Reproductive Organs of Male Domestic Animals Chap 1 PDF

Chapter 1 Reproductive Organs of Male Domestic Animals The male reproductive organs consist of two testes (or testicles)which are contained in the scrotum, ducts, accessory sex glands and the penis. The reproductive organs of the bulls are shown in Fig. 1.fand the comparative anatomy of the...

Chapter 1 Reproductive Organs of Male Domestic Animals The male reproductive organs consist of two testes (or testicles)which are contained in the scrotum, ducts, accessory sex glands and the penis. The reproductive organs of the bulls are shown in Fig. 1.fand the comparative anatomy of the male reproductive organs of different domestic animals is illustrated in Fig. 1.2. The testis produces spermatozoa and the male sex hormone (testosterone). The scrotum helps maintaining optimum temperature for thespermatozoa production. The other structures help for the passage of the spermatozoa to the site of deposition in the female's genitalia in a fairly good condition that may lead to fertilization of the ovum/ova. SCROTUM AND TESTES The scrotum is a cutaneous pouch (derived fromthe skin and fascia) in which testicles are located. The scrotum in all the domestic animals except in boar and cat is located in between thigh3( In boar andcat the scrotum is located caudal to thigh). The testis is fixed to the scrotum bymeans of scrotal ligament attached to its caudal end near the tailof the epididymis. The hairs on the scrotum are very scantly present. Different layer of tissues that are present in between the scrotal skin and the testis proper are shown in Fig. 1.3. (1..Tunica dartoslayer is present under the scrotal skin and is composed of smooth muscle fibers with fibrous and elastic connective tissuc Tunica dartoslayer surrounds both the testes and formsa nedial septum in between twotestes) 2. Loose connective tissue layer is present under the tunica dartos layer. 3.Vaginal process layer is present under the loose connective tissue layer. Vaginal process is an extension of peritoneum passing through the abdominal wall at theinguinal cana [he yaginal process layer is composed of (a) superficial layer called tunica vaginalis communis,which corres ponds to the parietal peritoneum of the abdominal cavity; and (b) deeper layer called tunica vaginalis propria,which corresponds the visceral layer of peritoneum of the abdominal cavit 1  and Artificial Insemination 2 Veterinary Andrology 11 12 2 3 6 10 7 13 1.Seminal vesicles 2. Ampulla of the vas deferens 3. Urinary bladder 4. Urethral muscles 8 5. Bulbocavernosus muscle 14 6. Ischiocavernosus muscle 7. Retractor penis muscle 8. Glans penis 9. Preputial cavity 10. Vas deferens 11. Rectum 12. Bulbourethral gland 13. Sigmoid flexure 14. Testis Fig. 1.1. Reproductiveorgans of the bull. 4. Tunica albuginea layer is the tough layer composed of the visceral layer of the vaginal process. fibromuscular tissuepresent beneath Extensions the tunica albuginea penetrate the of testicular parenchyma to join at Fibrous septa divided the testicular mediastinum. parenchyma into lobules containing the highly coiled ferous tubules About 75% of the semint testicular mass is composed of seminiferous tubules.The of the seminiferous tubules estimated in different species is as follows : length  Reproductive Organs of Male Domestic Animals 3 Bulbourethral gland Ampulla Vesicular gland Ampulla Prostate gland BULL Rectum. STALLION Bufbourethral gland Vesiculargland Bladder Vas deferens Retractor penis Vas deferens muscle Retractor penis Urethral muscle Sigmoid flexure process Cauda Testis epididyrmis Before intromission Testis - After intromission Caput epididyrnis Free end of penis Free end of penis Ampulla Vesicular gland Bulbourethral Vesicular gland Bulbourethral gland gland Rectum BOAR Retractor RAM Rectum penis muscle Vas Retractor penis deferens muscle Urethral Dorsal Cauda process Sigmoid flexure diverticulum epididymis Vas deferens of prepuce Testis Caput epididymis Testis Cauda Free end of penis Caput Free end of penis epididymis epididymis Bladder CAT Prostate gland DOG Prostáte gland Epididymis Testis Cowper's gland Vas deferens Bladder Vas deferens -Os penis Testis Os penis Epididymis Free end of penis Free end of penis Fg. 1.2. Diagrams showing comparative anatomy of male reproductive organs of bull, stallion, boar, ram, dog and cat.  Insemination 4 Veterinary Andrology and Artificial Loose connective tissue Testicular parenchyma Tunica dartos with seminiferous tubules Dermis Epidermis Parietal layer of vaginal process Visceral layer of vaginal process Tunica albuginea Mediastinum testis Scrotal septum Fig. 1.3. Schematic hoizontal section through scrotum to show different layers. Bull 5000 m Ram 4000 m BBR 2(Boar 6000 m ) Dog 150 m Cat 25 m The seminiferoustubules by germinal epithelium and produce spermatozoa. Th are lined seminiferoustubulesjoin the rete through straighttubules (the tubulirecti). From rete teste testes the sperm cellsare passed toefferent tubules (6 to 24 in number) and than to head of the epididymi (Fig. 1.4). In stallion there is no mediastinum testes and the collecting tubules join the efferent tubule Thus in bull the passage of the spermatozoa from seminiferous tubules is as follows : Seminiferoustubules Tubuli recti Rete testes Eferent tubules CVbs fett ( The Urethra Ampulla Vas deferens E Epididymis testis in the scrotal pouch by is held its tunics andthe spermatic cord)The is composed of the spermatic cot following: 1. Internal spermatic artery. Vaginal processis an extension of the peritoneum passing through abdominal wallat the inguinal anal. (Inguinal canal is the like space between the internal slit abdominal oblique muscle forming the internal inguinal ring (deep opening of the inguinal canal) and the external inguinal ring (superficial opening of the inguinal canat formetby the tendon of theexternal oblique muscle Rut is the certain definite period sexual excitement of in some wild animals (e.g. deer camel and elephant).In these animals spermatogenesis occurs only during this period.  Reproductive Organs of Male Domestic Animals 5 2. Internal spermatic vein. Head of Vas deferens 3. Vas deferens epididymis Tunica vaginalis 4.(Autonomic nerves from renal Vasa efferentia and caudal mesenteric plexus 5. Lymphatic vessels 6. Internal cremaster muscle 7. Tunica vaginalis propria. Seminiferous tubules 11 Septaof testis Tunica albuginea -Rete testis Body of epididymis Straight Fig.1.4. Schematic diagram to show duct seminiferous system of the testis and tubule epididymis. -Tail of epididymis The mesorchium isdelicate and double layer peritoneum connecting visceral and parietal of layer of vaginal process)(as mesentery connects visceral and parietal layer of abdominal peritoneum) and continues up to dorsolateral abdominal wall. Inbull, ram and buck the testicles are placed in the scrotum verticallyl In the stallion the testicles areplaced nearly horizontally in the scrotum but when these are retracted, they become nearly vertical)In boar the long axisof the testis is oblique (neither vertical nor horizontal). Testicular details in different species are given in Table 1.1. Table 1.1. Shape, colour of parenchyma and measurement of testis Horse Bull Ram Boar Cat Dog Shape Elongated [Oval Elongated Elliptical Bound to Round to ova! oval oval Oval Parenchyma Reddish Yellow Creamy Grayish to Reddish Reddish white dark red gray Measurement(cm) 11x6x 4 14 x7x7 10 6 x6x 13 x7 x7 1x 1.2to 1.2 x 0.7 to 4 x 2.5 2 x 1.5 Weight(gm) 200-300 250-300 200-300 150-200 7-15 Plane Vertical (Horizontal) Vertical Oblique Oblique Oblique 6 Veterinary Andrology and Artificial Insemination Thermoregulation of testes be maintained at. For optimum production of the spermatozoa, the temperature of the testis nperature lower by2to 5C than that of the Body of the animalThis lowering of the temperati f testis is maintained by the following mechanisms. 1. The scrotal skin lacks subcutaneous fat. 2. The scrotal skin is richly supplied by sweatglands. the cremaster and dartos muscles contract and thus testicles are hel 3./ During cold weather, close to the body during cold. During hot weather,thecrenmaster and dartos muscles relay to lower the testis in a thin walled pendulous scrotum. ) 4. The internal spermatic artery enters thetestis from the spermatic cord The testicular arter is highly convoluted and cone shaped onthe dorsalpole of the testis.(These arterial coil are enmeshed with the pampiniform plexus of the testicular vein (Fig. 1.5). This arrangemen furtherassists in the heat regulatory mechanisms of the testis. The arterial blood reaching the testis is cooled down by the venous blood leaving the teshs. Testicular artery Testicular vein Pampiniform plexus Cremaster muscle Tunica dartos Fig. 1.5. Diagrammatic view to show pampiniform plexus and other structures that help in thermoregulation of testes in bull.  Male Domestic Animals 7 ReproductiveOrgans of Functions of the testes L# Leydit The following functions are performed by the testes : Production of testosterone from he interstitial cells (Leydig's cells) lying between the seminiferous tubules(Endocrine nction).,) 2.(The spermatogonia situated peripherally in the seminiferous tubules undergo cell division and produce spermatozoa (Exocrine function))In bulls about 12-17 million spermatozoa are produced per gram of testicular thssue daily. The above two imposant functional roles of the testes are controlled by the gonadotropic hornones of the pituitarý(LH (CSH) controls the endocrine activity of theLeydig's cells to produce testosterone.Testoslerone produced by interstitial cels support the action ofthe F$H on spermatogenesis, develops and maintains the accessory sex glands, develops secondary sexual, characteristics, develops sexual behaviour andis responsibleforthe functional maintenance of jhe male reproductive system. FSH controlsspermatogenesis in the seminiferous tubules. 3. The blood testis barrier(atthe level of the basement membrane the seminiferous tubules of and also by some specialfeatures of sustentacular cells) protect the germinal epithelium from theimmunological damages. EPIDIDYMIS The epididymis is a coiled tube closely attached to the testis by fibrous tissue. The epididymis is more firm is consistency than thetestis:(Theepididymis consists of head (caput),body (corpus) and tail (cauda)) The length of the epididymal tube in different animals is : Bull 30 m - Ram 50 m B) fom Boar 50 m Horse 20 m The caput epididymis is broad, somewhat flat, U-shaped and covers nearly one third of the proximal end of the testis. The corpus epididymis is comparatively narrow part, running toward distal end of the testis along its posterior border. The cauda epididymis Is enlarged end of the epididymis at the distal poleof thetestis and is continuous with the vas deferens. /Histologically two prominent layers (1) circular muscle fibers layer and (2) pseudostratified columnar cells layer seeninthe epididymal wall) Based on histology,the epididymis can be are divided in three segments (these segments do not coincide with the gross anatomical segments i.e. head, body and til of the epididymis). The proximal segment has ciliated cells (having kinocilia) beating qut-words.(The lumen of the initial segment is almost obliterated (almost no lumen is present)he medusa formations seen inthe semen ejaculates are actually thedetachèd ciliated cels from this initial segmen of the epididymis In the middle segment of the epididymis, the lumen is wide andthe cilia arenot so straight. In the terminal segment of the epididymis the cilia are short,the lumen is very wide and is packed with spermatozoa. Functions of the epididymis Various functions of the epididymis'are as follows : 1. Absorption  Insemination 8 Veterinary Andrology and Artificial 2. Secretion 3. Maturation 4. Transportationand 5. Storage Absorption :The fluid released by testes is several times more than the volume of the semen 60 ml fluid daily whileonly about 1 m! ejaculate. It is estimated tht ram'stestes produce about of the tail region are semen ejaculate obtained (The epithelial cells of the epididymis, especially is thé spermatozoa suspension involved in the active absorptionof fluid. Thus in the cauda epididymis i Secretion storage. : highlyconcentrated. The secretionsof the epididymal cells maintain viability of the spermatozoa during Maturation :During the storageperiod in the epididymis, the spermatozoa undergo maturation chang.(there is migration of the cytoplasmic droplet from the neck of the spermatozoa (proxim: protoplasmic droplet) to the distal end of the middle piece (distal protoplasmic droplet) in bull) This change is associated with cytochemical changes in the spermatozoa leading to its increased capacity for motility and fertilizing ability. Transportation The transportation of the spermatozoafrom rete testis to theefferent tubules is mainly due to the presence of testicular fluid.)The further transport of the spermatozoa is due to action of the ciliated epithelium and the action peristaltic waves of the muscle fibers in the duct.) of The average duration of the epididymal journey of the spermatozoa in different species is : Bull 10 days Ram 13-15 days Boar 9-12 days Stallion 8-11days Storage :The epididymis is the store house for spermatozoa. The two epididymides in bull can accommodatg yp to 3-4 days production of spermatozoa by the testis (nearly up to 75 x 10 spermatozoa? The cauda epididymis stores nearly 50% of the extragonadal sperms) However, sperms in the epididymis remain in quiescentmetabolic state. VAS DEFERENS >The two ductus deferens or vas deferens extend from cauda epididymis to the pelvic urethra The ducts are firm with thick muscular walls and lumen quite small. The ducts are convoluted near the cauda epididymis and then run parallel to the corpus epididymis. Later, these pass through the inguinal canal into the abdominal cavity along with other components of the spermatic card. On reaching the abdominal cavity, the vas deferens separates from the spermatic card, passes upward and backward toopen intg the pelvic urethra. The vas deferens is about 3 mm thick in bull and about 6 mm thick in stallio(The terminal part of the vas deferens is enlarged and is called ampulla. The ampulla is furnished with branched tubular glands)The ampulla in bulls measures abous 10 to 12 cm in length and 1.0 to 1.5 cm in diameter. (There are no ampullae in dog and cat.The ampullae open in the cranial portionof the pelvic urethra through arounded prominence called *"coliculus seminalis". In the vas deferens the sperm transport is due to peristaltic waves.  Reproductive Organs of Male Domestic Animals 9 ACCESSORY SEX GLANDS 1. The vesicular glands (Seminal vesicles) The vesicular glands of the bull are paired accessory sex glands having distinct lobulations. These glands are located on the pelvicfloor cranial andlateral tothe ampullae. Branched tubularsecretory glandspresent in the vascular glands add volume, nutrition andbuffers in the semen. These glands open in the pelvic urethra near theopening of the ampullae (colliculusseminalis) or the ductof the vesicular gland andtheampulla may share a common ejaculatory orifice into the pelvic urethra. The approximate dimensions of the vesicular glands in different species are as follows : Length (cm) Breadth (cm) Thíckness (cm) Weight (gm) Bull 10-15 2.0-4.0 2.0 75.0 Stallion 15-20 2.5-5.0 5.0 Boar 12-15 5.0-8.0 4.0 200.0 Ram 4-5 2.0 1.5 5.0 /The secretions of the vesicular glands make up about 50% of the total semen ejaculat. Com pared to prostatic secretions, the vesicular secretions are more alkaline. The secretioncontains protein, fructose,ascorbic acid, citric acid. potassium bicarbonate, acid soluble phosphate and everal enzymes/ In the seminal fructose comes from vesicular glands.)The mammals most of esicular glands of the stalligg are elongated pear shaped sacs and the secretionsof these glands constitute gel to the ejacylate n bor the vesicular glands are large bag like and contains a milky and highl visçpusfluid n boar the vesicular secretion has high inositol contents and also contains) ergothioneineIn bulls fhe secretion of vesicular gland is yellow due to high riboflavincontents. Theseglands are absent in dog and cat.) 2.The prostate gland The prostate gland has forms in different species. In bull the glandis locatedon the pelvic different floor, on oraround the neck the bladder orthecranial portion of the pelvic urethra. The gland of opens intothe pelvic urethralateral to the "colliculus seminalis"(opening of theampullae) through many ducts, In dog there are only two excretory ducts of prostate gland. In bull the prostrate gland surrounds the pelvic urethra and has two parts, the body of the prostate (pars dimensions propria) of and the pars disseminata which surrounds the pelvic urethra)The approximate theprostate gland in bull and boar are as follows : Pars propria (cm) Pars disseminata (cm) Bull 3× x 1 I 12 x 1.5 x 1.0 Boar 3x3x1 17x 1.0 x 1.0 nram, the prostate gland has no body And is scattered over the large portion of the pelvic ethran stallion, the prostate gland consistS of two lateral lotbesXeach 7 x 4 x Icm) connected by isthmus (2%3 >x 0.5 cm). In dog the size of the prostate gland varies greatly and may be quite large in older dogs. Some disseminnt lobes are present in the urethral wall.  10 Veterinary Andrology and Artificial Insemination of the cells rather than enzymesyhat resemble interior milieu CThe prostatic secretions are rich in phosphatases, glyçosidases, the external milieu of the cells e.g. glycolitic enzymes, proteinases, nucleases and nuçleotidases.In dog the pH of the prostatic secretion is 6.5 and there are no reducing Canine contains citric acid and acid phosphatase. sugars. However, (canine prostare secretion plasma in the seminal is prostate secretion has high concentrationof zinc Zinccoicentration chieflydue to prostatic secretion. 3. The bulbourethral glands (Cowper's glands) In bull, the bulbourethral glandsare the paired glands lying on side of the pelvic urethra in either the regionnear the ischial arch. In bull, these glands are embedded under the bulbospongiosus muscle. These gland areovoidin bull, stallion and ramand areJarge and cylindrical in boar. These glandls are absent in dog. In cat these are of the size of the prostate. The dimensions of the bulbouretheral gland in different species of animals areas follows : Diameter (cm) Length (cm) Bull 1.5-3.0 Stallion 2.5-5.0 Ram 0.5-1.0 Boar 2.5-3.0 12.0 (in and boar each gland opens in urethra through a single duct, but in stallion each bull gland opens into the urethra through6 to 8 secretary ducts)In bulls, the dribbling seenfrom the prepuce prior to mounting are secretionsfrom the prostate and bulbourethral glands. These seçreions delete harmful substances if present in the urethra and clean it prior to semen ejaculatiOR The typical rubber ike white substance is filled in the Cowper's glands of the boar that isessential for gel formation in boar semet URETHRA The urethra in males is the commnon passage for the excretion of urine as well as for the portation of semen. The urethra has-three trans distinct parts (pelvic part, part): In bull, the pelvic part of bulb of urethra andthe penile urethra is about 20 cm in length and is situated on pelvic floor. The pelvic urethra is enclosed by heavy urethral muscle. The bulb of urethra is extra situated at ischial arch and is pelvic part bending ventral tothe pelvis. The penile urethra runs inside the penis proper. Urethralglands are seen in man. These gland are absent in bull and boar, urethral glands are distinct) stallion(Hwever in PENIS The penis the copulatory organ in males. is The penile body is largely composed of cavernosum penis. The corpus cavernosum penis arses as a corpus pair of crura or roots from the ischial arch under ischiocavernosus muscle. The carpus cavernosum penis is enclosed by a thick layer f tunica albuginea, which is made up of collagen fibres. Several trabeculae are sent from tunica albuginea toenter into the corpus cavernosum penis tor the support of cavernous (cave like) tissue. Ventral to the corpus cavernosum penis and surrounding the penile urethra is smaller corpus - SDOngiosum penis (also called corpus Spongiosum urethrae) As shown in Fig. The carpus t6  ReproductiveOrgans of Male Domestic Animals 11 Tunica albuginea -Corpuscavernosurm penis -Urethra -Corpusspongiosurn penis Connective tissue Fig. 1.6. Schematic diagram of the cross section of the penis of bull near caudal end. spongiosum penis in enlarged at ischial arch to form the penile bulb, The bulb is covered by bulbospongiosus muscle (also called bulbocavernosus muscle). The two corpora (corpus caver nosum penis and corpus spongiosum penis) have several spaces (blood sinusoids) regarded as enlarged and are continuous with veins in the penis.Distention of these spaces with capillaries blood, causes penile erection In bull, ram,and boar the penis is characterized by S-shaped curve, the sigmoid flexure, The sigmoid flexureis post-scrotal in bull and ram and pre-scrotal in boar. Sigmoid flexure is absent in horse. Inchiocavernosus muscle or erector penismuscle is a short paired muscle and helps penile erection by its compressing and pumping action, The retractor penis muscle is a smooth muscle and arises from sacral or first and second coccigeal regions, divides and meets again under the anus and attaches to the penis at the distal end of the sigmoid flexure with fibers extending dorsallyon the penis./Thethickened dorsal portion of this fibrous sheath is known as dorsal apical ligament of the penis. The retractor penis muscle draws the penis back into sheath by acting on sigmoid flexure. The penis of the bull is about 90 cm in length from its root to the tip of the glans. The diameter is about 4 to 5 cm on erection. The glans penis is 7.5 to 12.5 cm long and is rather pointed. The glans penis (terminal part) is pointed and slightly twisted. After intromission the spially arranged fibrous penile and prepenile prepuce is stretched and this causes the penis to spiral (Fig. 1.7). The penis of the bull is fibroelastic and the erectile tissue is too less compared to stallions. The penis of the stallionhas large amount of the erectile tissue. The length is about 50 cm and the diameter about 2.5 to 6.0 cm when not erect. A length of about 15 to 20 cm lies free in the prepuce. The length of the penis increases to about double and of the glans penis to about triple on erection. There is a prominent urethral process in the glans penis (Fig. 1.7) encircled by a shallow groove called as fossa glandis which forms urethral sinus or diverticulum, dorsal tothe urethral process. The diverticulum (sinus)is often filled with smegma and carries infection, causing contagious equine metritis. The retractor penis muscle is not as strong asin bulls. The penis of the ram is about 30 cm in length and 1.5 to 2.0cm in diameter and is characterized by urethral process, which extends 4 to 5 cm beyond the glans penis (Fig. 1.7). The penile length of the boar is about 45 to 55 cm. There is no glans penis but the cranial portion is twisted counter clockwise (Fig. 1.7). 12 Veterinary Andrology and Artificial lnsemination condition varies from about 6.5 to 24 cm The penile length of dog during non-erect depending by upon the size of the dog. The penis of dog has two separate corpora cavernosa (separated a bone called "os penis" which medial septum). The cranial free portion of the penis contains of two parts, Tha grooved'ventrallyfor urethral passage. The glans penis of the dog consists proximal on third part of the glans is "bulbus glandis" and the distal two third part is "pars Ion blood after the pe glandis".The proximal part "bulbus glandis" usually becomes engorged with enters the vagina of the bitch and the withdrawalof the penis is not possible for some time afte serviceuntil erection subsides. The penis of thecat is sbort and is directed caudally and ventrally. The urethra lies dorsaly in the penis. The os penis is eitherabsent or short.The bulbus glandis is also absent.The glans.penis is also absent but the terminal part (about I cm) contains several spines (about120) pointing backward Fig. 1.7). Because of the pain caused by these spines the queen emits a loudcry after service. Before ejaculation BULL After ejaculation RAM BOAR STALLION CAT Fig.1.7. Diagrams showing free end of penis in bull, ram, boar, stallion, dog and cat.  Reproductive Organs of Male Domestic Animals 13 PREPUCE The prepuce is the invaginated fold of skin surrounding the free end of the penis, when not erect. The prepuce in the bull is about 35 cm long and 4 cm in diameter. The prepucial orifice is 5 to 7cm behind umbilicus andis surrounded by tuft of hair. Inthe bulls of Indian breeds, the prepuce is in the form of pendulous sheath..The prepuce of the horse makes a double fold. The prepucial cavity is 15 to 20 cm deep and then there issecond foldto form the prepuce proper. Prepucial ring isprominent in between the two prepucial folds. The prepuce of ram is similar to bull but is relatively short. The prepuce of boar has a diverticulum (pouch) dorsal to the prepucial orifice. This diverti culum is filled with urine, secretions and dead cells and thus produces typical odour. BLOOD AND NERVE SUPPLY The testicle is supplied blood from spermatic artery originating directly from aorta. The internal internal spermatic veins run parallel tothe internal spermatic artery except near testis where it is more convoluted and tortuous to form pampiniform plexus, which plays important role in the thermoregulation of the testes. The nerve supply to the testis is through fibers from renal andcaudal mesenterjc plexus. These fibers run close to the internal spermatic artery. The blood to the scrotum is supplied by the external pudendal artery (also the internal pudendal artery in cat and boar). The nerve supply to the scrotum is by genital nerve (which is a branch of genito-femoral nerve arising from second to fourth lumber nerves and perineal nerve). The blood supply to the penis is through internal pudendal artery (to the root of the penis, obturator artery (to the body of and the external pudendal artery which gives rise to the penis) dorsal artery of the penis after passing through the inguinal canal. The nerve supply to the penis is from autonomic nerves from pelvic plexus and from pudendal and hemorrhoidal nerves. The pudendal and hemorrhoidal nerves are the motor nerves for retractor penis muscles. The dorsal nerve of the penis is a branch of pudendal nerve and supplies sensory fibers to the glans penis. These sensory fibers provide the afferent side for the reflex of erection and ejaculation. The reflex centers for erection and ejaculation are located in the lumber portion of the spinal cord. The blood supply the accessory sex gland in large animal is from internal to pudendal artery. In dog the supply to accessory sex glands is from prostatic artery (a branch of urogenital artery arising from internal iliac artery). The nerve supply to the accessory sex glands is through auto nomic nerves from hypogastric nerve and pelvic plexus.