what is the advantage of the hemoglobin saturation curve being sigmoidal rather

Question

what is the advantage of the hemoglobin saturation curve being sigmoidal rather than linear

1. What is the advantage to the flat part of the curve (between PO2 of 80 and 120 mmHg) (said otherwise, what if this were not flat over this range of values, but instead was only flat for a smaller range of PO2 values)? Be sure to explain the physiology taking place in the body.

2. What is the advantage to the steep part of the curve (between PO2 of 25 and 40mmHg)? Be sure to explain the physiology taking place in the body

Explanation / Answer

The advantage of haemoglobin saturation curve being sigmoidal is that it allows change in affinity for oxygen by haemoglobin. When pO2 is high, example in lungs, the oxygen affinity increases and haemoglobin gets saturated. When pO2 is low, in muscles, the oxygen affinity is low and the oxygen gets dissociated. A linear curve would imply that the oxygen affinity keeps on increasing and never reaches saturation.

1. The flat part of the curve between pO2 = 80 and 120 mmHg is that between these partial pressures, the haemoglobin is saturated with oxygen molecules. If the flat part existed for a smaller interval, oxygen gets dissociated in lungs itself, and there will be ineffecyiin transmission of oxygen to other parts of the body.

2. The steep part of the curve indicates oxygen dissocixdiss in muscles where concentration of oxygen is less. If the curve was not steep, dissociation of oxygen from haemoglobin would not happen effectively.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.