Chapter 25

systemic circulation

rest of body, left heart, high pressure

pulmonary circulation

lungs, right heart, low pressure

compliance

C= volume/pressure

cardiac cycle

Av valves close - onset of systole

1st heart sound - lub

isovolumetric contraction

semilunar valves open

ejection (blood rushes to body and lungs)

semilunar valves close - onset of diastole

2nd heart sound - dub

isovolumetric relaxation

AV valves open

ventricles fill w blood

AV valves close

cardiac output

CO= HR X SV

3 parts of stroke volume

preload, afterload, contractility

preload

volume, before the heart, de O2 blood

afterload

resistance, work after the heart

contractility

force of a contraction

Frank Starling mechanism

greater preload, greater contractility TO A POINT

lymph

returns tissue fluid back to veins

arteries anatomy

thick b/c of tunica media, vasoconstrict and vasodilate

veins anatomy

thin, stretchy, has valves

baroreceptors

stretch-sensitive, monitor BP

chemoreceptors

oxygen-sensitive, pH