Saturday, October 6, 2007

Spermatogenesis - LINK

Spermatogenesis is the process by which male spermatogonia develop into mature spermatozoa. Spermatozoa are the mature male gametes, in many sexually reproducing organisms. Thus, spermatogenesis is the male version of gametogenesis. In mammals it occurs in the male testes and epididymis in a stepwise fashion, and for humans takes approximately 64 days. Spermatogenesis is highly dependent upon optimal conditions for the process to occur correctly, and is essential for sexual reproduction. It starts at puberty and usually continues uninterrupted until death, although a slight decrease can be discerned in the quantity of produced sperm with increase in age. The entire process can be broken up into several distinct stages, each corresponding to a particular type of cell: