The small sac or vesicle near the surface of the ovary in the female that contains a developing egg cell.
A cell which contains an ovum.
A spherical structure in the cortex of the ovary consisting of an oogonium or an oocyte and its surrounding epithelial (follicular) cells. The follicles are of three types. The first type, or primary follicle, consists of an oogonium and a single layer of follicular cells. In the second type, or growing follicle, cells proliferate, forming several layers, and the first maturation division occurs. The third type, the vesicular (graafian) follicle, possesses a cavity (antrum) containing the follicular fluid (liquor folliculi). The oocyte lies in the cumulus oophorus, a mass of cells on the inner surface. The cells fining the follicle constitute the stratum granulosum. The follicle is a secretory structure producing estrogen and progesterone.