Human reproductive system

The human reproductive system includes the male and female parts of the body that help humans have babies. The male part makes and puts out tiny cells called sperm. The female part makes egg cells and also keeps and cares for a growing baby until it is born, called a fetus.

Humans usually have babies through a process called internal fertilization during sexual intercourse. In this process, the male releases semen that contains sperm into the female. If a sperm meets an egg, called an ovum, it creates a new cell called a zygote. This zygote moves to a place in the female’s body called the uterus, where it starts to grow. This growing period is known as pregnancy, lasting about nine months.

When the baby is ready, it is born through a process called childbirth. The baby then needs lots of care from adults. This care includes keeping the baby clean, comfortable, and fed. Feeding can happen through breastfeeding or with special milk called formula feeding. Babies depend on their caregivers for many months to stay healthy and happy.

Structure

Female

Main article: Human female reproductive system

The human female reproductive system has parts inside and around the lower body. It has three main parts: the vagina, which leads to the uterus; the uterus, where a baby grows; and the ovaries, which make eggs. The breasts help care for a baby but are not usually part of the reproductive system.

The vagina opens to the outside at a part called the vulva. The uterus connects to the ovaries through tubes called fallopian tubes. Each ovary holds many eggs. About every 28 days, a hormone helps an egg be released. If the egg meets sperm, it can grow into a baby inside the uterus.

Male

Main article: Human male reproductive system

The male reproductive system has parts that help make and deliver sperm. Sperm are made in the testicles, which are kept at the right temperature in a pouch called the scrotum. Other parts help make fluids that go with the sperm and tools used to place sperm inside the female.

Boys also change during their growing up, such as getting taller, deeper voices, more body hair, and broader shoulders. A key hormone in males is called testosterone.

Development

The human body starts growing its reproductive system very early, even before a baby is born. Boys and girls begin with the same basic parts, which later turn into different organs depending on whether the child will be male or female.

Special tubes and structures in the body change in different ways to create the organs needed for each gender. Hormones, which are like chemical messages, help guide this process so everything forms correctly. Even though the male and female reproductive systems look very different when grown up, they start from similar beginnings.

Reproduction

Further information: Human reproduction

Production of gametes

Main articles: Spermatogenesis and Oogenesis

Gametes are special cells in our bodies that help create new life. They are made in the gonads through a process called gametogenesis. This happens when cells go through meiosis to split their chromosomes into smaller parts.

In males, this process is called spermatogenesis and starts after puberty in the testes. The young sperm cells move to the epididymis, where they grow tails and learn to move. Each original cell makes four sperm cells.

In females, the process is called oogenesis and happens in the ovaries. It usually makes one mature egg cell and three smaller cells that aren’t used for making a baby.

Disease

Main article: Reproductive system disease

The human reproductive system can get sick, just like other parts of the body. These sicknesses can be grouped into four main types: genetic or congenital abnormalities, cancers, infections, and problems from the environment or injuries. Common issues include trouble with body functions and difficulty having children.

Some reproductive sicknesses can be signs of other health problems. Many have many possible causes, which makes them hard to sort into just one group. For example, some conditions affect men and women differently, and some diseases known for other symptoms can also cause problems with the reproductive system.