Male Reproductive System 2: Surrounding cells and hormones

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Structure of a sperm 

What is the function of nurse cells (sertoli cells)?

Nurse cells, also termed sustentacular or sertoli cells, play a key role in spermatogenesis through:
  1. Maintain of the blood-testis barrier (through tight junctions with outer basal layer and inner luminal compartment)
  2. Support mitosis and meiosis (through FSH and testosterone)
  3. Support spermatogenesis (surround spermatids, providing nutrients and stimulating development, phagocytose and shed cytoplasm of spermatids)
  4. Secrete inhibin (to depress FSH secretion)
  5. Secrete Androgen-Binding Protein (binds to testosterone, elevating concentration of hormones in the seminiferous tubules)
  6. Secrete Müllerian-Inhibiting Factor (descent of testes during birth)
Leydig cells (interstitial cells) are in between the seminiferous tubules and secrete androgens, most importantly in males, testosterone.

Testosterone and hormonal control

Testosterone is synthesised from cholesterol in Leydig cells and is released in response to luteinizing hormone from the anterior pituitary gland. Functions of testosterone include:
  • Controls development, growth and maintenance of male sex organs
  • Development and maintenance of male secondary sex characteristics, e.g. voice pitch
  • Stimulates bone and muscle growth
  • Sexual behaviour (libido)
  • Final maturation of sperm
  • Descent of the testes

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