vascular shunt Flashcards
what is vascular shunt
This redirection of blood flow towards working muscles during exercise and away from non essential organs
how much blood is directed towards the organs at rest
80%
how much blood is directed towards muscles at rest
20%
what does vasodilate mean
it is when the arteriole is relaxed to allow blood flow
what does the percentage blood redistribution depend on
how hard we are working
what is the precapillary sphincters and what does it do
Blood flow to the capillary beds is controlled by this
These are little muscle rings at the end of arterioles and these either:
what are arterioles
blood vessels that lead to capillary beds, which is where gaseous exchange occurs.
what happen to the distribution of blood during exercise
it switches and 80% goes to working muscles meaning 20% goes to vital organs
what are the 3 types of receptors
chemoreceptors, baroreceptors and propriorecptors
what is vasoconstriction
when the arterioles contract to restrict blood flow
what are the roles of the 3 receptors
Chemoreceptors (chemical changes)
-detect lactic acid and CO2 increases & –decreases in O2
-Detect a drop in blood pH
Baroreceptors (pressure changes)
-Detect increase in Blood Pressure
Proprioceptors
-Detect changes in movement
where is the vcc located
in the medulla oblongata where its receives info
what is the vcc
vasomotor control centre
how does the VCC send information to make the arteries vasoconstrict and vasodilate
the sympathetic nervous system
what happens if their is an Increase sympathetic stimulation
INCREASED vasoconstriction
how does the blood get redistributed during exercise( the systems)
-The Sympathetic Nervous System sends a signal via the sympathetic nerve, which constricts the Precapillary Sphincters & arterioles at the organs.
-But they vasodilate at the Precapillary Sphincters & arterioles at the muscles.
-This increases blood flow to the muscles during exercise
what happens if their is an Increase sympathetic stimulation
DECREASED vasoconstriction
