Heart and cardiac cycle Flashcards
what are the walls of the heart made of?
cardiac muscle
what is the purpose of having a heart
generate pressure to pump blood around body
overcome limitations of diffusion
for fast delivery of oxygen to cells
what is the function of coronary arteries and veins
coronary arteries carries deoxygenated blood into the vena cava
coronary veins carry oxygenated blood and glucose to the cardiac muscle for respiration
what is the order of the cardiac cycle
vena cava, right atrium, atrioventricular valve, right ventricle, semilunar valve, pulmonary arteries, LUNGS, pulmonary veins, left atrium, atrioventricular valve, left ventricle, semilunar valve, aorta.
when is the atrioventricular valve open and closed
open during atrial diastole (filling of the atria) to allow ventricles to fill up
stay open during atrial contraction so blood can flow from atria to ventricles
closed during ventricular systole to prevent backflow of blood into atria
what is the function of the valves in the heart
prevent backflow of blood
When are the semilunar valves open and closed
open during ventricular systole (ventricles - aorta + pulmonary artery)
closed during ventricular diastole to prevent backflow into ventricles
why is the left side of the heart bigger
contains more muscle
blood needs to pump a further distance
blood pressure is higher
right side only has to pump blood to the lungs
why are the left and right sides of the heart separated
oxygenated + deoxygenated blood do not mix
separated by a septum
blood can be umped at different pressures
what happens during diastole (relaxation)
atria and ventricles are relaxed
semilunar valves are closed
atrioventricular valves are open
blood moves from vena cava to the left atrium (some blood trickles into ventricles)
what happens during atrial systole
atria contract
atrioventricular valves are open
semilunar valves are closed
blood moves from atria to ventricles
what happens during ventricular systole
ventricles contract
atrioventricular valves are closed
semilunar valves are open
blood moves from ventricles to pulmonary artery/ aorta
