Physics Of Anesthesia

Front 1

that which tends to change the state or motion of an object

Back 1

force

Front 2

SI unit of force

Back 2

newton (N)

Front 3

force that will accelerate one kilogram one meter per second

Back 3

one newton (1 N)

Front 4

SI unit of pressure

Back 4

pascal (Pa)

Front 5

pressure of one newton acting over one square meter

Back 5

one pascal (1 Pa)

Front 6

approximate atmospheric pressure at sea level

Back 6

1 bar
100 kPa
760 mmHg
760 Torr
14.5 psi
1 atm
1033 cm H2O

Front 7

relationship of pressure to force

Back 7

P = f/a
where P = pressure
f = force
a = area

Front 8

type of flow in which fluid has no eddies or turbulence

Back 8

laminar

Front 9

where laminar flow through a tube is fastest

Back 9

center of tube

Front 10

required to drive fluid through a tube

Back 10

pressure differential

Front 11

Hagen-Poiseuille equation

Back 11

Q = (π P d^4) / (128 η l)
where Q = flow
π = 3.14...
P = pressure
d^4 = tube diameter raised to the 4th power
η = viscosity
l = tube length

Front 12

equation which describes the effect of pressure, tube length/diameter, and viscosity on laminar flow

Back 12

Hagen-Poiseuille equation

Front 13

index which estimates the onset of turbulent flow

Back 13

Reynolds number (cutoff is 2000)

Front 14

Reynolds number equation

Back 14

Reynolds number = vρd/η
where v = linear velocity
ρ = density
d = tube diameter
η = viscosity

Front 15

a decrease in this fluid property decreases the tendency toward turbulent flow

Back 15

density

Front 16

in laminar flow, as this fluid property decreases, flow increases

Back 16

viscosity

Front 17

type of flow usual in lower respiratory tract

Back 17

laminar

Front 18

type of flow usual in upper respiratory tract

Back 18

turbulent

Front 19

Laplace's law for sphere

Back 19

P = 2 X T / r
where P = pressure
T = surface tension
r = radius

Front 20

its presence results in surface tension increases as alveoli distend and decreases as alveoli contract

Back 20

surfactant

Front 21

fall of pressure at a constriction in a tube

Back 21

Bernoulli effect

Front 22

tube which takes advantage of Bernoulli effect to entrain gases or nebulize liquids

Back 22

Venturi tube

Front 23

tendency of stream of fluid or gas to continue to flow along a convex surface

Back 23

Coanda effect

Front 24

states that at constant temperature the volume of a given mass of gas varies inversely with the pressure

Back 24

Boyle's Law

Front 25

Boyle's Law equation

Back 25

P ∝ 1/V
where P = pressure
V = volume

Front 26

states that at constant pressure the volume of a given mass of gas varies directly with the temperature

Back 26

Charles' Law

Front 27

Charles' Law equation

Back 27

V ∝ T
where V = volume
T = temperature

Front 28

states that at constant volume the pressure of a given mass of gas varies directly with the temperature

Back 28

Third Perfect Gas Law
OR Gay Lussac's Law

Front 29

Third Perfect Gas Law equation

Back 29

P ∝ T
where P = pressure
T = temperature

Front 30

a change in the volume and pressure of the contents of a system without exchange of heat between the system and its surroundings

Back 30

adiabatic change

Front 31

states that in a mixture of gases the pressure exerted by each gas is the same as that which it would exert if it alone occupied the container

Back 31

Dalton's Law of Partial Pressures

Front 32

states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules

Back 32

Avogadro's hypothesis

Front 33

Avogadro's number

Back 33

6.022 X 10^23

Front 34

Universal Gas Constant equation

Back 34

PV = nRT
where P = pressure
V = volume
n = moles
R = constant
T = temperature

Front 35

temperature above which a gas cannot be liquified however much pressure is applied

Back 35

critical temperature

Front 36

vapor pressure of a substance at its critical temperature

Back 36

critical pressure

Front 37

critical temperature at which a gas mixture may separate into its constituents

Back 37

pseudocritical temperature

Front 38

process in which the rate of change of a quantity at any time is proportional to the quantity at that time

Back 38

exponential process

Front 39

the time a process would have been complete had the initial rate of change continued

Back 39

time constant

Front 40

relationship of time constant to half-life

Back 40

half-life = time constant X 0.693

Front 41

partial pressure of a vapor in a closed container and at equilibrium with the liquid phase

Back 41

vapor pressure

Front 42

states that at a particular temperature the amount of a gas dissolved in a liquid is directly proportional to the partial pressure of the gas in equilibrium with the liquid

Back 42

Henry's Law

Front 43

the volume of a gas which dissolves in one unit volume of a liquid at the temperature concerned

Back 43

Ostwald solubility coefficient

Front 44

the ratio of the amount of substance present in one phase compared with another the two phases being of equal volume and in equilibrium

Back 44

partition coefficient

Front 45

another word for partial pressure for gases in a solution

Back 45

tension

Front 46

a substance in its gaseous phase above its critical temperature

Back 46

a gas

Front 47

a substance in its gaseous phase below its critical temperature

Back 47

a vapor

Front 48

Dalton's Law equation

Back 48

Pmixture = P1 + P2 + P3...

Front 49

fall of alveolar oxygen concentration as a result of the dilution of alveolar oxygen by excretion of nitrous oxide

Back 49

diffusion hypoxia

Front 50

increase in concentration (partial pressure) of a gas in the alveoli when a more soluble gas diffuses quickly into the bloodstream - results in increased rate of diffusion for the second gas

Back 50

second gas effect

Front 51

point at which 50% of patients cease to move in response to a stimulus

Back 51

MAC (minimum alveolar concentration)

Front 52

rate of diffusion of a substance across a surface or membrane is proportional to the concentration gradient

Back 52

Fick's Law

Front 53

states that the rate of diffusion of a gas is inversely proportional to the square root of its molecular weight

Back 53

Graham's Law

Front 54

states that depression or reduction of vapor pressure of a solvent is proportional to the molar concentration of the solute

Back 54

Raoult's Law

Front 55

a mixture which vaporizes in the same proportions as the volume concentrations of the components in solution

Back 55

azeotrope

Front 56

pathway with length greater than width

Back 56

tube

Front 57

pathway with width greater than length

Back 57

orifice

Front 58

point at which increased pressure results in turbulent flow but below which flow is laminar

Back 58

critical point

Front 59

variable orifice flowmeter

Back 59

Thorpe tube

Front 60

contributors to body pH according to Stewart

Back 60

1) partial pressure of CO2
2) strong ion difference
3) total weak acids

Front 61

strong ions according to Stewart

Back 61

K, Na, Cl, lactate

Front 62

weak acids according to Stewart

Back 62

albumin, phosphate

Front 63

effect of decreasing the strong ion difference on body pH according to Stewart

Back 63

decreases pH

Front 64

property of He which makes it useful for decreasing resistance to flow through narrowed lower airways

Back 64

low density

Front 65

force per area of molecules in a liquid as they interface with the gas above it

Back 65

vapor pressure

Front 66

a compressed gas is any mixture or material having in a container at least one of these

Back 66

1) >104 psia @ 130F
2) >40 psia @ 70F
3) >40 psia @ 100F for any liquid flammable material

Front 67

to determine time left on a cylinder of nitrous oxide, you must determine the volume of gas available from both...

Back 67

the liquid phase and the vapor phase

Front 68

unit of measure for osmotic activity

Back 68

osmole

Front 69

6.02 X 10^23 particles of dissolved solute that cannot diffuse through a semipermeable membrane

Back 69

1 osmole

Front 70

pressure exerted by 1 gmw of a nonionizing, nondiffusible solute in 22.4L of water

Back 70

1 atm

Front 71

pressure exerted by 1gmw of a monovalent, ionizing, nondiffusible solute in 22.4L of water

Back 71

2 atm

Front 72

states that even in isolation from the environment, a gas cools when expanded and warms when compressed

Back 72

Poisson adiabatic equation

Front 73

Which of the following does NOT affect rate of laminar flow? pressure gradient, fluid viscosity, tube length, fluid density, tube diameter

Back 73

fluid density

Front 74

At low rates of flow, the orifice of a variable orifice flowmeter is more like what?

Back 74

a tube

Front 75

tendency toward turbulence increases when this fluid property is increased

Back 75

density

Front 76

tendency toward turbulence decreases when this fluid property is increased

Back 76

viscosity

Front 77

As tube diameter is doubled, rate of flow _________ by a factor of _____.

Back 77

increases, 16

Front 78

As tube length is halved, rate of flow ____________ by a factor of _____.

Back 78

increases, 2