Ovary

The ovaries are part of the female reproductive system.

Function of the ovaries

The ovaries are the female gonads and are therefore the place where ovules are produced. They contain follicles (400,000 in women) which are already formed at birth. After puberty, one follicle matures in each menstrual cycle and releases an ovule which migrates towards the uterus. The ovarian follicle then converts into a yellow body (corpus luteum) if the ovule is fertilised. If not, it degenerates.

The ovaries are also the female sex glands which produce the female sex hormones. Endocrine ovarian function is carried out by the follicular cells which surround the oocyte during its development and from which the corpus luteum forms. Endocrine ovarian function is cyclical in the same way as gamete formation: ovarian hormones are secreted according to a rhythm superimposing the genital cycle.

The ovary secretes four groups of hormones:

• Oestrogens;
• progesterone;
• small amount of androgens;
• and the inhibin and cybernin group.

Structure of the ovaries

There are two ovaries, one on each side of the pelvis connected to each other by the Fallopian tubes. Each ovary weighs approximately 10 grams and is almond-shaped (1x0.5x 0.1 centimetres). The ovaries are fixed by ligaments which connect them to the uterus and peritoneum.

The external part of the ovary is called the cortex whereas the internal part which is highly vascularised and innervated is called the medulla.