The blood enters the main pulmonary artery, which then branches into the right and left lung where the blood absorbs oxygen. The blood, now rich in oxygen, returns to the heart and enters the left atrium. It crosses the mitral valve into the left ventricle. Skip to main content. Home Heart. Heart explained. Actions for this page Listen Print. Summary Read the full fact sheet. On this page. The four chambers of the heart The heartbeat Blood vessels of the heart Heart disorders Symptoms of heart disease Where to get help.
The four chambers of the heart Your heart has a right and left side separated by a wall called the septum. The heartbeat Each atrium is connected to its ventricle by a one-way valve. Blood vessels of the heart The blood vessels of the heart include: venae cavae — deoxygenated blood is delivered to the right atrium by these two veins.
One superior vena cava carries blood from the head and upper torso, while the other inferior vena cava carries blood from the lower body pulmonary arteries — deoxygenated blood is pumped by the right ventricle into the pulmonary arteries that link to the lungs pulmonary veins — the pulmonary veins return oxygenated blood from the lungs to the left atrium of the heart aorta — this is the largest artery of the body, and it runs the length of the trunk. Oxygenated blood is pumped into the aorta from the left ventricle.
The aorta subdivides into various branches that deliver blood to the upper body, trunk and lower body coronary arteries — like any other organ or tissue, the heart needs oxygen.
The coronary arteries that supply the heart are connected directly to the aorta, which carries a rich supply of oxygenated blood coronary veins — deoxygenated blood from heart muscle is 'dumped' by coronary veins directly into the right atrium.
Heart disorders Some disorders of the heart include: coronary heart disease — fatty deposits or plaques build up inside one or more of the coronary arteries atherosclerosis. This narrows the artery. Unlike other types of muscle, cardiac muscle never gets tired. Your heart is divided into four hollow chambers.
The upper two chambers are called atria. They are joined to two lower chambers called ventricles. These are the pumps of your heart. One-way valves between the chambers keep blood flowing through your heart in the right direction. As blood flows through a valve from one chamber into another the valve closes, preventing blood flowing backwards. As the valves snap shut, they make a thumping, 'heart beat' noise. Blood carries oxygen and many other substances around your body.
Oxygen from your blood reacts with sugar in your cells to make energy. The waste product of this process, carbon dioxide, is carried away from your cells in your blood. Your heart is a single organ, but it acts as a double pump. The first pump carries oxygen-poor blood to your lungs, where it unloads carbon dioxide and picks up oxygen. It then delivers oxygen-rich blood back to your heart. The right ventricle pumps the blood to the lungs for a little freshening up.
In the lungs, carbon dioxide is removed from the blood and sent out of the body when we exhale. What's next? An inhale, of course, and a fresh breath of oxygen that can enter the blood to start the process again. And remember, it all happens in about a minute! When you go for a checkup, your doctor uses a stethoscope to listen carefully to your heart.
A healthy heart makes a lub-dub sound with each beat. This sound comes from the valves shutting on the blood inside the heart. The first sound the lub happens when the mitral and tricuspid valves close. The next sound the dub happens when the aortic and pulmonary valves close after the blood has been squeezed out of the heart. Next time you go to the doctor, ask if you can listen to the lub-dub, too. Even though your heart is inside you, there is a cool way to know it's working from the outside.
It's your pulse. You can find your pulse by lightly pressing on the skin anywhere there's a large artery running just beneath your skin. Two good places to find it are on the side of your neck and the inside of your wrist, just below the thumb. You'll know that you've found your pulse when you can feel a small beat under your skin. Each beat is caused by the contraction squeezing of your heart. If you want to find out what your heart rate is, use a watch with a second hand and count how many beats you feel in 1 minute.
When you are resting, you will probably feel between 70 and beats per minute. When you run around a lot, your body needs a lot more oxygen-filled blood. Your heart pumps faster to supply the oxygen-filled blood that your body needs. You may even feel your heart pounding in your chest. Try running in place or jumping rope for a few minutes and taking your pulse again — now how many beats do you count in 1 minute? Most kids are born with a healthy heart and it's important to keep yours in good shape.
Here are some things that you can do to help keep your heart happy:. Your heart deserves to be loved for all the work it does. It started pumping blood before you were born and will continue pumping throughout your whole life.
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