VIX: Gas Exchange

Question 1

Definition of diffusion

Answer 1

Random movement of particles from a place of high concentration to a place of low concentration

Question 2

In the higher concentration section is there more or less energy

Answer 2

More

Question 3

Definition of net motion

Answer 3

Difference between tendency to move in one direction and tendency to move in the opposite

Question 4

Composition of air, N2

Answer 4

78%, 600mmHg

Question 5

Composition of air, O2

Answer 5

21%, 160mmHg

Question 6

Composition of air, NOBLE GASES

Answer 6

1%

Question 7

Atmospheric/barometric pressure equals to the

Answer 7

Sum of partial pressures of gases

Question 8

What does partial pressure of a gas depend on

Answer 8

On its concentration and solubility coefficient

Question 9

What does diffusion depend on

Answer 9

Area and thickness of membrane

Question 10

HENRY’S LAW is used to calculate

Answer 10

Partial pressure

Question 11

What do you need to know to calculate partial pressure of a gas using Henry’s law

Answer 11

The concentration of the other components in the air

Question 12

HENRY’S LAW,

Answer 12

Partial pressure = [Dissolved gas] / solubitlity coefficient

Question 13

Solubility coefficient of O2

Answer 13

0.024

Question 14

Coefficient solubility CO2

Answer 14

0.57

Question 15

Coefficient solubility CO

Answer 15

0.018

Question 16

From less to most, solubility coefficient of O2, CO2, CO

Answer 16

CO, O2, CO2

Question 17

Therefore, is CO2 is 20x more soluble than O2, how is are the pO2, pCO2 related

Answer 17

PCO2 will be 20x less than PO2
This is because according to Henry’s law, a greater solubility coefficient will lead to a smaller partial pressure. Therefore since the solubility coefficient of CO2 is 20x more than for O2, that will mean that the PCO2 is 20x less than for PO2

Question 18

Relationship between inflow/outflow of a gas into alveolar space/blood and partial pressure of the gas

Answer 18

DIRECTLY PROPORTIONAL

Question 19

Gas diffusion direction depends on

Answer 19

Differences in gas partial pressures between the 2 systems

Question 20

Time it takes for erythrocyte to travel capillary surrounding an alveolus is

Answer 20

0.75s

Question 21

Alveolar PO2, PCO2

Answer 21

PO2 - 105mmHg

PCO2 - 40mmHg

Question 22

In deoxeginated blood, PCO2 and PO2

Answer 22

PO2 - 40mmHg

PCO2 - 45mmHg

Question 23

Why does gas exchange take place

Answer 23

Because of the differences in partial pressure

Question 24

Relationship between alveolar membrane thickness and gas diffusion

Answer 24

INVERSERLY PROPORTIONAL

So an increase in thickness of alveolar membrane will lead to a decreased gas exchange and viceversa

Question 25

Relationship between alveolar membrane surface area and gas diffusion

Answer 25

DIRECTLY PROPORTIONAL

Question 26

Relationship between gas diffusion coefficient and gas exchange

Answer 26

DIRECTLY PROPORTIONAL

Question 27

Relationship between pressure gradient and gas diffusion

Answer 27

DIRECTLY PROPORTIONAL

Question 28

Relationship between contact time and gas exchange

Answer 28

DIRECTLY PROPORTIONAL

Question 29

Interstitial edema, COPD, pneumonia, pulmonary fibrosis are examples of

Answer 29

Increased alveolar membrane thickness resulting in DECREASED RATE OF DIFFUSION

Question 30

Pulmonary emphysema (smoking) is an example of

Answer 30

Reduced surface area resulting in DECREASED GAS EXCHANGE RATE

Question 31

Ficks law

Answer 31

Vgas = [(P1-P2)/X] x A x D

P1-P2 is the pressure gradient
A is area
X is thickness
D is diffusion coefficient