Untitled Deck Flashcards
What are thoroughfare channels?
Channels that take blood from terminal arteriole to postcapillary venule and bypass the capillary
What are metabolites that cause local vasodilation?
Adenosine, phosphate, lactate, pCO2, H-, K+
What are some factors that impact preload?
Venous return, skeletal muscle pump, respiratory pump, venoconstriction
Describe catecholamines throughout exercise.
They begin rising early and continue rising
Describe cortisol throughout exercise.
It peaks at the beginning but goes back down quickly
Describe glucagon throughout exercise.
It rises for about 90 minutes but then plateaus
What happens to SV with exercise?
It increases; preload is increased from greater venous return and sympathetic activation boosts contractility
What happens to HR with exercise?
It increases; this initially is due to PSNS withdrawal but then is due to sympathetic activation
Which has a greater impact on CO during exercise: SV or HR?
HR
How does flow to the brain change during exercise?
It doesn’t! This results in the overall percentage traveling to the brain to decrease
Flow to ___, ____, and ____ increases during exercise.
Skin, skeletal muscle, and brain
How does blood pressure/MAP change with exercise?
Systolic increases, and diastolic changes are ambiguous. The systolic increase raises MAP.
What does it indicate if SBP does not increase with exercise?
Mortality
What happens to SVR during exercise?
It drops
How does a-vO2 change during exercise?
It widens as venous O2 content falls. This means more oxygen is being extracted from the blood
What is the Fick equation?
Q = (VO2)/(CaO2-CVO2)
Is aerobic or anaerobic a ‘burst’ exercise?
Anaerobic
What is isotonic contraction?
Constant tension with muscle shortening
What is isometric contraction?
Muscle does not shorten
What is resistive training?
A combination of isotonic and isometric contraction
Chronically, how does the nervous system adapt to exercise?
Increased resting PSNS tone and decreased resting SNS
How does exercise impact resting BP and HR?
Lowers both
The compliance of the LV is ___ as an adaptation to exercise.
Increased
What does exercise do to myocardial capillary density?
Increases it
Describe the changes to the heart in athletes.
They have adaptive hypertrophy. There is no fibrosis and the ventricles are compliant, but increased preload, EDV, and SV at rest cause some hypertrophy
What are some complications of exercise?
Muscle avulsion, coronary event, sudden death
What is commotio cordis?
A blow/blunt impact at a vulnerable period in the electrical cycle (during T wave) can cause someone to go into v fib
