Wk 10 - LE 17: Respiratory (diffusion & gas exchange)

Question 1

Pgas = ______ x ____

Answer 1

Pgas = Total Pressure (mm Hg) x Fgas

Question 2

PO2 = _______ x ____

Answer 2

PO2 = Total Pressure (mmHg) x Fo2

Question 3

Most of the total O2 content is bound to _____

Answer 3

haemoglobin

Question 4

What are 4 factors that weaken the affinity of Hb in exercise?

Answer 4

1) Temp
2) [H+] (acidity)
3) PCO2
4) 2-3DPG

Question 5

During exercise the binding of oxygen to Hb gets stronger (T/F)

Answer 5

False. It gets weaker.

Question 6

During exercise the PO2 gradient between alveoli and pulmonary capillary blood increases (T/F)

Answer 6

True

Question 7

Alveolar PO2 decreases from 159 to 100 mmHg (T/F)

Answer 7

False. Alveolar PO2 increases!

Question 8

CO increases relatively more than the alveolar ventilation (T/F)

Answer 8

False.

Question 9

Under normal exercise conditions, alveolar PO2 and arterial PO2 are different/similar?

Answer 9

Similar

Question 10

The lung is considered to or not to limit O2 delivery and O2 uptake?

Answer 10

Not to

Question 11

If pulmonary gas exchange becomes impaired, this results in a ______ in the difference between alveolar and arterial PO2

Answer 11

increase

Question 12

Normoxaemia is…?

Answer 12

Normal blood oxygen saturation

Question 13

Hypoxaemia is…?

Answer 13

Low blood oxygen saturation

Question 14

Arterial hypoxaemia is due to to either ____ limitation or inadequate _____

Answer 14

diffusion limitation or inadequate ventilation

Question 15

In non athletes, alveolar PO2 is ______ during exercise. But this has little effect on ____

Answer 15

increased, little effect on PCo2

Question 16

In elite ____ the response of alveolar PO2 is highly variable

Answer 16

athletes

Question 17

Often PO2 is _____ in athletes than nonathletes

Answer 17

lower

Question 18

Gas diffusion across air-blood barrier can be described as…?

Answer 18

Ficks law of diffusion

Question 19

Ventilation and perfusion influence gas diffusion most via ? (2)

Answer 19

1) their influences on the partial pressure gradients for O2 and CO2

Question 20

The time for complete oxygenation of pulmonary capillary blood as it transits across alveoli is _____ in exercise

Answer 20

reduced

Question 21

The O2 cascade illustrates the stepwise decline in PO2 from the ______ to the ____

Answer 21

atmosphere to the cells