heart is at the center of your circulatory system, which is a network of blood vessels
that delivers blood to every part of your body. Blood carries oxygen and other important
nutrients that all body organs need to stay healthy and to work properly.
heart is a muscle, and its job is to pump blood throughout your circulatory system.
How does my heart pump blood?
Your heart is divided
into two separate pumping systems, the right side and the left side.
right side of your heart receives oxygen-poor blood from your veins and pumps it to
your lungs, where it picks up oxygen and gets rid of carbon dioxide.
side of your heart receives oxygen-rich blood from your lungs and pumps it through
your arteries to the rest of your body.
The right atrium receives oxygen-poor blood from the body and
pumps it to the right ventricle through the tricuspid valve.
The right ventricle
pumps the oxygen-poor blood to the lungs through the pulmonary valve.
left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle
through the mitral valve.
The left ventricle pumps the oxygen-rich blood through
the aortic valve out to the rest of the body.
The left and right atria
are smaller chambers that pump blood into the ventricles. The left and right ventricles
are stronger pumps. The left ventricle is the strongest because it has to pump blood
out to the entire body. When your heart functions normally, all four chambers work
together in a continuous and coordinated effort to keep oxygen-rich blood circulating
throughout your body. Your heart has its own electrical system that coordinates the
work of the heart chambers (heart rhythm) and also controls the frequency of beats
How does my heart maintain its normal
The task of your heart is to pump enough blood to deliver a continuous
supply of oxygen and other nutrients to the brain and the other vital organs. To do
this, your heart needs to:
Regulate the timing of your heartbeat.
Your heart's electrical system controls the timing of the
pump. The electrical system keeps your heart beating in a regular rhythm and adjusts
the rate at which it beats. When the electrical system is working properly, it maintains
a normal heart rate and rhythm. Problems with this electrical system can cause an
arrhythmia, which means that your heart chambers are beating in an uncoordinated or
random way or that your heart is beating too fast (tachycardia) or too slow (bradycardia).
your heart muscle healthy. The four chambers of your heart are made of a special
type of muscle called myocardium. The myocardium does the main pumping work: It relaxes
to fill with blood and then squeezes (contracts) to pump the blood. "Contractility"
describes how well the heart muscle squeezes. After pumping, your heart relaxes and
fills with blood. The muscle must be able to relax enough so that it can fill with
blood properly before it pumps again. The health of your heart muscle affects both
its contractility and its ability to relax, both of which determine whether your heart
is able to pump enough blood each time it beats. Problems with the contractility of
your heart can be caused by problems with the muscle itself (such as a viral infection
of the heart muscle or an inherited heart muscle disorder) or by problems with the
blood supply to the heart muscle (such as reduced blood flow to the heart muscle,
called ischemia). Your heart muscle needs its own supply of blood because, like the
rest of your body, it needs oxygen and other nutrients to stay healthy. For this reason,
your heart pumps oxygen-rich blood to its own muscle through your coronary arteries.
blood flowing efficiently. Your heart has four valves that control the flow of
blood in and out of the chambers. There are valves between the atrium and the ventricle
on each side of your heart. There is also a valve controlling the flow of blood out
of each of your ventricles. The valves are designed to keep blood flowing forward
only. When each chamber contracts, a valve opens to allow blood to flow out. When
the chamber relaxes, the valve closes to prevent blood from leaking back into the
chamber and to allow the chamber to fill with blood again. A problem with your heart
valves can disrupt the normal flow of blood and cause problems for your heart.
Hoit BD, Walsh RA (2011).
Normal physiology of the cardiovascular system. In V Fuster et al., eds., Hurst's
The Heart, 13th ed., vol. 1, pp. 94-117. New York: McGraw-Hill.
ByHealthwise Staff Primary
Medical ReviewerRakesh K. Pai, MD - Cardiology, Electrophysiology Martin J. Gabica, MD - Family Medicine Adam
Husney, MD - Family Medicine Specialist Medical
ReviewerStephen Fort, MD, MRCP, FRCPC - Interventional
This information does not replace the advice of a doctor.
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