Cardiovascular System

The cardiovascular system begins its activity when the fetus is barely 4 weeks old and is the last system to cease activity at the end of life. This body system is so vital that its activity helps define the presence of life.

The heart, arteries, veins, and lymphatics form the cardiovascular network that serves the body's transport system. This system brings life-supporting oxygen and nutrients to cells, removes metabolic waste products, and carries hormones from one part of the body to another.

The cardiovascular system, often called the circulatory system, may be divided into two branches: pulmonary and systemic circulations. Inpulmonary circulation, blood picks up oxygen and liberates the waste product carbon dioxide. Insystemic circulation(which includes coronary circulation), blood carries oxygen and nutrients to all active cells and transports waste products to the kidneys, liver, and skin for excretion.

Circulation requires normal heart function, which propels blood through the system by continuous rhythmic contractions. Blood circulates through three types of vessels: arteries, veins, and capillaries. The sturdy, pliable walls of the arteries adjust to the volume of blood leaving the heart. The aorta is the major artery arching out of the left ventricle; its segments and sub-branches ultimately divide into minute, thin-walled (one cell thick) capillaries. Capillaries pass the blood to the veins, which return it to the heart. In the veins, valves prevent blood backflow.

PATHOPHYSIOLOGIC MANIFESTATIONS

Pathophysiologic manifestations of cardiovascular disease may stem from aneurysm, cardiac shunts, embolus, release of cardiac enzymes, stenosis, thrombus, and valve incompetence.

Aneurysm

An aneurysm is a localized outpouching or dilation of a weakened arterial wall. This weakness can be the result of either atherosclerotic plaque formation that erodes