Flashcards in Physics Quiz #4 Deck (59)

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1

## Both liquids and gases are fluids?

### True

2

## What are the forces associated with fluids(3)?

###
-gravity

-pressure

-friction

3

## What is friction?

###
-the resistance to flow from the surface interaction

-it is proportional to viscosity

4

## What is viscosity?

### The inherent property of a fluid that resists flow

5

## What is the result of pressure forces in a fluid established by differences in pressure from one point to another, which creates a pressure gradient?

###
-flow

-all flow moves from higher pressure, or resistance to lower

6

## What is Laminar flow?

### a type of flow which all molecules of a fluid travel in a parallel path within the tube

7

## Which molecules in laminar flow encounter the least adhesive force of the walls of the tube?

### molecules in the center of the tube

8

## Molecules in the center of the tube move at a velocity twice that of the mean flow?

### True

9

## True laminar flow predominates in the smallest airways(terminal bronchioles)?

### True

10

## What is transitional flow?

### a mixture of laminar flow along the walls of the tube with turbulent flow in the center

11

## What is turbulent flow?

### described as chaotic with irregular eddies throughout

12

## Which law is described: In straight circular tubes, the radius will have the most dramatic effect on flow = constancy X Radius to the 4th power(r^4) X pressure gradient

### Poiseuille's Law

13

## According to Poiseuille's law, doubling the radius will result in_____-fold increase in flow; tripling of the radius increases the flow by_____-fold?

###
-doubling=16 fold

-tripling-81 fold

14

## Resistance is inversely proportional to r^4(the greater the radius, the smaller the resistance).

###
True

15

## When the radius of a tube is tripled, how much will the resistance decrease?

### 81 fold

16

## Resistance is directly proportional to fluid viscosity(the greater the blood viscosity, the greater the resistance).

### True

17

## Resistance is directly proportional to tube length(the longer the tube, the greater the resistance).

### True

18

## How are flow and resistance related?

###
-flow through a tube is inversely proportional to resistance

-if resistance doubles, flow is halved

-if resistance is halved, flow is doubled

19

## Whose law is described: When considering flow through a tube, the gradient in hydrostatic pressure(inflow pressure minus outflow pressure) equal flow times resistance.

### Ohm's Law

20

## Whose law is described: MAP-CVP = CO x SVR or SVR = (MAP-CVP)/CO x 80

### Ohm's Law

21

## What happens to flow and what happens to resistance when the radius of the tube increases? When radius of the tube decreases?

###
-When the radius of a tube increases, resistance to flow decreases and flow increases

-When the radius of a tube decreases, resistance to flow increases and flow decreases

22

## Is flow through 16 gauge IV catheter greater or lesser than through a 20 gauge catheter?

###
-16 gauge

-the greater the radius, the more flow

23

## What happens to fluid flow if viscosity is increased?

### flow decreases

24

## Patients with polycythemia have ___ blood flow due to ___ viscosity of blood. Patients with anemia have ___ blood viscosity, hence ___ flows through tissues.

###
Polycythemia = decreased, greater

Anemia = decreased, greater

25

## How will flow be affected when length of a tube increases? If the length of tube is decreased by 50%? If the length of a tube is doubled?

###
-flow will decrease

-flow will double

-flow will be decreased by half

26

## If the radius of a tube decreases to 1/3 of its original size, flow will decrease to 1/81 of its original value?

### true

27

## Which of the following will decrease peak inspiratory pressure? 1. change ETT from 8.0 to 6.0 or 2. change ETT from 6.0 to 8.0?

### changing ETT from a 6.0 to a 8.0 will decrease the PIP, PIP is greater when inflow resistance is higher and vice versa

28

## These interventions are a direct manipulation of whose law: To improve flow when delivering a unit of PRBC's a large-diameter IV catheter is recommend, a pressure bag may be placed on the unit of PRBCs to increase the driving pressure(pressure gradient) and the PRBCs may be diluted with normal saline to lower viscosity.

### Poiseuille's Law

29

## Which factor will have the most dramatic improvement on flow: increasing the pressure, thinning the liquid(less viscous), shortening the tube, or increasing the diameter of the IV catheter?

### increasing the diameter of the catheter

30