Functional Effects of Haemoglobin (PK6)

Question 1

What is the association part of the haemoglobin dissociation curve and what does it ensure?

Answer 1

• The flat part at the top
• Ensures complete loading of Hb despite potential small fluctuations in level of PO2

Question 2

What is the dissociation part of the haemoglobin dissociation curve and what does it ensure?

Answer 2

• The steep part
• Adequate delivery of O2 to tissues whilst still maintaining arterial PO2 levels high (for diffusion)

Question 3

What factors move the Hb dissociation curve to the right?

Answer 3

• Increased PCO2
• Decreased pH
• Increased temperature
• Increased 2,3-DPG concentration

Question 4

What are increased PCO2 and pH shifting the Hb dissociation curve to the right known as collectively?

Answer 4

Bohr effect

Question 5

What factors increase/decrease 2,3-DPG concentration?

Answer 5

• I = chronic hypoxia, altitude
• D = acidosis, storage in blood banks

Question 6

What is P50?

Answer 6

PO2 at which the curve (Hb) is 50% saturated

Question 7

What effected does the curve shifting left/right have on P50?

Answer 7

• L = decreases P50
• R = increases P50

Question 8

What is autoregulated delivery?

Answer 8

Amount of O2 delivered depends on how far curve is shifted rightward, which depends on how much PCO2/[H+] + temperature have changed, which depend on how much metabolism has increased