Lecture 8- matching ventilation to perfusion

Question 1

Where does ventilation of lungs occur

Answer 1

through airways

Question 2

where for perfusion occur

Answer 2

blood vessels

Question 3

why are apical alveoli bigger than basal alveoli in upright position

Answer 3

effect of gravity

Question 4

does apical or basal alveoli have better ventilation and why

Answer 4

basal because they can expand more than apical alveoli

Question 5

define lung parenchyma

Answer 5

part of lung involved in gas transfer

Question 6

where is the maximum hydrostatic pressure

Answer 6

at the bottom of the lung

Question 7

Why is zone 1 known as alveolar dead space

Answer 7

no perfusion so no gas exchange can take place

Question 8

Give the relationships between alveolar, pulmonary arterial and pulmonary venous pressures in zone 1

Answer 8

PA>Pa>Pv

Question 9

Give the relationships between alveolar, pulmonary arterial and pulmonary venous pressures in zone 2

Answer 9

Pa>PA>Pv

Question 10

Give the relationships between alveolar, pulmonary arterial and pulmonary venous pressures in zone 3

Answer 10

Pa>Pv>PA

Question 11

what is the ideal ventilation/perfusion ratio

Answer 11

1

Question 12

is the ventilation/perfusion ratio higher or lower than 1 in apical regions

Answer 12

lower (around 0.6)

Question 13

is the ventilation/perfusion ratio higher or lower than 1 in basal regions

Answer 13

higher (around 3.3)

Question 14

define physiological dead space

Answer 14

part of each breath that does not take part in gs exchange (anatomic dead space+alveolar dead space)