ovulation The release of an egg cell from the ovary, which in mammals is stimulated by luteinizing hormone. The developing egg cell within its follicle migrates to the ovary surface; when mature, it is released from the follicle (which breaks open) into the body cavity, from where it passes into the oviduct. See also menstrual cycle.

ovulation The release of a ripe egg on bursting from the ovarian follicle of a mammal, frequently stimulated by a pituitary hormone. The egg is discharged on to the surface of the ovary and then passes into the oviduct. See also GRAAFIAN FOLLICLE. compare EJACULATION.

ovulation (ov-yoo-lay-shŏn) n. the process by which an ovum is released from a mature Graafian follicle. The fluid-filled follicle distends the surface of the ovary until a thin spot breaks down and the ovum floats out and starts to travel down the Fallopian tube to the uterus.