<<

sxtr05_bkd_ch7_ls20.fm Page 407 Tuesday, December 14, 2004 2:46 PM

Name ______Date ______Class ______

The Endocrine System and I Section Summary The Male and Reproductive Systems Key Concepts

I What is ? I What are the structures and functions of the male and female reproductive systems? I What events occur during the ? An egg is the female . A is the male sex cell. The joining of a sperm and an egg is called fertilization. Fertilization is an important part of sexual reproduction, the process by which living things produce new individuals of the same type. Sexual reproduction involves the production of eggs by the female and sperm by the male. The egg and sperm join together during fertilization. When fertilization occurs, a fertilized egg, called a , is produced. are structures in the cells that carry the information that controls inherited characteristics. The male is specialized to produce sperm and the hormone testosterone. Its structures include the testes, scrotum, and penis. The testes are the organs in which sperm are produced. The testes also produce the hormone testosterone, which controls the development of male physical characteristics. The testes are located in an external pouch called the scrotum. Sperm mix with fluids. This mix of sperm cells and fluids is called semen.

Semen leaves the body through an organ called the penis. The male urethra The Endocrine System

runs through the penis. Semen and urine leave the body through the urethra. and Reproduction The role of the female reproductive system is to produce eggs and, if an egg is fertilized, to nourish a developing baby until birth. The organs of the female reproductive system include the , fallopian tubes, uterus, and vagina. The ovaries are located slightly below the waist, one on each side of the body. The ovaries produce both egg cells and hormones. One hormone, estrogen, triggers the development of some adult female characteristics. Each is located near a fallopian tube. The two fallopian tubes are passageways for eggs. Fertilization usually occurs in the fallopian tubes. Each month, one of the ovaries releases an egg. The egg moves through a fallopian tube, which leads to the uterus. The uterus, or womb, is a hollow muscular organ. If the egg has been fertilized, it remains in the uterus and begins to develop. The vagina is a muscular passageway leading to the outside of the body. The menstrual cycle is a monthly cycle of changes that occurs in the female reproductive system. During the menstrual cycle, an egg develops in an ovary. At the same time, the uterus prepares for the arrival of an . At the start of the menstrual cycle, an egg starts to mature in one of the ovaries, and the lining of the uterus begins to thicken. About halfway through the cycle, the mature egg is released from the ovary into a fallopian tube. This process is called ovulation. If it is not fertilized, the egg and the lining of the uterus break down. The extra blood and tissue of the thickened lining pass out of the body through the vagina. This process is called menstruation.

© Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.