CVS physiology 4 - cardiac cycle Flashcards
what is the first stage of the cardiac cycle
late distole= both sets of chambers are relaxed and the ventricles fill passivley
what is the second stage of the cardiac cycle
atrail synstole- where the atrial contaction and forces a small amount of blood into the venticles
what is the thirsd stage of teh cardiac cycle
isovolumnic ventricular contraction - whre the av vacles are closed but it does not create enough pressure to open the semilumanr valces(pulmonary valve and aeotora)
at what stage is end distolic voluem
end of isovolumic ventila contration
what is the 4th stage of the cardiac cycle
when the vencitla contraction - generates enough pressure to open the semilumanr valves and av remains closed
what is the 5th stage of the cardiac cycle
ventricular relaxation , pressue in the venticle sfals, blood flow back into the csps of the semiluar valces an snaps them closed.
what point is the end systolic vole
end of stage four whe bood sis elased semilunar valves
what happens to left ventricle pressure in a norla cardiac cycle
the left atrium will open will, the av valve will then open and push blood into the venticle causing an increase in pressure and then a dip as the atrium stops contracting and the mital valve colsoes, the ventrice will then contract and cause a large increase in ventrilce pressure causing the valve to open, this will continue to happen after the valve has opened. after most of the blood is removed the aorta val will close and the pressure will begin to decreaws, the resse will then decrease more until the fully back to zero , the mtria valve ones again
explain the change sin left atrium pressure
the mitral valve is open,first there is atrial contractio , increase the pressure, , then mitra valve closes, the mitral valve i spused back int the atrial valve cuas an incre in pressure than a decrea in pressure, then there is a increase in pressure as the atrium fills again until the mtiral valve opens and the atriaum decrease in presure
explain the changes in teh aterial pressure in the aorta
first ther is a decres in pressure as it relaxes, ,then the aortic valve opens, then it increase last pressure as it fills with blood from the ventilce, it increase until aorta is full and the venticle is as empty as necessary, it then decreas in pressure slightly and closes once the aeota is full, there is then an increase inpressure tod to the elasit recoil of the aeota, then the moral valve opens and it fully drains of bldo back to diastolic pressure
what is the mean arterial pressure and what is it rounly
average pressure of systoli and disstolic, 66% of dysotlic , 33% of systolic
what cause hte aeota to close
blood falling from back down to decrease presure
systolic pressure
pressure at maxium of the aorta
distoi prssue
minimu presure of the aeorat
what i sejection fraction
the ammount of blood in you heart that is pumped out with each heart beat
