Gas Transport

Question 1

What circulation runs in series with the pulmonary circulation?

Answer 1

Systemic circulation

Question 2

How is pulmonary circulation specialised ?

Answer 2

1. Pressure is low
2. Pulmonary arterial walls are thin and contain little smooth muscle
3. Vascular resistance is low

Question 3

Effect of gravity on ventilation and perfusion. Why ?

Answer 3

Perfusion and ventilation decreases as you go from the base to top of the lungs.
More blood and airflow at the base of the lungs.
Because blood pressure is greater at the base

Question 4

Va:Q (alveolar ventilation rate:blood flow) can vary from 0 to infinity. What does this mean ?

Answer 4

0- blood passes through lung without coming into contact with alveolar air
Infinity- anatomical dead space, or ventilated alveoli that are not perfused

Question 5

What do fish use to maximise gas exchange ?

Answer 5

Countercurrent flow

Question 6

How would you describe the binding of oxygen molecules to haemoglobin ?

Answer 6

Co-operative

Question 7

What is the Bohr shift ?

Answer 7

Haemoglobin’s affinity for oxygen decreases in response to increased carbon dioxide, increased temp and lower PH levels.
This means that more oxygen is released to tissues when needed.

Question 8

Haemoglobin oxygen capacity

Answer 8

Has 4 Fe-containing heme groups which allows it to carry 4 oxygen molecules

Question 9

Myoglobin oxygen capacity

Answer 9

Similar to single Hb subunit.
Stronger affinity for oxygen than Hb.

Question 10

What respiratory pigment do Crustacea have ?

Answer 10

Haemocyanin, a copper containing molecule (bright blue).
Freely found in plasma.

Question 11

What are carbamino compounds ?

Answer 11

CO2 forms carbamino compounds on Hb, which releases oxygen to metabolising cells.