WOLGMC18_0130840833.QXD
5/19/04
12:58 am
Page 373
COMMON DISEASES AND DISORDERS OF THE CIRCULATORY SYSTEM
The following points summarize the basic differences between the arteries and veins:
■ All arteries carry blood away from the heart.
■ All veins carry blood back to the heart.
■ All arteries (except the pulmonary artery) carry oxygenated blood.
■ All veins (except the four pulmonary veins) carry deoxygenated blood.
Inactivity and Blood Circulation
When a patient is inactive, the blood circulation tends to slow down. The patient may also
have a lower blood pressure (force of the blood pushing against the walls of the blood vessels). Sometimes this can cause the blood to form clots. Blood clots are dangerous. Sometimes a clot flows with the blood and becomes lodged in the blood vessels of the lungs.
This condition, called a pulmonary embolism, is life threatening.
If you have orders to help a patient out of bed for the first time after an illness or after
surgery, remember that the patient’s circulation is slower and the blood pressure may be
lower. Therefore, be sure the patient moves carefully and slowly. Allow the patient to sit at
the edge of the bed and dangle the legs until the circulation stabilizes (comes back to normal). Then carefully help the patient to a standing position.
Sometimes this procedure will cause the blood to leave the brain suddenly, and the patient may be dizzy or feel faint. You may need more than one person to help you with the
patient. Be sure to check the patient’s activity restrictions with your supervisor.
The Circulatory System
and the Normal Aging Process
As a person grows older, the movement of blood through the body tends to slow down.
The heart muscle weakens, so the heart pumps with less force. It must work harder to
keep the blood moving, yet it works less effectively. Thus, the blood flow decreases. The
reduced output of the heart is one reason older people tend to tire more easily and have
less reserve energy than younger people.
The heart may change in size. If it works harder to circulate the blood through the vessels, the greater work causes this muscle to grow larger. (In general, muscles get larger when
they perform more work.) When some people age, they drastically reduce their physical activity. For such people, the heart may become smaller because it does not work as hard.
The blood vessels change as well. With age, they may harden and lose their ability to
stretch. This causes them to become narrow. Fatty deposits and other substances may clog
these narrowed vessels. Such changes further diminish blood flow and increase blood pressure. They also increase the risk of a blood vessel rupturing or becoming blocked. Thus,
changes in the blood vessels can bring about physical and mental problems.
Common Diseases and Disorders
of the Circulatory System
Among the diseases and disorders that most often affect the circulatory system are the
following:
■
■
Arteriosclerosis: The walls of the arteries become thicker with fatty deposits and less
elastic than they should be for the normal regulation of blood flow and blood pressure.
Angina pectoris: Heart pain that results from insufficient blood flow and oxygen to
the heart muscle.
373