Physics and Chemistry

Question 1

vapor pressures for VAA’s are at what temperature?

Answer 1

20 degrees C

Question 2

Whats the Vapor Pressure? Sevoflurane

Answer 2

170 mmHg (7-sevo0

Question 3

Whats the Vapor Pressure? Enflurane

Answer 3

172 mmHg

Question 4

Whats the Vapor Pressure? Isoflurane

Answer 4

240 mmHg

Question 5

Whats the Vapor Pressure? Halothane

Answer 5

244 mmHg

Question 6

Whats the Vapor Pressure? Desflurane

Answer 6

669 mmHg (des 6)

Question 7

is the vapor pressure a function of volume, temperature, or pressure?

Answer 7

temperature

Question 8

the pressure at which the gaseous state is in equilibrium with either the liquid or solid state, or with both is known as what?

Answer 8

the saturated vapor pressure (SVP)

Question 9

Volatile agent in a flask is an ex of whose law

Answer 9

daltons

Question 10

if Iso is added to a flask of Oxygen, what is the percent of oxygen and percent of iso In the flask above the liquid?

Answer 10

the VP of iso is 240 mmHg the Partial pressure of oxygen is 760 mmHg
The partial pressure of O2 after Iso is added is 520 mmHg (760-240=520mmHg)
%O2 = (520mmHg / 760 mmHg) x 100% = 68.4% O2
%iso = (240mmHg / 760 mmHg) x 100% = 31.6% iso

Formula is %gas = P gas / P total

Question 11

Adding VAA to the wrong vaporizer:

what are the mnemonics?

Answer 11

HLH- high VP in Low VP = High concentration delivered

LHL- Low VP in High VP = Low concentration delivered

Question 12

If halothane is added to Enflurane or servo what concentration will be delivered?

Answer 12

hal- 244 enf 172 Sevo 170
HLH
High concentration delivered

Question 13

If halothane is added to iso vaporizer what concentration would be delivered?

Answer 13

Halothane 244 Iso 240

about the same

Question 14

If ENF or Sevo added to Halothane or Iso vaporizer what concentration would be delivered?

Answer 14

ENF 172 sevo 170 Hal 244 iso 240
LHL
Low concentration

Question 15

Desflurane vaporizer is heated to what temp

Answer 15

39 degrees C

Question 16

why is des vaporizer heated

Answer 16

it is heated to almost 2 atmospheric pressures, this high pressure drives des to the gas outlet where it’s diluted

Question 17

unit conversions:

1 mmHg = ____ cm H2O

Answer 17

1.36 cmH2O

Question 18

unit conversions:

1 atm = ____ mmHg = ___psi = ___kPa = ___ bar

Answer 18

1 atm = 760mmHg = 14.7 psi = 101 kPa = 1 bar

Question 19

1 psi = ____ mmHg

Answer 19

54mmHg

Question 20

what are gauges that measure HIGH pressures (cylinder pressures)

Answer 20

bourdon gauges

Question 21

do Bourdon pressure gauges measure th pressure relative to atmospheric pressure or the absolute pressue

Answer 21

the pressure relative to atmospheric pressure

Question 22

when the Bourdon gauge reads 0 the pressure inside the cylinder is equal to what?

Answer 22

atmospheric pressure

Question 23

what is the formula for the law of laplace? cylindrically- shaped structures

Answer 23

T=P x r
T= wall tension
P= pressure
r = radius

Question 24

Law of laplace:

states that as the structure expands (radius increases) the tension (force) in the wall of the structure does what?

Answer 24

Increases

Question 25

Law of laplace: | application

Answer 25

a cappillary will withstand a pressure of 100mmHg for better than a vein, b/c the capillary has a tiny radius compared to a vein, so the tension in the wall of the capillary is extraordinarily smaller than that in the vein

Question 26

Law of laplace: | Application

Answer 26

an aortic aneurysm is much more likely to rupture than a normal segment of the aorta b/c the radius is much larger, thereby increasing the tension on the wall to the "breaking point"

Question 27

who's law states that the greater the tension in ventricular wall at end diastole, the greater the stroke volume

Answer 27

frank-starling law

Question 28

law of laplace: Spherically shaped | what is an ex of a spherically shaped structure

Answer 28

alveoli

Question 29

law of laplace: Spherically shaped | what is the formula

Answer 29

T= P x r / 2 | or 2T= P x r

Question 30

law of laplace: Spherically shaped | facts

Answer 30

tension is independent of radius for all spheres where there is a liquid-air interface (soap bubble. the pressure inside the bubble will change with its size. the smaller the radius of the bubble the greater the pressure inside the bubble.

Question 31

how does the law of laplace: Spherically shaped apply to alveoli? with ARDS

Answer 31

b/c pressure in the smaller alveoli is higher than th larger alveoli. the law of laplace explains why smaller alveoli empty into larger alveoli causing atelectasis in pts w/ ARDS

Question 32

how does the law of laplace: Spherically shaped apply to alveoli? with Normal lungs

Answer 32

for alveoli with surfactant , tension increases w/ increases in radius, b/c alveolar wall tension increases in proportion to increases in radius, the pressure within the alveolus does not change. the law of laplace explains why small alveoli do not empty into larger alveoli

Question 33

Flow of liquids: | Laminar (streamlined) flow is described mathematically by whose law

Answer 33

hagen-Poiseulle's law

Question 34

Flow of liquids: | with laminar flow where is flow the fastest

Answer 34

Middle

Question 35

Flow of liquids: | w/ laminar flow, what is the flow like against the wall

Answer 35

zero flow (think of why plaque builds up in arteries)

Question 36

what is the formula for flow

Answer 36

Q= pie x radius^4 x pressure gradient / 8 x viscosity x length Look at page 306 to see pic

Question 37

Flow of liquids: | doubling the radius increases flow by how much

Answer 37

16 times

Question 38

Flow of liquids: | what factor alters flow the most?

Answer 38

radius

Question 39

what is the property of a fluid that determines flow when the flow in laminar

Answer 39

viscosity

Question 40

Flow of liquid: | is it directly or inversely proportional to radius

Answer 40

directly- doubling the radius increases flow by 16 times

Question 41

Flow of liquid: | is it directly or inversely proportional to hydrostatic pressure gradient?

Answer 41

directly- rising the IV pole increases hydrostatic pressure in the fluid delivered to the pt via gravity.

Question 42

Flow of liquid: | is it directly or inversely proportional to viscosity

Answer 42

Inversely- thicker blood slower flow

Question 43

Flow of liquid: | is it directly or inversely proportional to length

Answer 43

inversely- reducing the needle length increases flow.

Question 44

Flow of liquid: | what is the formula for resistance

Answer 44

R= change in pressure / flow

Question 45

what are 4 things that increase turbulent flow

Answer 45

Faster flow Bigger tubes Density increased Viscosity decreased

Question 46

resistance to flow (increases or decreases) when flow becomes turbulant

Answer 46

increases

Question 47

what is the name the predicts when flow through a cylinder tube changes from laminar to turbulent

Answer 47

Reynolds number

Question 48

when the Reynolds number exceeds _____ - _____ flow changes from laminar to turbuilant

Answer 48

1500-2,000 (2,000 is the magical number)

Question 49

when flow in turbulent what determines flow?

Answer 49

density | -this is why we use helium (its density is lower and and better for obstructions)

Question 50

who's principle does the venturi effect full under

Answer 50

Bernoulli's principle

Question 51

when fluid flows through a constricted region of a tube (venturi tube) the velocity of the flow does what?

Answer 51

increases (think of a narrowing of a stream - it gets faster)

Question 52

when fluid flows through a constricted region of a tube (venturi tube) the velocity of the flow INCREASES and the lateral pressure (pressure exerted by the fluid on the walls of the tube) does what?

Answer 52

Decreases (think thats why you can park a boat on a deck int he river the walls have less pressure)

Question 53

when fluid flows through a constricted region of a tube (venturi tube) the velocity of the flow INCREASES and the lateral pressure (pressure exerted by the fluid on the walls of the tube) DECREASES what effect is this termed

Answer 53

Bernoulli effect