æggestok

æggestok, the Danish term for the ovary, refers to the paired female reproductive organs in humans and most mammals. Each æggestok lies in the pelvic cavity on its respective side of the uterus, connected by the ovarian ligament and supplied by the ovarian vessels. The organ consists of an outer cortex containing follicles at different developmental stages and a central medulla rich in blood vessels, with a tunica albuginea as a connective-tissue covering.

Functions include oogenesis, the production of oocytes, and endocrine activity through the secretion of estrogens and progesterone. Oocytes develop within follicles from primordial germ cells. At puberty, cyclic recruitment of follicles occurs, leading to the ovulation of a mature oocyte and the formation of the corpus luteum, which secretes progesterone (and some estrogens) if pregnancy does not occur. The corpus luteum regresses if pregnancy does not take place, forming a corpus albicans.

Hormonal regulation is governed by the hypothalamus–pituitary–ovarian axis. Gonadotropin-releasing hormone stimulates FSH and LH release; FSH promotes follicle growth, while a surge of LH induces ovulation and corpus luteum formation. Estrogens and progesterone provide feedback to regulate pituitary hormone output and coordinate the reproductive cycle.

Clinical relevance includes functional ovarian cysts (such as follicular or corpus luteum cysts), polycystic ovary syndrome (PCOS), and ovarian torsion or ovarian cancer, the latter often of epithelial origin and increasing with age. Menopause reflects the long-term decline of ovarian function and estrogen production.