Ventilation and perfusion balance

Question 1

What reduces partial pressures in alveolar

Answer 1

‘wet air”

Question 2

What is the amount of gas transferred proportional to

Answer 2

Pressure gradient 
Surface area available for diffusion 
1/length of the pathway 
solubility 
1/root molecular weight

Question 3

In terms of Partial Pressure of 02 and C02 leaving the pulmonary capillary and the alveolus, what is the relationship between them

Answer 3

Pulmonary capillary pressure is essentially the same as the partial pressures of gas in the alveolus

Question 4

What are the typical gas values in a healthy adult (Arterial PaO2 and PaC02

Answer 4

PaO2 = 13Kpa (100mmHg)
PaC02= 5.3kPa (40mmHg)

Question 5

What are the typical gas values in a healthy adult (venous l PaO2 and PaC02

Answer 5

PaO2 = 5Kpa (37mmHg)
PaC02= 6kPa (45mmHg)

Question 6

is oxygen soluble in plasma

Answer 6

Not very a tall

Question 7

What is Hb

Answer 7

Haemoglobin

Question 8

Explain Haemoglobin

Answer 8

Oxygen carrying pigment
Contained within red cells
Each Hb molecule can bind 4 molecules of oxygen

Question 9

How many ml of O2 does 1g of Hb hold

Answer 9

1.3ml oxygen

Question 10

How many mmol/l do we need for oxygen content in blood

Answer 10

9 mmol/l

Question 11

Draw a saturation of Hb with O2 over PO2 graph

Answer 11

k bos

Question 12

Is the O2 content and the PaO2 a linear graph

Answer 12

yer ma g

Question 13

how is the majority of CO2 carried in the blood

Answer 13

Bicarbonate and Carbamino

Question 14

What are the perfusion related causes of V/Q inequalities

Answer 14

Gravity, Respirator disease and pulmonary embolus

Question 15

Where is the ventilation higher in the lungs

Answer 15

Base

Question 16

What effect does gravity have on the lungs

Answer 16

Apex more stretched than lower bits

Question 17

Where is perfusion higher

Answer 17

Base of lungs

Question 18

What can sometimes get arterioles to constrict

Answer 18

Hypoxic pulmonar

Question 19

What is cor pulmonale

Answer 19

Right heart failure

Question 20

What does a decreased blood flow to the region of lung cause

Answer 20

Decreased Air flow

Question 21

What does a decreased air flow to region of lung cause

Answer 21

Decreased blood flow

Question 22

What do the local adaptions to V/Q inequalities help

Answer 22

divert blood and air flow away from local area of disease to healthy areas

Question 23

What happens when Pulmonary air flow is decreased to a specific area of lung

Answer 23

Lung Blood PO2 decreases
Vasoconstriction of pulmonary vessels
Thus Decreased blood flow