L2 cardiac cycle

Question 1

pressures in the vena cava, aorta and pulmonary artery

Answer 1

vena cava - 0mmHg
aorta - 90mmHg
lungs - 25mmHg
-all relative to atmospheric pressure

Question 2

why is pressure in the blood flow important in the CVS

Answer 2

to make sure that the metabolic demands are met

Question 3

what is cardiac cycle

Answer 3

-alternating contraction and relaxation of the heart making a heartbeat each time

Question 4

what is diastole

Answer 4

-where the heart relaxes and blood fills in

Question 5

what is sytstole

Answer 5

-the heart contracts and ejects blood out

Question 6

what is cardiac output (CO) and eqn for it

Answer 6

CO is the pumping activity of the heart

- CO=SV x HR

Question 7

events leading to ejection or filling of blood

Answer 7

electrical events > contraction or relaxation . changes in pressure > volume changes

Question 8

events in the cardiac cycle regarding blood in systole and diastole

Answer 8

1. ventricular diastole so AV valve opens and aortic valve closed. blood flows in
2. atrial systole - blood goes in to the ventricles
3. isovolumetric contraction (ven systole )
4. ventricular ejection (ventricular systole 2) - blood ejected out
5. isovolumetric relaxation (ventricular diastole)
6. back to ventricular diastole where blood fills in

Question 9

events in the cardiac cycle regarding valves and pressure in systole and diastole

Answer 9

1. ventricular diastole- Pv < Partial so AV valve opens and Pv Partial so AV valve closes but the aortic valve still closed
2. ventricular ejection (ventricular systole 2) - Pv>Paortic so Aortic valve opens
3. isovolumetric relaxation (ventricular diastole) - all valves closes
4. back to ventricular diastole where blood fills in