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Heart Anatomy1

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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.

Video Details

Duration: 3 minutes and 29 seconds
Country: United Kingdom
Language: English
Views: 649
Posted by: lolaceituno on Sep 18, 2009

Description of the function of heart and its parts.

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