Cardiovascular physiology II Flashcards
What is found in the left and right sides of the heart?
An atrium and a ventricle, between them there is a one way valve called atrioventricular valves (AV)
What effect does pressure have on the valves?
Pressure opens and closes the valves: when pressure in the atricle is higher than the ventricle the valve opens. Blood flows from A –> V
What is systole contraction?
Repetitive contraction
What is diastole contraction?
Relaxation chambers
What are the 5 stages of contraction?
1) Late diastole: both chambers are relaxed and ventricles fill passively
2) Atrial systole: atrial contraction forces small amounts of blood into ventricles
3) Isovolumic ventricular contraction: ventricular contraction pushes the AV valves shut
4) Ventricular ejection: ventricular pressure exceeds arteries and semilunar valves open so blood is injected
5) Isovolumic ventricular relaxation: ventricles relax, pressure falls, blood flows back to cups of semilunar valves and snaps them closed
What are the semilunar valves?
3 cups at the base of aortas and pulmonary artery, preventing blood flow back to the heart
What are the 4 kinds of valves?
Biscuspid - left side, two skin flaps
Tricuspid - right side, three skin flaps
Pulmonary semilunar
Aortic semilunar
Which valves cause the ‘lubdub’ sound?
LUB: AV valve closing
DUB: aortic valve closing
What is cardiac output and its formula?
The amount of blood pumped in one minute, measuring heart performance
CO = stroke volume x heart rate
What is stroke volume?
The amount of blood ejected from a single heartbeat:
end diastic volume - end systolic volume
What is intrinsic regulation?
Response of ventricular muscle to end diastic volume
What is extrinsic regulation?
The effect of the hearts nerve supply on the hearts activity - ANS
