Lesson 20 (Part 1)

Question 1

What are 2 types of flow?

Answer 1

1. Laminar
2. Turbulent
   - non laminar

Question 2

What are 3 types of laminar flow?

Answer 2

1. Plug flow
2. Parabolic
3. Disturbed flow

Question 3

Where is plug flow?

Answer 3

At the entrance to tubes

Question 4

How does blood move in plug flow?

Answer 4

As a unit

Question 5

What is the speed in plug flow?

Answer 5

The same speed across the vessel

Question 6

Where is parabolic flow?

Answer 6

After entering the straight tube

Question 7

What is an example of parabolic flow?

Answer 7

Common carotid artery

Question 8

Where is the speed the fastest in parabolic flow?

Answer 8

In the center of the tube

Question 9

Where is the speed the slowest in parabolic flow?

Answer 9

At the tube walls

Question 10

What is the average flow speed in the parabolic flow?

Answer 10

1/2 the fastest speed

Question 11

Laminar

Answer 11

Layers

Question 12

When do you get disturbed flow? (2)

Answer 12

1. At a stenosis

2. At bifurcation

Question 13

What is disturbed flow still considered?

Answer 13

Laminar flow, but the streamlines are not straight

- non-parabolic

Question 14

When does turbulent flow occur?

Answer 14

Usually after a significant stenosis

Question 15

Turbulent flow

Answer 15

Chaotic, multidirectional, multispeed flow

- non-laminar

Question 16

What does turbulent flow have?

Answer 16

Eddies

Question 17

Eddies

Answer 17

Flowing circles

Question 18

What is the overall flow in turbulent?

Answer 18

Forwards

Question 19

What kind of noise could you hear with turbulent flow?

Answer 19

Bruit

- main reason to get an ultrasound

Question 20

What does turbulent flow depend on?

Answer 20

Reynolds number

Question 21

What is the critical reynolds number for blood?

Answer 21

2000

Question 22

What can be produce with critical reynolds?

Answer 22

Turbulent flow

- flow must surpass a critical Reynolds number to cause turbulent flow

Question 23

What is the formula for Reynolds number?

Answer 23

Re = pvd/n
Re = renolds number 
p = density of fluid 
v = velocity of fluid 
d - diameter of pipe 
n = viscosity

Question 24

What happens to Re if velocity goes up?

Answer 24

It increases

Question 25

What happens to Re if the diameter of the vessel increases?

Answer 25

It increases

Question 26

What happens to Re if viscosity goes up?

Answer 26

It decreases

Question 27

Re

Answer 27

Reynolds number = turbulence

Question 28

Stenosis

Answer 28

Partial blockage

Question 29

Occlusion

Answer 29

Complete blockage