Chapter 23. Function of the Male Reproductive System
Full development and function of the seminiferous tubules require
In human males, testosterone is produced mainly by the
NOS contributes to erection by:
A. raising cAMP levels that relax smooth muscles and increase blood flow.
B. blocking phosphodiesterases to increase cGMP levels that release smooth muscle and increase blood flow.
C. activating soluble guanylyl cyclases to increase cGMP levels that relax smooth muscle and increase blood flow.
D. raising intracellular Ca2+ concentrations that relax smooth muscles and increase blood flow.
A. in the testes after reduction of dihydrotestosterone.
B. in Leydig cells from cholesterol and pregnenolone precursors.
C. by LH in Leydig cells.
D. as a precursor for several membrane lipids.