Cardiovascular Physiology: Exercise Flashcards
how to calculate fick equation
Q x a-vO2
Cardiac output x difference between arterial and venous O2
The difference is the amount delivered
What is hyperemia
increased blood flow.
During exercise what happens to flow, CO, BP, metabolism
Flow increases (hyperaemia)
-vasodilation to heart and skeletal muscle
CO increases
-both HR and SV increase
BP maintained or increases
Active hyperaemia flowchart
metabolism increases -> release metabolic vasodilators (NO) ->arterioles dilate -> TPR decrease -> flow increases -> o2 and nutrient supply increases
process is to get more nutrients for higher metabolism
What is the metabolic vasodilator
nitric oxide (nitroglycerin)
What happens to the distribution of blood flow during exercise
flow to brain same
heart increases 5x
muscle increases 4x
viscera flow decreases
what happens to BP during increasing intensity exercise
systolic increases linearly
diastolic remains constant
what happens to variables on MAP = QxTPR during exercise
map and Q increase
TPR decrease
What is afterload
force required to overcome TPR
what happens to EDV and ESV during incremental exercise
EDV increases. ESV decreases.
more filling more emptying
what is preload?
increased contractile force needed by heart to push greater vol of blood in ventricle due to more filling
what is ejection fraction>
the PERCENT of blood that gets pumped out of heart.
SV/EDVx100
what chronic cardiovascular adaptations occur to training
systolic and diastolic BP decrease at rest and sometimes submax exercise.
for hypertensive people, decrease at rest is more extensive and there is always a decrease for submax exercise
How does the body allow very high BP during exercise
Central command: Feedforward data from brain to baroreceptors instruct them to adjust sensitivity range towards higher BP (up and to the right on the graph) .
Pressor reflex shifts the operating point of the baroreceptors. This is more optimal for controlling BP.
what happens to BP and HR during lifting heavy weights.
HR increases a little but MAP dramatically increases. this causes a strong pressor load on the heart.
what happens to BP during aerobic exercise
BP, systolic BP, SV increase proportionally. This causes more venous return and volume load on the heart.
what heart adaptations can a resistance trained athlete acquire over time
left ventricle CONCENTRIC hypertrophy as a result of pressor overload. allows for more contractibility. This does not affect ventricular volume.
what heart adaptations can an aerobic trained athlete acquire over time
left ventricular eccentric hypertrophy as a result of volume overload. This means that there is an increase in ventricular volume and some increase in left ventricle size and force.
What adaptations can happen to the cardiovascular system for an aerobic athlete
SV, Q, and VO2 maxes increases. Blood vol also increases
B/c SV increases, HR decreases for the same Q as before (Q= SVxHR)
Why does SV increase for a trained individual.
more filling, more emptying, more total L. ventricle vol, better EF
how does SV change during incremental exercise (SV vs. VO2 graph)
it increases then plateaus
what is the difference between physiological and pathological hypertrophy
their effects are similar but not the same.
Physiological hypertrophy is adaptive remodelling of the heart meaning the change assists the heart function. The thickening is proportional to the expansion of the cavity and the effect is completely reversible.
Pathological hypertrophy is a maladaptive remodelling of the heart. This means the adaptations impair heart function instead of improving it. The hypertrophy is primarily cell lengthening which creates longer and weaker cells. this effect is permanent.
how can cardiac remodelling be a risk factor for athletes?
often the differences between maladaptive and adaptive hypertrophy and their effects overlap. This can obscure a potential life threatening issue.
What are the most common CV related deaths in high performance athletes.
males: hypertrophic cardiomyopathy
females: congenital coronary artery anomalies
Males are 6.5 times more likely to suddenly die from CV diseases
