Maturation of spermatozoa

Spermatozoa (sperms) mature in the epididymis (spermatogenesis). Each one consists of a head (caput) and a tail (flagellum). The head contains the acrosome and the tail comprises a neck, middle, principal and end piece. Mature sperms are freely motile. After ejaculation, they pass through the vagina into the cervical canal (canalis cervicalis uteri). They drift down through the uterus, becoming more mobile as they proceed. Capacitation of the sperm occurs in the female reproductive tract, taking about 7 hours, whereby a glycoprotein layer and proteins from the ejaculate are shed from the surface of the sperm. The spermatozoa are now able to penetrate the corona radiata, so as to bind to the zona pellucida and undergo the acrosome reaction.