Anatomy and Physiology of the Male Reproductive System

Abstract

The male reproductive system is an incredibly complex yet balanced network of central nervous system circuits and internal and external pelvic organs. The feedback circuit composed of the hypothalamic–pituitary– gonadal (HPG) axis leads to reproductive tract formation and development during embryogenesis, sexual maturation at puberty, and testosterone and sperm production by the testis. The HPG axis continues to stimulate androgen production throughout adulthood to maintain adequate testosterone and sperm production. This axis and the internal and external pelvic organs are the key components in themale reproductive system. This chapter outlines the anatomy and physiology of the male reproductive system, including the HPG axis, control of testosterone production and spermatogenesis within the testis, maturation of sperm within the epididymis, and the transportation of sperm from the distal epididymis through the ejaculatory duct during seminal emission (Figure 1.1).