Female organs of reproduction

The internal genital structures of the female include the ovaries, the Fallopian tubes, the uterus (womb) and the vagina. The ovaries or "egg sacs" are a pair of female reproductive organs located in the pelvis, one on each side of the uterus. Each ovary is about the size and shape of an almond. The ovaries have two functions: they produce eggs (ova) and female hormones. Each month, during the menstrual cycle, an egg is released from one ovary. The egg travels from the ovary through a Fallopian tube to the uterus. The ovaries are the main source of female hormones (estrogen and progesterone). These hormones control the development of female body characteristics, such as the breasts, body shape, and body hair. They also regulate the menstrual cycle and pregnancy. The Fallopian tubes, one on each side, transport the egg from the ovary to the uterus (the womb). The Fallopian tubes have small hair-like projections called cilia on the cells of the lining. These tubal cilia are essential to the movement of the egg through the tube into the uterus. These tubes bear the name of the 16th-century Italian physician and anatomist Gabriele Falloppio. The uterus is a hollow, pear-shaped organ located in a woman's lower abdomen, between the bladder and the rectum. The upper part is the corpus. The corpus is made up of two layers of tissue. In women of childbearing age, the inner layer of the uterus (endometrium) goes through a series of monthly changes known as the menstrual cycle. Each month, endometrial tissue grows and thickens in preparation to receive a fertilized egg. Menstruation occurs when this tissue is not used, disintegrates, and passes out through the vagina. The outer layer of the corpus (myometrium) is a muscle that expands during pregnancy to hold the growing fetus and contracts during labor to deliver the child. The cervix is the lower, narrow part of the uterus. It forms a canal that opens into the vagina. The vagina is the muscular canal extending from the cervix to the outside of the body. The word "vagina" is a Latin word meaning "a sheath or scabbard", a scabbard into which one might slide and sheath a sword. The "sword" in the case of the anatomic vagina was presumably the penis.