week 3

Question 0

solubility coefficient of co2

Answer 0

0.067 ml / 100 ml blood / mmHg of co2

Question 1

solubility coefficient of oxygen

Answer 1

0.003 ml / 100 ml blood / mmHg of o2

Question 2

Henry’s law states that the amount of gas that will dissolve in solution is __ to the partial pressure of the gas in contact with the solution.

Answer 2

proportional

Question 3

fiO2 x 5 = paO2

Answer 3

“x5 is a good start to remember”

Question 4

Henry was a blood gas guru

Answer 4

He was always calculating the dissolved gas via paO2 and paCO2

Question 5

Diffusion is the process of net movement of one type of molecule through space as a result of __

Answer 5

random motion intended to minimize a concentration gradient.

Question 6

Molecules with a smaller mass will diffuse __

Answer 6

faster

Question 7

Graham’s law

does the big graham cracker or the little graham cracker dissolve in the milk faster?

Answer 7

smaller molecules diffuse faster than larger molecules

Question 8

Graham’s law in scientific mumbo jumbo

Answer 8

a gas diffuses at a rate that is INVERSELY proportional to the square root of its molecular weight

Question 9

semi-permeable or selectively permeable means some molecules can pass through while others _

Answer 9

Canr

Question 10

osmosis is the movement of WATER across a semi-permeable membrane to equilibrate a concentration __

Answer 10

gradient

knock knock, who’s there? WATER

Question 11

OSMOTIC pressure is a force needed to stop _ from occurring

Answer 11

Osmosi

Question 12

ONCOTIC pressure is the OSMOTIC pressure caused by __

Answer 12

plasma proteins and electrolytes in capillaries

Question 13

normal onCotic pressure is approximately _

Answer 13

28 mmHg

Question 14

Most capillary walls are permeable to small solutes like __ and __ etc. so small solutes do not exert an osmotic effect

Answer 14

Na+
Cl-

Ions do not penetrate the lipid bilayer so they diffuse via channels.
The capillaries of the brain have the BBB and are exceptions to the above

Question 15

Albumin has a molecular weight of __ and does not penetrate the capillary wall. It provides the onCotic pressure of the blood and is the major determinant of intravascular volume.

Answer 15

69,000 g/mol

Question 16

Diffusion is a __ process.

Answer 16

passive

Question 17

Nitrous diffuses into air-filled cavities, therefore it is contraindicated in patients with pneumothorax, or where air-filled cavity expansion is undesirable such as eye, ear, cranial surgery.

Answer 17

Nitrous expansion of ETT cuffs may cause tracheal mucosal damage

Question 18

Fick’s law for diffusion of a gas across a tissue plane is a big A law that accounts for five things, what are they?

Answer 18

partial pressure gradient (p1-p2= change in p)
membrane area
solubility of gas in membrane
membrane thickness
square root of the molecular weight

Question 19

fick’s law equation

Answer 19

diffusion rate = [(p1-p2) x area x solubility] / [membrane thickness x square root of molecular weight]

“maybe you do need to know it” - Katrin

Question 20

Fick’s law explains three concepts- what are they?

Answer 20

concentration effect
second gas effect
diffusion hypoxia

Question 21

concentration effect- the higher the concentration of agent delivered the faster anesthesia is achieved, AKA __

Answer 21

overpressuring

Question 22

second gas effect- two anesthetics of varying onset are given together, and the slower gas achieves anesthetic level more quickly than if given alone. Usually __ and another gas

Answer 22

nitrous

Question 23

nitrous is __ times more blood soluble than nitrogen

Answer 23

34

Question 24

what is the blood:gas partition coefficient of nitrogen?

Answer 24

0.014

Question 25

what is the blood:gas partition coefficient of nitrous?

Answer 25

0.470

Question 26

- compared with nitrous, the carrying capacity of blood for nitrogen is very poor - according to Fick's law of diffusion, the rate of diffusion of a gas into or out of the blood is __ to its blood solubility

Answer 26

proportional

Question 27

explain concentration effects as it relates to uptake of nitrous and alveolar volume

Answer 27

slide 45 | diffusion gradient remains high because the alveoli shrinks as nitrous diffuses into the blood

Question 28

explain the correlation between concentration and second gas effects

Answer 28

slide 47 basically, as nitrous diffuses it shrinks the alveoli and thus increases the concentration of the second gas (iso/sevo/des) which therefore reaches anesthetic concentration much quicker.

Question 29

explain the dilutional effect when nitrous is shut off for emergence and the phenomenon of "dilutional hypoxia" or "diffusion hypoxia"

Answer 29

slide 50 | when the nitrous is turned off, the alveoli expand and thus decreased paO2 and cause a temporary hypoxia

Question 30

CO2 diffuses __ times faster across alveolar and capillary membranes than O2

Answer 30

20x

Question 31

equilibrium of an inhalational agent occurs in the body when the partial pressure of the gas is the __ everywhere

Answer 31

same

Question 32

how does the fetus receive O2 and drugs across the placental barrier?

Answer 32

diffusion

Question 33

diffusion of a gas from alveoli to blood or blood to alveoli requires a difference in partial pressure (p1-p2 = change in p)

Answer 33

represented by delta P

Question 34

what are the main factors determining diffusion rates across membranes for non-gases is the __ for non-ionized or the __ gradients for ions also __ __ and __

Answer 34

diffusion gradients electrochemical gradients lipid solubility size

Question 35

both liquids and gases are fluids. Forces associated with fluids include _, _, and _

Answer 35

gravity pressure friction

Question 36

friction is resistance to flow from the surface interaction and is __ to viscosity

Answer 36

proportional

Question 37

viscosity is the property of a fluid that resists __

Answer 37

flow

Question 38

all flow moves from higher pressure to __

Answer 38

lower

Question 39

Laminar flow is __

Answer 39

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

Question 40

in laminar flow, the molecules in the center of the tube encounter the least adhesive force from the walls of the tube and therefore __

Answer 40

move at twice the velocity of the mean flow

Question 41

flow decreases approaching the walls and __ at the wall

Answer 41

ceases

Question 42

true laminar flow predominates in the smallest airways or __

Answer 42

terminal bronchioles

Question 43

transitional flow is a __ of laminar flow and turbulent flow

Answer 43

mixture

Question 44

turbulent flow is described as __

Answer 44

chaotic with irregular eddies throughout

Question 45

Poiseuille's law states that __ will have the most dramatic effect on flow

Answer 45

radius

Question 46

state Poiseuille's law

Answer 46

flow = (pi x radius^4 x pressure gradient) / (8 x viscosity x length of tube) PR4P/8VL

Question 47

doubling the radius of the tube results in a __ fold increase in flow, tripling the radius increases the flow by __ fold

Answer 47

16 fold | 81 fold

Question 48

end lecture on slide 23

Answer 48

reynolds law