This key circulatory system structure is comprised of four chambers. One chamber on the right receives blood with waste from the body and another chamber pumps it out toward the lungs where the waste is exhaled. One chamber on the left receives oxygen-rich blood from the lungs and another pumps that nutrient-rich blood into the body.
The muscular wall of the heart has three layers. The outermost layer is the epicardium or visceral pericardium. The epicardium covers the heart, wraps around the roots of the great blood vessels, and adheres the heart wall to a protective sac. The middle layer is the myocardium.
The innermost layer, the endocardium , lines the interior structures of the heart. The left atrium and right atrium are the two upper chambers of the heart. The left atrium receives oxygenated blood from the lungs. The right atrium receives deoxygenated blood returning from other parts of the body. Valves connect the atria to the ventricles, the lower chambers. Each atrium empties into the corresponding ventricle below.
The ventricles are the two lower chambers of the heart. Blood empties into each ventricle from the atrium above, and then shoots out to where it needs to go. The inferior and superior vena cava bring oxygen-poor blood from the body into the right atrium. The pulmonary artery carries oxygen-poor blood from the right ventricle into the lungs, where oxygen enters the bloodstream.
An electrical system that stimulates contraction of the heart muscle. Search Encyclopedia. About the Heart and Blood Vessels The heart is the hardest working muscle in the human body. How the heart works The heart is a large, muscular organ that pumps blood filled with oxygen and nutrients through the blood vessels to the body tissues.
It's made up of: 4 chambers. Here is the process: The right atrium receives blood from the body. The left atrium receives blood from the lungs. This blood is rich in oxygen. These bring blood to the lungs, where oxygen enters the bloodstream, and then to the body: The inferior and superior vena cava bring oxygen-poor blood from the body into the right atrium. The pulmonary veins bring oxygen-rich blood to the left atrium. The aorta carries oxygen-rich blood to the body from the left ventricle.
A network of arteries and veins also carry blood throughout the body: Arteries transport blood from the heart to the body tissues. Cardiomyopathy is a disease in which your heart muscle weakens and has difficulty pumping blood. Read about its causes, risk factors, treatment, and…. Experts say there are a number of ways to make it easier to go to bed at a proper time, including when you exercise and when you eat. Left bundle branch block is a condition in which there's slowing along the electrical pathway to your heart's left ventricle.
Ejection fraction is a test that's used to determine the percentage of blood that leaves your left ventricle each time your heart beats. A new study of over 2. Experts say middle-aged people with iron deficiency have a higher risk of heart disease later. You can increase iron levels with diet and supplements. Health Conditions Discover Plan Connect. How Your Heart Works. Medically reviewed by Stacy Sampson, D. Heart chambers Heart valves Blood flow Crown Your heart The human heart is one of the hardest-working organs in the body.
Your heart is located underneath your sternum and ribcage, and between your two lungs. Blood flow through the heart. Read this next. Is It a Stroke or a Heart Attack?
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