Female Reproductive Organs

In a woman's body, several organs work together so that a baby can be conceived, can grow and can be born. Together these organs make up the female reproductive system. To study them clearly, we divide them into two main groups. The external organs are the ones on the outside of the body. The internal organs lie protected inside the lower part of the abdomen. Besides these, the breast is counted as an accessory organ, because it provides milk for the baby after birth.

• External organs: the parts on the outside of the body, known together as the vulva.
• Internal organs: the vagina, the uterus, the fallopian tubes and the ovaries, all inside the body.
• Accessory organ: the breast, which makes milk for the baby.

The female reproductive organs that can be seen on the outside of the body, between the thighs, are together called the vulva. The vulva is not one single organ. It is made of several parts, and they are easiest to learn in order from top to bottom.

Taken in order from top to bottom, the mons pubis comes first. The labia majora lie on both sides, with the labia minora inside them. Where the labia minora meet at the top sits the clitoris, covered by a small hood of skin called the prepuce. The space between the labia minora is called the vestibule, and it holds two openings. The small upper one is the urethral opening, through which urine leaves the body. The larger one below it is the vaginal opening. Below these lie the perineum and, last of all, the anus.

Further inside, protected within the lower part of the abdomen, lie the internal reproductive organs. There are four of them:

• the vagina
• the uterus
• the fallopian tubes
• the ovaries

These organs are joined to one another. The uterus sits in the middle. From each side of its upper part, a fallopian tube reaches out towards an ovary. The narrow lower end of the uterus opens into the vagina, and the vagina opens to the outside at the vulva. In this way the organs form one connected passage from the ovaries to the outside of the body.

The vagina lies between the thighs, with the urinary bladder in front of it and the rectum behind it. It is about 15 cm long and 3 to 6 cm wide. Because it links the outer organs with the inner ones, it works like a bridge between the two. Its walls can stretch a great deal when a baby is born and then shrink back again. The vagina has these functions:

• It receives the man's penis during sexual intercourse.
• It receives the sperm during sexual intercourse.
• It forms the birth canal, the passage through which a baby is born.
• It lets menstrual blood from the uterus flow out of the body.

The uterus is wide at the top and narrow at the bottom, so it looks like an upside-down pear. Its upper part is joined to the fallopian tubes on each side, and its lower part is joined to the vagina. It is a sac that can stretch, so as a baby grows inside it, the uterus grows larger too. Normally it weighs only about 30 to 40 grams.

The uterus is divided into three parts:

• Fundus: the rounded top part of the uterus
• Body (corpus): the main middle part
• Cervix: the narrow lowest part, the neck of the uterus, which opens into the vagina

The wall of the uterus is made of three muscular layers. From the outside in, they are:

• Perimetrium: the outermost layer
• Myometrium: the middle layer
• Endometrium: the innermost layer, which lines the inside of the uterus

When a fertilized egg reaches the uterus, it attaches to the inner surface. There its cells divide again and again, and it develops into a foetus. The foetus stays in the uterus for nine months until it is fully developed, and then the baby is born. The functions of the uterus are:

• It keeps the menstrual cycle regular.
• It prepares a suitable environment for the foetus.
• It receives the fertilized egg and gives it nutrients and protection.
• It lets the foetus grow and develop, and helps the baby to be born after nine months.

The fallopian tube is also called the uterine tube. At the outer end of each tube are finger-like parts called fimbriae. The fimbriae spread out close to the ovary, so they are ready to catch the egg as soon as the ovary releases it and guide it into the tube.

The main job of the tube is to receive the egg from the ovary and carry it to the uterus. Fertilization also usually takes place inside this tube. The fertilized egg then moves on into the uterus and settles there.

Each ovary holds many immature cells called Graafian follicles, or ovarian follicles. Once a girl reaches puberty, one of these follicles ripens every month and an egg comes out. It happens in this order:

• One follicle ripens.
• The ripe follicle bursts and releases one egg.
• The fimbriae catch the egg.
• The egg moves along the fallopian tube towards the uterus.

As well as releasing eggs, the ovaries produce two hormones, oestrogen and progesterone. These same hormones also make a girl's breasts grow.

The breast does not take part in conceiving or carrying a baby, but it makes the milk the baby needs once it is born. That is why it is called an accessory organ. Breasts begin to develop when a girl reaches puberty. They grow once the ovaries start producing oestrogen and progesterone, and during pregnancy the production of these hormones becomes even stronger. After the baby is born, the pituitary gland produces a hormone called prolactin, which helps the breasts make milk.

Each breast is made of fatty tissue together with fibrous tissue. In the very centre of the breast is a dark tip called the nipple. The milk made inside the breast comes out through the nipple.