How Does The Heart Pump Blood?

If you fell asleep in biology class, learn how the heart pumps blood at MadeMan.  You undoubtedly know that the heart is one of your body’s vital organs (crucial to life), but you might not know that your heart is actually a muscle divided into four chambers: the upper atria and the lower ventricles that help it to pump and circulate blood through your veins . Every time your heart beats (approximately 100,000 times per day), it goes through this cardiac cycle.

The cardiac cycle begins with electrical impulses telling the heart to contract; this is called the "systolic" phase. (Systole is also the top number of your blood pressure reading.) During systole the heart pumps blood from the right atria down to the left ventricle. Both chambers then contract (simultaneously) to pump low oxygen blood out of the heart to circulate it throughout the body.

The opposite of systole is diastole (the bottom number on your blood pressure reading). During this stage of the cardiac cycle, the arteries fill with blood. Think of it like an ocean wave drawing back after crashing onto the shore.  The heart is sort of at rest while the low oxygen blood then flows back to the heart through the veins and enters the right atrium. This chamber empties blood through into the right ventricle.

During this stage in the cardiac cycle, the right ventricle pumps the low oxygen blood to the pulmonary valve (upper atrium) and then into the pulmonary artery. This is where blood becomes oxygenated. (Note: Oxygen is what gives blood its red pigment. Before your blood is oxygenated, it appears blue). Blood then travels through the pulmonary veins to the left atrium. From there it passes through the mitral valve and enters the left ventricle.

The left ventricle then pumps the (red) oxygen-rich blood out through the aortic valve and into the aorta. The aorta takes the blood and circulates it through the rest of the body. This intricate process occurs every time your heart beats.

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How the heart works

The heart in action