final exam concepts/terms: CV dynamics Flashcards
(30 cards)
anatomy of the heart
4 chambers
2 atria
2 ventricles
2 sides are separated by septum
anatomy of valves
pulmonary semilunar valve
aortic semilunar valve
left AV valve (bicuspid, mitral)
right AV valve (tricuspid)
cardiac cycle
atrial systole: atrial contraction forces blood into ventricles
EDV = max blood in ventricles (135mL)
“lub”
isovolumetric ventricular contraction: first phase pushes AV valves closed but does not open semilunar valves
ventricular ejection: semilunar valves open and blood is ejected as pressure rises
ESV = minimum amount of blood in ventricles (65mL)
isovolumetric relaxation: blood flows back into cups of semilunar valves as ventricles relax
‘Dub”
is blood found in the arteries always oxygenated?
not always
cardiac output equation
co = heart rate x stroke volume
what factors affect SV?
EDV, total peripheral resistance and contractility
Frank-Starling law
(a) is state of myocardial sarcomere just before filling
Actins overlap, actin-myosin interactions are reduced and contraction would be weak
In (b,c and d) there is increasing interaction of actin and myosin allowing more force to be developed
how does the ANS affect SV?
in fight or flight the vessels contract and in rest and digest they dilate
what does venous return refer to? how is it accomplished?
the rate at which blood flows from the body’s veins back into the heart
pressure gradient created between systemic venous system and right atrium
what is “total peripheral resistance”? what contributes to TPR?
the resistance the heart must overcome in order to pump blood
vessel diameter
blood viscosity
total vessel length
what is poiseulle’s equation and how is it derived?
Blood flow (Q) = ΔPr^4(π)/ηL(8)
flow = p/r
vessel length (L)
viscosity (n)
where does most peripheral resistance occur?
the arterioles
what can cause vasoconstriction? vasodilation?
vasoconstriction:
increased myogenic activity
increased oxygen
decreased co2
increased sympathetic stimulation
vasodilation:
decreased myogenic actiivty
decreased oxygen
increased co2
decreased sympathetic stimulation
what is MAP? how is it calculated? why is it important?
Mean Arterial Pressure
diastolic pressure + 1/3 pulse pressure (PP)
PP = systolic pressure - diastolic pressure
represents the average blood pressure throughout cardiac cycle
cardiac output
amount of blood pumped out by each ventricle in one minute
edv
volume of blood in ventricles at end of diastole
stroke volume
amount of blood pumped by each ventricle with each heartbeat, 70mL average for adult at rest
esv
minimum amount of blood in ventricles (65mL)
myocardium
middle muscular layer of heart wall
semilunar valve
heart valves that prevent blood from moving backwards into ventricles
bicuspid/mitral valve
aortic valve that contains only two cups or flaps instead of three
tricuspid valve
valve that separates the right atrium and ventricle
ventricular systole
when the ventricles pump out the blood
pulmonary artery
vessels that carry oxygen oor blood from the right side of your heart to the lungs
