Male Physiology

Question 1

What are Sertoli and Leydig cells? Where are they found? What roles does each have?

Answer 1

• Sertoli cells (AKA sustentacular cells) line the seminiferous tubules of the testes; they maintain the blood-testes barrier (via tight junctions), secrete inhibin, secrete Mullerian-inhibiting factor, secrete androgen binding protein, support mitosis and meiosis, support spermatogenesis
• Leydig cells are interstitial cells around the tubulues; they secrete testosterone and other androgens

Question 2

Which steps are involved in spermatogenesis?

Answer 2

• 1 spermatogonium (46; 2N, 2C; found in the basal section of the seminiferous tubules protected by blood-testis barrier)
• 1 primary spermatocytes (46; 2N, 4C; outside the BTB)
• 2 secondary spermatocytes via meiosis I (23; 1N, 2C)
• 4 spermatids via meiosis II (23; 1N, 1C)
• 4 mature sperm via spermiogenesis (23; 1N, 1C; found in the adluminal section/epididymis)
• (spermatogensis takes about 2 months)

Question 3

Other than sperm, what else is found in semen?

Answer 3

• 60% is from the seminal vesicles, containing fructose, prostaglandins, fibrinogen, and alkaline fluid
• 25% is from the prostate, containing citrate and PSA (PSA is actually an enzyme that liquefies coagulated semen!)
• remainder is from the bulbourethral glands