L8 - integrative cardiovascular, and cardiac responses to e. Flashcards
aerobic power and fitness depend on…
increase CO
how much carry arterial oxygen
redistribution of blood flow to active muscles. (to support active muscles.
extract oxygen from blood in those muscles (equally locomotive and respiratory)
where do females and elite athletes suffer in VO2 = CO x (CaO2 - CvO2)
the a-vo2 difference. as you can carry as much as you can carry and it will not increase.
which side of the heart is thicker
left side as it has to create more pressure to get around the whole body.
electrical properties of the heart.
autorhythmicity -beat by itself from the nodes
long AP - seperate contractions, governing the timing of contractions
electrical conduction system - coordinating the hearts contractions
metabolic profile of the heart.
lots of mitochondria.
uses mainly fatty acids at rest
lactate under hard exercise.
cardiac cycle
systole (contraction)
diastole (relaxation)
isovolumetric phases.
duty cycle at rest vs at ex
the systole will be shorter at rest than diastole to ensure enough blood will fill. whereas in exercise the systole will be longer to get the blood out asap.
Sex & fitness differences in Cardiac Output
in submax exercise:
5-10% lower in trained.
5-10% higher in females (less oxygen in each ml of blood)
in max exercise
can increase 4-5 times in untrained, versus 6-8 times in trained.
max CO around 20% higher in males (they need more more muscle mass and they have testosterone.
STROKE VOLUME response with exercise TIME
SV will increase as soon as our body anticipates e, sympathetically opens crucial veins to carry blood + ventricles release more blood. Then platuaes
athletes will have higher SV (stronger and larger heart)
less rise in arm exercise. (higher blood pressure after load decreasing SV)
STROKE VOLUME response to exercise INTENSITY
athletes can have a higher SV at rest. allowing them to have a lower HR. They can keep the increased SV over bigger range of intensity.
elite - increase SV around 100% VO2 max
untrained- 40%
how does the preload affect stroke volume
How much you can pump relies on how much you have preloaded your ventricle.
HR response with e time.
rapid increase to large plateau. As decrease PNS to SA node and increase SNS.
as athletes have a higher SV they do not need a high HR.
more rise in arm exercise as more SNS activity
HEART RATE response to exercise INTENSITY
linear untill 100% VO2max.
basis of submaximal intensity tests.
athletes will have a lower HR at rest and less HR rise as a function of absolute workrate
athletes and untrained will reach similar HR but athletes at a much higher workrate.
HR with age, relationship and why?
linear effect. your max will decrease (equation)
decrease in muscle qaulity and valve stiffness (more pressure when pumping the blood out)
major component of lower CO with age.
factors that effect HR in E.
mostly the SA node (depolarisation rate)
PNS will come off progressively whereas SNS will come on progressively.
small effect is heat - if your heart is hotter your heart will beat faster as the SA node will reach threshold faster.
