Anatomy of a Human Heart

Your heart does a lot of work to keep the body going. Learn about the organ’s amazing power and the functions of its many parts.

7:00 AM

Author | Michigan Medicine

Anatomy of heart beating

This story was updated on January 31, 2020. 

Each day, the average human heart beats about 100,000 times, pumping 2,000 gallons of blood through the body.

That's a lot of work for an organ no bigger than a large fist and weighing 8 to 12 ounces.

LISTEN UP: Add the new Michigan Medicine News Break to your Alexa-enabled device, or subscribe to our daily audio updates on iTunes, Google Play and Stitcher.

In fact, the heart does more physical work than any other muscle over a lifetime.

Located between the lungs in the middle of the chest, the heart pumps blood through the network of arteries and veins known as the cardiovascular system. It pushes blood to the body's organs, tissues and cells.

Blood delivers oxygen and nutrients to every cell and removes the carbon dioxide and other waste products made by those cells.

Blood is carried from the heart to the rest of the body through a complex network of arteries, arterioles and capillaries. Blood is returned to the heart through venules and veins.

( Michigan Medicine)

Parts of the human heart

The heart is made up of four chambers: two upper chambers known as the left atrium and right atrium and two lower chambers called the left and right ventricles.

MORE FROM MICHIGAN: Sign up for our weekly newsletter

It is also made up of four valves: the tricuspid, pulmonary, mitral and aortic valves.

  • The right atrium receives non-oxygenated blood from the body's largest veins — superior vena cava and inferior vena cava — and pumps it through the tricuspid valve to the right ventricle.

  • The right ventricle pumps the blood through the pulmonary valve to the lungs, where it becomes oxygenated.

  • The left atrium receives oxygenated blood from the lungs and pumps it through the mitral valve to the left ventricle.

  • The left ventricle pumps oxygen-rich blood through the aortic valve to the aorta and the rest of the body.

The coronary arteries run along the surface of the heart and provide oxygen-rich blood to the heart muscle.

A web of nerve tissue also runs through the heart, conducting the complex signals that govern contraction and relaxation. A sac known as the pericardium surrounds the heart.

The outer layer of the pericardium surrounds the roots of the heart's major blood vessels, and the inner layer is attached to the heart muscle.


More Articles About: Heart Health Cardiovascular: Diagnostics & Procedures Frankel Cardiovascular Center Cardiovascular: Preventive Cardiology Hospitals & Centers
Health Lab word mark overlaying blue cells
Health Lab

Explore a variety of health care news & stories by visiting the Health Lab home page for more articles.

Media Contact Public Relations

Department of Communication at Michigan Medicine

[email protected]

734-764-2220

Stay Informed

Want top health & research news weekly? Sign up for Health Lab’s newsletters today!

Subscribe
Featured News & Stories blood vessel up close with red cells and yellow inside
Health Lab
Drug candidate successfully treats atherosclerosis, fatty liver disease in large mammals 
A compound that was previously found to treat severe fatty liver disease also reduces atherosclerosis, a primary driver of cardiovascular death, in non-human primates. The drug candidate was developed at the University of Michigan.
woman pregnant sitting holding tea and glasses on brown hair
Health Lab
Revolutionizing prenatal care: new guidelines to transform 100-year model
The American College of Obstetricians and Gynecologists, which collaborated with Michigan Medicine teams, is recommending significant changes to the way prenatal care is delivered in the United States, according to newly released clinical guidance.
Health Lab
10-year-old becomes first child to receive total artificial heart in Michigan
Within 24 hours, Lev’Veon went from a healthy 10-year-old playing at his sister’s birthday party to flatlining in the intensive care unit. There was only one option to save him, but it involved a high risk surgery that had never been done on a child in the state: a total artificial heart implantation. He would then become among the smallest and youngest patients in the world to receive one.
Health Lab
How LASIK surgery can help athletes perform at their best
Laser eye surgery can help improve athletic performance. Learn about LASIK eye surgery, including what to expect, side effects, and typical recovery times.
Health Lab
LASIK vs. PRK: Which vision correction surgery is right for you?
Both eye surgeries have the same intent — though they are different. A Michigan Medicine ophthalmologist explains how he helps patients make the best choice.
congestive heart failure folder on desk
Health Lab
What is congestive heart failure?
A doctor talks about key facts and insight about congestive heart failure.