Lecture 20

Question 1

Plug flow is at ________ to tubes

Answer 1

Enterance

Question 2

Plug flow blood moves as

Answer 2

A unit

Question 3

In Plug flow there is the same ______ across the vessel

Answer 3

Speed

Question 4

Two types of flow

Answer 4

Laminar

Turbulent (non-laminar)

Question 5

3 types of laminar flow

Answer 5

Plug flow
Parabolic
Disturbed flow

Question 6

Parabolic/ laminar happens when

Answer 6

After entering the straight tube

Question 7

The fastest speed in parabolic is where

Answer 7

The center of the tube

Question 8

During doppler we assess where in the tube

Answer 8

The centre

Question 9

The slowest speed in parabolic is where

Answer 9

Tube wall

Question 10

Average flow speed in parabolic is

Answer 10

Half the fastest speed

Question 11

Disturbed flow occurs at a

Answer 11

Stenosis or bifurcation

Question 12

Disturbed flow is still _______ flow but streamlines are not ____

Answer 12

Laminar

Straight

Question 13

Disturbed flow is non- _____

Answer 13

Parabolic

Question 14

Turbulent flow usually occurs after a

Answer 14

Significant stenosis

Question 15

Turbulent flow can also be called what 4 things

Answer 15

Chaotic, multidirectional, multispeed flow, non laminar

Question 16

Turbulent flow is related to

Answer 16

Eddies —> flow in circles but still with forward net flow

Question 17

With turbulent flow physician may hear a

Answer 17

“Bruit”

Often main reason for the ultrasound

Question 18

Turbulent flow depends on

Answer 18

Reynolds number

Question 19

Critical reynolds number =

Answer 19

2000 for blood

Question 20

Flow must surpass ________ to cause turbulent flow

Answer 20

a critical reynolds #

Question 21

Reynolds number equation

Answer 21

Re= pvd/n

, p = density of fluid
, v = velocity of fluid 
, d = diameter of pipe
, n = viscosity 
, Re= reynolds number

Question 22

What is a stenosis

Answer 22

Partial blockage

Question 23

Occlusion

Answer 23

Complete blockage

Question 24

In compliant vessels we observe

Answer 24

Added forward flow and reversal of flow

Question 25

Compliance is

Answer 25

Expansion and contraction of non-rigid vessels during systole and diastole

Question 26

Added forward flw aka

Answer 26

Windkessel effect

Question 27

Systole

Answer 27

The vessel expands

Question 28

Diastole

Answer 28

Vessel contracts, resulting in extended flow without driving pressure from heart

Question 29

Flow reversal occurs during

Answer 29

Diastole

Question 30

Blood doesn tflow back into the heart becuase

Answer 30

Valve closes

Question 31

In distal circulation, in some locations, when pressure decreases and vessel contracts there will be ____

Answer 31

Reversal of flow

There are no valves present to stop it

Question 32

At the stenosis the speed goes

Answer 32

Up

Question 33

Why does the speed go up in stenosis

What is the concept called

Answer 33

To keep volumetric flow rate (Q) constant at all 3 regions (before, at and after)

Continuity rule

Question 34

Laminar flow is flow in which

Answer 34

Layers of fluid slide over eachother in straight lines