How the Human Heart WorksBy Maia R. 2012

The heart has many purposes in the body. It pumps blood to every inch of your body to keep it alive. The heart is so important that you can’t live without it. Did you know that people in Ancient Egypt did not think the heart was important? Learn more about the amazing human heart in this awesome report.

What is the Heart?

The human heart is a hollow cone-shaped muscle. The heart is slightly larger than a fist and it weighs about 8 to 12 ounces when you are an adult. It is slightly to the left side of your body. The heart is held in place by all the veins and arteries attached to it. The heart’s job in the body is to pump blood, oxygen, and nutrients to all parts of the body. It is the most important organ in the entire body. The heart never stops pumping blood nor does it ever tire of pumping blood.

The Structure of the Heart

The heart is sort of like a tilted house; it has two floors divided into four rooms (chambers) and two front doors (valves) and many other doors (valves). The upper chambers are called the atrium chambers and the lower chambers are called the ventricle chambers. Between the lower and upper chambers there are valves that work like one way doors. The heart is supported by a muscle called the septum. The septum is located in between the two sides of the heart. The two sides of the heart work to pump blood to different places. The left side pumps blood to everywhere in your body except the lungs when the right side of the heart pumps only to the lungs. Seeing that the left side of the heart pumps to everywhere in the body, it has a lot more work than the right side. The left side is stronger and it has walls that are thicker. The left side pumps blood with six times the force than it does on the right side. The heart is the main organ in the cardiovascular system. The heart is made out of a muscle called the cardiac muscle. The heart is the only place you can find the cardiac muscle in the body.
how the heart works m.r science diagram.jpg
Figure 1 How the Human Heart Works

How the Heart Works

This is how the heart works. A valve opens and lets the blood into the heart. A valve called the tricuspid valve opens and closes so the blood in the right atrium (the right top chamber) flows to the right ventricle (bottom right chamber). Then the electricity in the sinus node is released making the heart contract pushing the blood out of the heart and into the pulmonic valve. The pulmonic valve leads to the pulmonary artery valve. The blood goes into tubes called blood vessels that go around and give blood to all of your body. The valves slams shut during that process and it happens all over again. This process is called a heart pump. Your heart pumps 100,000 times every day. The sinus node is like a battery. It releases electricity that contracts the heart pushing the blood out of the body. It puts out electricity 70 to 80 times a minute. The heart works basically the same way as a gas pump. It pumps blood into your body so you can do anything you want.

Exercising the Heart

When you do activities like soccer, football, swimming, running, and brisk walking you are doing endurance exercises.Endurance exercises are exercises that make your heart beat faster. By doing that you make your heart stronger. You are supposed to do at least 20 minutes of endurance exercises at least four days a week. Exercise lowers the chances of having high blood pressure. High blood pressure is a big reason why people have heart attacks. If you exercise it lowers the chances of heart attacks which is obviously a good thing. Once you get past the age of 30, your heart slows down its beating rate by eight percent each decade. That is why it is so important that adults exercise because if they don’t their heart will get very weak.

hearts running.gif
Figure 2 Hearts Running

Blood, Cells, and Plasma

The heart, blood vessels, and blood work together to supply cell with things they need. You have red cells and white cells and platelets that make up your blood. All the cells float around in a pale gold clear-like liquid that is called plasma. Plasma makes up a little more than half our bodies. Plasma is mostly water but also has a lot of proteins, minerals, and sugars used to fix cells. Plasma carries around nutrients from digested food to cells so they can use them as fuel. Plasma is a liquid which means it can pass through tiny blood vessels to the cells. Blood plasma can help control your body temperature by moving heat from the center of the body to the outer edges of the body. Red blood cells are the most common cells. People have about 25,000,000,000 red cells. That means we have hundreds of more cells in our body than stars in the Milky Way. We have hundreds of billions of cells in our body. Red blood cells contain chemicals called hemoglobin that when combined with oxygen, they turn red. That is why your blood is red. Red blood cells are made in bone marrow.


Atrium Chamber: Blood passes through it into the ventricle.
Cardiovascular System: The cardiovascular system is a system that involves the heart and blood vessels.
Endurance: Is the ability to do stuff that tires your body but be able to remain active for long periods of time.
Hemoglobin: Hemoglobin is iron that has oxygen in it.
The Pulmonary Artery Valve: The Pulmonary Artery Valve is a valve that affects the lungs.
Sinus Node: The Sinus Node is like a battery. It lets out an electrical shock that pushes the blood out of the heart.
The Ventricle Chamber: The Ventricle Chamber is a chamber the blood flows into from the atrium chamber. The blood in this chamber goes into an artery (a large vein) that brings the blood to different parts of the body.


“Heart.” Britannica Elementary Encyclopedia. Encyclopaedia Britannica Omline School Edition. Encyclopaedia Brtannica, Inc.,1202.Web. 24 Sept. 2012
Henderson, Roger “How the Heart Works” netdoctor 2012. Web. 9/17/12.
Hurst, J. Willis The Heart: The Kids’ Question and Answer Book. New York: McGrawHill, 1999. Print.
Simon, Seymour The Heart: Our Circulatory System. New York: Morrow Junior Books, 1996. Print.