a. The male reproductive tract consists of external genitals and internal organs.

These organs are located in the pelvic cavity (see figure 1-8). The male’s reproductive system begins to develop in response to testosterone during early fetal life.

Essentially no testosterone is produced during childhood. Resumption of testosterone production at the onset of puberty stimulates growth and maturation of the male’s reproductive structures and secondary sex characteristics. Testosterone is the male sex hormone secreted by the interstitial cells of the testes.

b. The primary function of the male’s reproduction system is to produce male sex cells, which are called sperm cells. The primary organs of the male’s reproduction system are the two testes in which the sperm cells are formed. The other structures are the duct system and the accessory glandular structure.