Introduction

The female reproductive system consists of the external and internal genital organs. (The breasts are sometimes considered part of the reproductive system (see Section 22, Chapter 251).) However, other parts of the body also affect the development and functioning of the reproductive system. They include the hypothalamus (an area of the brain), the pituitary gland (located directly below the hypothalamus), and the adrenal glands (located on top of the kidneys). The hypothalamus orchestrates the interactions among the genital organs, pituitary gland, and adrenal glands. These parts of the body interact with each other by releasing hormones. Hormones are chemical messengers that control and coordinate activities in the body. The hypothalamus produces gonadotropin-releasing hormone, which stimulates the pituitary gland to produce luteinizing hormone and follicle-stimulating hormone. These hormones stimulate the ovaries to produce the female sex hormones, estrogen and progesterone, and some male sex hormones (androgens). (Male sex hormones stimulate the growth of pubic and underarm hair at puberty and maintain muscle mass in girls as well as boys.) After childbirth, the hypothalamus signals the pituitary gland to produce prolactin, a hormone that stimulates milk production. The adrenal glands produce small amounts of female and male sex hormones.