L17;C8 Flashcards
How is load and HR related? When one increases what happens to the other?
As load increases, Hr increases as well in accordance to power
What is the relationship with exercise and SV early on?
Stroke volume will increase rapidly early on and around 60% of maximal exercise it will plateau.
When O2 uptake increases pass 60% max exercise, what happens to SV?
It plateus and doesn’t keep increasing
What happens to SV compared to supine position and upright position?
During supine position, you have greater resting SV since there is no assistance with gravity, therefore HR decreases. But overall not as large increase in SV during exercise compared to upright since blood doesn’t pool in lower extremities
During upright, resting SV is less than supine, but once exercise starts there is a greater SV due to lower extremity need
As HR increases, what linearly increases with it?
CO
Explain what happens to elite athletes SV and HR? Why?
Elite athletes don’t decrease SV over time due to their fitness levels, they have maximal HR and lower resting HR levels
What are three factors that increase SV? Describe them
increase in Preload: EDVentrcular stretch (Frank starling mechanism—> an increase in stretch leads to an increase in contraction strength
Increase in Contractility: Inherent Ventricular Property—> Norepinephrine or epinephrine increases contractility. This is independent of EDV which increases ejection
decrease in Afterload: this is aortic resistance
Metabolically, CO stays the same through lying down and upright exercises, that means which two factors have to increase and decrease?
Heart rate and stroke volume
During resistance exercises, what has a periodically large increase?
MAP
What is the formula for MAP? Using Q?
Q x peripheral resistance
When there is less pressure to the heart, what happens to stroke volume?
Stroke volume will decrease
True or false: there is till O2 in venous blood.
True
