An almond-shaped organ in a shallow fossa on the pelvic side wall, close to the external iliac vessels and the ureter
Ovary — its fossa is bounded by the external and internal iliac vessels.
Anatomy · Glands & the immune system
Ovary
The female gonad — one on each side of the pelvis
Reproductive and endocrine systems · female pelvis
One of a pair of almond-sized organs on each side of the female pelvis, lying against the pelvic side wall below and behind the opening of the uterine tube. Each ovary holds the follicles in which egg cells mature, releases one egg roughly every month from puberty until the menopause, and makes the hormones oestrogen and progesterone. It is held in place by ligaments to the uterus and the pelvic wall and is not wrapped in peritoneum.
How to spot them
- ▸Oval, almond-sized organ with a slightly bumpy surface, lying in a shallow ovarian fossa on the pelvic side wall
- ▸Lies close to the frilly fimbriae at the end of the uterine tube, which sweep the egg in
- ▸Attached to the uterus by the ovarian ligament and to the pelvic wall by the suspensory ligament, which carries its vessels
- ▸In section, a dense outer cortex containing round follicles of different sizes, around an inner vascular medulla
- ▸Surface lined by a single layer of cuboidal 'germinal' epithelium over a tough tunica albuginea
What to know
Holds one to two million immature egg cells at birth, of which only a few hundred are ever released
Ovary — the oocytes in its follicles; about 400,000 remain at puberty.
Unusually for an organ lying in the peritoneal cavity, it has no covering of peritoneum
Ovary — its surface is epithelium over the tunica albuginea, exposed to the cavity.
Its blood vessels travel in the suspensory ligament, the artery arising directly from the aorta
Ovary — the ovarian artery comes off the aorta below the renal arteries.
A yellow endocrine body forms in it after the egg is shed, making progesterone
Ovary — the corpus luteum, later shrinking to a scar, the corpus albicans.
A fluid-filled follicle that bulges from its surface before the egg is shed is named for a Dutch anatomist
Ovary — the Graafian follicle, after Reinier de Graaf.
A frilly funnel catches what it releases each month
Ovary — the fimbriae of the uterine tube.
Key ideas
- Each cycle FSH from the pituitary recruits a cohort of follicles; usually one becomes dominant, bursts at ovulation and leaves the egg to be caught by the fimbriae.
- The follicle cells make oestrogen; after ovulation the corpus luteum makes progesterone and oestrogen, preparing the uterine lining.
Quick-fire facts
- •Each is roughly 3 cm long, comparable to an almond in its shell
- •The number of egg cells falls from one to two million at birth to about 400,000 at puberty and is essentially exhausted after the menopause
- •Ovulation releases one egg (occasionally two), about mid-cycle
- •The right ovarian vein drains into the inferior vena cava and the left into the left renal vein
- •The ovarian ligament joins the ovary to the uterus; the suspensory ligament joins it to the pelvic wall; the mesovarium fixes it to the back of the broad ligament
- •Follicle stages in order: primordial, primary, secondary, tertiary (Graafian), then corpus luteum and corpus albicans
- •The ureter passes close behind the ovary and may be damaged during pelvic surgery
- •Reinier de Graaf (1641–1673) described the follicles that bear his name in 1672, though he mistook the whole follicle for the egg
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