Heart Structure Notes

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Heart

Made of 4 chambers - 2 atria and 2 ventricles

Right atrium

receives deoxygenated blood from all parts of the body by the venae cavae

this deoxygenated blood passes into the right ventricle and leaves by the pulmonary artery to go to the lung

The blood becomes oxygenated in the lung and returns to the heart by the pulmonary veins into the left atrium then leaves by the aorta

AV valves

Allow blood to flow from atria to ventricles and prevents backflow from ventricles

Semi Lunar Valves

Open during ventricle contraction and allows blood to flow into the arteries

Cardiac Cycle

Is a pattern of systole and diastole

Diastole (relaxation)

Blood returns to the heart via the venae cavae and the volume of the blood in the atria increases

When the volume is larger than in the ventricles, the AV valves open and FLOW INTO THE VENTRICLES

Atrial Systole

the atria contract at the same time, they send the rest of the blood into the ventricles through the AV valves.

The ventricles fill and the SL valves stay shut.

Ventricular Systole

The volume of the blood in the ventricles is now greater than in the arteries.

So the SL valves are pushed open and blood is pumped out into the aorta and pulmonary arteries.