Ovary

Ovary, in anatomy, organ of female animals, including humans, that produces reproductive cells called eggs, or ova (see Reproductive System). In humans they are oblong, flattened, ductless glands, about 3.8 cm (about 1.5 in) long, on either side of the uterus, to which they are connected by the fallopian tubes. Each ovary is composed of two portions: an external, or cortical, portion, and a deep, medullary portion. The cortical portion in the adult contains an enormous number of follicles, or sacs, varying in size. Called Graafian follicles, they contain the ova, the female reproductive cells. The ovary secretes hormones (see Hormone) that, together with secretions from the pituitary gland, contribute to secondary female sexual characteristics and also regulate menstruation. The union of the male sperm cell with the ovum results in fertilization.

The ovary may be the site of several disease conditions. It can be the site of acute and chronic inflammation; this may arise from injuries during labor, operations in the pelvic area, or gonorrheal infection spreading from the vagina. The ovary also may be the site of neoplasms (tumors) of several varieties. Some are fluidic enlargements of one or more Graafian follicles and may attain an enormous size; these are known as ovarian cysts. Other growths, of a solid nature, are known as dermoid cysts. These enlargements, usually benign, occasionally prove to be cancerous (see Cancer). For a discussion of ovaries in plants, see Flower; Fruit; Ovule.