The female reproductive system

The female reproductive system has the ovaries, the oviducts (Fallopian tubes), the uterus, the cervix, the vagina and the external genitalia, all in the pelvis. The mammary glands are also accessory parts.

The two ovaries are the primary female sex organs. Each is almond-shaped, about 2-4 cm long, and makes ova and the ovarian hormones (steroids). Inside, the stroma has an outer cortex and an inner medulla.

Each oviduct is about 10-12 cm long and has three parts:

• The infundibulum, a funnel near the ovary, whose edge has finger-like fimbriae. They help collect the ovum after it is released.
• The ampulla, the wider middle part.
• The isthmus, the last, narrow part, which joins the uterus.

The uterus (womb) is shaped like an upside-down pear. Its wall has three layers:

• Perimetrium: the thin outer layer.
• Myometrium: a thick middle layer of smooth muscle, which contracts strongly during childbirth.
• Endometrium: the inner glandular lining, which changes through the menstrual cycle.

The uterus opens into the vagina through a narrow cervix. Together, the cervical canal and the vagina form the birth canal.

The external genitalia are the mons pubis, the labia majora and labia minora, and the clitoris. The opening of the vagina is often partly covered by a membrane, the hymen, which can be torn by exercise or many other causes and is not a reliable sign of anything.

Each mammary gland contains 15-20 lobes made of clusters of cells, the alveoli, which secrete milk. The milk flows through tubules into ducts, collects in a wider ampulla, and leaves through a lactiferous duct to the nipple.