Page 150 - 84 human physiolofy part-1

Chapter 8

drugs, or disease.

Systolic Pressure

Systolic Pressure is the highest when the blood is being pumped out of the left ventricle into the
aorta during ventricular systole. The average high during systole is 120 mm Hg.

Diastolic Pressure

Diastolic blood pressure lowers steadily lowers to a low of 80 mm Hg during ventricular diastole.

Cardiovascular Disease

Cardiovascular disease refers to the class of diseases that involve the heart and/or blood vessels
(arteries and veins). While the term technically refers to any disease that affects the cardiovascular
system, it is usually used to refer to those related to atherosclerosis (arterial disease). These conditions
have similar causes, mechanisms, and treatments. Over 50 million Americans have cardiovascular
problems, and most other Western countries face high and increasing rates of cardiovascular disease. It
is the number 1 cause of death and disability in the United States and most European countries. By the
time that heart problems are detected, the underlying cause (atherosclerosis) is usually quite advanced,
having progressed for decades. There is therefore increased emphasis on preventing atherosclerosis by
modifying risk factors, such as healthy eating, exercise and avoidance of smoking.

Hypertension

Hypertension or high blood pressure is a medical condition wherein the blood pressure is
chronically elevated. Persistent hypertension is one of the risk factors for strokes, heart attacks, heart
failure and arterial aneurysm, and is a leading cause of chronic renal failure

Atherosclerosis

Atherosclerosis is a disease affecting the arterial blood vessel. It is commonly referred to as a
"hardening" or "furring" of the arteries. It is caused by the formation of multiple plaques within the
arteries. Arteriosclerosis ("hardening of the artery") results from a deposition of tough, rigid collagen
inside the vessel wall and around the atheroma. This increases the stiffness, decreases the elasticity of
the artery wall. Atherosclerosis typically begins in early adolescence, is usually found in most major
arteries, and yet is asymptomatic and not detected by most diagnostic methods during life. It most
commonly becomes seriously symptomatic when interfering with the coronary circulation supplying
the heart or cerebral circulation supplying the brain, and is considered the most important underlying
cause of strokes, heart attacks, various heart diseases including congestive heart failure and most
cardiovascular diseases in general.

Plaque

Plaque Atheroma or commonly known as plaque is an abnormal inflammatory accumulation of
macrophage white blood cells within the walls of arteries.

150 | Human Physiology