Cardiac physiology flashcards
End diastolic volume
amount of blood in ventricle at the end of ventricular filling
End systolic volume
amount of blood remaining in the ventricle at the end of ventricular contraction
stroke volume
output during a single heart beat; SV = EDV - ESV
cardiac output
blood volume circulating per minute; CO = SV x HR
total peripheral resistance (TPR)
amount of resistance to blood flow in the vascular system
TPR = PVR
systemic blood pressure
pressure exerted on the vessels in the systemic system, often calculated by arterial pressure
SV x HR x TPR
SV x HR x PVR
CO x PVR
ejection fraction
percentage of blood ejected from the heart during ventricular systole/ventricular contraction
EF = SV / EDV
Mean arterial pressure (MAP)
average arterial pressure throughout one cardiac cycle
1/3 systolic + 2/3 diastolic
Normal: 70-100
Low: <60
High: >160
RAAS effects own MAP
aldosterone increases sodium reabsorption leads to increased plasma volume; angiotensin II leads to smooth muscle contraction which leads to vasoconstriction
Autonomic system effects on MAP
baroreceptors in carotid sinus and aorta leads to effect on cardiac output; also affects SVR which can cause vasoconstriction to increase SVR
SA node bpm
60-100 bpm
AV node bpm
40-60 bpm
His-purkinje fiber system bpm
20-40 bpm
Contractile cells
contain actin, myosin, troponin, tropomyosin
sarcoplasmic reticulum
Signal is propagated through ____
gap junctions
