Anatomy of the Testes

Testes Structure and Function

• The testes are situated outside the abdominal cavity within a pouch called scrotum, which maintains a low temperature (2-2.5°C lower than normal internal body temperature) necessary for spermatogenesis.
• Each testis is oval in shape, with a length of about 4-5 cm and a width of about 2-3 cm.
• The testis is covered by a dense covering and has about 250 compartments called testicular lobules.

Testicular Lobules

• Each lobule contains one to three highly coiled seminiferous tubules where sperms are produced.
• The seminiferous tubules are lined on the inside by two types of cells: male germ cells (spermatogonia) and Sertoli cells.
• Male germ cells undergo meiotic divisions, leading to sperm formation, while Sertoli cells provide nutrition to the germ cells.

Interstitial Spaces

• The regions outside the seminiferous tubules are called interstitial spaces, containing small blood vessels and interstitial cells or Leydig cells.
• Leydig cells synthesize and secrete testicular hormones called androgens.

Male Sex Accessory Ducts

• The male sex accessory ducts include rete testis, vasa efferentia, epididymis, and vas deferens.
• The seminiferous tubules of the testis open into the vasa efferentia through rete testis.
• The vasa efferentia leave the testis and open into the epididymis located along the posterior surface of each testis.
• The epididymis leads to vas deferens, which ascends to the abdomen and loops over the urinary bladder.
• The vas deferens receives a duct from the seminal vesicle and opens into the urethra as the ejaculatory duct.

Urethra

• The urethra originates from the urinary bladder and extends through the penis to its external opening called urethral meatus.
• The urethra is responsible for transporting sperms from the testis to the outside.

Testes Structure and Function

• The testes are situated outside the abdominal cavity within a pouch called scrotum, which maintains a low temperature (2-2.5°C lower than normal internal body temperature) necessary for spermatogenesis.
• Each testis is oval in shape, with a length of about 4-5 cm and a width of about 2-3 cm.
• The testis is covered by a dense covering and has about 250 compartments called testicular lobules.

Testicular Lobules

• Each lobule contains one to three highly coiled seminiferous tubules where sperms are produced.
• The seminiferous tubules are lined on the inside by two types of cells: male germ cells (spermatogonia) and Sertoli cells.
• Male germ cells undergo meiotic divisions, leading to sperm formation, while Sertoli cells provide nutrition to the germ cells.

Interstitial Spaces

• The regions outside the seminiferous tubules are called interstitial spaces, containing small blood vessels and interstitial cells or Leydig cells.
• Leydig cells synthesize and secrete testicular hormones called androgens.

Male Sex Accessory Ducts

• The male sex accessory ducts include rete testis, vasa efferentia, epididymis, and vas deferens.
• The seminiferous tubules of the testis open into the vasa efferentia through rete testis.
• The vasa efferentia leave the testis and open into the epididymis located along the posterior surface of each testis.
• The epididymis leads to vas deferens, which ascends to the abdomen and loops over the urinary bladder.
• The vas deferens receives a duct from the seminal vesicle and opens into the urethra as the ejaculatory duct.

Urethra

• The urethra originates from the urinary bladder and extends through the penis to its external opening called urethral meatus.
• The urethra is responsible for transporting sperms from the testis to the outside.