A section through the ovary would show the outer covering called the tunica albuginea. Beneath the tunica albuginea, there would be a layer of connective tissue called the ovarian cortex. Within the cortex, there would be multiple follicles at various stages of development, ranging from primordial follicles to mature (Graafian) follicles. The follicles are composed of an oocyte surrounded by multiple layers of follicle cells. At the time of ovulation, the mature follicle ruptures and releases the oocyte into the abdominal cavity. The remaining follicle cells form the corpus luteum, which secretes progesterone to maintain the endometrium in preparation for a possible pregnancy. If pregnancy does not occur, the corpus luteum degenerates and forms a scar called the corpus albicans.