Anatomy of the Female Reproductive System
The ovaries of sexually mature females are solid, ovoid structures that are about 1.4 inches long, 0.8 inches wide, and 0.4 inches thick. They are positioned in the upper pelvic cavity on both sides of the uterus. The lateral portion of the ovary is in contact with the open ends of the fallopian tube.
The paired fallopian tubes transport the egg from the ovaries to the uterus. Each tube is about 4 inches long and 0.3 inches in diameter. The egg takes 4-5 days to move through the tube. If enough viable sperm are ejaculated into the vagina during intercourse, fertilization will occur within hours. The fertilized egg (now a zygote) moves toward the uterus where implantation occurs.
The uterus is a hollow, thick-walled, muscular organ that is shaped like an upside-down pear. In its nonpregnant state it is about 2.8 inches long, 2 inches wide (through its broadest region), and 1 inch in diameter. The anatomical regions include the fundus (the uppermost part), the body (the enlarged main portion), and the cervix (the inferior constricted portion opening into the vagina). The outer covering is the perimetrium, the thick layers of muscle is the myometrium (thickest in the fundus and thinnest in the cervix - arranged in longitudinal, circular, and spiral patterns), and the inner mucosal lining of the uterus is the endometrium. During pregnancy, the weight of the uterus increases from about 60 grams to about 1,000 grams and its capacity increases from about 2.5 milliliters to 5,000 milliliters.
The vagina is about 3.6 inches in length. It receives sperm, serves as the birth canal, and provides the passage of menses. The middle muscularis layer of the vagina consists of longitudinal and circular bands of smooth muscle interlaced with distensible connective tissue. The distension of the layer is especially important during delivery when the baby is coming through.
The mammary glands are located in the breasts and are associated with the female reproductive system since they secrete milk for the nourishment of the young.