Brain-testicular
Axis
1) Hypothalamus monitors i
hormone levels.
2) FSH and ICSH are released.
3) FSH stimulates release of ABP
(androgen binding protein).
4)  ICSH causes release of
testosterone -ABP binds
testosterone to stimulate
spermatogenesis.
5)  Negative feedback by
testosterone and inhibin
suppresses gonadotropins.
inhibin
ICSH
FSH
Sustentacular cell