Ok. Let’s get down to business.
A woman has two ovaries. These small, almond-shaped glands hold and develop a woman’s eggs. One egg, or ovum, is about the size of the head of a pin. Girls are born with all the eggs they’ll ever have — some 250,000 in each ovary. Each month, beginning in puberty, a mature egg is released from one of the ovaries. This process is known as ovulation.
When an egg leaves the ovary, it is caught by the fringes located at the end of one of the fallopian tubes. It then travels through the tube toward the uterus. Fertilization, the joining of an egg and sperm cell, can occur if sperm are present in the female body close to the time of ovulation. This process takes place in the fallopian tube.
The uterus is a hollow, muscular organ about the size of a fist. Actually, it’s shaped much like an upside-down pear. When a woman is pregnant, the fertilized egg develops in the uterus. In the first eight weeks of life, the developing egg is known as an embryo; from that point until birth, it is referred to as the fetus.
Each month, a woman’s body prepares itself in case pregnancy occurs. The endometrium, or uterine lining, thickens to nourish a developing fetus. If the egg isn't fertilized, a woman doesn't become pregnant, and the endometrium is shed. Menstruation refers to the passing out of the body, of the blood, tissue, and fluids that make up endometrium. Periods usually happen at regular intervals — using your body’s clock, not a calendar — and can be tracked using something like our period calculator and calendar.
The cervix is the rounded lower portion, or neck, of the uterus, which protrudes into the vagina. During a woman's period, menstrual fluid passes through the opening of the cervix (which is about the size of a match head) through the vagina and out of the body.
And finally, the vagina is the very flexible passageway that leads from the internal reproductive organs to the outside of the body. It is also called the birth canal. Although the walls of the vagina usually lie flat against each other, they can greatly expand. This flexibility makes it possible for a baby to pass through the vagina during childbirth. It also makes wearing a tampon comfortable and easy. The vagina slants toward the back, a helpful fact to know when inserting a tampon.