altitude cure shift

[Monkey12]

---

Members do not see this ad.

Go to the mountains...Right or Left Hb curve shift?

 

[a1359m]

i think left b/c the affinity of the hemoglobin for the scarce O2 is high

 

[willthatsall]

Right, so the hemoglobin can unload the O2 to the tissues more easily. Not positive, but pretty sure.

 

[ComicBookHero20]

it'd be right because there needs to be a higher [O2] in the blood bc it is more scarce in the air

 

[DieselPetrolGrl]

yep right
same as woking out
unloads better to muscles

 

[bella_dottoressa]

right.

your bod wants to get more 02 to tissue.

 

[kidgorgeous]

I thought it was to the left because you need to pick up the atmospheric oxygen whose partial pressure is lower at high altitudes than at sea level. At least that's what that first full length from kaplan(llahma and horse) question taught me. I am not sure though.

 

[Fusion]

The curve depicts the behavior of hemoglobin with O2 already attached and moving through the circulation. Higher elevations will cause a rightward shift in the curve.

Just think of the curve as how Hb behaves in response to increased or decreased oxygen demands. It shifts to the right when you need oxygen, and shifts to the left when your O2 demand is decreased.

This and related topics were recently discussed at length in a similar thread in the MCAT forum.

 

[Tranceradu]

the reason the curve moves right, though, is because there is increased 2,3-DPG (=2,3-BPG) production. The curve shifts left originally, but the body counteracts this by producing a.) more DPG, b.) increasing myoglobin production... now the question is, what do we put down if they ask us this tomorrow, since, originally, it does go to the left (and experiments have shown that animals at higher altitudes have a dissosciatoin curve that is omre to the left than normal), but then this gets counteracted...

 

[ChyLn]

There is less O2 at high altitude, resulting in a lower pO2, the hemoglobin will need to be able to more efficiently bind the scarce O2 in order to deliver it to your body; it's a leftward shift.

I'm absolutely positive about this. The ability of hemoglobin is largely regulated by a molecule called 2,3 BPG, which is also responsible for fetal hb binding O2 more tightly. At high altitudes your body produces less of it, allowing the hb to bind O2 better.

Good luck tomorrow!

 

[AxlxA]

HOW DARE YOU ALL CONFUSE ME!!!!

Someone be brave and pick one final answer and you have to be able to refute the other

 

[Monkey12]

haha, so whats the answer

 

[OHare]

Negative. 2,3BPG DECREASES Hb's affinity for O2. 2,3BPG is NOT responsible for fetal Hb having a higher affinity than adult Hb. Fetal Hb has a different SUBUNIT which binds tighter.

2,3 BPG is released at high altitudes (Hypoxia) to unload the O2. You don't want all your O2 all bound up if you're going into hypoxia! You can simply deepen your respiration rate to get more O2 at low PO2s!

There is less O2 at high altitude, resulting in a lower pO2, the hemoglobin will need to be able to more efficiently bind the scarce O2 in order to deliver it to your body; it's a leftward shift.

I'm absolutely positive about this. The ability of hemoglobin is largely regulated by a molecule called 2,3 BPG, which is also responsible for fetal hb binding O2 more tightly. At high altitudes your body produces less of it, allowing the hb to bind O2 better.

Good luck tomorrow!

 

[willthatsall]

I'll post this excerpt from Kaplan: At high altitudes the partial pressure of O2 in the atmosphere declines, making it more difficult to get sufficient oxygen to diffuse into the capillaries. The body can compensate for these conditions in a variety of ways, such as by increasing the rate of ventilation (hyperventilation), and by increasing the production of red blood cells to carry more oxygen (polycythemia). In addition, the affinity of hemoglobin for oxygen decreases to facilitate unloading of oxygen in tissues, and there is greater vascularization of periperal tissues.

Looks like a shift to the right to me.

 

[OHare]

It's definitely a right shift. Low pH, High Temp, High PCO2-->right shift. This is the Bohr Effect. Think exercise.

2,3 BPG is released at high altitudes (Hypoxia) to unload the O2. You don't want all your O2 all bound up if you're going into hypoxia! You can simply deepen your respiration rate to get more O2 at low PO2s!

 

[medtechv79]

There is less O2 at high altitude, resulting in a lower pO2, the hemoglobin will need to be able to more efficiently bind the scarce O2 in order to deliver it to your body; it's a leftward shift.

I'm absolutely positive about this. The ability of hemoglobin is largely regulated by a molecule called 2,3 BPG, which is also responsible for fetal hb binding O2 more tightly. At high altitudes your body produces less of it, allowing the hb to bind O2 better.

Good luck tomorrow!

But if that was the case and all yer RBC bind hgb tightly yer tissues go into a state of hypoxia and don't get enuff O2. I think yer wrong....High altitudes u have inc. Hgb, thus u want inc. 02 release to tissues... if u have inc 2,3 DPG u have decreased affinity for 02 and its released to tissues, dec. 2,3 DPG u have inc. affinity for 02 and less 02 release to tissues...wow...this is all on the MCAT? I studied this for my MT program it seems like more clinical stuff than hardcore sciences....