The Ovaries: Anatomy, Oogenesis and Hormonal

The ovaries are the paired female gonads, almond-shaped organs roughly 3 by 2 by 1 cm in reproductive-age individuals, situated against the lateral pelvic walls and suspended by the ovarian ligament (which tethers them medially to the uterus) and the infundibulopelvic, or suspensory, ligament (which anchors them laterally and carries the ovarian vessels). They perform two essential roles: oogenesis, the production and cyclic release of oocytes, and steroidogenesis, the production of the hormones that regulate the menstrual cycle, support pregnancy, and drive secondary sex characteristics. The ovarian cortex houses follicles in progressive stages of development, while the inner medulla carries blood vessels, lymphatics, and nerves. Each cycle, a cohort of follicles is recruited, one becomes dominant, and ovulation releases its oocyte; the remaining structure becomes the corpus luteum, which secretes progesterone to ready the endometrium for implantation. Why this matters clinically: Ovarian physiology underpins fertility, the menstrual cycle, and early pregnancy. In the first trimester, the corpus luteum sustains the pregnancy by producing progesterone until the placenta assumes that role around 8 to 10 weeks; this is why the hCG...