(i) Testis, the male gonad, the accessory ducts and glands along with external genitalia form the male reproductive system.
(ii) Testes:
1. Testes are male gonads with dimensions of about 4.5. cm length, 2.5 cm width and 3 cm thickness.
2. There are about 200 to 300 lobules in each testis in which there are seminiferous tubules that form rete testis.
3. Testes produce sperms and secrete male sex hormone, androgen or testosterone.
(iii) Accessory ducts : Rete testis, vasa efferentia, epididymis, vas deferens, ejaculatory duct and urethra together form the accessory ducts of male reproductive system.
1. Vasa efferentia : Vasa efferentia are 12-20 fine tubules. They arise from rete testis and end into the epididymis. The sperms from the testis are carried by these ducts to the epididymis.
2. Epididymis : Epididymis are long and coiled tubes having three parts, viz. caput, corpus and cauda epididymis. They are located on the posterior border of each testis. The sperms undergo maturation in epididymis.
3. Vasa deferentia:
- Vasa deferentia are a pair of 40 cm long tubular structures that arise from cauda epididymis.
- Each vas deferens enters the abdominal cavity through the inguinal canal and then ascends in the form of spermatic cord.
- Vas deferens of each side is joined by the duct from seminal vesicle to form ejaculatory duct.
4. Ejaculatory duct : About 2 cm long pair of ducts formed by joining of vas deferens and a duct of seminal vesicle are the ejaculatory ducts. Both ejaculatory ducts open into urethra near the prostate gland. Seminal fluid containing spermatozoa are carried by ejaculatory duct to the urethra.
5. Urethra : The male urethra provides a common passage for the urine and semen hence is also called urinogenital duct.
(iv) Accessory glands : Associated with male reproductive system are :
(a) Seminal vesicles
(b) Prostate gland and
(c) Cowper’s or Bulbourethral glands. Every accessory gland has secretion which helps in functions of reproductive system.
(v) External genitalia : External genitalia consists of penis and scrotum.
1. Penis:
- Penis is the copulatory organ used for insemination or deposition of sperms in female genital tract.
- It is cylindrical, erectile and pendulous organ through which passes the urethra.
- It contains three columns of erectile tissues which has abundant blood sinuses.
- The tip is called glans penis while the retractible fold of skin on penis is called prepuce.
2. Scrotum : The scrotum is a pouch of pigmented skin arising from lower abdominal wall. It protects testes within it. Scrotum acts as thermoregulator. Testis are suspended in scrotum by spermatic cord.
