Why do individuals who are anemic generally not exhibit an increa...

Question

Why do individuals who are anemic generally not exhibit an increase in respiratory rate or tidal volume, even though their blood is not carrying enough oxygen?

Accepted Answer

Welcome everyone. Our next question says, when the blood has a lower oxygen carrying capacity due to anemia, the oxygen hemoglobin saturation curve shifts to the right. This means that a hemoglobin saturation is low, leading to higher partial pressure oxygen b, hemoglobin, hemoglobin releases oxygen more readily to the tissues. C hemoglobin does not dissociate easily with oxygen causing tissue hypoxia or d the oxygen carrying capacity of hemoglobin is compromised. So let's look at our situation and first just remind ourselves of what the goal would be of the body in this situation that can help us keep straight whether the answer we come up with seems to make sense. So we're saying the blood, there's anemia going on. So the blood has a lower oxygen carrying capacity. So what would you need to happen? Less oxygen is being carried by the blood. You would want more oxygen going to the tissues. You'd want the hemoglobin to release oxygen to the tissues more easily. So let's remind ourselves of what is going on in the oxygen hemoglobin saturation curve. It's a graph where the Y axis is the percent of hemoglobin molecules that are saturated with oxygen. So how much of the hemoglobin is carrying oxygen versus has released the oxygen. And the X axis is the partial pressure of oxygen. So essentially the amount of oxygen or concentration of oxygen in the blood. So this is a curve that goes steeply upward at low partial pressures of oxygen and then sort of plateaus off or rises more slowly, I should say at higher pressures of oxygen. So we see that when there's less oxygen present, the amount of hemoglobin that saturated with oxygen rises very quickly and then slows down as there's more oxygen. So if we shift this entire curve to the right, that means that more of the hemoglobin has given up its oxygen even at higher partial pressures of 02. So that means essentially that hemoglobin is releasing its oxygen more easily. We don't have to have dropped down to a lower oxygen level to have the hemoglobin release its oxygen. So that's a situation when the curve shifts to the right. So let's look at our answer choices with this in mind. Choice. A says hemoglobin saturation is low leading to higher partial pressure of oxygen. Well, this is not our correct answer. Hemoglobin saturation is lower because the curve is shifted to the right at lower partial pressures of oxygen. But this is not leading to higher partial pressures of oxygen, this just is lower because it's releasing it's oxygen more readily. So choice A is not a correct description of the situation. Choice B is hemoglobin releases oxygen more readily to the tissues. And this is our correct answer. That's exactly what's going on to help deliver more blood in the, in the context of that reduced oxygen carrying capacity. Do I see hemoglobin does not dissociate easily with oxygen causing tissue hypoxia? Well, this is incorrect because it does dissociate easily, which enhances oxygen delivery, not causes hypoxia. And then finally choice d the oxygen carrying capacity of hemoglobin is compromised. Well, because we have anemia, the oxygen carrying capacity of the blood has been compromised because there are fewer red blood cells. But it doesn't affect the oxygen carrying capacity of the hemoglobin except to the extent that the hemoglobin gives up its oxygen more readily. But this is a compensatory mechanism for the overall decreased carrying capacity of the blood. So that's not really a correct description of what's going on here. So twice d not our answer. So again, when the oxygen hemoglobin saturation curve shifts to the right. When the blood has a lower oxygen carrying capacity, this means that choice b, hemoglobin releases oxygen more readily to the tissues. See you in the next video.

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Why do individuals who are anemic generally not exhibit an increase in respiratory rate or tidal volume, even though their blood is not carrying enough oxygen?

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