Human Reproductive System: Testes and Scrotum

Testes and Scrotum

• The testes are located outside the abdominal cavity within a pouch called the scrotum.
• The scrotum helps maintain a lower temperature (2-2.5°C lower than normal body temperature) necessary for spermatogenesis.
• During the 7th month of fetal life, the testes descend into the scrotal sacs in the presence of testosterone hormone.

Development and Structure of Testes

• Each testis is oval in shape, approximately 4-5 cm in length and 2-3 cm in width.
• The testis is covered by a dense covering and enclosed in an outer tough capsule of collagenous connective tissue called the tunica albuginea.
• Each testis has about 250 compartments called testicular lobules, which contain highly coiled tubules called seminiferous tubules.
• Each seminiferous tubule is lined by two types of cells: male germ cells (spermatogonia) and Sertoli cells.

Functions of Sertoli Cells

• Provide nourishment to developing spermatozoa and regulate spermatogenesis by releasing inhibin to check FSH over-activity.
• Absorb parts being shed by developing spermatozoa.
• Release anti-müllerian factor (AMF) to prevent development of müllerian duct/oviduct in males.
• Release Androgen Binding Protein (ABP).
• Form blood-testis barrier.

Castration

• Castration is the removal of testes, leading to failure of development of secondary sex organs and characters, and removing the ability to reproduce due to a deficiency of testosterone.