Fundamentals of Anatomy and Physiology

478 Chapter 1 9

health Alert

Infertility continued

hormone (which causes sperm cells to

mature) and leutenizing hormone, and low

testosterone levels also reduce sperm cell

counts. Fertility can also be reduced due to

abnormal sperm cell development.

Female infertility occurs in 10% of

women. This can be caused by a number of

factors such as obstruction of the uter-ine or

fallopian tubes, a diseased ovary or conditions

that prevent implantation of the

fertilized egg into the uterine wall lining, and

reduced hormone secretions from the ovaries

and pituitary gland.

Today, there are numerous techniques

utilized to assist infertile couples to have a

child. One includes collecting and concen-

trating the male’s sperm cells from several

ejaculations and introducing them into the

female reproductive tract via artificial

insemination.

As the Body Ages

The reproductive systems of both sexes mature at puberty, which begins earlier in

females at about age 10 and a year or so later in males. Prior to that time, the

system is in its juvenile or immature state.^

For females, the reproductive cycle occurs once a month from menarche (the

first menstrual cycle) to menopause (the cessation of the cycle). Meno-pause in

women varies, occurring somewhere between the mid 40s and 50. The number of

follicles decreases dramatically until very few remain. This re-sults in a decrease in

the female sex hormones estrogen and progesterone. The^

lining of the uterus becomes quite thin, and the uterus decreases in size over time. The wall of

the vagina thins with less production of mucus, the connective tissue becomes more elas-tic, and

the vaginal opening narrows. Sexual excitement during intercourse takes longer to develop, but

sexual desire does not decline in any major way.

During menopause, many women experience hot flashes with profuse sweating. In addition,

women may experience depression, mood swings, weight gain, inability to sleep, and headaches.

About 10% of all women will experience some form of breast cancer. Risk is greater for those

women with a history of breast cancer in their family. This type of cancer risk increases between

the ages of 45 and 65. The risk for uterine cancer peaks at age 65 but cervical cancer is more

common in younger women. Ovarian cancer is the second most com-mon cancer in older

women.

For males, the change in the reproductive system is not as dramatic as it is in females.

Healthy males can still produce sperm well into their 80s and have been known to father chil-dren

well into their 60s. Some men do experience a small decrease in the size of their testes, but

sperm cell production does not cease.

After the age of 60, approximately one-third of males experience an enlargement of the

prostate gland. This is known as benign prostatic hyperplasia (BPH). This enlargement

compresses the prostatic urethra, resulting in difficulty in urination. These males experience

frequent urinations with small amounts of urine, a decrease in the strength of the urinary stream,

occasional bed-wetting, and a sense of incomplete voiding. Approximately 15% of