stroke volume, heart rate and cardiac output

what is the stroke volume and what is the resting stroke volume

the volume of blood pumped out by the left ventricle per beat

70ml

what is cardiac output

the volume of blood pumped out the left ventricle per minute

what does stroke volume depend on

• venous return - the volume of blood returning to the right side of the heart

• the elasticity of cardiac fibres - the degree of stretch of cardiac tissues during diastole, the more cardiac fibres the greater the ejection fraction

what is ejection fraction

the amount of blood pumped out of the ventricle vs total amount of blood in the ventricle 

what is myocardium

the middle layer of the heart

what happens during exercise

• demand for O2 by muscles increases

• the role of CV system is to increase oxygen supply to working muscles so they can continue to work aerobically

cardiac output formula and what are they all measured in

SV x HR = Q

SV = ml

HR = bpm

Q = L

what are features of submaximal intensity

• low to moderate

• aerobic

• longer duration

what are features of maximal intensity

• high intensity

• anaerobic

• fatigue

what is a regular resting heart rate

60 - 72bpm

what is a regular submaximal heart rate

100 - 130bpm

what is a regular maximal heart rate

220 - age

what is bradycardia

when the heart does not have to beat as often so resting heart rate will decrease, below 60bpm

what is starlings law

• SV of heart will increase if there is an increase in end diastolic volume

• the heart can contract with more force when the volume of blood returning to the heart increases

what are the steps of starlings law

1. increased  venous return 

2. greater  diastolic filling  of the heart

3.  cardiac muscles  ( myocardium ) are stretched

4. more force of contraction

5. increased  ejection fraction