Your Body’s Reproductive System Chapter 19

The Male Reproductive System Reaches maturity during early teen years The testes begin to produce testosterone (male sex hormone) Testosterone initiates physical changes such as broadening of shoulders, development of muscles, facial and other body hair, and deepening of the voice. Testosterone also causes the production of sperm (male reproductive cells) The Male Reproductive System

Testes: also known as testicles Two small glands that produce sperm 100 million a day Hang outside of the body in a sac called the scrotum The scrotum protects sperm by keeping the testes at a temp below normal body temp. Tight clothing around testes can interfere with sperm production.

External Male Reproductive Organs Penis: a tube shaped organ attached to the trunk of the body just above the testes. Composed of spongy tissue with many blood vessels With increased blood flow, the penis becomes enlarged and erect Erections can happen due to friction of clothing, for not reason at all, or because of sexual arousal External Male Reproductive Organs

At the height of sexual arousal, a series of muscular contractions known as ejaculation may occur. During ejaculation, semen-a thick fluid containing sperm and other secretions- is propelled from the penis. If this happens during sexual intercourse, fertilization may be initiated. Fertilization is the union of a reproductive cell from a male and one from a female.

External Male Reproductive Organs Circumcision – surgical removal of the foreskin covering the tip of the penis This is usually a parental decision that happens at the birth. External Male Reproductive Organs

Internal Male Reproductive Organs Urethra – moves liquid waste Epididymis – large coiled tube connected to the tubes in the testes. It is a temporary storage facility for sperm. Sperm mature here. Vas deferens – pair of connecting tubes that lead to the seminal vesicles and the prostate gland. Thick muscular walls of the vas deferens propel sperm forward then it is combined with a fluid produced by the seminal vesicles. Internal Male Reproductive Organs

This fluid contains nutrients and mixes with the sperm to make it more mobile. Vas deferens and seminal vesicles meet to form the ejaculatory duct.

As the sperm continues to travel, it is then mixed with fluid from the prostate gland (small gland that surrounds the urethra) and fluid from the Cowper’s glands (located below the prostate gland). Semen is now formed. Semen and urine leave the body via the urethra.

Care of the Male Reproductive System Cleanliness Shower daily Clean the penis and scrotum Uncircumcised males must practice extra hygiene Protection Wear a protector or supporter during strenuous activity to help shield the groin Self-examination Monthly to check for signs of cancer Lumps, thickenings, or change in texture or size of testes Care of the Male Reproductive System

STDs Inguinal hernia – near the top of the scrotum – sometimes the abdomen can tear and part of the intestine pushed through. Surgery is necessary. Sterility – inability to reproduce Enlarged prostate gland – caused by infections, old age, or tumors Prostate cancer – 2nd highest incidence of cancer in males Cancer of the testes – occurs frequently in males 15-35 in the U.S. First sign is slight enlargement of one testicle. Problems

The Female Reproductive System Ova – female reproductive cells Sperm enters through the vagina- a muscular, elastic passageway that extends from the uterus to the outside of the body Ova are stored in the ovaries- the female sex gland The two ovaries are located in the lower abdominal area The Female Reproductive System

Ovulation – process of releasing one mature ovum each month When a mature ovum is released, it moves into the fallopian tubes- pair of tubes with fingerlike projections that draw the ovum in.

Fertilization occurs in the fallopian tubes Zygote – cell that results from the union of an ovum and sperm Uterus – small, pear-shaped, muscular organ where the zygote travels to and attaches itself

If the ovum does not become fertilized then the lining of the uterus breaks down into blood, tissue, and fluids which pass through the cervix- neck of the uterus Menstrual flow happens once a month and lasts 3-5 days After the menstrual cycle ends, the process begins again. The uterus lining thickens again preparing for the possibility of receiving a fertilized egg. Most females start between the ages of 10 and 15 The menstrual cycle may be irregular at first Poor nutrition, stress, and illness can affect the cycle Menstruation

Care of the Female Reproductive System Cleanliness Vagina is a self-cleansing organ Slight vaginal discharge is normal Especially important during menstrual cycle Sanitary napkins (pads) and tampons must be changed every few hours Breast examinations are important Should be done once a month In the shower, in front of a mirror, or lying down Care of the Female Reproductive System

Problems Menstrual Cramps – abdominal cramps Premenstrual Syndrome (PMS) – several days to 2 weeks before the menstrual period Nervous tension, mood swings, irritability, anxiety, depression, fatigue, etc Toxic Shock Syndrome (TSS) – rare but serious disease that may be fatal Presence of the bacterium Staphylococcus aureus Signs include aching muscles, bloodshot eyes, sore throat, fever, vomiting, rash, etc Problems

Problems That Can Cause Infertility Blocked Fallopian Tubes – leading cause of infertility Endometriosis – uterine tissue grows outside of the uterus Pelvic Inflammatory Disease – infection of the fallopian tubes, ovaries and surrounding areas. Usually caused by STDs Ovarian cysts – fluid-filled sac on the ovary Cervical cancer – early sexual activity and family history are related to an increased incidence of cervical cancer Pap tests help detect Problems That Can Cause Infertility