Lecture 11 Flashcards
How many letters of blood is pumped per minutes
5L - amount of blood in body
In order to have a controlled (and a variation of) flow you must have
Pressure (high)
- need a driving pressure
Cardiac output is ______ to all organs
Distributed
The parallel design of systemic circulation:
- continual branching of arterial network
- divides blood flow among the regional (organ) circulations
Distribution of cardiac output at rest - dont memorise numbers
Distribution of cardiac output during exercise
- it I spread around as needed especially skeletal muscle and gut
- learn arrows at side
- increasing heart rate increasing stroke volume
- brain blood flow the same
Diretubution of cardiac output yappage
- parallel branches
- because of arterioles we can chose which ones we open and close meaning you can get a sensible distribution while at rest and then push into places of Ned during exercise
During exercise there is an increase in blood flow to:
- muscle
- heart
- skin
During exercise there is a decrease in blood flow to:
- GI tract
- kidneys
During exercise there is a constant blood flow to:
Brain
Divergent flow depending on
Metabolic needs
The only this that allows us to redistribute the blood is
The parallel circuit
How is MAP controlled during excise
Systemic circulation:
- increased cardiac output
- decreased TPR (vascodilation)
- constant mean arterial pressure (MAP)
MAP = CO x TPR
Resistance in muscle vs kidney in rest and eversise
Muscle:
- increased flow = decreased resistance
Kidneys:
- decreased flow = increased resistance
Control of arterioles (resistance vessels) to change resistance
- contraction and relation of smooth muscle (precapillary sphincters)
Arterioles are the _____ vessels while capillaries are the _____ vessels
Arterioles are the resistance vessels while capillaries are the delivery vessels
Resistance to blood flow and vessel radius - equation
Luminal size determines
Resistance
Decreasing luminal diameter, increases resistance by a factor of
16
Small diameter means, _____ resistance, which means _____ flow
Larger
Reduced
Change the size reduce the resistance by
HEAPS
Blood flow to an organ or region is controlled by adjusting…
Arteriolar ‘vascular’ tone to arteries
Halving diameter means
16 times less flow
How blood flow to an organ or region is controlled by adjusting arteriolar ‘ vascular’ tone and radius
