The Cardiac Cycle Flashcards
What are the two types of valves in the heart?
The atrioventricular valve and the semilunar valve
Where does the aorta supply blood to?
The body
Where does the pulmonary artery supply blood to?
The lungs
What type of blood does the right side pump?
Deoxygenated blood - to the lungs
The left ventricle has thicker/thinner walls? Why?
Thicker, because it has to contract powerfully to pump blood round the whole body
The atria have thicker/thinner walls? Why?
Thinner, because they just need to push blood a small distance
What do the atrioventricular valves link?
The atria and ventricles, to stop blood backflow
What do the semilunar valves link?
The ventricles to the pulmonary artery and aorta
What is systole?
Contraction
Blood returns to the heart during atrial systole due to…
The action of skeletal and gaseous exchange muscles as you move and breathe
What pressure is blood under as it flows into the atria (atrial systole)
Low pressure
As the atria fill during atrial systole, what happens to the ventricles?
The pressure of blood against the atrioventricular valves pushes them open and blood leaks into the ventricles.
When do the atria walls contract, forcing more blood into the ventricles?
During atrial systole
During ventricular systole what part of the heart contracts?
The ventricles contract, increasing the pressure in the ventricles, pushing blood up and out through the arteries and aorta
The pressure of blood against the atrioventricular valves opens/closes them during ventricular systole? Why?
It closes them, to prevent blood flowing backwards into the atria
During diastole what do the atria and ventricles do?
Relax
How is pressure lowered in the atria and ventricles during diastole?
Elastic recoil of the relaxing heart walls
Is blood under higher/lower pressure in the the arteries (diastole)?
Higher pressure, so its drawn back towards the ventricles, closing the semilunar valves and preventing further backflow
What arteries fill during diastole?
Coronary arteries
How are the coronary arteries filled during diastole?
Low pressure in the artria helps draw blood into the heart from the veins
