Term
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Definition
The flow of oxygen, or any gas, (V) across a barrier is proportinal to its diffusing capacity (Dl)in the barrier and its concentration gradient across the barrier (P1 - P2).
V = Dl x (P1 - P2) |
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Term
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Definition
| Diffusion is inversely proportional to the square root of the molecular weight of the gas |
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Term
| What is the rate limiting step in oxygen diffusion? |
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Definition
| Diffusion in the tissues because the distances are much longer |
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Term
| How does the CV system minimize diffusion distance? |
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Definition
| By increasing capillary density, increasing the rate of delivery of oxygenated blood to the tissues by increasing flow rates or by increasing the oxygen carrying capability of the blood |
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Term
| How is methemoglobin formed? |
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Definition
| When iron in hemoglobin is oxidized by nitriles or sulfonamides. Incapable of binding oxygen |
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Term
| What is the O2 carrying capacity of blood? |
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Definition
20.1 mL of O2 per 100 mL of blood
O2 deliver to the tissues would be about 1000 mLs of O2 per minute. Normal consumption is about 250 mls/min |
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Term
| In what direction of the curve does affinity decrease/increase? |
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Definition
Decrease - to the right
Increase - to the left |
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Term
| Does a left shift increase or decrease oxygen loading in the lung? |
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Definition
| It increases oxygen loading in the lung. |
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Term
| How does increased temp affect the curve? |
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Definition
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Term
| How does increased pH affect the curve? |
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Definition
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Term
| How does increased PCO2 affect the curve? |
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Definition
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Term
| How does increased 2,3 DPG affect the curve? |
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Definition
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Term
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Definition
| It is a heme containing molecule that is unlike hemoglobin in that it is a monomer and shows no allosteric cooperativity. It begins unloading O2 around at a pressure of 20mmHg. |
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Term
| How does CO affect hemoglobin? Which way does it shift the curve? |
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Definition
| It binds Hb with a 240 fold increased affinity. CO significantly increases the affinity of Hb for oxygen. Shifts the curve way to the Left. Therefore, the affected Hb will not be able to unload oxygen at the level of the tissues. |
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Term
| Which way does nitric oxide shift the curve? |
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Definition
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Term
| How does venous blood compare to arterial blood in terms of the curve? |
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Definition
| Curve is shifted to the right in venous blood due to the Bohr effect vs. arterial blood. Makes sense b/c arterial blood should facilitate unloading moreso than venous blood. |
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Term
| Why do dialysis patients normally become anemic? |
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Definition
| Because EPO is synthesized in the kidneys, and this directly affects the levels of RBCs in the blood. If the kidneys are not functioning or are removed, the levels of RBCs will be low. |
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