Flashcards in Regulation of stroke volume and heart rate Deck (12):
regarding stroke volume, what does starlings law state?
the energy of contraction Is proportional to the initial length of the cardiac muscle fibre
what is the afterload?
the load against which the muscle tries to contract
if the afterload increases, what will happen to the stroke volume?
increase in afterload = increase in aortic pressure = increase in TPR
therefore the ventricle will have to work harder to push the blood which will be less effective as it is using up more energy.
this results in a decrease in SV
afterload is set by the aortic pressure which depends on what?
what is the parasympathetic affect on stroke volume?
it has little effect because the vagus nerve doesn't innervate the ventricular muscle
does hypercalcaemia cause an increase or decrease in stroke volume?
does ischaemia cause an increase or decrease in stroke vol?
does hypocalcaemia cause an increase or decrease in stroke vol?
how does the heart compensate for a reduction in pumping ability?
the heart will compensate by working around a greater EDV.
this however results in a lower ejection fraction and reduced exercise capacitance
name a type of drug which causes a decrease in stroke volume?
heart rate X stroke volume = ?