Question

3. If one or both testes do not complete the migration into the scrotum and remain in the abdominal cavity, they must be surgically moved into the scrotum. If the testes remain in the abdominal cavity, the individual will become sterile. Explain why.

Answer 1

During embryonic development, testes are primarily placed in abdominal cavity beneath posterior abdominal wall.

Gradually they descend down to the inguinal canal in about mid-pregnancy. Thereafter the testes descend into the scrotal sac just few days before the birth.

Scrotal sac maintains a temperature of 2-2.5°C below the body temperature which is essential for the process of spermatogenesis.

This low temperature maintainence is due to their anatomical location, pampiniform plexus of blood vessels and cremasteric muscle which contracts on exposure to cold and relaxes in warm environment.

Failure of migration of testes from abdominal cavity into scrotal sac during foetal development is a condition of Undescended testes or can be called as cryptorchidism.

The descent from abdominal cavity to inguinal region depends on Mullerian inhibiting substance and from inguinal region to scrotal sac depends on testosterone.

These undescended testes affects sperm production greatly because the temperature is high in abdomen. High temperature degenerates most of the spermatic tissue and affects spermatogenesis.

This leads to decreased sperm count or azospermia which results in infertility in most of the cases. Incidence of malignant tumors is also significantly more in case of undescended testes.

Surgical correction within 2-4 years of birth can help in normal process of spermatogenesis. Delaying beyond that period of time naturally leads to infertility and the person will become sterile.