Redistribution of blood Flashcards
What is vascular shunt?
The redirection of blood from one part of the body to another.
What is vasodilation?
The widening of blood vessels to increase blood flow.
What is vasoconstriction?
The narrowing of blood vessels to reduce blood flow.
Where does vasodilation occur?
Skin, muscles, and coronary vessels
Where does vasoconstriction occur?
The internal organs
How is vasodilation and vasoconstriction triggered?
- Chemo/baro/propio receptors detect a change and send signals to the medulla oblongata
- Stimulates the vasomotor centre
- This leads to a vascular shunt
- Triggers vasodilation to the skin, muscles, and coronary vessels
- Triggers vasoconstriction to the internal organs
What are pre-capillary sphincters?
Rings of muscle, at the opening of capillaries, that relax during exercise to increase blood flow
How much blood goes to the muscles at rest?
15-20%
How much blood goes to the muscles during exercise?
80-85%
Does blood flow to the brain change during exercise?
No, as oxygen is required to maintain brain functioning
Why shouldn’t athletes eat 2 hours prior to exercise?
As more blood will be redirected to the gut for digestion, therefore the muscles don’t receive as much oxygen and performance will decline.
Why is blood redistributed to the skin?
To cool down
Why is more blood directed to the heart during exercise? (venous return)
As it is a muscle so requires O2. It also requires more energy to beat.
