Redistribution of blood Flashcards
1
Q
Define vascular shunt
A
- The redirection of blood from one part of the body to an other.
2
Q
Redistribution of blood during exercise?
A
- During exercise the distribution of blood flow is different at rest compared to during exercise.
- During exercise, more blood is needed at the working muscles in order to provide them with O2.
- At rest: 15-20% is distributed to the muscles.
- During exercise: 80-85% is distributed to the muscles.
3
Q
Define vasodilation
A
- The widening of the blood vessels to increase the flow of blood into the capillaries.
- At muscles (require more O2), skin (temp regulation), coronary vessels (more O2 to the heart).
4
Q
Define vasoconstriction
A
- The narrowing of the blood vessels to reduce blood flow into the capillaries.
- Internal organs/ gut- not necessary during exercise.
5
Q
Redistribution of blood during exercise (pt.1)
A
- Increase in CO2 levels and acidity in the blood is picked up by chemoreceptors.
- Movement of joints is picked upby proprioceptors.
- An increase in blood pressure is picked up by the baroreceptors.
6
Q
Redistribution of blood during exercise (pt.2)
A
- Signals are sent from these receptors to the medulla oblongata which stimulates the vasomotor centre/ sympathetic nervous system. This begins a vascular shunt.
- This triggers vasodilation to areas that require the blood (muscles, skin and coronary vessels).
- And vasoconstriction to areas that do not require as much blood (internal organs).
7
Q
What are pre-capillary sphincters?
A
- They are rings of muscle that are located at the opening of capillaries.
8
Q
What do pre-capillary sphincters do during exercise?
A
- During exercise they will relax to allow more blood flow into the capillaries/ increase blood flow.
9
Q
Brain
A
- Blood flow to the bran remains the same at rest and during exercise.
- Oxygen is required to maintain brain function.
