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44 Cards in this Set
- Front
- Back
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Hb-O2 CURVE
y-axis is? x-axis is? |
Hb %saturation
pO2 |
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Hb-O2 CURVE
- Hb w/ 100% saturation @ what pO2? - this pO2 is equivalent to that of blood? |
100 mmHg
Arterial Blood |
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Hb-O2 CURVE
- Hb w/ 75% saturation @ what pO2? - this pO2 is equivalent to that of blood? |
40 mmHg
Mixed Venous Blood |
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Hb-O2 CURVE
- Hb w/ 50% saturation @ what pO2? |
25 mmHg
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Hb-O2 CURVE
- P50 means what? - occurs @ what pO2? |
- 50% of Hb is saturated w/ O2
(or average of 2 or 4 heme groups) - 25 mmHg |
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Hb-O2 CURVE
- shape of curve? - what property causes this shape? |
Sigmoid
Positive Cooperativity |
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Hb-O2 CURVE
- Define Positive Cooperativity |
Binding 1st O2 molecule increases affinity for 2nd O2 molecule, which increases affinity for 3rd O2 molecule, ....etc.
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Hb-O2 CURVE
- Hb has the Highest Affinity for which O2 molecule? |
- 4th O2 molecule
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Hb-O2 CURVE
- Flat portion of the curve represents facilitation of? |
- O2 Loading
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Hb-O2 CURVE
- Steep portion of the curve represents facilitation of? |
- O2 Unloading
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Hb-O2 CURVE
- in the lungs, what pO2 is seen (and with what value?) - @ these pO2 levels, what would the O2 affinity be expected to be? |
- Alveolar pO2 is 100 mmHg
- "arterialized" pulmonary capillary blood pO2 is 100 mmHg - Very High Affinity of Hb for O2 |
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Hb-O2 CURVE
- in the lungs, the tight binding of O2 by Hb causes what effect on the Free O2? - resulting effect on Partial Pressure Gradient of Free O2 |
- Keeps Free O2 Concentration Low
- Keeps Free O2 partial pressure Low - Maintains Partial Pressure Gradient (driving O2 diffusion) |
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Hb-O2 CURVE
- in the lungs, tight binding of Hb O2 will Facilitate what process? |
- Diffusion
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Hb-O2 CURVE
- in the lungs, describe the character of the curve. |
- Flat
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Hb-O2 CURVE
- Curve is Most Flat at what pO2 value ranges? - What does this imply about humans tolerating changes in Patm? |
60 mmHg to 100 mmHg
Humans can tolerate various changes of Patm (& pO2) WITHOUT compromising O2 carrying capacity |
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Hb-O2 CURVE
- in the Tissue, what is the affinity for O2 by Hb? - in Tissue, this affinity facilitates what for O2? |
- Low Affinity
- Release of O2 in to tissue |
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Hb-O2 CURVE
- in the Tissues, describe the character of the curve |
- Steep
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Hb-O2 CURVE
- Right shift occurs with what O2 affinity? - thus facilititating? |
- Decreased O2 affinity
- O2 Unloading |
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Hb-O2 CURVE
- Bohr effect reflects which shift? - describe Bohr effect? - Bohr effect will facilitate? |
- Right shift
- increased H+ causes Decreased O2 affinity - O2 Unloading |
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Hb-O2 CURVE
- Right shift effect on P50? |
- Increases P50
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Hb-O2 CURVE
- Causes of Right shift with Increased what? |
(CADET faces right)
- CO2 - Altitude/Acid - DPG - Exercise - Temperature |
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Hb-O2 CURVE
- Causes of Right shift with Decreased what? |
- pH
(or increased H+) |
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Hb-O2 CURVE
- 2,3-DPG binds to what? - 2,3-DPG effects on O2 affinity - 2,3-DPG facilitates |
- Beta chains of DEOxyHb
- Decreases O2 affinity - O2 Unloading (into tissue) |
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Hb-O2 CURVE
- Adaptation to Chronic Hypoxemia (i.e. - living @ high altitudes) occurs with increased synthesis of? |
- 2,3 DPG
(thus increased facilitation of O2 Unloading into tissues) |
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Hb-O2 CURVE
- Causes of Left shift with Increased what? |
- pH
- Fetal Hb (or decreased H+) |
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Hb-O2 CURVE
- Causes of Left shift with Decreased what? |
- CO2
- Altitude/Acid - DPG - (none) - Temperature |
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Hb-O2 CURVE
- Fetal Hb (HbF) causes what shift? - why? |
- Left shift
- HbF does NOT bind 2,3-DPG as well as adult Hb |
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CARBON MONOXIDE POISONING
- CO competes with what? for what? - CO affinity for Hb? |
- competes with O2 for Hb binding sites
- 200x more than O2 |
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CARBON MONOXIDE POISONING
- effects on O2 |
- Decreases O2 Content
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CARBON MONOXIDE POISONING
- CO binding, will affect additional Hb binding how? |
- Increases affinity of remaining sites for O2 (or more CO)
(thus display Positive Cooperativity) |
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Decrease in 2,3-DPG causes what effect on HbF?
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Increases O2 Affinity for HbF
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Define Hypoxemia
Hypoxemia requires what Equation? |
Decrease in Arterial pO2
A-a Gradient = pAO2 - paO2 |
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Define Hypoxia
Hypoxia requires what Equation? |
Decrease in O2 Delivery (to tissues)
O2 Delivery = CO x O2 Conent |
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A-a Gradient
- used to do what clinically? - normal A-a Gradient? |
- compare causes of Hypoxemia
- Less than 10 mmHg |
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A-a Gradient
- describe in words |
- Difference in partial pressure of Alveolar air & Arterial Blood
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A-a Gradient
- Equation (in humidified air) |
= (150 - pCO2/0.8) - pO2
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A-a Gradient
- Increases if O2 does NOT ....? |
- Equilibriate
btw Alveolor gas & Arterial Blood |
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HYPOXIA
- O2 Content depends on what factors? |
- Hb Concentration
- O2 Binding Capacity - % Saturation of Hb by O2 (which depends on pO2) |
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HYPOXIA
- Hypoxia can be caused what changes in pulmonary properties? |
- Decreased CO
- Decreased O2 Binding Capacity - Decreased paO2 ( = Hypoxemia) |
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Causes of Hypoxemia with NORMAL A-a Gradient
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- High Altitude
- Hypoventilation |
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Causes of Hypoxemia with INCREASED A-a Gradient
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- Diffusion Defect (i.e. - fibrosis)
- V/Q defect - Right-to-Left Shunt |
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Fibrosis
- Obstructive or Restrictive? - Defect of what process? - Causes Hypoxemia or Hypoxia? |
- Restrictive
- Defect in Diffusion - Hypoxemia |
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Fibrosis
- changes in arterial pO2 - A-a Gradient - Hypoxemia or Hypoxia? |
- Decreases paO2
- Increases A-a gradient - Hypoxemia |
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Name causes of Hypoxia
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- Cardiac Output Decrease
- Hypoxemia - Anemia - Poisoning w/ Carbon Monoxide - Poisoning w/ Cyanide |
