Humangrowth

Human Growth and Development5th Grade Science

Definition of Human Reproduction

The process by which human beings are made

Structure and Function

Pituitary Gland– Located: base of

brain– Called: “Master

Gland” • Controls the growth

patterns of the body


Body Changes– During adolescence, hormones produced

by the pituitary stimulate changes in the reproductive organs.

– Hormones cause quick changes: physically, emotionally, and psychologically

– Growth and development of the body vary from individual to individual. Girls usually mature before boys.


Body Changes Continued– Adolescence begins between the age of 9-14

years. Ask your parents when they changed and you will change around that same age.

– This stage is called puberty. During puberty, your body’s sex organs develop. At this time, it is physically possible to reproduce and secondary sex characteristics begin to appear.

Reproductive System

The anatomy and physiology of the male and female reproductive systems are different, but compliment each other to make reproduction possible.

Adolescence- hormones cause the egg and sperm cells to mature. Then, reproduction is made possible.

Male Reproductive System

Scrotum: holds testesTestes: produce and store sperm. Penis: needed for intercourse and urinationUrethra: carries urine and sperm to the outside of the bodyVas Deferens: carries sperm from the testes to the urethraSeminal vesicles and prostate gland: produce semen


Scrotum: a loose sac that holds the testes outside the body. The scrotum allows the testes to maintain a temperature two or three degrees below body temperature. It does this by pulling the testes closer to the body in cold conditions and relaxing to let them hang farther from the body in warm conditions. This temperature maintenance is related to sperm production.


Testes: Two testes or testicles (located in the scrotum) produce and store the sperm and are each about the size of a walnut. The mature sperm are continuously being produced by the testes from puberty to well into old age. Hormones from the pituitary stimulate the sperm production. The mature sperm are released during sexual intercourse or they disintegrate.


Penis: External organ that is necessary for intercourse and urination. It consists of fine, spongy material and the urethra.

Urethra: The tube inside the penis that carries both urine and sperm to the outside of the body, but never at the same time. A valve prevents urine and sperm from being in the urethra at the same time.


Vas Deferens: The long tube that carries the sperm from the testes to the urethra.

Seminal Vesicles and Prostate Gland: Are two glands that produce semen, the thick, white fluid in which the sperm float.

Female Reproductive System

Ovaries: store eggsFallopian Tubes:a tube where the egg travels through to the uterusUterus or Womb: fertilized egg developsCervix: protects the unborn child from the outsideVagina: sperm is deposited here


Ovaries: Two small glands, each about the size of an almond, where the egg cells mature. Hormones from the pituitary stimulate the eggs to mature. The ovaries contain 300-400,000 eggs from the time of birth. These eggs ripen at the rate of about one per month with the start of menstruation.


Fallopian Tubes: When the mature egg leaves the ovary, it travels through the tube to the uterus. The tubes or oviducts are three to five inches long. It takes the egg three to six days to travel through the tubes to the uterus. During this time, if the sperm meets the egg and penetrates it, fertilization takes place and pregnancy begins. If fertilization does not take place, the egg leaves the body through the uterus and vagina.


Uterus or Womb: The place where the fertilized egg develops and grows for nine months.Cervix: Is the neck of the uterus. It closes off the uterus to protect the unborn child from the outside.Vagina: Is where the sperm is deposited during intercourse. It is also the birth canal. (Sperm must swim up to the Fallopian tube to meet the egg.)

Education

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