When blood travels through the pulmonary artery to the lungs, it passes through tiny capillaries that connect on the surface of the lung’s air sacs, called the alveoli.

Systolic pressure: This shows how much pressure the blood creates against the artery walls during systole.ĭiastolic pressure: This shows how much pressure is in the arteries during diastole. The high number is the systolic blood pressure, and the lower number is the diastolic blood pressure. When a person takes their blood pressure, the machine will give a high and a low number. Systole: The ventricles contract and pump blood out of the heart as the atria relax, filling with blood again.

Once the left ventricle is full, it contracts and pushes the blood back out to the body via the aorta.ĭiastole: The ventricles relax and fill with blood as the atria contract, emptying all blood into the ventricles.

The left atrium contracts, pushing the blood into the left ventricle.

Newly oxygenated blood returns to the left atrium via the pulmonary veins.

The left side of the heart receives blood from the lungs and pumps it to the rest of the body. In the lungs, the blood picks up oxygen and offloads carbon dioxide.

Once the right ventricle is full, it contracts and pumps the blood to the lungs via the pulmonary artery.The right atrium contracts, and blood passes to the right ventricle.The right atrium receives deoxygenated blood from the body through veins called the superior and inferior vena cava.The right side of the heart receives deoxygenated blood and sends it to the lungs. The atria and ventricles contract and relax in turn, producing a rhythmic heartbeat. The left and right sides of the heart work in unison. Learn more information about a “normal” heart rate here. But this can increase to 100 beats per minute (bpm) or more.

The rate at which the heart contracts depends on many factors, such as:Īt rest, the heart might beat around 60 times each minute.

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