The Human Heart
By: Eddie S.

This is a picture of a heart rate monitor, wich shows the heart rate of a person if they are in a hostpital.

The human heart is the main organ that pumps blood throughout the body, using itself, and the cardiovascular system.
After the blood passes through the heart, it gets pumped out from the body and more than a gallon of blood passes through the heart every minute.

The heart is about the size of a human fist, and on average, ways 8-10 ounces on an adult. It is made of very tough muscle, that muscle being cardiovascular muscle, not being found anywhere else in the body. The heart pumps blood throughout the body by squeezing and relaxing in a regular, monotonous rhythm, and we know this rhythm as the heartbeat. The heart squeezes and relaxes, and beats about 70 times per minute, and during an average lifetime, a heart will beat about two billion times.

The heart is divided by left and right halves, and they are divided by a thick muscle called septum. The halves also have upper and lower chambers, creating what we know as the four chambers. The upper chambers combined are called the atria, and just one by itself is named an atrium. The lower chambers are called the ventricles, and that is the only name for just one or both. The heart is protected by the lungs, and to protect the heart, it is surrounded by a thin tissue called pericardium.
The way that blood gets pumped through the body goes like this. Blood goes into the heart, through the right ventricle. Then the right ventricle pumps blood into the lungs, which forces the blood to release wastes like carbon dioxide, and at the same time, the lungs are filling the blood with oxygen. Then, the blood, now healthy and oxygen rich, gets pumped back into the heart through the left ventricle, and out through the rest of the body. Although this process sounds slow, it is actually almost instantaneous.

Diagram of the Heart

This is a diagram of the human heart, representing the four chambers of the heart, and the arteries and explaining the the veins

There are many problems that can occur with the heart, including irregular heartbeat, which is when that regular rhythm is no longer regular, and a heart attack, which is when a part of the heart muscle dies or stops working all together. That is why you should always exercise and make good choices with what you eat, so that you can keep your heart healthy. Also, you should just take care of yourself in general, which means not doing stupid things that could seriously injure you or damage your heart in a fatal way.

The system for carrying blood throughout the body consists of a series of veins, arteries, and capillaries. To control the blood flow, valves are attached to the atria and they open and close every so often. The job of the arteries is to carry blood out from the heart. The job of the veins is to bring blood back to the heart. Also, the arteries expand and contract to keep blood moving from the heart, and the veins contain small valves that prevent blood from flowing back to the heart. The capillaries do not have that important of a job; they just connect the veins and the arteries to the body’s tissue.

Many organs interact with the heart, blood and cardiovascular system, in order to keep the heart healthy and working properly. For example, many organs filter the blood to keep it healthy, like the kidneys, which get rid of things like minerals and water in the blood. Also, the heart and the other organs work to supply blood cells to particular places in the body.
When the force of blood in the blood cells and in the blood vessels gets too high, this creates high blood pressure, which can result in a stroke if not treated properly and immediately. This can also result in failure and or weakness of other organs in the body.
Extra Facts:
- The blood is made up of red and white blood cells
- Mammals, birds and humans are the only living things on earth that have four chambers in their heart, the rest have three, or just tubes for their heart
- The heart is an involuntary muscle, which means it does the things that it needs to do on its own, without any help from the person that the heart is in
- The heart never stops beating, unless it’s time
Works Cited:
Seymour Simon. The Heart, Our Circulatory System. New York City: Morrow Junior Books, 1996. Print.
Carol Ballard. The Heart and Circulatory System. Austin, TX: Steck Vaugn Company, 1997. Print.
T1 - Heart
Y1 - 2011
SO - Encyclopædia Britannica
Online School Edition
UR -
ER -
T1 - Cardiovascular System
Y1 - 2011
SO - Encyclopædia Britannica
Online School Edition
UR -