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Home , Body of penis, Perineal raphe, Posterior scrotal nerves, Prostatic ducts, Prostatic urethra, Pudendal arteries

Abdominopelvic cavity – sixth part

Male urogenital system Hypogastric plexuses Internal iliac Testis

An ovoid organ

Is suspended (hangs) in the by the

The left is suspended more inferiorly than the right

Is covered with a tough fibrous coat – the

Produces sperms (spermatozoa; male germ cells) and hormones, principally testosterone Sperms (spermatozoa; male germ cells)

Are formed in the long, convoluted seminiferous tubules that are joined by straight tubules to the

The rete testis- a network of canals at the termination of the straight (seminiferous) tubules

The efferent ductules transport the sperms from the rete testis to the where they are stored

A closed peritoneal sac partially surrounding the testis, which represents the closed-off distal part of the embryonic processus vaginalis Two layers: parietal and visceral The slitlike recess of its - the sinus of the epididymis - between the body of epididymis and the posterolateral surface of the testis Cavity of tunica vaginalis- with small amount of fluid allows the testis to move freely in the scrotum (hydrocele- an accumulation of fluid) The layers of tunica vaginalis The visceral layer covers the surface of each testis, except where the testis attaches to the epididymis and spermatic cord

The visceral layer is closely applied to the testis, epididymis, and inferior part of the deferent duct

The parietal layer adjacent the internal spermatic is more extensive than the visceral layer and extends superiorly for a short distance into the distal part of the spermatic cord The testicular Long and slender Arise from the abdominal aorta, just inferior to the renal arteries Pass retroperitoneally in an oblique direction, crossing over the and the inferior parts of the external iliac arteries to reach the deep inguinal rings Enter the inguinal canals through the deep rings, pass through the canals and exit them through the superficial inguinal rings Enter the spermatic cords to supply the testes The pampiniform plexus A venous network Emerge from the testis and the epididymis Consists of 8 to 12 veins, lying anterior to the deferent duct and surrounds the in the spermatic cord The part of the termoregulatory system of the testis Drains into the testicular vein The left testicular vein empties into the left (almost a 90° angle- varicoceles because of unfavorable angle- leads to decreased fertility) The right testicular vein enters the inferior vena cava The lymphatic drainage of the testis

To the lumbar lymph nodes The of the testis

Arise as the testicular plexus of nerves on the testicular artery, which contains vagal parasympathetic fibers and sympathetic fibers from the T7 segment of the spinal cord Epididymis The organ of storage and maturation for the spermatozoa Is formed by minute convolutions of the duct of the epididymis On the posterior surface of the testis The convoluted duct of the epididymis (epididymal duct) becomes progressively smaller as it passes from the head of its on the superior part of the testis to its tail The deferent duct begins at the tail of the epididymis The parts of the epididymis

Head - the superior expanded part (composed of lobules formed by the coiled ends of 12 to 14 efferent ductules) Body - consists of the convoluted duct of the epididymis (the epididymal duct) Tail - continuous with the deferent duct (transports sperms from the epididymis to the for expulsion into the prostatic part of the ) Scrotum

A cutaneous fibromuscular sac for testes and associated structures

Is situated posteroinferior to the and inferior to the pubic symphysis

The bilateral embryonic formation (labioscrotal swellings) of scrotum is indicated externally by the midline scrotal raphe, which is continuous on the ventral surface of the penis with the penile raphe and posteriorly along the median line of the with the Scrotum Is divided internally by the septum of the scrotum into the right and left compartments Consists of two layers, heavily pigmented skin and the closely related fascia Dartos fascia- a layer of smooth muscle fibers responsible for the rugose (wrinkled) appearance of the scrotum which is attached to the skin, its contraction helps to regulate the loss of heat through the skin of scrotum The superficial dartos fascia Scrotum of scrotum is devoid of fat

Is continuous anteriorly with the membranous layer of subcutaneous tissue (Scarpa’s fascia) of the anterolateral abdominal wall

Posteriorly is continuous with the subcutaneous tissue of the perineum (Colles’s fascia) The layers of scrotum and testis

Are formed by the layers of the anterior abdominal wall during developmental descent of the testis As the testis descends it carries with it a finger-shaped process of peritoneum (vaginal process) through the inguinal canal The vaginal process becomes obliterated and separated from the peritoneal cavity at the internal (deep) inguinal ring Tunica vaginalis- a closed sac within the scrotum which is formed by the peritoneum The layers of scrotum and testis Tunica albuginea Tunica vaginalis Internal spermatic fascia Cremasteric fascia External spermatic fascia Subcutaneous tissue (dartos fascia) and dartos muscle Skin The arterial supply and venous drainage of the scrotum Arteries: Posterior scrotal arteries from perineal branch of the Anterior scrotal arteries from external pudendal branches of the Cremasteric branch of the inferior epigastric artery Veins: Accompany the arteries Lymphatic drainage of the scrotum

Lymphatic vessels Drain into the superficial inguinal lymph nodes The nerves of the scrotum Genital branch of the genitofemoral (L1,L2), supplying the anterolateral surface Anterior scrotal nerves-branches of the (L1), supplying the anterior surface Posterior scrotal nerves-branches of the perineal branch of the (S2 through S4)- supplying the posterior surface Perineal branches of the posterior femoral cutaneous nerve (S2,S3) supplying the inferior surface Spermatic cord Suspends the testis in the scrotum Contains structures running to and from the testis Begins at the deep inguinal ring Passes through the inguinal canal Exits at the superficial inguinal ring Ends in the scrotum at the posterior border of the testis Is surrounded by fascial coverings derived from the anterolateral abdominal wall during prenatal development The coverings of the spermatic cord Internal spermatic fascia- derived from the transversalis fascia

Cremasteric fascia-derived from the fascia of the superficial and deep surfaces of the internal oblique muscle and transverse abdominal muscle, contains loops of the cremaster muscle (draws the testis superiorly)

External spermatic fascia derived from the external oblique aponeurosis The constituents of the spermatic cord

Deferent duct (ductus deferens) Testicular artery Artery of the deferent duct (from the inferior vesical artery) Cremasteric artery (from the inferior epigastric artery) Pampiniform plexus Sympathetic nerve fibers on arteries and sympathetic and parasympathetic nerve fibers on the ductus deferens Genital branch of the Lymphatic vessels Ductus deferens (deferent duct) A muscular tube approximately 45 cm long Transports sperms from the epididymis to the ejaculatory duct during ejaculation The continuation of the duct of the epididymis Passes lateral to the inferior epigastric vessels- this relationship should be noted in operations on the inguinal ring Crosses over the external iliac vessels and enters the pelvis Passes along the lateral wall of the pelvis, external to the parietal peritoneum Ductus deferens (deferent duct) Crosses superior to the near the posterolateral angle of the bladder, running between ureter and the peritoneum to reach the fundus of the bladder Posterior to the bladder at first lies superior to the seminal vesicle, then descends medial to the ureter and the seminal vesicle Enlarges to form the ampulla of the ductus deferens Narrows and joins the excretory duct of seminal vesicle to form the ejaculatory duct The nerves of the deferent duct

Derived from the inferior hypogastric plexus Sympathetic nerve fibers richly innervate the smooth- muscle fibers of the duct thereby facilitating its rapid contraction for expulsion of sperms during ejaculation Seminal vesicle

An elongated structure, approximately 5 cm long Between the fundus of the bladder and the rectum, superior to the Does not store sperms! Secretes a slightly alkaline fluid (makes up 70% of the volume of the ejaculate) and is very high in fructose that mixes with the sperms The excretory duct joins the deferent duct to form the ejaculatory duct Posterior to the ureters

Peritoneum of the rectovesical pouch separates superior ends from rectum

Inferior ends are closely related to the rectum and are separated from rectum only by the rectovesical septum (membranous partition)

Enlarged can be palpated during a rectal examination Ejaculatory ducts

The union of the excretory duct of the seminal vesicle with the deferent duct Approximately 2.5 cm long Pass anteroinferiorly through the posterior part of the prostate and along the sides of the Converge to open on the or just within the opening of the prostatic utricle Prostate The firm, walnut-sized Approximately 3 cm long The largest accessory gland of the The glandular part comprises approximately two-thirds of its, other third is fibromuscular Surrounds the Has a dense fibrous prostatic capsule that is surrounded by a fibrous prostatic sheath, which is continuous with the puboprostatic ligaments Extraperitoneal (subperitoneal) organ Prostate A base- closely related to the neck and fundus of the An apex- is in contact with fascia on the superior aspect of the external urethral sphincter and deep perineal muscles Anterior (muscular) surface- is separated from the pubic symphysis by retroperitoneal fat in the retropubic space Posterior surface- is related to the ampulla of the rectum Inferolateral surfaces- are related to the levator ani The lobes of prostate

Two (right and left) lateral lobes form the major part of the prostate, on either side of the urethra Median lobe- joins the lateral lobes, between the urethra and the ejaculatory ducts, is closely related to the neck of the urinary bladder Prostatic isthmus- anterior to the urethra, fibromuscular, continuation of the urethral sphincter muscle Prostate

Urologists and sonographers divide the prostate into peripheral (outer) and central (internal) zones The central zone is comparable to the middle lobe Enlargment of the prostate

Benign prostatic hyperplasia (BPH) is common after middle age Projects into the urinary bladder and impedes urination by distorting the prostatic urethra Enlargment of the middle lobe obstructs the internal urethral orifice Urethral obstruction leading to nocturia, dysuria and urgency May be examined by digital rectal examination The

Open chiefly into the grooves- the prostatic sinuses- that lie on either side of the seminal colliculus on the posterior wall of the prostatic urethra

Transurethral resection of the prostate (TURP)- surgical removal of the prostate by means of a cystoscope passed through the urethra The seminal colliculus

A rounded eminence with a slitlike orifice- opens into the prostatic utricle (a vestigial remnant of the embryonic uterovaginal canal- a blind pouch analogous to the uterus and vagina) and opening of an ejaculatory ducts The prostatic fluid

A thin, milky fluid

Contains compounds that are very important for active sperm motility and a protein (prostate-specific antigen, PSA) whose serum levels are frequently elevated in patients with a prostatic malignancy

Provides approximately 20% of the volume of semen Semen

A mixture of the sperms which is produced by the testes and glandular secretion by seminal vesicles, prostate and

Smells as a chestnut Arterial supply of the prostate

Branches of the , especially the inferior vesical arteries

The internal pudendal arteries

Middle rectal arteries Prostatic venous plexus

Is formed by the veins

Between the fibrous capsule of the prostate and the prostatic sheath

Drains into the internal iliac veins

Is continuous superiorly with the vesical venous plexus

Communicates posteriorly with the internal vertebral venous plexus Lymphatic drainage of the prostate

Lymphatic vessels terminate chiefly in the internal iliac and sacral lymph nodes Innervation of the prostate

Parasympathetic fibers arise from the pelvic splanchnic nerves (S2 through S4)

Sympathetic fibers derive from the inferior hypogastric plexus Bulbourethral glands (Cowper’s glands) Two, small, pea-sized Posterolateral to the intermediate (membranous) part of the urethra in the deep transverse perineal muscle Ducts of them open through minute apertures into the proximal part of the in the bulb of the penis Secrete a clear, watery fluid that prepares the urethra for the passage of the sperm during sexual arousal Penis

The common outlet for urine and semen The male copulatory organ Consists of a root, body and Composed of three cylindrical bodies of erectile cavernosus tissue: the corpora cavernosa and corpus spongiosum The deep fascia of the penis (Bucks’s fascia) forms a strong membrane covering the bodies and binding them together Penis

The bodies have an outer fibrous covering capsule - the tunica albuginea The root of the penis The attached part Consists of the crura, bulb and muscles (ischiocavernosus and bulbospongiosus) Is located in the superficial perineal pouch, between the perineal membrane superiorly and the deep perineal fascia inferiorly The crura and bulb contain masses of erectile tissue Each crus is attached to the inferior part of the internal surface of the corresponding ischial ramus, anterior to the ischial tuberosity The body of the penis The free part that is pendulous in the flaccid condition

Has no muscles

Consists of thin skin, connective tissue, blood and lymphatic vessles, fascia, corpora cavernosa and corpus spongiosum (contains the spongy urethra) which distally expands to form the conical glans penis The glans penis

Forms the head of the penis The corona of the glans, the margin of the glans, is formed by the ends of the corpora cavernosa The neck of the glans is an obliquely grooved constriction that separates the glans from the The external urethral orifice is near the tip of the glans The skin of penis

Thin, dark and connected to the tunica albuginea by loose connective tissue The prepuce ()- double layer of prolongated skin and fascia, at the neck of the glans, covers the glans to a variable extent The frenulum of the prepuce- a median fold that passes from the deep layer of the prepuce to the urethral surface of the glans The suspensory ligament of the penis

A condensation of deep fascia that arises from the anterior surface of the pubic symphysis

Passes inferiorly and splits to form a sling that is attached to the deep fascia of the penis at the junction of its root and body The fundiform ligament of the penis

Is a band of elastic fibers of the subcutaneous tissue

Extends from the linea alba superior to the pubic symphysis

Splits to surround the penis before attaching to the fascia of the penis Arterial supply of the penis Branches of the internal pudendal arteries: - Dorsal arteries- run in the interval between the corpora cavernosa on each side of the deep dorsal vein, supplying the fibrous tissue around the corpora and the penile skin - Deep arteries- pierce the crura and run within the corpora cavernosa, supplying the erectile tissue in these structures - Artery of the bulb of the penis Branches of the external pudendal arteries Venous drainage of the penis From the cavernous space by a venous plexus that joins the deep dorsal vein of the penis in the deep fascia Deep dorsal vein passes deep to the arcuate pubic ligament and joins the prostatic venous plexus From the superficial coverings of the penis drain into the superficial dorsal vein, which ends in the superficial external pudendal vein Lymphatic drainage of the penis

The superficial inguinal lymph nodes receive most of the lymph from penis The nerves of the penis

Derive from the S2 through S4 segments of the spinal cord, passing through the pudendal nerve and the pelvic plexuses The dorsal nerve of the penis – a terminal branch of the pudendal nerve A variety of sensory nerve Branches of the ilioinguinal nerve supply the skin at the root of the penis The superficial perineal muscles Superficial transverse perineal Bulbospongiosus - compresses bulb of penis and the corpus spongiosum to expel last drops of residual urine and/or semen. - assists erection by pushing blood into body of penis and compressing outflow veins Ischiocavernosus - surrounds the crura in the root of the penis - maintains erection of penis by compressing outflow veins and pushing blood into body of penis from the cavernosus spaces in the crura Erection Depends on parasympathetic stimulation (S2-S4 through the cavernous nerves from the prostatic nerve plexus) – dilates the coiled arteries(relaxe) supplying the erectile tissue The helicine arteries straighten, enlarging their lumina and allowing blood to flow into and dilate the cavernous spaces in the corpora of the penis The bulbospongiosus and ischiocavernosus muscles compress the venous plexuses impeding the venous return Emission and ejaculation

Emission is a sympathetic response (L1 and L2 nerves)- stimulation during friction to the glans penis Semen is delivered to the prostatic urethra after peristalsis of the deferent duct and seminal vesicles and prostatic fluid is added Ejaculation- the result of closure of the sphincter of the urinary bladder (prevents the entry of urine into the prostatic urethra and the reflux of the semen into the bladder)

The external urethral orifice is on the ventral aspect of the glans penis Congenital malformation Phimosis Phimosis – condition in which the prepuce cannot be retracted easily over the glans of penis- narrow opening Smegma - the oily secretion of cheesy consistency is produced by sebaceous glands in the prepuce Circumcision - surgical excision of the prepuce Male urethra

A muscular tube (18-20 cm long)

Conveys urine from the internal urethral orifice of the urinary bladder to the external urethral orifice at the tip of the glans penis

Provides an exit for semen Male urethra Internal urethral orifice Preprostatic urethra - in the bladder neck Prostatic urethra Intermediate (membranous) part of the urethra - the shortest and narrowest part (except external orifice), Traverses the deep perineal pouch (surrounded by the external urethral sphincter) Spongy urethra - the longest part (the ducts of the bulbourethral glands and mucus-secreting urethral glands open into this part) Navicular fossa (part of spongy urethra) External urethral orifice Internal iliac artery

Begins anterior to the sacroiliac joint at the bifurcation of the at the level of the intervertebral disc between L5 and S1 vertebrae Descends posteriorly to the greater sciatic foramen Supplies the pelvic viscera, musculosceletal part of pelvis and the gluteal region The branches of the anterior division are mainly visceral Two parietal branches pass to the buttock and thigh Hypogastric plexuses (superior and inferior)

Are networks of autonomic nerves Superior hypogastric plexus The main part lies just inferior to the bifurcation of the aorta and descends into the pelvis

The inferior prolongation of the intermesenteric plexus, which also receives the L3 and L4 splanchnic nerves

Branches enter the pelvis and descend anterior to the sacrum as the left and right hypogastric nerves

Descend lateral to the rectum and then spread in a fanlike fashion as the inferior hypogastric plexuses Inferior hypogastric plexuses Contain both sympathetic and parasympathetic fibers

Extensions of them send autonomic fibers along the blood vessels, which form visceral plexuses on the wall of the pelvic viscera such as prostate, seminal vesicles and inferolateral surfaces of the urinary bladder

Situated above levator ani muscle, on the sides of the rectum, uterine cervix and the urinary bladder The pelvic splachnic nerves

Contain parasympathetic fibers derived from S2, S3 and S4 spinal cord segments and visceral afferent fibers from cell bodies in the spinal ganglia of the corresponding spinal nerves Merge with the hypogastric nerves to form the inferior hypogastric plexuses Pudendal nerve

Derived from the anterior divisions of the ventral rami of S2 through S4

Accompanies the internal pudendal artery

The main nerve of the perineum and the chief sensory nerve of the external genitalia THANK YOU!