Lesson 20 (Part 1) Flashcards Preview

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Flashcards in Lesson 20 (Part 1) Deck (29)
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1

What are 2 types of flow?

1. Laminar
2. Turbulent
- non laminar

2

What are 3 types of laminar flow?

1. Plug flow
2. Parabolic
3. Disturbed flow

3

Where is plug flow?

At the entrance to tubes

4

How does blood move in plug flow?

As a unit

5

What is the speed in plug flow?

The same speed across the vessel

6

Where is parabolic flow?

After entering the straight tube

7

What is an example of parabolic flow?

Common carotid artery

8

Where is the speed the fastest in parabolic flow?

In the center of the tube

9

Where is the speed the slowest in parabolic flow?

At the tube walls

10

What is the average flow speed in the parabolic flow?

1/2 the fastest speed

11

Laminar

Layers

12

When do you get disturbed flow? (2)

1. At a stenosis
2. At bifurcation

13

What is disturbed flow still considered?

Laminar flow, but the streamlines are not straight
- non-parabolic

14

When does turbulent flow occur?

Usually after a significant stenosis

15

Turbulent flow

Chaotic, multidirectional, multispeed flow
- non-laminar

16

What does turbulent flow have?

Eddies

17

Eddies

Flowing circles

18

What is the overall flow in turbulent?

Forwards

19

What kind of noise could you hear with turbulent flow?

Bruit
- main reason to get an ultrasound

20

What does turbulent flow depend on?

Reynolds number

21

What is the critical reynolds number for blood?

2000

22

What can be produce with critical reynolds?

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

23

What is the formula for Reynolds number?

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

24

What happens to Re if velocity goes up?

It increases

25

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

It increases

26

What happens to Re if viscosity goes up?

It decreases

27

Re

Reynolds number = turbulence

28

Stenosis

Partial blockage

29

Occlusion

Complete blockage