o o o 0 Q» 0: Leona 2: E meeeS Hoe .Sm Km e ; mo 0 H00 93m >2 H35 00 s a 1 07m 1 Que pcmmmnm .nsp ummflmpmHa .Q. y J. J -... .. \. q.) o .4. 1.. 1 diva UJIVH >e+ccrcdng erowycnorco macaw no HrnHoQSQ m - re c . : . . .L mneomfilenom .Lam no HcrHonso .03» couch whom Hoo aer >H¢ H5239 :aov HHsm .muena no .Hoo nchmm .nwm so .Hoo .asHm lxblv 1\chm Hoo. 5am LMHSQSB A500 mmhox 1" ..rursr- .I Goo My 1r..3OJ AxvcwWiHmmww Wmem saw nuns: pandas .nuama :oHpenomm moose emu mo mchHH mwcst srp mo MdHrHH ncmH» Mo mama Hmch< WMwaHze oHameoa Mme a0 02 secretion in the tubules and ducts is finely granular, eosinOphilio, and appears to be serous in nature. Contrary to all other animals in which mucous cells pre- in the The Bull. The capsule consists of nonmusoular ' ' ‘ ' ' e s. dense white fibrous tissue With a few elastic fib r Lesbouyruxus (1949), Sisson and Grossman (1953) and Traut- ' " "" ~ ' ed the distinctly mann and Fiebiger (1931) also Lention ' . ' ' ue se ta fibrous nature of the Capsule. The connective tiss I? ' 'n a few divide the gland into indistinct lobes and contai ' uscle. smooth muscle cells but no striated m ' ture. The gland is compound tubular in na The (.3 b ‘- \\ JN ' 7" 0‘ .. ‘4'... A _ _ bdtulbb r- lined r. elm,le Columnar cells 8-27 p tall (I) _‘ .43, ... ~ and 4 13 } lu-. -ne den e staining, small, rounded, basally locate} nuclei contain coarse or .romatin and prom- inent nucleoli. The cytoplasm gives a strong mucin reac- tion with toluidine blue (plate 67). The cell outline is fairly distinct, and in hex itcxylin and eosin prepara— tions the glanl res {hhlc s a typical mucous gland (plate be). PGCri“l fat cells reported by Lesbouyries (1949) were not observed in the present study. The ducts are lined by hizh cuboidal or columns r epithelium which becc: es transitional as the excretory ducts apgumxuni tre ir te :nlnation in the cul- de- sac of t4“ uFEthrsl valve. The presence of this valve, mentioned by Lesbouyries (133(0), was determined grossly in the ischial re gion of tin; urethra. histologically it revealed a transi— . . . , ,. . . . } ‘ tional epithelial lining Similar to tuat of the urethral lumen fou" at the same level (plate 68). The presence O. ‘ . 0 + 01 such a valve may have some role in the eJaculatory "'3 111.31811 in the bull. The Buck. in general the gland resembles that The fibro-elastic capsule 15 Of the bull (plate 69). thinner than in the bull and contains large amounts of - ' ' ' the fat Close to the urethra. The septa, which lelde smooth muscle cells. The gland into indistinct lobBS. contain ' .t, 'n nature. ‘ is compound tucular l I“! _. '1 $115 (Slat-Au v.3- ”‘IZQ (7') ‘ ‘3) vv fiw’y‘y‘y, A tucuie- a-, lined by simple ocluzznar cells 15—27 F tall and 9-12 F Wide. .he small nuclei are spherical, dense .ing, con n coarse chromatin granules and occupy 4 exam the basal one-fo urth of the co ls. The cytoplasm of the Cells reVeals the mixed sero-muoous nature of the gland; however, "w mucous cells predominate. The cells which show a stron' mucin reaction with toluidine blue, as those in the hull, appear foamy with large vacuole ted spaces in the buck. The serous cells contain highly granular oytOplasm, as mentioned by Yao and Eaton (1954). The ducts are lined by cuboidal or columnar epithelium wlicn show seromucous glandular outpocketings P, (plate Tl, similar glandular outpocketings in the ram). Occasionally the collecting sinuses become distended with the accumulation of secretion products and appear cystic. .233_33m. The gland resembles that of other ruminants. The fibro-elastic capsule and septa resemble the t of the buck, dividing the gland into indistinct lobes. ihe parenchyma oontc ins compound tubular glands. The tubules are lined by tall columnar CB 118 that are more or less pyramidal in shape and are 6—17 F tall and 5-14 F wide. The nuclei are oval or crescentic and occupy the basal one- -fifth of the cell. The cytOplasm of the majority of the cells gives a strong mucin reaction by tOluidine blue, similar to that seen in the bull and the I4 H ’d (I L? ,4 buck. in 'toxylin and eosin preparations the same cells show scattered eosiLOphilic granules. A few tubules, with dense eosinophilic cytoplasm, show a serous secretion in their lumina (plate 70). *J .r‘\ “‘3 car. The fibre—elastic capsule contains tn mixed smooth and striated muscle cells and gives rise to septa of a similar nature dividing the gland into lobes. Echenzie et al. (1938) also mentioned the presence of smooth and s riated muscle strands in the septa. The cap— sule presents an abundance of fat cells and nerves close to the urethra (plate 72). The gland is compound tubulo—alveolar, as preVi- ously described by mcKenzie ct al. (1938). The tubular ‘Lithelial cells are simple columnar, pyramidal in appear— ance, and are 10-25 F tall and 6-16 y wide. The small, OVal nuclei are very densely stained and are basally Situ- atom. The cytOplasm shows a strong mucin reaction. The cell outline is faint, and the free surface of the cells ~ = 'oned b McKenzie presents blebs and streamers, also menti y at al. (1938). The glands and ducts appear distended and cystic ' ' re— at places, due to an accumulation of the thick waxy sec ' ducts tion which is characteristic of the gland. The . . , . m. are lined by flattened cubOidal epitheliu of the in the immature .nimal the tubular nature ECO nonsecreting gland is well preserved and the connective tissue stroma is abundant (plate 59). The Cat. The fibro-elastic capsule is not well marked and the gland is more or less completely surrounded by the striated muscle. The interlobular connective tissue septa contain a mixture of smooth and striated muscle fibers. The gland is compound tubular in nature. The tubules are lined mainly by simple columnar epithelial cells 10-20 F tall and 4-8 p wide. it places the epithelium appears to be pseudostratified. The basally located round nuclei present homogenous dispersion of the chromatin 'ranules and a characteristic centrally located Single large nucleolus. The cytoplasm shows a muCin reaction with toluidine blue, but in hematoxylin and eosin prepa- rations, fine eosinophilic granules are seen scattered ' ~ ' ' ' tinct. throughout the cell, making the cell outline indis ‘ h Streamers are seen on the free suriace of the cells whic occasionally reveals a brush border. The ducts bear strat- . . . a ' to ard ified COlUlhIlaI‘ epithelium WillCh becomes tranSitional W . r‘ ' . ‘ r fibro their urethral terminations. lhe interglandula ' sionall rich in blood vessels. Occa y elastic tissue is fat cells (plate 73) 1‘ the lobules contain large masses oi ‘ ethra (plate and eXtensions of cavernous Spaces lrom the ur 35). .306 mg» Ca pammnm ma vcmam an? * am: on: x~CHrzv cascozznttq, flow .pun 1.mnv 1 omIOH Hoo.aaflw pma:n:9.aaoo who 1 faxes Tsar: at execs: H.5a0hso A oa-o a muuoa Hou.maan .>He.asnsa.asoo neon .ascoxa aficwcfiv ago unsucamu penssaco ho firewopzn 1 eaun 1 wane Hoo.msfim headpse.asoo awn ”encore hfizwraa ascoraucnim .fioc no He: clan 1 mann 1.>m Hog. as Sam amasnse.maoo xosm msoozu .Hoo no Havflonsu 1 Cale R swim Hoo. asam pmH595m.maoo Hadm .Hoo Hasao so .nuw .mdan ho as t rows arrhnm no H:,.om so .asam 1 film .R walm Hmnflowso .>H¢.H5339.mnoo empom . C 4 0 rpeue anther epasa cowamuocm macaw app mo madmaq mcscdm esp wojmsflcflq esmam mo mafia Hasas< qufisz 0 Emcfiog ‘0 he mu Oquu . Vet HHH mumme Afixmwmmu Iaqum wry PLATE 64 Cross section through the bulbo-urethral gland of the horse. H & 5; X225 1. Central collecting sinus. 2. Granular eosinophilic secretion of the gland. 3. Columnar cells lining the gland. 4. Striated muscle in the septa. — 203 PLATE 6’+ 204 PLATE 65 Cross section through the bulbo-urethral gland of the horse showing rare mucous secreting cells (x) in the gland. Toluidine blue; X1800 PLATE 65 206 PLATE 66 Cross section through the bulbo-urethral gland of the bull. - H & E; X200 1. Central collecting sinus. 2. Tall columnar cells lining the tubules. 3. Scanty interstitial connective tissue. “O7 PLATE 66 208 PLATE 67 Cross section through the bulbo-urethral gland of the bull. Toluidine blue; XlOOO 1. White fibrous capsule. 2. Tall columnar cells with dense staining bas- ally located nuclei and strong mucin reaction in the cytoplasm. 3. Mucous secretion in the lumina of the tubules. 209 4 n p) .. .. c (.3... . z‘ PLATE 67 210 PLATE 68 Longitudinal section through the cul-de-sac of the urethral valve found in the ischial region of the bull. H & E; X200 1. Transitional epithelium lining the urethral valve. 2. Duct and tubules extending from the bulbo— urethral gland toward the urethral valve. 211 i . I] I ..I’ u/{H , .s, ol.l.¢lrl I #7}... n-¢.v¢fl.wn.¢ ( ‘ z. '1 I a k- " t I, ll ' ‘3 N. ' Wu»... 4 7 l PLATE 68 PLATE 69 Cross section through the bulbo-urethral gland of the buck. H & E; X170 1. Fibrous capsule. 2. Fat cells near the urethra. 3. Mucous secreting columnar cells lining the tubules. 4. Central collecting sinus. 5. Fibre—muscular septa. an"! 7 ..fi. O D? o 213 PLATE 69 F.) f.) 43 PLATE 70 Cross section through the bulbo-urethral gland of the ram. Toluidine blue; X180 1. Serous tubules. 2. Mucous tubules. 3. Duct. 4. Interlobular septa. 21S PLATE 70 216 PLATE 71 Longitudinal section through the excretory duct of the bulbo-urethral gland of the ram. Toluidine blue; X330 1. Lumen of duct. 2. Columnar cells lining the duct. 9. Glandular outpocketings from the duct con- taining sero-mucous cells. 217 PLATE 71 218 PLATE 72 Cross section through the bulbo-urethral gland of the boar. Trichrome; X145 Fibro-muscular capsule sending septa into the gland. Fat cells and nerves on the urethral aspect Mucous secreting tubules. Tubules distorted by the accumulation of the thick waxy secretion in the mature animal. 219 PLATE 72 220 PLATE 73 Cross section through the bulbo-urethral gland of the tom cat. H & E; X40 1. Striated muscle surrounding the gland. 2. Thin fibro-elastic capsule. 3. Central collecting sinuses. 4. Fat cells between the lobules. \x‘gggm‘ v 1 . I ' l .- a 3.... .-.u ‘ u' ' ‘ fl’ - . .‘ _ . . PLATE 73 SUMLARY AND CQNCLUSIOJS Comparative histological studies of the urethrae and accessory sex glands were made on fifty-two domestic ‘ 0 animals 3. U) even Species. lhe pelvic urethra in the male ruminants and the boar contains the disseminate prostate. In the bull, the disseminate prostate is located mainly on the dorso- lateral aspect of the urethral lumen, and the tubules are eercmucous in nature. The boar has a more extensive disseminate prostate which is radially arranged and co— cupies a major portion of the urethral wall. The tubules are serous in nature. She buck and the ram possess a D. p U) (I) (I E: F) :1 {D C? e rrostate similar to the bull, but extensive cavernous spaces are present in the urethral submucosa. q H , Q A . . . ihe exceptionally large cavernous Spaces are a distinctive feature in the buck. A distinct division of the pelvic urethra into a 'prostatic urethra' and a 'membranous ureth- ra' is seen only in the dog. The cat possesses ‘prepros- tatic‘, 'prostatic' and 'postpros atic' segments. The prostate g and does not surround the urethra as in the dog Lamellated corpuscles are frequently present in the urethral wall of the cat. 1n the horse, the dissem- inate prostate is represented by the scattered 'Glands of Littre'. in this species the connective tissue 222 , intersecting the extensive cavernous spaces, are rich in longitudinally placed smooth muscle bundles. in all the male anirals, the cavernous spaces increase in size from the tladder-neck toward the ischi al region. The stria t d ure ril muscle completely encircles the ‘urethra in all thu male animals except in the bull and the bear. in these two species, the urethral muscle is pres ent ventrolatesally with a fibrous tunic covering the urethra dorsally. Lhe penile urethra presents marked variations in different speCies. Ihe horse and the cat have a dis— tinct ventrallv ;laced bulbocavernous muscle. In the ruminants ah} the boar, tne collagencus tunic derived from the tunica albaginea of th e corpus cavernous penis surrounds the urethra completely. The urethra of the dog is covered by an cs penis on its dorso-lateral aspect. ‘Jentrall5, it is covered by a fibrous tunic derived from the periosteun of the es penis. The cat has an os penis in the penile tip which is related dorsally to the ureth a. in the horse the urethra is flanked E5 the fossa glandis a the level of the glans. The submucosa.ccntains smooth muscle bundles in addition to the di 5") tinct cavernous sosc w J. O (D m Ihe cavernous spaces are most extensive in the buck and the tra becul e are hizhly elastic. The ram.has a submucosa similar to that seen in the buck, but the cavernous spaces are smaller and the connective tissue is less elastic. .ne bull 34KB sensentrically arrtinged cavernous spaces whicrizi:iear spirally arranged due to tre eccentric ureth— ral lumen. in all animals the cavernous spaces increase in size peripherally to the lumen. In the boar, the ca er Spaces are extensive and the urethra appears to be con- taincd ‘nder a peripheral Sinu O) Cnly tne stallion, bull, buck and the ram have a processus urethrae. in the bull the processus urethrae 'wi in the glans. On its medial aspect it is i:.ti:ately related to the tunica albuginea of the corpus caVerncsum of the glans. It ccrtains rudimentary erectile tissue. in the horse, an erectile envelope surrounds the urethral canal in the process us urethrae. In the buCk and *1 t I (f 2- C 9». P- (1’ *1 (I I 0 L0 *1 (t *1 H '-LLOUS cords flank the urethral canal in the urethral processus and Siecialized nerve ending Anonb the female domestic animals, the urethra cf the mare conta ins thick lon itudi nal smooth muscle bundles in the submucosa. The cow urethra has cavernous opac;s tunbzr the cpi theliu All the ruminants possess a suburetzxal diverticulum near the external urinary ori- lice which 1 best developed in the cow. The ewe has fat 0) cells ix} the muscularis. In general, the cavernous spaces increase in size toward the external urinary orifice. Ihe carnivores present the most extensive cave nous Spaces 1n the sucnacosa. Lamellated corpuscles occasionally g I" J \jW seen ix: axe urethral wall of the carnivores occur more ihe function of the cavernous spaces in the wall of the pelvic urethra of the male animal is not clearly ‘unierstcuxi. it may he suggested that while the urethral muscularis directs the outward flow of the seminal ejacu— ed cavernous Spaces close the urethral lumen an; heip'to check the hack flow of the ejaculate on nerative pressure in the glands. in the female anitals the occurrence of the cavernous spaces appears to be directly proportionate to use duration of coitus in diff rent species. A possible function of the cavernous Spaces in the female urethra (I may to hypothesized to t to close the urethral lumen with engorgei corpus cavernosum urethrae during coitus and thus check the possibility of leakage of urine. fmue large rancher of lamellated corpuscles around the urethra and near the vagina, and the presence of horny papillae on the penis of the male oat, may play some role in the ovulatory mechanism of this species. lt is suggested that the presence of such structures in the male and fe- male (mats might be an aid for sending impulses during coitus for neurohormonal release initiating ovulation. the seminal Vesicles are absent in the dog and cat. ln the other Species they vary considerably. In the horse each gland is a true vesicle. The ruminant f‘\ r O ( Seminal vesicle is truly :‘jlani‘ilar while that of the boar ‘..‘.'\. ‘vu Mu; gA‘LJ *4. ‘I s ‘ “"\ 7“ v‘ "‘I .“" ‘ r I is stzio . .erneoiate to the horse nd the ruminants. f.) i‘he glen}. is compound tubular in the horse and boar, and J ‘bilo—a veolzir in the ru::.inants. I‘he tubules and the 6' r ducts are lined ty simple columnar epithelium in the horse an; the tour, and pseudostratified columnar epithelium in ruminants. :ne mature tull pres~:nts fat in the basal Cells of the epithelium. in sheep, the adult animals do not snow fat in the basal cells, while in the ram lambs it is distinctly seen. L‘he secretion is mainly serous in a l S;.';Cic;3. Spermatozoa ar: frequently seen in the lamina of the tubules in the buck and the ram. the prostate gland is present in all the domestic animals. ’i‘he ..orse, do and cat possess a corpus pros- tatae. 'i‘ne tuck anl the ram ”time a pars disseminate while the bull and the boar contain both the corpus prostatae and the pars disseminate. The corpus prostatae is musculo- glandular and is located outside the urethral muscle. The pars disseminate is generally non—muscular and has teen described with the pelvic urethrae of the male animals. i‘he prostate gland is compound tubulo—alveolar in the ruminants and is compound tubular in the remainder Of the animals. l‘ne epithelium lining the tubules is simple columnar in all animals. The epithelium lining the ducts varies as they extend from the gland toward the urethral lunwn. It may vary from a simple or stratified cubcdxtxl or columnar e ithelium to one resembling the F4 W urethral epithelium at the same level. The secretion is serous in the horse, do; and cat. In the boar the Q n a? 7“ ' .‘V‘fi QM ‘ 't‘n +7") #31 I th Ucv-~vA-v.l lo a AAA lJ uerJD \V]. .L uAuceS O- mucus. n e runninants, 2142,31anis are mainly serous toward the bladder, while tuna, are acre-mucous toward the bulbo—urethral glands. Concret*‘ t'e hull, and corpora amylacea in the dogs } 0 0 v o ('7 *1 : t (I) are occasicnally 3 en. lhe halts-urethral glands are absent in the dog. 1332,;land capsule located under the striated com- pressor muscle is libro-elastic with mixed smooth and striated muscle in the horse and the boar. In the cat (‘9 :T (D H H (7 “rcus capsule is very thin, and th gland is mainly covered by the =triatei compressor muscle. The ruminants have a dense collagenous capsule which is thickest in the bull. 2&u2.fibro-elastic septa in the gland contain smooth and striated muscle fibers in the horse, boar and eat. like striated muscle is lacking in the septa of the ruminants. lntexflxnnzlar fat cells and cavernous spaces are frequently seen in the cat. Ihe gland is compound tubular in all animals except in the horse and the boar. In the latter speCies it is compound tutulo-alveolaru The tubules and the ducts are lined by simple columnar epithelium in all animals. .flus ecretion varies considerably in most species. U) a se'cus sesretion with traces of mucus. I}: ' :1 C X‘s .3 ocLi \) s ‘ ‘ I ‘ " ‘ ‘ k 7' . r r v Vq ‘ r. '. . . ‘3 heel $54 :56 ~04? hive a mucous secretion while the tucm, ram and out have mainly mucous with some serous secretion. I‘AEiT I I . l.i.) L37Ji-.JIC;‘~.L lfiaxln'fiCN C" THE URINARY BLADDER-NECK TJDINS CCIC’N IN THE DOG tn 'V’N‘. wv-I" T~v‘ ~-V . , N .LHlK.) 1.3.; .../.40‘4 IHIhCJUCTILN As a tart of a continuing study on the urethral epithelium Ehnraiwaj and Calhoun, 1959), the surgical finsertion c’ the urinary tladder-neck into the descending cz‘lon was carried out in dogs with a view to studying the .gross as Well as histological alterations resulting from the pIEHMLLCQ or the ahsence of the flow of urine in -- (l) the dysfunctional urethral stump, (2) the functional new ckmuuizl. This work may prove useful to SUTEGODS and ' veterinary and numan medical fields. ... _ patnclc,ists in . nEViEW OF LITJRATUAE eamer (1399) gave an illustrative description m of a successful technique to divert the passage of urine from the bladder'to the colon in the cat. However, he :nade no anatomical or histOpathological studies on the hi (I H 9) ('fi (v $4.. ozggins. oempster and paniel (1950), Kubiak et al. (1954), Lrinher (1337), pesautels (1&5?) and martin et al. (1959) have dtxne various surgical experiments on the urinary system cf the dog, but they mentioned no anatomical or histologi- cal studies of the involved organs. hattner et al. (1959) studied the microscopic appearance of the ileal urinary conduit in man. The tis- sues examined were CXposed to urine from three weeks to ”' ‘ ' ' st strikin three years. ine authors mentioned that the mo 5 ' ' in— feature of the ileal segments is varying degrees of ' ' 'on and flammation, ranging from minimal to acute ulcerati n tes Lnfiltration.of the mucosa and submucosa by lymphocy tflfii plasma cells. After a three year period the conduit Showed necrotic ulceration and foci of calcification in addititnu to the above mentioned cellular infiltration. ‘At all stages the ileal pattern was retained, and there ‘WaS no anatomical reason to suspect that the absorptive ability of the mucosa was changed by eXposure to urine. 231 “ TShIALS ND ESTHCDS Four dogs were used in this study. These in- cluded two nonepregnant females, one pregnant female at aid-gestation, and one male dog. The surgical technique employed was essentially the same as that established by Beamer (1959) for cats. .he advocated that a polyethylene tube passing from the bladder through,the colon to the outside should be allowed to reaain in place for seven days. However, in the present ‘work, this did not appear necessary and the tube was re- moved on the third day after the Operation. Two different sites of insertion of the bladder ‘Were chosen. In one of the non-pregnant females, the blad- der neck was inserted into the nearest loop of the small rntestine. This animal showed considerable emaCiation and was sacrificed on the eighteenth day. In the other three animals, the bladder neck These was surgically attached to the descending colon. animals were sacrificed after three months. . . . m— The organs of the sacrificed animals were exa h ing colon ined in situ. The urethral stump and the desce d .1 v ' histological were renoved, examined grossly, and fixed for o Stu. _" J. - ' I. tially the same as mentioned in part 919 A m nid'JLTS AND LISCUSSICN LoLno. 1. Lnon-iregnant female). The urinary bladder- neck was inserted into the nearest loop of the small in— testine. it was not feasible to use a polyethylene tube to provide a temporary channel from the bladder through the small intestine to the outside. After the operation the animal showed signs of constant straining and frequently passed feces mixed with urine. The appetite was completely lost. because of COFLSldEI‘flble emaciation, the animal was sacrificed on the eighteenth day after the Operation. lost mortem examination revealed visible signs of cystitis and peritonitis, and the intestines were ed- ematous. Because of the obvious drastic effects on the animal, the site of implantation was considered impractical for future use, and the tissues were not examined further. Dog no. 2. [non-pregnant femalei and Dog no. 3. (female at mid-gestation period). In these cases the bladder-neck was inserted into the descending colon. A polyethylene tube was left in the animals for the passage of urine from the bladder through the colon to the outside for the first three days after operation. The recovery was unevent- ful, and after a week the animals ate normally and remained 233 '0 active. i‘he excreta contained mixed urine and feces and was voided with no difficulty. The animals did not lose any weight in their post-operative life of three months. On post mortem examination the bladder showed some thickening, but the remaining organs appeared to be normal. The healing of the vesico-colic union was complete. The urethral stump showed considerable regression in size (plate 74). The interior of the bladder and the colon revealed a clear Opening of the bladder—neck into the colon. The mucosal folds on the ventral aspect of the colon showed a lonxritadizal arrangement to provide a channel for the passage of urine (plate 75). en histological examination, the submucosa of the urethral stump showed an increase in fibrous tissue and a definite decrease in the cavernous spaces (plate 76, compare with plate 30 of the normal animal). The lining epithelium showed desquamation with cellularzhr- filtration and marked vascularization in the tunica propria Which also appeared edematous. The urethral and bladder lumina contained exfoliated cell debris and granular eos- inophilic exudate (plates 77 and 79). The vesico-colic union showed complete healing in the fibrous and muscular coats but the epithelial lining remained incomplete (plate 78). The muscular coat of the bladder was considerably thickened. The mucosa was infiltrated by lymphocytes and plasma cells, signifying a chronic inflammatory condition (plates 79 and 80). hattner et al. (1959) observed a similar increase of plasma cells in the mucosa of the small intestine used as urinary conduit in man. The longitudinal folds of the descending colon preSented a.relatively normal histological architecture of the organ (plate 81). hattner et al. (1959) observed similar maintenance of morphology in the small intestine of man. [he Operation did not reveal any adverse effects on the pregnant animal and the fetuses. Five normal healthy pups were born upon completion of the gestation period. Dog no. 4“ @Lature male). Considerable difficulty was encountered in the male animal, both.with regard to the Operaidxni and the recovery of the patient. The animal had.en1.initial attack of peritonitis. This condition and :its subsequent treatment delayed the usual recovery period. Aftex'zi.fortnight the animal behaved normally for the rest of his post-Operative life of three months. on post mortem examination the peritoneal cover- ing over'tflue bladder and the colon was thickened, and there 'was a marked increase in the vascularity in this region. The urethral stump, consisting of the prostate gland and the membranous urethra, showed regression in size (plate 82). 436 The bladder wall was considerably thickened (uni the longitudinal arrangement of the colic mucosa to provide a urinary channel was not well marked (plate 83, compare with plate 75 of the female). 0n histological examinations the vesico-colic thiion, the membranous and penile urethra (plate 84) and the colon presented Changes similar to those described in the females. in addition to these the prostate gland snowed a marxed decrease in the glandular parenchyma with a noticeable increase in the connective tissue strmma boompare plate 89 of tne patient to the plate 28 of the normal animal). Insertion of the urinary bladder-neck into the descending colon did not produce any visible adverse ef- fects in adult females. it also did not interfere with the normal gestation period and prenatal development of ‘Ums fetuses. However, the technique has some obvious disadvantages in the male animal. 31.72.1111!th AND CQIIC USIONS The urinary bladder—neck was surgically inserted into the small intestine of a female dog, and in two other females and a male dog, the bladder—neck was inserted into the descending colon. The surgical technique employed was essentially the same as established by Beamer (1959) for cats. The insertion of the bladder into the small intestine was ccnmdered impracticable because of its overall drastic effects on the general condition of the animal. In the animals in which the bladder was inserted into the descending colon, the observations were made on -- (l) the dysfunctional urethral stump, (2) the functional new channel, (3) the accessory structures associated with the urethra and (4) the prenatal deveIOpment of the fetuses. The Operation had no adverse effects on the eXperimental females nor on the prenatal development of the fetuses carried by one of the females. In the male animal, considerable difficulty was encountered both with regard to the operation and the recovery of the patient. In all the animals the descending colon presented a grossly visible longitudinal rearrangement of the mucosal folds to provide a compensatory channel for the passage of urine. In the male animal this rearrangement was not marked. HistolOJical examination of the urethral stump revealed 237 238 an increased fibrosis, decrease in cavernous spaces, exuda- tion, cellular infiltration, and desquamation of the ureth- ral epithelium. Plasma cells appeared to be the main cells in the Cellular infiltrations at all sites. The healing f the vesico-colic union was complete in all layers of the organs, but the epithelial lining remained interrupted OVer the scar even after three months of post-operative life. 'I‘he normal architecture of the descending colon used as a passage for urine remained unaltered. The pros- tate gland of the addlt male dog showed a decrease in the glandular parenchyma and an increase in the stroma. 239 PLATE 74 Post-mortem examination of the viscera of the experi- mental female dog (No. 3) operated at the mid-gesta- tion period. 1. Body of the uterus. . Descending colon. 2 3. Urinary bladder. 4. Urethral stump. PLATE 71+ 241 PLATE 75 interior of the vesico-colic union of the experimental female dog (No. 5) operated at the mid-gestation period. 1. Urinary bladder. 2. Normal circularly arranged mucosal folds of the descending colon. 3. Compensatory rearrangement of the colic- mucosa into longitudinal folds to prov1de a channel for the passage of urine. Opening of the urinary bladder into the colon. 5. Anus. PLATE 7S 245 PLATE 76 Cross section through the disfunctional of the non-pregnant experimental female Note the increase in fibrous tissue and the cavernous spaces in the sub-mucosa. H & E; X50 urethral stump dog (No. 2). a decrease in PLATE 76 245 PLATE 77 Cross section through the dysfunctional pelvic urethra of the experimental male dog. H & E; X300 1. Desquamation of the epithelium. 2. Eosinophilic exudate in the urethral lumen. 3. Cellular infiltration in the submucosa. 246 5a. 6‘: ..( can». 9\ i‘§‘ PLATE 7? 247 PLATE 78 Longitudinal section through the vesico—colic union of the experimental male dog showing a complete heal- ing of the different layers of the bladder and the colon. Note that the epithelial lining remains in- terrupted even three months after the operation. H & E; X50 PLAE 78 249 PLATE 79 Mucosal changes in the urinary bladder of the experi— mental female dog (No. 3) operated at the mid—gesta- tion period. H & E; X350 Cellular infiltration in the connective tissue. Increase in blood capillaries in the tunica propria and submucosa. Desquamation of the epithelium. Eosinophilic exudate. . . . .. . . . .. . o . . . ~ ,. I t . . . . . . - .. . . . . I .. . . . . ... . . ~ . . .. . . .. . . . . C1 . . ..ommb... w. «flimr‘ 0.... ... ..~ . .... a“. ...w .... ...w. “a .. ..‘W‘AIKJLO...M. V ..o.... x . . ..W/fx-M..y..ofiwm$./01.t ..f/fl. . . . .. .. .. . p .. . f2... ...» i”. ‘ if. at . . . . . u , . ... ...... . x 5 .K, . .. 1 Q .10. I. ll. _ . . ... ... .... . ..4 .W;%. :W; . mfigaquukc . Jw‘ruuwu .1 A w .. . ., n . .... ._ .. .. .. 34.‘4~31‘WM»\W.. ; 471... .iKflm. . ., +4... ,..r......¢ ..w «Kw . .. .. ..H a... a... .. 1...... 'vnay .... .. t . . .J .- K . . O . i. . _ . .o r .- .. -L .."’?m .. ...”; s PLATE 79 PLATE 80 A high power study of the infiltrating cells revealing them to be mainly plasma cells. H & E 253 PLATE 81 Cross section through the longitudinal mucosal folds of the descending colon of the experimental female dog (No. 3) operated at the mid-gestation period. Note that the normal architecture of the colon remains unaltered even three months after the operation. H & E; X50 255 PLATE 82 I Post-mortem examination of the viscera of the experi- mental male dog (No. 4). l. Descending colon. 2. Urinary bladder. 3. Prostate gland in the dysfunctional urethral stump. PLATE 82 257 PLATE 83 Interior of the vesico-colic union of the experimental male dog (No. 4). l. 2. Urinary bladder--note the thickened wall due to cystitis. Normal circularly arranged mucosal folds are well marked in the descending colon prox1mal to the site of the vesico-colic union. Slight rearrangement of the colic mucosa into longitudinal folds to provide a channel for the passage of urine (Compare with Plate 75)- 258 PLATE 83 [\\ \“ \t PLATE 84 Cross section through the dysfunctional penile urethra of the experimental male dog (No. 4). H & E; X60 1. Urethral lumen with desquamated cell debris. 2. Os penis. 3. CaVernous spaces. - , ‘1‘-"— 260 ~70 (‘5‘ e‘ n y I‘ \ 261 PLATE 85 Cross section through the prostate gland of the experi- mental male dog (No. 4). H & E; X30 1. Urethral lumen with desquamated epithelial cells and eosinophilic exudate. 2. Regression of the glandular parenchyma. 3. Increase in the fibrous stroma (Compare with Plate 28). 262 PLATE 85 LITLRATUhE CITED Aitken, h. N. C. 1955. A histological study of the sem— inal vesicle of the sheep. J. Anat. 89:430-439. beamer, h. J. 1959. Uretrocolostomy for relief of urinary stenosis in the domestic cat. J.A.V.M.A. 134: her; 6. A. 1958. The normal prostate gland of the dog. Acta Endocrin. 27:129—139. hnaradwaj, M. 8., and m. L. Calhoun. 1959. Histology of the urethral epithelium of domestic animals. Bullon, A., and F. L. Lopez. 1959. Uber die Innervation der menschickon Samblase und des homologen or- ganes beim Hunde. Zeitschr. mikrosk. anat. Forsch. 65:133-152. (Original article not seen; the present information is from Basic Med. 80., vol. 35. no. 18686). Christensen, G. C. 1954. Angioarchitecture of the canine penis and the process of erection. Am. J. Anat. C (I :x U. U N. 1957. 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