Movement of Blood & Fluid

Question 1

Define bulk flow in relation to blood.

Answer 1

The movement of blood by means of pressure difference (energy derived from hydrostatic pressure difference).

Question 2

Define hydrostatic pressure.

Answer 2

The pressure that a fluid exerts on its container – in this case, blood within a
blood vessel.

Question 3

Define perfusion pressure.

Answer 3

The difference in pressure between two points in a blood vessel.

Question 4

What generates perfusion pressure?

Answer 4

Pumping action of the ventricles.

Question 5

What is absorption and filtration (n.b. capillaries)?

Answer 5

Absorption - bulk flow into the capillary
Filtration - bulk flow out of the capillary

Question 6

Define transmural hydrostatic pressure.

Answer 6

Pressure across the vessel wall and is calculated as the difference between the pressure exerted by the fluid
inside the vessel and outside the vessel.

Question 7

Is absorption/filtration of water favoured within the capillaries and why?

Answer 7

The transmural hydrostatic
pressure within capillaries tends to exceed the pressure outside and hence favours filtration of water
out of the vessel and into the ISF along the pressure gradient.