Diffusion

Question 1

method of O2 and CO2 diffusion

Answer 1

passive diffusion

Question 2

Normal pO2 on alveolus, pulm art, pulm vein

Answer 2

alv - 100
art - 40
vein - 90

Question 3

Normal pCO2 on alveolus, pulm art, pulm vein

Answer 3

alv - 40
art - 47
vein - 40

Question 4

3 important alveolar cells

Answer 4

type 1 and 2 pneumocytes, macrophages

Question 5

method of air travel from mouth to alveolus

Answer 5

bulk flow

Question 6

name of “holes” between alveoli

Answer 6

pores of kohn

Question 7

5 ways to improve diffusion across membrane

Answer 7

1. larger membrane surface area
2. more pressure
3. incr. membrane solubility
4. thinner membrane
5. smaller molecule (low MW)

Question 8

Law that sums up movement across membrane

Answer 8

Ficks law

Question 9

Which will diffuse faster O2 or CO2 and why

Answer 9

CO2, larger molecular weight, but 20 times as soluble

Question 10

definition of diffuse limited

Answer 10

diffusion across membrane is rate limiting step

Question 11

what makes something diffusions limited (3)

Answer 11

1. not affected by perfusion
2. carried by blood in sig. quantities
3. cannot diffuse rapidly across alveoli

Question 12

example of diffusion limited gas and use

Answer 12

CO - measure diff. capacity

Question 13

what makes something perfusion limited

Answer 13

1. very soluble
2. rapid membrane transit
3. not carried in great quantities in blood

Question 14

exmaple and use of perfusion limited gas

Answer 14

NO2 to measure cardiac output

Question 15

at rest, how are O2 and CO2 limited

Answer 15

perfusion limited

Question 16

during excersise, how are CO2 and O2 limited

Answer 16

O2 - diffusion

CO2 perfusion - always very soluble

Question 17

how to measure diffusion

Answer 17

single breath of CO He and O2 mix

- measure amount of diffused CO

Question 18

2 steps to get gas from alv to body

Answer 18

1. cross membrane

2. bind to Hgb

Question 19

3 blood realated probs with diffusion

Answer 19

1. low volume
2. low Hb
3. embolism

Question 20

why is He in diffusion test

Answer 20

to measure the TLC

Question 21

how does He dilution test work

Answer 21

give He and use C1V1=C2V2

Question 22

what does it mean is He measured vol is much lower that pleth volume

Answer 22

blockage

Question 23

what will happen to DLCO in anemia

Answer 23

down

Question 24

what will happen to DLCO in polycythemia

Answer 24

up

Question 25

what will happen to DLCO in embolism

Answer 25

down

Question 26

what will happen to DLCO in hemmorage into alveoli

Answer 26

up

Question 27

what will happen to DLCO in lowered suface area such as emphysema

Answer 27

down