cardiovascular homestasis Flashcards
what is cardiac output
the volume of blood pumped out per ventricle
factors affecting heart rate
postitive chronotropic caffeine epinephrine negative chronotropic sedative beta blockers
what causes pressure changes
hypotension
hamorrhage
bainbridge reflex
when there is an increase in the blood volume HR increases
factors affecting stroke volume
preload
amount of the ventricles are stretched by the EDV
contractibility
ability of cardiac muscle to increase the strength of pumping
after load
force placed on the ventricle wall during ejection
precise stroke volume
end diastole vol -end systolic vol
preload
amount that the ventricles are stretched by the EDV
contractibility
ability of cardiac muscle to increase the strength of pumping
afterload
force placed on the ventricle wall during ejection
frank starling law
automatic reflex
volume of blood ejected by the ventricle depends on the volume present in the ventricle at the end of diastole
how does preload affect SV
increased venous return would increase SV
decreased venous return decreases SV
effects on blood volume
hypovolemic shock caused by:
blood loss
dehydration
what does the body do to compensate after hypovolemic shock
increases HR
vasoconstriction
Renin- angiotensin- aldosterone system
RAAS
renin released from the kidney
converts ANG to ANG
Angiotension converting enzyme to ANGII
ANGII is a vasoconstrictor (increases BP) and causes adrenal glands to release aldosterone (increases water reabsorption)
what inhibits angiotensin covertering enzyme
ACE inhibitors
