Blood supply, gas exchange, ventilation and perfusion 2

Question 1

How much o2 is dissolved per litre of plasma?

Answer 1

3ml

Question 2

What does haemoglobin increase the amount of o2 carried by blood too?

Answer 2

200ml/L

Question 3

how much of arterial o2 is extracted by peripheral tissues at rest?

Answer 3

25%

Question 4

haemoglobin co-operatively binds with 4 molecules of o2. Is this oxidation or oxygenation?

Answer 4

Oxygenation - as it is a fleeting relationship not permanent.

Question 5

what determines the saturation of haemoglobin?

Answer 5

The partial pressure of o2 of arterial blood (same as the partial pressure in alveoli)

Question 6

What continues until the haemoglobin is fully saturated?

Answer 6

Haemoglobin takes o2 from arterial blood, so o2 keeps going into the arterial blood from the alveoli.

Question 7

When does co-operation become evident in the haemoglobin curve?

Answer 7

When the partial pressure of oxygen falls below 60 - they all start to unbind quickly.

Question 8

Explain how the blood has a huge reserve of o2?

Answer 8

deoxygenated blood (resting cells) are still 75% oxygenated.

Question 9

Why do foetal haemoglobin and myoglobin have a steeper curve than normal haemoglobin?

Answer 9

They have a higher affinity for oxygen. This means they can extract o2 from maternal / arterial blood.

Question 10

how is the bulk of co2 transported?

Answer 10

in various forms, in solutions in plasma.

Question 11

is the concentration or the partial pressure the same in the plasma and the alveoli?

Answer 11

Same partial pressure but not the same concentration.

Question 12

What is anaemia?

Answer 12

any condition where the o2 carrying capacity of the blood is compromised. - e.g iron deficiency, haemorrhage.