Function of Heart Flashcards
Myocardium
Heart Muscle
Systole
Contraction
Diastole
Relaxation
Cardiac cycle
Atrial systole > Ventricular Systole > Diastole
Atrial Systole
Atria contract, pump blood to ventricles; AV valves open, ventricles relaxed
Ventricular Systole
Ventricles contract, AV valves closed, blood opens semi-lunar valves, blood-> pulmonary artery & aorta
Diastole
Atria and ventricles in diastole, blood -> atria, AV valves open, blood -> ventricles (period of filling atrium from body)
Sympathetic Stimulation (fight/flight)
SA node activity^; heart rate^ (chronatropic)
AV node conduction^; force of myocardium contraction^ (inotropic)
Chronatropic
heart rate^
Parasympathetic stimulation (feed/breed)
SA node activity v, heart rate v (chronotropic) ; AV node conduction v, no effect on strength of contraction
Sympatholytic =
Parasympathomimetic
Cardiac output
rate x stroke volume
1 min = ___L of blood
5L
heart can pump - x more blood when demand is higher
4-5x more
bigger size of person = ___ heart rate
slower
gender (M) = ____ heart rate
slower
age^ = ____ heart rate
slower
Starlings law of the heart
greater the stretch = stronger force of contraction
Inotropic effect
force of contraction^ without stretching
Left forward heart failure
less blood to body -> cyanosis
Left backward heart failure
blood backs up in lungs = pulmonary edema (fluid in lungs)
Right forward failure
can’t pump to lungs
Right backward failure
back up in body/systemic circulation (juggular vein distention); blood accumulates from liver, spleen, digestion; pitting edema ->)
Emphysema
hard for blood to be pumped into lungs;damage to air sacs in lungs; short breath
Myocardial infarcts
effects ability to pump= heart failure later
Chronotropic
V heart rate
