Reproductive System

The reproductive system is responsible for the creation of new life. Humans have sexual reproduction. This means that a male and female come together to form a new baby.

Female Reproductive System

Ovary

The female has two oval shaped ovaries located in the pelvis above the uterus. They are the major female sex organs and produce ova or eggs. Each ovary contains thousands of ova.

Ovum

The tiny female sex cell that unites with a male sperm to form a fertilized egg.

Fallopian Tube

A female has two Fallopian tubes. These tubes connect each ovary to the uterus. Each tube is 1 1/2 to 2 inches long in an adult female and about as wide as a piece of spaghetti. One end of the Fallopian tube has a fringed funnel that wraps around much of the ovary and scoops up a released egg or ovum. Tiny hairs in the tube help push the egg or ovum down to the uterus.

Uterus or womb

A sac shaped like an upside down pear with a thick lining and muscles in the pelvic area in which a fertilized egg or zygote comes and grows into a baby.

Cervix

The opening to the uterus which is about the size of a straw's opening.

Vagina

Also called the birth canal, it is a muscular passageway from the cervix to the outside of the female's body in the lower pelvic area. It receives the sperm laden semen from a male and also is the pathway from which a baby leaves its mother's body at birth. The vagina measures three to five inches in the adult female.

Menstruation or monthly period

An ovum leaves one ovary once a month and travels down the Fallopian tube to the uterus. If the ovum hasn't been fertilized by a sperm it settles into the uterus lining. The lining is shed along with some blood around once a month in a process called menstruation. Menstruation begins during the female's preteen or teen years or adolescence and end during middle age at menopause.

Male Reproductive System

Testes or testicles

Each human male has two testes or testicles which are the major male sex organs and produce and store millions of sperm. They are located below the pelvic area outside of the body's trunk. The testes are two inches long and one inch wide. The testes produce a hormone or chemical called progesterone that causes a male's voice to deepen and to grow more bodily hair. The epididymis and the vas deferens make up the duct system of the male reproductive organs. The vas deferens is a muscular tube that passes upward alongside the testicles and transports the sperm-containing fluid called semen. The epididymis is a set of coiled tubes that connects to the vas deferens.

Sperm

The tiny male cells that unite with a female ovum to form a fertilized egg or zygote.

Semen

A fluid which contains millions of sperm. During the process of ejaculation the sperm laden fluid leaves the male.

Scrotum

The sac that holds the testes. Since the testes are located outside of the body, the scrotum is temperature controlled to help preserve the sperm contained in the testes as sperm must be kept at a cooler temperature than the body's.

Penis and urethra

The penis contains a long tube called the urethra which is responsible for carry sperm from the male to be place in the female's vagina.

Prostate

A gland which makes some of the parts of semen, surrounds the ejaculatory ducts at the base of the urethra, just below the bladder.

Conception, gestation and birth

Conception

When an egg or ova leaves the ovary, it travels down the Fallopian tube. If the male has deposited semen-filled sperm in the female's vagina and one of the sperm reaches the egg in the Fallopian tube by swimming up the vagina, through the cervix and uterus, it can then become a fertilized egg or ova zygote. This process is called conception.

The fertilized egg becomes multicellular and is called a blastocyst. The blastocyst enters the uterus and nestles into its lining filled with blood called the endometrium. This is called implantation.

Birth

Pregnancy, the time a mother carries the baby from conception until birth, lasts about nine months.

When the baby is ready to be born, its head presses against the cervix which then relaxes. The mucus plug at the cervix loosens and the amniotic fluid flows out of the vagina when the mother's water breaks.

As labor begins, the cervix open wider, the muscles contract to help push the baby through the vagina and out of the mother's body. The baby usually come out head first with the umbilical cord attached and the placenta also comes out which is then called the afterbirth. The umbilical cord is cut from the baby who is now ready to be nourished with mother's milk from the breasts.