Lecture 2: Fluids/Solutions Study Guide for Quiz

Question 1

What are two types of fluids?

Answer 1

Liquids and gases

Question 2

Fluids take the ___

Answer 2

Shape of their container

Question 3

What does Pascal’s principle state about pressure?

Answer 3

Pressure is exerted equally regardless of the size of the container—i.e.: arterial blood pressure monitoring

Question 4

What do hydrometers measure?

Answer 4

Density of fluids

Question 5

What is hydrodynamics?

Answer 5

The study of fluids in motion

Question 6

What is laminar flow?

Answer 6

Flow that is smooth, orderly

Question 7

What is turbulent flow?

Answer 7

Flow that is chaotic, always changing

Question 8

In anesthesia, we strive for ___ flows

Answer 8

Laminar flows

Question 9

What is the venturi flow meter?

Answer 9

• Venturi flow meter was originally used to measure speed in a pipe—they found that the speed was greatest at the narrowest part of the pipe
• Today, Venturi flow meters are the basis behind nebulizers

Question 10

What is Pouisielle’s Law?

Answer 10

The laminar flow rate is proportional to the fourth power of the pipe’s radius

Question 11

Pouiseuille’s Law applies to ___ flow only

Answer 11

Laminar flow only

Question 12

What two things have the greatest effect on laminar flow?

Answer 12

Radius and length

Question 13

What are 3 possible ways to increase the fluid flow rate through a catheter or needle (based on Poiseuille’s Law)?

Answer 13

1. Raise IV bag height or add a pressure bag
2. Use a large gauge IV catheter
3. Use a shorter length IV catheter

Question 14

What is Bernoulli’s Principle?

Answer 14

Pressure of a fluid varies inversely with speed—as the speed of a fluid increases, the pressure exerted by the fluid decreases

Question 15

Bernoulli’s principle—an increase in speed = a ___ in pressure

Answer 15

Decrease

Question 16

Bernoulli’s principle—a decrease in speed = ___ in pressure

Answer 16

Increase

Question 17

According to Bernoulli, pressure is ___ in the narrow part of the tube

Answer 17

Lower (because speed increases in the narrow part of the tube)

Question 18

Bernoulli’s principles are seen in the ___

Answer 18

Venturi tube flowmeter

Question 19

What is viscosity?

Answer 19

Measure of a fluid’s resistance to flow

Question 20

Fluids with a high viscosity…

Answer 20

Do not flow very readily (i.e.: honey)

Question 21

Fluids with a low viscosity…

Answer 21

Flow more easily (i.e.: water)

Question 22

The closer a molecule is to a wall, the ___ it moves

Answer 22

Slower (speed is essentially zero)

Question 23

Molecules in the center move…

Answer 23

The fastest (parabolic shape, laminar flow)

Question 24

Less viscosity =

Answer 24

Better flow

Question 25

How does length affect flow?

Answer 25

More length = less flow | Shorter = more flow

Question 26

Speed of fluid vs. cross-sectional area

Answer 26

Speed of fluid is INVERSELY proportional to the cross-sectional area

Question 27

Flow rate =

Answer 27

Volume/time (i.e.: 3L/min)

Question 28

Flow is directly proportional to the ___ power of the radius

Answer 28

Fourth power

Question 29

If you double the radius of your tube (i.e.: ETT, IV tubing), you would increase the flow by ___

Answer 29

16 (2^4)

Question 30

If you triple the radius of your tube, you would increase the flow by ___

Answer 30

81 (3^4)

Question 31

What has the most dramatic effect on flow?

Answer 31

A change in radius

Question 32

How does the length of a tube affect flow?

Answer 32

- Shorter tube has more flow through it | - Longer tube has less flow through it

Question 33

Viscosity of blood

Answer 33

Blood is viscous; flows slowly

Question 34

Increase in viscosity =

Answer 34

Decrease in flow

Question 35

Decrease in viscosity =

Answer 35

Increase in flow

Question 36

Viscosity is related to ___ flow

Answer 36

Laminar flow

Question 37

Density is related to ___ flow

Answer 37

Turbulent

Question 38

What increases when flow becomes turbulent?

Answer 38

Resistance

Question 39

What can you do to lessen turbulent flow?

Answer 39

Change the density when you have turbulent flow—decrease the density to make the flow less turbulent (i.e.: heliox is less dense than oxygen, makes the flow less turbulent)

Question 40

What is Reynold’s number?

Answer 40

The measure of the tendency for turbulence to occur

Question 41

When Reynold’s number rises above ___, turbulence will usually occur

Answer 41

2000 | Even in a straight, smooth vessel!

Question 42

Reynold’s number is directly proportional to ___

Answer 42

Velocity (how fast it’s flowing), density, and diameter

Question 43

Reynold’s number is INVERSELY proportional to ___

Answer 43

Viscosity

Question 44

What is a solution?

Answer 44

A homogeneous mixture that consists of one or more solutes uniformly dispersed throughout a medium known as a solvent

Question 45

What is a solvent?

Answer 45

Part of a solution; present in the larger amount

Question 46

What is a solute?

Answer 46

Part of a solution; present in the smaller amount

Question 47

Molality (m)

Answer 47

Moles of solute / kg solvent

Question 48

Molarity (M)

Answer 48

Moles of solute / L solution | More applicable to our profession

Question 49

Molality and molarity...

Answer 49

NEVER equal each other

Question 50

What is solubility?

Answer 50

The amount of solute that will dissolve in a given amount of solvent

Question 51

Lipid solubility is related to the ___ of a drug

Answer 51

Potency

Question 52

Drugs with a greater lipid solubility have a ___ potency

Answer 52

Greater potency

Question 53

Protein-binding is related to...

Answer 53

Duration of action of drugs (i.e.: local anesthetics)

Question 54

Solubility deals with the ___ of a drug

Answer 54

Potency

Question 55

Protein-binding deals with ___

Answer 55

Duration of action of a drug, particularly for local anesthetics

Question 56

Drugs with decreased solubility (i.e.: desflurane)

Answer 56

Faster induction, faster wake up...because blood and other tissues aren’t taking up the drug, the drug is going right to the target site (brain)

Question 57

Increased solubility of drugs =

Answer 57

Slower induction, slower wake up...because every place along the path is taking some of that drug, less is going to the brain

Question 58

Blood solubility of a drug determines...

Answer 58

The speed of induction (less soluble = faster, more soluble = slower)

Question 59

As temperature goes down, solubility ___

Answer 59

Increases

Question 60

Gas is more soluble at ___ temperatures

Answer 60

Cold temperatures

Question 61

Solubility =

Answer 61

Potency

Question 62

How does cardiac output relate to anesthetic gas?

Answer 62

Slow cardiac output = more anesthetic delivered to the brain because there’s more time for the gas to jump onto the alveoli, and then the blood takes it up to the brain

Question 63

Tonicity

Answer 63

Relative concentration of solutes in osmotic systems

Question 64

Isotonic

Answer 64

Equal concentration of particles

Question 65

Hypertonic

Answer 65

Greater concentration

Question 66

Hypotonic

Answer 66

Lower concentration

Question 67

Osmosis

Answer 67

Diffusion of water

Question 68

Diffusion occurs from ___ to ___

Answer 68

High concentration to low concentration