The circulatory system is made up of the heart muscle and the miles and miles of blood vessels that circulate blood throughout the body. It's one of the most vital components of the body when it comes to survival and normal function. The heart acts as the pump to move blood through the body, and the blood provides nutrients to and removes waste from virtually every cell throughout the body.
The heart is made up of four chambers: a right and left atrium and a right and left ventricle. The atria are the chambers that take blood in from the rest of the body, and the ventricles are the chambers that pump the blood back out into the body. A number of valves in the heart keep the blood flowing in the correct direction, into and out of the heart, from and back to the body.
Among the blood vessels, veins are the vessels that carry blood toward the heart, and arteries carry blood away from the heart. Arteries and veins get smaller and smaller as they branch out and subdivide into various portions of the body. The smallest veins, which exchange material with body tissues and cells and also connect the arteries to the veins, are known as capillaries.
Various problems can affect the circulatory system, but heart disease is a main one. Overall, heart disease is the No. 1 killer of both men and women in the United States. Other problems related to circulation include a heart attack, when the heart suddenly stops working, or a stroke, caused when a blood vessel bursts or gets blocked. Some individuals develop an arrhythmia, which is an irregular heartbeat, or have valve problems, when the blood does not pump properly through the heart. Heart failure occurs when the heart cannot pump enough blood to meet the body’s demands. And there are also diseases that directly affect the blood vessels of the body, such as peripheral artery disease. These are just a few of the many diseases that can affect the body’s circulatory system.
SOURCES: Heart Foundation; American Heart Association; U.S. National Cancer Institute