Background Information on the Heart Lesson

Heart Diagram

Parts of the heart labeled in diagram. The heart is the life-giving, ever-beating muscle in your chest. From inside the womb until death, the thump goes on. The heart for the average human will contract about 3 billion times; never resting, never stopping to take a break except for a fraction of a second between beats. At 80 years of age, a person's heart will continue to beat an average of 100,000 times a day. Many believe that the heart is the first organ to become functional. Within weeks of conception the heart starts its mission of supplying the body with nutrients. The primary function of the heart is to pump blood through the arteries, capillaries, and veins. There are an estimated 60,000 miles of vessels throughout an adult body. Blood transports oxygen, nutrients, disease causing viruses, bacteria, hormones and has other important functions as well.

The heart is responsible for pumping blood through the blood vessels by repeated, rhythmic contractions. The heart is composed of cardiac muscle, an involuntary muscle tissue that is found only within this organ. The term "cardiac" (as in cardiology) means "related to the heart" and comes from the Greek word kardia, for "heart." It has a four-chambered, double pump and is located in the thoracic cavity between the lungs.

The circulatory system is extremely important in sustaining life. Unfortunately, even though Americans have many options to take care of their heart and circulatory system, the leading cause of death in the US is a direct result of an arterial system that has been slowly and progressively compromised by years of deterioration.

So Cardiovascular Disease would be....

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.

So what is Atherosclerosis you ask?

Atherosclerosis is a disease affecting the arterial blood vessel. It is commonly referred to as a "hardening of the arteries." It is caused primarily from fatty deposits of cholesterol and other material on the inner walls of the arteries. It is considered the most important underlying cause of strokes, heart attacks, various heart diseases including congestive heart failure and most cardiovascular diseases in general. As the walls of the coronary arteries narrow, the flow of oxygen-rich blood to the heart decreases. This then causes the part of the heart that is deprived of oxygen to die and eventually the heart cannot circulate the blood effectively.

Let's see what you've learned so far in this module! Complete the matching activity below:

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