There are many organ systems within our body that ensure we stay alive. Arguably, however, one of the most important systems for guaranteeing our survival for generations is the reproductive system, as it allows us to produce children. To be able to have children, we first go through puberty—changes in the body that are the stepping stone to sexual maturation.

The reproductive systems of males and females are specialized for their roles in human reproduction. Females produce eggs, also called ova, which meet with reproductive cells from males, called sperm, in a process called fertilization. This joining of egg and sperm is necessary to complete the genetic makeup of the newly formed cell, which is called a zygote. The zygote divides into what becomes a fetus—which will become a baby—and the placenta, a temporary organ attached to the wall of the uterus that nourishes the fetus during pregnancy.

Organs of the Reproductive System

The female reproductive system is primarily made up of:

• Ovaries—a pair of oval-shaped organs that produce ova and chemical messengers called hormones, including estrogen and progesterone, which play a major role in the female reproductive cycle;
• Fallopian tubes—narrow tubes between the ovaries and uterus that ova travel through;
• Uterus—also called the womb, the uterus is the organ where a fetus develops;
• Vagina—a canal that leads from the uterus to the outside of the body; and
• Breasts—which contain milk-producing mammary glands.

The male reproductive system is primarily made up of:

• Testes (testicles)—a pair of oval-shaped organs that produce sperm and most of the primary male sex hormone testosterone; and
• Penis—the male reproductive organ that carries sperm and urine outside the body.

Hormones—including testosterone—control sperm production and maturation. When the testes release sperm, they mix with seminal fluid that the prostate—a small gland located between the penis and bladder—produces. Seminal fluid helps transport sperm out of the body.

Puberty and Reproduction

As we move from childhood to adolescence, the male and female reproductive systems and hormones help our bodies mature during puberty. For males, this includes deepening of the voice, pubic hair growth and other physical changes. For females, this includes pubic hair growth, breast enlargement and starting to menstruate.

During puberty, females begin to experience cycles of egg maturation in preparation for pregnancy. This cycle continues until females reach the end of their reproductive life (menopause). Each month, hormones stimulate a new egg to mature so the ovaries can release it for potential fertilization (ovulation). At the same time, hormones work together to get the uterus ready for a potential pregnancy by creating a lush, nutrient-rich environment where a newly fertilized egg can develop. If fertilization does not occur, the egg and this lining are shed during menstruation.

These are all signs of not only growing up, but also of our reproductive capacity as we move into adulthood.