The parts of the female body that are involved in pregnancy and childbearing are called the reproductive organs. They include the two ovaries, the two fallopian tubes, the uterus (womb), and the vagina. These organs lie inside the lower part of the abdomen, called the pelvis, and are protected by bones and muscles (see Figure 3.1). The breasts are also affected by pregnancy and, of course, are essential for breastfeeding the baby.
Many people, even adults, do not know about the organs inside the body, and do not understand how pregnancy happens. This chapter provides a basic description and illustrations of the organs involved, and is helpful for understanding later chapters on "How Pregnancy Happens" (Chapter 4), "Family Planning and Child Spacing" (Chapter 17), and "Infertility" (Chapter 19). The parts of the body are referred to here using technical terms. Terms from local languages can be used for group discussions or counselling instead of, or in addition to, the terms used here.
A woman has two ovaries, one on either side of the womb; each one is the size of a small nut. The ovaries produce the eggs which, if fertilised by sperm from the man, will develop into a baby during the following nine months. This process is described in Chapter 4. The ovaries also produce two important female hormones called oestrogen and progesterone. These hormones greatly influence the growth, development, and function of the entire female body, and especially the reproductive organs, throughout a woman's life. For example, hormones cause the breasts to grow, and cause menstruation every month.
Figure 3.1: Internal Reproductive Organs of the Female
The two fallopian tubes connect the ovaries to the womb on either side (see Figure 3.1). The tubes are 4-5 inches (10-12 centimetres) long. When the egg is released from one of the ovaries every month, it is pulled into the fallopian tube and is very gently moved along the tube towards the womb. The man's sperm meets and fertilises the egg inside the fallopian tube. The fertilised egg then begins a slow journey to the womb, which it reaches about five days after being released from the ovary.
THE UTERUS (WOMB)
Before pregnancy, the womb is about the size of a small mango or pear. It is about 3-4 inches (nine centimetres) long, and weighs only two ounces (60 grams). The lower end of the womb is called the cervix, and connects with the upper part of the vagina. The fertilised egg attaches itself to the lining on the inside of the womb, and the womb then protects and nourishes the new life until a fully developed baby is born. During pregnancy, the womb gradually grows to hold the growing baby, the bag of fluid which surrounds it, and the placenta (the afterbirth). By the time the baby is born, the womb alone weighs about two pounds (nearly a kilo) and holds an average of ten pounds or about five kilos (the baby, placenta, and the fluid around the baby).
The cervix is sometimes called the neck of the womb. It connects the womb to the vagina, and normally has a very small opening. During pregnancy this opening stays small, so that the baby stays inside the womb. During labour the cervix opens up (dilates) so that the baby can be born.
The vagina is the channel between the womb and the outside. Menstrual blood flows out of the womb through the vagina. The vagina also produces fluids; the amount of fluids, and their colour and texture, varies at different times of the month. During sexual intercourse, the man puts his penis inside the vagina. When he "comes" or ejaculates, sperm from the penis enters the vagina. It then passes through the womb and into the fallopian tube, where it may fertilise the egg. During childbirth the baby leaves the womb and enters the world through the vagina. This is why it is sometimes called the "birth canal". The walls of the vagina are elastic and can stretch to allow the passage of the baby's head and body.
The vulva is the area around the opening of the vagina which can be seen from the outside (see Figure 3.2). The outer folds of skin, called the labia majora, are thick and covered with hair. The two inner folds of skin, called the labia minora, are much thinner. These inner folds form a hood around the clitoris, a small, sensitive organ above the vagina that responds to stimulation and makes sexual intercourse pleasurable. Inside the vaginal opening is a pair of glands that produce a thin fluid which moistens the vagina, especially during sexual excitement. In countries where female genital mutilation is practised, some women may have either the clitoris, or the clitoris and labia, removed. In some cases the labia may be sewn together (see Chapter 2 for a discussion on the effects of female genital mutilation).
Figure 3.2: External Reproductive Organs of the Female (Vulva)
The main external feature of the breast is the nipple and the dark skin around it, called the areola. Inside, the breasts consist of fat and sacs called "glands" that produce milk. In many women, one breast is larger than the other. Often, both breasts swell slightly during the menstrual period. During pregnancy, the glands grow in size as they produce milk (see Figure 3.3); often some liquid comes out of the nipple even before the baby is born.
Figure 3.3: Breasts of the Adult Female
The man plays a brief but vitally important role in reproduction. He produces the sperm which fertilises the egg to begin a new life. After fertilisation, the man's biological role in pregnancy is over, although his responsibility toward the woman and child continue. As described below, a man's major reproductive organs lie outside his body.
THE TESTES (TESTICLES)
The two testes produce the sperm which fertilise the woman's egg to start the process of reproduction. They are two egg-shaped organs, in front of and between the thighs, within a sac of skin known as the scrotum (see Figure 3.4). From puberty until old age, men's testes produce sperm all the time. While a woman releases one egg every month, a man releases 100-300 million sperm every time he ejaculates, or reaches climax, during sexual intercourse. During ejaculation, the sperm are carried in a liquid called semen that is produced by the man's reproductive organs. The semen passes through a tube called the vas deferens and out of the penis. One of the millions of sperm may reach an egg and fertilise it; the rest simply die in a few days and disappear.
The penis is the organ that carries the semen with the sperm into the vagina. During sexual excitement, blood is pumped into the muscles of the penis. This makes the penis stiffen or become erect so it can enter the vagina. Although both semen and urine pass through the tube called the urethra in the penis, at the time of ejaculation the opening from the bladder is closed so that only semen comes out of the penis. After ejaculation, the blood quickly drains away into the body and the penis returns to its normal state.
Figure 3.4: Reproductive Organs of the Male
Summary: The Reproductive Parts of the Female and Male Bodies
The female and male bodies play different but complementary roles in creating a baby.
THE FEMALE BODY:
THE OVARIES produce the eggs which are fertilised by the man; fertilised eggs grow to become babies. The ovaries also produce hormones that influence the development of the female body.
THE MALE BODY:
THE TESTES are two egg-shaped organs in front of and between the thighs, inside a sac of skin called the scrotum. The testes produce the sperm which fertilise the woman's egg to begin reproduction.
THE PENIS is the organ that places the sperm in the woman's vagina. The sperm are carried in a liquid called semen produced in the man's body.