Reproductive System, Male Health Article

Definition

The male reproductive system is composed of organs that work together to produce sperm and deliver them to the female reproductive tract for fertilization of the ovum.

Description

The normal male reproductive system is composed of numerous anatomical structures, including the testis, the excretory ducts, the auxiliary glands, the penis, and the various hormones that control reproductive functions.

Testis

The testis is responsible for the production and maturation of sperm in a process called spermatogenesis. It is also the site of synthesis and secretion of androgens (male sex hormones). The testes (plural) develop in the abdomen and descend into the scrotum in the normal male. The scrotum is a muscular sac in which the testes hang from the spermatic cord.

The testis is subdivided into the tubular compartment and the interstitial compartment. The tubular compartment is composed of up to 900 seminiferous tubules, which are populated by three main types of cells: germ cells, peritubular cells, and Sertoli cells. Germ cells become mature sperm in the spermatogenic process. Peritubular cells produce various factors that aid in the

transportation of mature sperm to the epididymis. Sertoli cells secrete various factors that determine the sperm production and testis size of an adult male.

Androgens are produced in the interstitial compartment of the testis. Leydig cells are responsible for the production and secretion of testosterone. Immune cells such as macrophages and lymphocytes are also found in the interstitial compartment, and aid in the proliferation and hormone production of Leydig cells.

Sperm cells are composed of a head (containing the nucleus and acrosome); the body (containing the mitochondria, or energy-producing organelles); and the tail. The nucleus contains the cell's genetic material (chromatin) while the acrosome contains enzymes that are capable of penetrating the protective layers around the egg. The mitochondria provide energy for tail motility; this is essential for movement of the sperm through the female reproductive tract.