An ongoing sequence of of contraction (systole) and relaxation (diastole) of the Atria and Ventricle to keep blood continously circulating round the body
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What factor changes the pressure? Give a description
The changes in chamber volume- decreasing the volume of a chamber by contraction will increase the pressure of a chamber
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What are the three stages the Cardiac cycle can be simplified to?
The Ventricles are relaxed the atria contracts. decreasing the volume of the chamber and increasing the pressure inside the chamber= pushes the blood into the ventricles
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Describe the second stage of the Cardiac cycle a)
The Atria relax the ventricles contract ( decreasing their volume) increasing their pressure. The pressure becomes higher in the V. than the A. which forces the A.V valves to prevent back flow
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Describe the second stage of teh Cardiac Cycle b)
The pressure in the Ventricles is also higher than in the aorta and pulmonary artery, which forces open the SL valves and blood is forced into the Arteries
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Describe the third stage of the Cardiac cycle a)
The Ventricle and atria but relax. The higher pressure in the P.A and Aorta closes the S.L valves to prevent back flow into the ventricles
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Describe the third stage of the Cardiac cycle b)
Blood returns to heart and Atria fill again due to high pressure in the Vena cava and the Pulmonary Vein+increases pressure in the Atria
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Descrive the third stage of the Cardiac Cycle c)
As the ventricles continue to relax the pressure falls below the pressure of the atria and so the AV valves open.This allows blood to flow passively ( without being pushed by Atrial contraction) into the V. from the A. Process happens again
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Other cards in this set
Card 2
Front
What factor changes the pressure? Give a description
Back
The changes in chamber volume- decreasing the volume of a chamber by contraction will increase the pressure of a chamber
Card 3
Front
What are the three stages the Cardiac cycle can be simplified to?
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