ovarian cycle
Last reviewed 01/2018
The ovarian cycle is the normal process whereby ova mature and are released during the menstrual cycle.
At the start of the menstrual cycle, several several primordial follicles begin to enlarge, with cavitation occurring to form an antrum. Normally one of the follicles becomes dominant; the rest regress.
The maturing follicle at this stage is called a graafian follicle; the cells of the theca interna of this structure produce oestogens.
Ovulation occurs at about day 14 of the cycle (of a 28 day cycle), with the rupturing of the follicle. The follicle itself fills with blood; there may be brief pain - mittelschmerz.
After ovulation the theca and granulosa cells proliferate and luteal cells form the yellow body, or corpus luteum. These cells secrete progesterone and oestrogens.
If pregnancy does not occur the corpus luteum beguns to degenerate about four days prior to menses.