The Female Reproductive System
The uterus, located in a woman's abdomen, is a hollow, elastic reproductive organ, where a baby develops during pregnancy.
Human Reproduction
Biological Basics and Terminology
Female Reproductive Anatomy
The uterus, also called the womb, is a muscular organ about the size and shape of a pear. This is where an embryo can implant and mature during pregnancy. The baby receives its nourishment from the mother through the umbilical cord while inside the uterus.
The cervix is the round opening at the end of the vagina that leads to the uterus. It is through this opening which sperm can enter to fertilize an egg and through which a baby leaves the uterus.
The vagina is the passage between the uterus and the outside of the body. This is the passage through which a baby is delivered and where the penis enters during sexual intercourse.
The ovaries are two walnut-sized structures located on either side of the uterus. Each holds thousands of tiny egg follicles. The ovaries also produce essential hormones.
The fallopian tubes connect the ovaries and the uterus. About four inches long, they each begin at an opening on either side of the uterus and end in a funnel that surrounds each ovary. Each tube is thin and narrow, no wider than the head of a pin.
Ovulation
About once a month, the endometrium, or lining of the uterus, begins to thicken in preparation to receive and nourish a fertilized egg. Meanwhile, several egg follicles begin to mature, but usually only one develops fully, with a mature egg inside. It moves to the surface of the ovary, and the follicle ruptures, releasing the egg into the fallopian tube. This process is called ovulation.
Over the next few days, the sides of the fallopian tube squeeze periodically, pushing the egg down into the uterus. If the egg is not fertilized during this time it will disintegrate in the uterus. Since the thickened uterine lining is no longer needed, it will be shed over a period of three to eight days. This discharge, containing blood and other secretions, is the menstrual flow, or a period. The time interval from one period to the next is called the menstrual cycle.
Related Links
- Human Reproduction: Contraceptive Information Resource (Contracept.org)
- Female Reproductive System: Epigee Women's Resources (Epigee.org)
