Organs of the Male Reproductive System
Draw a neat diagram of male reproductive system and describe the coverings, sturctures, blood supply and clinical significance of testis
The Testis
Coverings
The layers of tissue enclosing each testicle are derived from the layers of the anterior abdominal wall. Notably, the cremasteric muscle arises from the internal oblique muscle.
Outer – tunica vaginalis - derived from peritoneum
Middle – tunica albugenia – fibrous - ingrowths form septae dividing the glandular structure into lobules
Inner – tunica vasculosa - network of capillaries
Structure
200 to 300 lobules
Each lobule consists of 1 - 4 Convoluted loops composed of germinal epithelial cells – called seminiferous tubules. Produce – sperms
Between tubules groups of interstitial cells (of Leydig) - They secrete the hormone testosterone
At the upper pole of the testis the tubules combine to form a single tortuous tubule – the epididymis
Epididymis continues as deferent duct (vas deferens) in the spermatic cord
Epididymis
collects sperms from the testes
Situated posterolateral to the testis
Has a head and body
Continues as vas deferens
Vas deferens
A tubular structure which transmits the sperms to the prostatic urethra
Blood supply
Testicular arteries - from abdominal aorta - descend through inguinal canal
Scrotum and the rest of the external genitalia - supplied by the internal pudendal artery from internal iliac artery
Lymphatic drainage
Lymphatic drainage of the testes follows the testicular arteries back to the paraaortic lymph nodes, while lymph from the scrotum drains to the inguinal lymph nodes.
Clinical significance
Testis is formed in the abdomen and descends into the scrotum before birth - incompletely descended testis - e.g. . in the inguinal canal
Fluid collection deeper to the tunica vaginalis - called vaginal hydrocele
Tumour metastases found in the epigastrium in the paraaortic nodes
