W8/L2: Lung physiology

Question 1

What are the 3 main functions of the lung?

Answer 1

Oxygenation
Removal of CO2
Acid0base balance

Question 2

How much O2 do we normally use at rest?

Answer 2

250 ml/min

Question 3

How much CO2 do we normally produce at rest?

Answer 3

200 ml/min

Question 4

What does SaO2 mean?

Answer 4

The amount of O2 bound to Hb

Question 5

What does PaO2 mean?

Answer 5

The amount of O2 dissolved in the plasma of the arteries

Question 6

How are PaO2 and SaO2 related?

Answer 6

They’re proportional, but non-linear:

PaO2 is the driving force for Sa02, but obviously SaO2 levels off at a certain point

Question 7

A gram of fully saturated Hb combines with how much O2?

Answer 7

1.3mL

Question 8

In what 3 forms is CO2 transported in in the blood?

Answer 8

Dissolved in the plasma
Attached to proteins
As bicarbonate

Question 9

What % of blood CO2 is dissolved in the plasma?

Answer 9

10%

Question 10

What % of blood CO2 is attached to proteins (including Hb)

Answer 10

30%

Question 11

What % of blood CO2 is as Bicarbonate?

Answer 11

60%

Question 12

What enzyme facilitates the formation of bicarbonate?

Answer 12

Carbonic anhydrase

Question 13

How long does it take for PAO2 to reach PCO2?

Answer 13

.25 sec