Transcript for Heart Anatomy1

About the size of your fist, the human heart is the most important muscle in the body.

It can beat more than 100,000 times a day.

pumping about 2,000 gallons of blood

through a 60,000 miles network of vessels in the body

The human heart is made up of four major chambers:

The right side of the heart receives blood

that is low in oxigen from veins all over the body.

It then comes the blood through the pulmonary arteries

into the lungs where they become reoxigenated.

The left part of the heart receives this oxigen-rich blood from the lungs

then it pumps the blood through the aorta

back up to the rest of the body through a complex network

of arteries, arterials and capillaries.

While blood is circulating through the body

it delivers oxigen and nutrients to tissue through the capillaries

and at the same time picks up carbon dioxide and other waste materials.

The veins return the dioxigenated blood to the right atrium

and the cycle begins again.

The heart has four valves

Each valve is like a one-way door

that keeps the blood in the heart flowing in the same direction.

The valves are made up of two or three small but strong flaps of tissue

called leaflets.

Leaflets open to allow blood to flow through the valve

and close to prevent blood from flowing backwards.

The opening and closing of the valves is controlled by blood pressure changes

within each heart chamber.

The tricuspid valve is positioned in the heart's right side

between the right atrium and right ventricle.

The pulmonic valve separates the right ventricle

from the pulmonary artery.

The mitral valve is positioned in the heart's left side

between the left atrium and the left ventricle.

The aortic valve separates the left ventricle

from the aorta.

As blood circulates through the heart

some of the blood flows into much smaller blood vessels

that provide blood directly to the heart.

These arteries called coronary arteries

surround or crown the heart

These separate circulatory system called

coronary circulation

keeps the heart nourished and oxigenated

The two main branches of the aorta that nourish the heart are the

right and left main coronary arteries

Coronary artery disease, which occurs when there is a build up of cholesterol plaque

affects the arteries of this circulatory system

and causes a decrease in blood flow to the heart muscle

resulting a possible damage to the heart or a heart attack.

The beating of the heart which at its rythm is regulated by electrical impulses

generated by your heart muscle.

These impulses begin in the Sinoatrial node

and cause your heart to contract.

Sometimes the Sinoatrial node is also refered to as your heart's natural pacemaker

since it keeps your heart beat constant and consistent

The impulses then travel to the Atrioventricular node

where the signal is checked and then sent through the ventricles

what causes them to contract.

Your heart rate can change based on external conditions

such as diet, exercise, stress or even hormonal factors.