Quiz 4

Question 1

diffusion is directly proportional with?

Answer 1

Solubility

Question 2

Diffusion is inversely proportional with?

Answer 2

square root of Molecular weight

Question 3

movement of gases in and out of the tissues is equal to?

Answer 3

diffusion rate of gas through water

Question 4

each breath replaces how much of FRC?

and what does this prevent?

what does it allow?

Answer 4

• 1/7th
• sudden change in gas concentration
• respiratory control mechanisms to be more stable

Question 5

alveolar ventilation is inversely proportionate to what?

Answer 5

-Time (normal 17 seconds, half ventilation 34 seconds)

Question 6

What affects alveolar P02? (3)

Answer 6

• Rate of Ventilation
• O2 Pressure
• Exercise

Question 7

Alveolar Pco2 increases in proportion to?

Answer 7

CO2 Secretion

Question 8

Pco2 decreases inversely to?

Answer 8

Alveolar ventilation

Question 9

tissue thickness is inversely proportional to?

And what law?

Answer 9

Diffusion

Ficks Law

Question 10

What law figures out Diffusion of gas through a tissue membrane

Answer 10

Ficks Law

Question 11

Ficks law equation includes? (4)

Answer 11

• cross sectional area of membrane
• driving pressure/PP difference
• Gas coefficient
• Tissue thickness

Question 12

What physiologic state could inhibit diffusion?

Answer 12

Pulmonary edema

Question 13

The ability to exchange gas between alveoli & pulmonary blood expressed in quantitative terms

Answer 13

Diffusing Capacity

Question 14

Exercise increases?

Answer 14

• Pulm blood flow

- Alveolar ventilation

Question 15

How is co2 diffusion capacity estimated and why?

Answer 15

Diffusion coefficient

because it is unmeasurable

Question 16

When V/Q is below normal

Answer 16

a shunt (airway obstruction)

Question 17

When V/Q greater than normal

Answer 17

Dead space (PE)

Question 18

What is the minimal O2 flow needed to survive?

Answer 18

250ml/min O2