Pulmonary blood flow, gas exchange and transport

Question 1

What is the difference between bronchial and pulmonary circulation?

Answer 1

Bronchial circulation is supplied via the bronchial arteries arising from systemic circulation to supply oxygenated blood to airway smooth muscle, nerves and lung tissue.
Pulmonary circulation is a unique system, with high flow but low pressure, which carries the entire cardiac output from the right ventricle and supplies a dense bed of capillaries around alveoli then carries oxygenated blood back into the left atrium via the pulmonary vein.

Question 2

What is partial pressure?

Answer 2

Partial pressure is the pressure a gas within a mixture would exert if it occupied the volume the whole mixture does.
Percentage of the gas in mixture multiplied by the pressure of the whole mixture.

Question 3

Describe “shunt”.

Answer 3

When well oxygenated blood is diluted by poorly oxygenated blood from areas with good perfusion but no ventilation.

Question 4

What are some factors which may affect the affinity of oxygen for haemoglobin?

Answer 4

pH
Temperature
PCO2
2, 3-diphosphoglycerate (DPG)

Question 5

What is perfusion?

Answer 5

The pumping of a fluid through an organ or tissue.

Question 6

The rate of diffusion is directly proportional to the…

Answer 6

Partial pressure gradient
Gas solubility
Available surface area

Question 7

The rate of diffusion is inversely proportional to the…

Answer 7

Thickness of the membrane

Question 8

In what forms are CO2 carried in the blood?

Answer 8

7% is dissolved in plasma and erythrocytes
23% combines in the erythrocytes with deoxyhaemoglobin to form carbamino compounds
70% combines in the erythrocytes with water to form carbonic acid, whihc then dissociates into bi carbonate and H+ ions