Gross Anatomy of male internal genitalia Dr Namani Sathya.

Functions of male reproductive system Testis produces sperms Various parts of genital tracts carry the sperms to the exterior They provide for maturation and nutrition of sperms all along the tract Accessory glands of male genitalia besides providing nutrition add quantity to semen

Parts of male internal genitalia Testis Epididymis Vas deferens Seminal vesicle Ejaculatory duct Prostate Cowpers gland

Components of male internal genitalia Testes Duct system Accessory glands

Testis

Shape & Size Male gonad It is ovoid in shape 3.5cm long, 2.5cm broad and 1.8cm thick Weight 10 to 15 gm

External Features 2 poles upper and lower (upper attached to spermatic cord) 2 borders (anterior convex and smooth posterior straight partially covered by tunica vaginalis) Epididymis separated by testis by sinus of the epididymis. 2 surfaces medial and lateral

Coverings of Testis Tunica vaginalis – lower persistent portion of processus vaginalis ( parital and visceral layer cavity in between them) Tunica albuginea – dense white fibrous coat, its posterior border is thickened to form incomplete vertical septum is called mediastinum testis.( numerous septa extend from mediastinum to inner surface of tunica albuginea this divides the testis into 200 to 300 lobules) Tunica vasculosa it’s the innermost vascular coat

Internal Structure of Testis 1.Septa 2.Semeniferous tubule 3.Lobule 4.Straight tubule 5.Efferent ductules 6.Rete testis

Internal structure of testis Testis is covered by tunica albugenia It is thickened in the posterior part to form mediastinum testis Mediastinum is traversed by network called rete testis It sends septa to tunia albugenia Dividing testis into 300 lobules

Internal structure of testis Each lobule has 2-4 seminiferous tubules They are lined by multilayered epithelium Responsible for production of spermatozoa Seminiferous tubules join to form 20 to 30 straight tubules Straight tubules anatomose to form rete testis 12 to 30 Efferent ductules arise from rete testis

Efferent ductules Efferent ductules emerge from upper end of mediastinum testis They are 12-30 in number Efferent ductules open into single duct of epididymis

Epididymis The epididymis is 6 meters long Epididymis is highly coiled It is comma shaped It consists of head ,body and tail Vas deferens emerges from the tail of epididymis Reservoir of spermatozoa

Epididymis Artery- testicular artery Venous similar to testis Nerves – sympathetic nerves through testicular plexus T11 to L 1

Blood supply of testis Testicular artery Artery of ductus deferens Venous drainage is by pampiniform plexus ( anterior part around testicular artery middle part around ductus deferens and its artery posterior part isolated) The plexus is responsible for maintenance of subnormal temperature This is require for normal spermatogenesis to occur

Lymphatic and Nerves Lymphatic drain into pre and paraarotic groups of lymph node. Nerves – arises from T 10 through renal and aortic plexus

Descent of testis Testis is formed in the lumbar region ( mesonephros) T10 to 12 3rd month IUL iliac fossa Testis is near deep inguinal ring at 4th to 6 th month 7th month tranverse inguinal canal At superficial inguinal ring at 8th month At 9th month or about birth it descends into scrotum

Clincal - testis Undescended testis (cryptorchidism). (anorchism) absence of both testis. The absence of one testis is termed monorchism the testis, emerging at the subcutaneous inguinal ring, slips down between the scrotum and thigh and comes to rest in the perineum. This is known as perineal ectopia testis Hydrocele - vaginal hydrocele, congenital hydrocele, the fluid is in the sac of the tunica vaginalis, but this cavity communicates with the general peritoneal cavity infantile hydrocele, encysted hydrocele of the cord.

Vas deferens It is thick walled muscular duct Also called as ductus deferens It is thick walled muscular duct It begins at the inferior pole of testis then posterior border of testis It passes in the posterior part spermatic cord transverse the canal to reach the deep ring of inguinal ring. In greater pelvis hooks around inferior epigastric artery In lesser pelvis runs downwards and backwards on the lateral wall of pelvis Reaches base of bladder

Vas deferens It joins the duct of the seminal vesicle to form the ejaculatory duct Each tube is about 45cm long Arterial supply-artery to vas deferens usually arises from superior vesical artery. Veins- joins vesical venous plexus then into internal iliac vein They propel the sperm forward In vasectomy it is cut as a permanent method of sterilization

Seminal vesicle They are 2 tubular glands posteroinferior to bladder (between bladder and rectum) 5 cm in length Each gland forms as an outpocketing from the wall of ampulla of vas deferens The duct of the seminal vesicle opens into vas deferens to form the ejaculatory duct It secretes significant portion of semen and concerned with nutrition of spermatozoa. Alkaline (fructose and vesiculase Coa Ezy)

Ejaculatory duct They are 2 cm in length It is formed by the union of vas deferens and duct of the seminal vesicle They enter and pass through the prostate and empty into urethra

Prostate

Prostate gland It is a male gland It secretes slightly alkaline fluid Constitutes 30% of volume of semen It surrounds urethra just below the urinary bladder Can be felt in the rectal examination The part of urethra in the prostate is called the prostatic part Ejaculatory ducts open into this part

Size and shape It is an inverted cone Its measures 3.5 cm across the base and length is 3 cm It has upper base lower apex four surfaces Anterior Posterior Two inferolateral surfaces

Capsules It has outer false capsule made of pelvic visceral fascia It has inner true capsule formed by fibromuscular tissue There is prostatic venous plexus in between the capsules The capsule should not be disturbed in surgery as it will lead to heavy bleeding The plexus communicates with internal vertebral venous plexus Cancer can spread to brain without blood passing through the heart

Lobes Lobe in front of urethra is the anterior lobe In the posterior part the lobe above the ejaculatory duct is the median lobe The lobe below the ejaculatory duct is the posterior lobe

Lobes Lobes on either sides of anterior lobe are the lateral lobes This is done by an imaginary line at the level of ejaculatory ducts So there are five lobes: Two lateral lobes Anterior lobe Median lobe Posterior lobe

Showing lobes of prostate

Relations Base related to -neck of bladder Apex related to -urogenital diaphragm Lateral surfaces related to- levator ani muscle

Relations Anteriorly related to -pubic bone separated by retropubic pad of fat Posteriorly related to rectum separated by rectovesical septum Pierced by ejaculatory ducts

Structures within prostate Prostatic urethra transverse btw ant 1/3rd and post 2/3rd There is a longitudinal ridge called urethral crest In its lower end there is swelling called the seminal colliculus On it there are opening on either side for ejaculatory ducts An blind opening in the centre called prostatic utricle It is similar to uterus in females On either side of the urethral crest there is a fossa called prostatic sinus and prostatic ducts open here

Prostatic urethra Seminal colliculus Ejaculatory ducts Prostatic utricle

Blood supply Prostate is supplied There are two types of branches Internal pudendal arteries Inferior vesicle arteries Middle rectal arteries There are two types of branches Capsular Urethral Urethral branches mainly supply median lobe Urethral branches Capsular branches

Venous drainage Prostatic venous plexus is between the capsules Drains into internal vertebral venous plexus (walveless communication) Cancer can spread to vertebral column and skull

Lymphatic drainage- Internal iliac Sacral External iliac

Nerve supply Parasympathetic from S 2-4 Sympathetic from T11 –L2

Zones of prostate It consists of 3 distinct zones Central zone Transitional zone Peripheral zone. Benign prostate hypertrophy occurs in – Central zone Prostate cancer occurs in -peripheral zone

Zones Central zone consists of median lobe Peripheral lobe consists of posterior lobe

Age changes in prostate At birth- Contains fibromuscular tissue with rudimentary duct system This will continue for 9 years At puberty Testosterone levels increase Duct system increases Fibromuscular tissue condenses Prostate becomes doubles the size During 3rd decade Follicles increase in size With infoldings of epithelium During 30-45 years Size remains constant But infolding are lost and becomes regular After 45 years Either undergo hypertrophy Or atrophy because of hormonal imbalance

Applied anatomy Rise in acid phophatase in blood occurs in cancer of prostate because it is not excreted In benign prostatic enlargement Median lobe is mainly involved Frequency of micturation Enlarged median lobe distorts the internal urethral sphincter Leading to trickling of urine drops and causing frequency Precipitancy of micturation Trickling drops elicits micturation reflex leading to wetting of cloths before reaching bathroom Urine stagnation Median lobe enlargement can close the urethral sphincter while straining to pass urine Leading to stagnation Hesitancy of micturation Median and lateral lobe enlargement Can close the urethra completely Unable to start micturation