Chronic hypoxemia and cyanosis increase the levels of which substances?

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Multiple Choice

Chronic hypoxemia and cyanosis increase the levels of which substances?

Chronic hypoxemia signals the body that tissues aren’t getting enough oxygen, and the body adapts to improve oxygen delivery. The kidneys respond to low oxygen by increasing production of erythropoietin, which stimulates the bone marrow to produce more red blood cells, raising hemoglobin levels. At the same time, red blood cells ramp up 2,3-bisphosphoglycerate production. 2,3-BPG binds to deoxyhemoglobin and lowers its affinity for oxygen, shifting the hemoglobin-oxygen dissociation curve to the right. This makes it easier for oxygen to be released from hemoglobin to the tissues that need it, which is especially important when arterial oxygen is chronically low. So the principal substances increased in this situation are 2,3-BPG and erythropoietin. Hemoglobin can rise as a consequence of more red blood cells, but the targeted compensatory changes that directly facilitate oxygen delivery are those two. Carbon dioxide and nitric oxide aren’t the primary, consistent increases seen with chronic hypoxemia and cyanosis in the same way.

Chronic hypoxemia signals the body that tissues aren’t getting enough oxygen, and the body adapts to improve oxygen delivery. The kidneys respond to low oxygen by increasing production of erythropoietin, which stimulates the bone marrow to produce more red blood cells, raising hemoglobin levels. At the same time, red blood cells ramp up 2,3-bisphosphoglycerate production. 2,3-BPG binds to deoxyhemoglobin and lowers its affinity for oxygen, shifting the hemoglobin-oxygen dissociation curve to the right. This makes it easier for oxygen to be released from hemoglobin to the tissues that need it, which is especially important when arterial oxygen is chronically low.

So the principal substances increased in this situation are 2,3-BPG and erythropoietin. Hemoglobin can rise as a consequence of more red blood cells, but the targeted compensatory changes that directly facilitate oxygen delivery are those two. Carbon dioxide and nitric oxide aren’t the primary, consistent increases seen with chronic hypoxemia and cyanosis in the same way.

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