Term
| Describe the two ways in which O2 is carried, and which is the dominant method. |
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Definition
1. Dissolved in plasma (very small percentage)
2. Combined w/ Hemoglobin (Hb) - dominant method. |
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Term
| When Hb is fully saturated, how many O2 molecules does it carry? |
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Definition
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Term
| What is the normal Hb level? |
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Definition
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Term
| Describe the shape of the oxygen dissociation curve. |
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Definition
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Term
| On the O2 dissociation curve; with a change in pO2 have greater effect on Hb saturation between 60 and 80pO2, or between 80 and 100pO2? Why? |
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Definition
| greater effect on Hb saturation between 60&80pO2, because of the properties of the sigmoid curve. |
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Term
| Describe the Bohr effect. |
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Definition
| A shift of the O2 Dissociation Curve to the R, which enables Hb to give up O2 more readily, but could also mean that Hb can't hold O2 as well as it should be. |
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Term
| What are the three major (most common) reasons for the Bohr effect? |
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Definition
Increased [H]
Increased CO2
Increased temperature
----> All of these are caused by exercise. |
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Term
| Which has higher Hb saturation for the same pO2; blood w/ normal pH, or acidic blood? |
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Definition
| blood w/ normal pH. If it's acidic, the curve has shifted to the right, so at the same pO2 the point on the shifted curve is lower than that on the normal curve, indicating a lower Hb saturation, comparitively. (The pic of the graph is helpful for understanding this one.) |
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Term
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Definition
| Abnormally low level of O2 in the blood. |
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Term
| What are the 5 major reasons for hypoxemia? |
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Definition
1. Low V/Q (poor V/Qmatching)
2. Hypoventilation
3. Diffusion problem btw alveoli and blood
4. A shunt
5. Going to a high altitude, where pO2atm is decreased. |
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Term
| Describe a shunt in terms of blood. What causes it? |
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Definition
| Deoxygenated blood is put into the arterial side of the heart. The blood passes directly from the R to the L sides of the heart without going to the lungs for oxygenation. This dilutes the O2 of arterial blood. It's a congenital heart defect - hole in the heart. |
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Term
| A PO2 of less than what is always considered abnormal (except in v. young or v. old people)? |
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Definition
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Term
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Definition
| Fraction of Inspired O2: The amount (percentage) of O2 a person is breathing in. |
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Term
| What is the importance of FiO2? |
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Definition
| It is necessary to take into account whether a person's O2 levels are normal with or without assistive O2. (If a pt is on 4LO2 with normal pO2, they won't necessarily have a normal pO2 when the extra O2 is taken away and their FiO2 is decreased.) |
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Term
| Which of the following will decreased Hb cause; Hb saturation or oxygenation? |
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Definition
| Oxygenation. The ability of the remaining Hb to carry O2 hasn't been compromised. Only the number of Hb molecules available to carry O2 has been compromised. |
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Term
| What causes cyanosis? Low Hb levels, or low Hb saturation? |
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Definition
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Term
| If a person has low Hb, but normal saturation, what is the name of their condition? |
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Definition
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