Cardiac Cycle Flashcards
How does atriaventricula systole occur
The atrial walls are relaxed and they stretch as they fill with blood when the pressure exceeds the pressure in the ventricle sthe av valve open and blood flows to the ventricle aided by gravity he ventricle walls are also relaxed so fill with boood reducing the pressure in the ventricle
What happens in atrial systole
The atrial walls contract which forces blood remaining in the atrium into the ventricle
What happens in ventricle systole
A short time after the pumping of the atrial the ventricle walls recoil and contract which increases the pressure pressure is higher in ventricles than aorta so av valves close this further increases pressure and blood is pumped forcefully the pressure in the aorta and pillory artery greater than the ventricle so av valves close to prevent backlog W
What are valves
Flaps of tough fibrous tissue which prevented the unwanted backflowof blood by closing to prevent undesired back flow of low pressure to high pressure
What does the semi lunar valves do
They prevent the back flow of blood when the ventricles contract and the pulmonary artery and aorta recoil it prevents the blood flowing back to ventricle when pressure exceeds than that of the ventricle
What do pocket valves do
Ensure when veins are squeezed blood continues to flow the right way
