Intro | Anterior Pituitary | Adrenal Glands | Ovaries | Pancreas | Posterior Pituitary | Testes | Thyroid
Part 1: Image-Mapped Tutorial
Part 2: Matching Self-Test
Part 3: Multiple-Choice Self-Test
The Ovaries are the female gonads, or reproductive glands. These glands produce and secrete the hormones that control the development of female sexual characteristics and the reproductive function of the adult female. The ovaries respond to the control of gonadotropins, which are secreted by the anterior pituitary.
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The ovaries produce and secrete estrogens and progesterone in response to the release of follicle-stimulating hormone and luteinizing hormone from the anterior pituitary. Estrogen and related hormones have both organizing and activating effects on physiology, anatomy, and psychology. The organizing effects of estrogen emerge during the third month of gestation (pregnancy). When estrogen is present in greater levels than the male sex hormone, the fetus will develop the characteristics of a female. The feminizing effect of estrogen not only modifies the reproductive organs, but also the development of the central nervous system.
One cerebral region that develops differently depending on the relative level of female versus male hormone level is the hypothalamus, the endocrine control center that modulates sexual responses. Another organizing effect of estrogen includes the increased tendency for nurturing, maternal behavior. Activating effects of estrogen typically occur later in life when this hormone triggers short-term responses to environmental changes, such as sexual receptivity in response to an attractive potential partner. In addition, cognitive functions vary throughout the menstrual cycle of females in response to changing levels of estrogen. Progesterone is the hormone that prepares for and maintains pregnancy.
Both the organizing and activating effects of the sex hormones are mediated via the presence of the X and Y sex chromosomes. A normal female human is equipped with two X chromosomes, and a normal male human is equipped with one X and one Y chromosome. Chromosome abnormalities (e.g., XXY), abnormal response to circulating sex hormones, and the introduction of artificial hormones can alter the normal balance and effects of sex hormones on the developing and mature human brain.