Shift of the oxygen dissociation curve to right is caused by the following factors EXCEPT
**Core Concept**
The oxygen dissociation curve is a graphical representation of the relationship between the partial pressure of oxygen and the saturation of hemoglobin with oxygen. Shifts in the curve can indicate changes in the affinity of hemoglobin for oxygen, which can be influenced by various physiological and pathological factors.
**Why the Correct Answer is Right**
A shift of the oxygen dissociation curve to the right indicates a decrease in the affinity of hemoglobin for oxygen, making it easier for oxygen to be released to tissues. This is typically seen in conditions that require increased oxygen delivery to tissues, such as acidosis, hyperthermia, or increased levels of 2,3-bisphosphoglycerate (2,3-BPG). The correct answer should be a factor that does not cause a decrease in hemoglobin-oxygen affinity.
**Why Each Wrong Option is Incorrect**
**Option A:** 2,3-Bisphosphoglycerate (2,3-BPG) is a molecule that binds to hemoglobin and decreases its affinity for oxygen, causing a right shift of the oxygen dissociation curve. Therefore, it is not the correct answer.
**Option B:** Acidosis, such as lactic acidosis or diabetic ketoacidosis, also causes a decrease in hemoglobin-oxygen affinity and a right shift of the curve. This is due to the increased concentration of hydrogen ions, which bind to hemoglobin and reduce its affinity for oxygen.
**Option C:** Hyperthermia or increased body temperature also causes a right shift of the oxygen dissociation curve by increasing the concentration of 2,3-BPG and decreasing hemoglobin-oxygen affinity.
**Clinical Pearl / High-Yield Fact**
Remember that the Bohr effect describes the decrease in hemoglobin-oxygen affinity in response to increased carbon dioxide levels, which is an important concept in understanding respiratory physiology.
**Correct Answer: D**