Blood Supply, Gas Exchange, Ventilation and Perfusion

Question 1

What pulmonary blood vessel travels away from the heart?

Answer 1

Pulmonary Artery

Question 2

What pulmonary blood vessel travels towards the heart?

Answer 2

Pulmonary Vein

Question 3

What does pulmonary circulation deliver to the lungs?

Answer 3

Carbon Dioxide

Question 4

What circulation delivers oxygenated blood to airway smooth muscle, nerves and lung tissue?

Answer 4

Bronchial circulation

Question 5

The entire cardiac output from the right ventricle is carried by what circulation?

Answer 5

Pulmonary circulation

Question 6

The dense capillary network surrounding the alveoli is supplied by what circulation?

Answer 6

Pulmonary circulation

Question 7

What gradients drive gas exchange?

Answer 7

Partial pressure gradients

Question 8

What do the following abbreviations stand for:
A
a
ṽ
in relation to blood?

Answer 8

A = alveolar
a = arterial blood 
ṽ = mixed venous blood

Question 9

What kind of membrane do gases move across?

Answer 9

Permeable

Question 10

The rate of diffusion across the membrane is directly proportional to what?

Answer 10

The partial pressure gradient
The gas solubility
The available surface area

Question 11

What is more soluble in water, carbon dioxide or oxygen?

Answer 11

Carbon dioxide

Question 12

In Emphysema, what are the values of Alveolar PO2 and Capillary PO2 relative to normal values?

Answer 12

Alveolar PO2 – normal or low

Capillary PO2 –low

Question 13

In Fibrotic Lung Disease, what are the values of Alveolar PO2 and Capillary PO2 relative to normal values?

Answer 13

Alveolar PO2 – normal or low

Capillary PO2 – low

Question 14

What effect does the thickened alveolar membrane in fibrotic lung disease have on gas exchange?

Answer 14

It slows the rate of gas exchange

Question 15

In Pulmonary Oedema, what are the values of Alveolar PO2 and Capillary PO2 relative to normal values?

Answer 15

Alveolar PO2 – normal

Capillary PO2 –low

Question 16

In what lung condition would both Alveolar PO2 and Capillary PO2 be lower than normal?

Answer 16

Asthma

Question 17

What pressures influence the distribution of blood flow in the lungs?

Answer 17

Hydrostatic blood pressure and alveolar pressure

Question 18

At the base of the lungs, blood flow is

Answer 18

high

Question 19

At the apex of the lungs, blood flow is

Answer 19

low

Question 20

When arterial pressure is less than alveolar pressure, blood flow will be

Answer 20

low

Question 21

There is a mismatch in Ventilation:Perfusion when the ratio is

Answer 21

1.0

perfectly matched when ratio is 1.0

Question 22

If ventilation decreases in a group of alveoli, what effect will this have on PCO2 and PO2?

Answer 22

PCO2 - increases

PO2 - decreases

Question 23

What is “shunt”?

Answer 23

The passage of blood flow through areas of the lung that are poorly ventilated

Question 24

What effect is there on arterioles when there is decreased tissue PO2 around under-ventilated alveoli?

Answer 24

Arterioles will constrict

Question 25

What is the purpose of arteriole constriction?

Answer 25

To divert the blood to better ventilated alveoli

Question 26

Constriction in response to hypoxia is particular to what vessels?

Answer 26

Pulmonary

Question 27

Alveolar dead space is

Answer 27

alveoli that are ventilated but not perfused