Lesson 19 (Part 3)

Question 1

What is the driving force behind fluid flow?

Answer 1

Pressure

Question 2

What is the formula for pressure?

Answer 2

P = F/A
P = pressure 
F = force 
A = area

Question 3

What is pressure difference required for?

Answer 3

Fluid to flow

Question 4

What is a pressure difference also known as?

Answer 4

Pressure gradient

Question 5

What is the formula for pressure gradient?

Answer 5

Delta P = P2-P1

Question 6

What is the unit for pressure? (2)

Answer 6

1. Pa

2. N/m^2

Question 7

How does fluid flow?

Answer 7

From an area of high pressure to an area of low pressure

Question 8

What does Q represent?

Answer 8

Volumetric flow rate

Question 9

Volumetric flow rate?

Answer 9

Volume of blood passing a point per unit of time

Question 10

What is the unit for Q?

Answer 10

mL/s

Question 11

What is the formula for volumetric flow rate?

Answer 11

Q = delta P/R
Q = volumetric flow rate 
P = pressure 
R = resistance

Question 12

What is Q applied?

Answer 12

To a long straight tube

Question 13

What is the formula for resistance?

Answer 13

R = 8Ln/pie r^4
R = resistance 
L = length of tube (cm)
n = viscosity 
r = radius (cm)

Question 14

What happens to the resistance when the length of the tube increases?

Answer 14

It increases also

- longer the tube the higher the resistance

Question 15

What happens to the resistance when the viscosity increases?

Answer 15

It increases

- the higher the viscosity the higher the resistance

Question 16

What happens to the resistance when the radius increases?

Answer 16

It decreases

Question 17

Viscosity

Answer 17

Resistance to flow offered by a fluid

Question 18

What is the unit for viscosity?

Answer 18

Poise

Question 19

What is the viscosity of anemia compared to polycythemia?

Answer 19

It will be lower

Question 20

What has the strongest effect on resistance of all the parameters?

Answer 20

Radius or diameter

Question 21

What happens to the resistance if the radius doubles?

Answer 21

Resistance decreases by 16x

Question 22

Vasoconstriction

Answer 22

Smaller blood vessels, so it restricts the blood flow

Question 23

Vasodilation

Answer 23

Larger blood vessels, which allows more blood flow

- when it is needed

Question 24

What is Poiseuille’s equation?

Answer 24

Q=deltaP pie d^4/128Ln

- long straight tube

Question 25

What is the formula for radius?

Answer 25

r = 1/2d
r = radius 
d = diameter