Term
| Is most of the O2 carried in hemoglobin or as dissolved? |
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Definition
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Term
| Which is more soluble in water: CO2 or O2? |
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Definition
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Term
| Which can hold more CO2, plasma or whole blood? |
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Definition
- Plasma
- If you take plasma without cells then you can get in more CO2 than with whole blood
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Term
| What does combined CO2 mean? |
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Definition
- CO2 carried in some other form
- Ex: bicarbonate
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Term
| Which is more acidic, arterial or venous blood? |
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Definition
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Term
| What is the pH of arterial blood? |
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Definition
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Term
| What happens to dissolved O2 when you raise the partial pressure? |
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Definition
- Dissolved O2 will rise proportionally to a rise in partial pressure
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Term
| What happens if you increase the partial pressure of O2? |
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Definition
- Increases the volume of O2 in the blood
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Term
| How can more oxygen be delivered to the tissues when more oxygen is needed? |
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Definition
- Increase oxygen loading in the lungs
- Increase oxygen unloading in the tissues
- Increase in blood flow to the tissues
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Term
| What is methemoglobin reductase? |
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Definition
- Prevents formation of methemoglobin, where its 3+ instead of 2+ and a poor oxygen transporter
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Term
| Describe the structure of hemoglobin. |
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Definition
- Consists of:
- Globin (a protein)
- 4 heme (iron porphyrin prosthetic groups)
- 4 polypeptide chains
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Term
| What does hemoglobin bind?E |
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Definition
- Iron in the ferrous state is bound to each heme
- Each heme group binds a molecule of oxygen
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Term
| What is the difference between F hemoglobin and A hemoglobin? |
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Definition
- F is fetal hemoglobin
- Gamma chains replace beta chains
- A is adult hemoglobin
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Term
| Where are the dynamic differences in hemoglobin between species found? |
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Definition
- Globin portion of the hemoglobin molecule
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Term
| What is the pO2 of arterial blood? |
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Definition
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Term
| What is the pO2 of venous blood? |
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Definition
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Term
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Definition
- Tells the amount of pO2 at which 50% of hemoglobin is saturated
- If p50 is higher, its a right shift
- If p50 is lower, its a left shift
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Term
| How does hemoglobin know when to bind or release oxygen? |
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Definition
- pO2 of the environment
- If hemoglobin goes into a low oxygen environment, it lets go of oxygen
- If hemoglobin goes into a high oxygen environment, it binds oxygen
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Term
| At what pressure is hemoglobin 100% saturated? |
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Definition
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Term
| What percent saturation of hemoglobin does arterial and venous blood have? |
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Definition
- Arterial: 97%
- Venous: 70%
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Term
| What happens to hemoglobin with temperature changes? |
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Definition
- Temp increase= hemoglobin gives up more oxygen
- Activities that cause heat require more oxygen
- Temp decrease= hemoglobin binds oxygen tighter
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Term
| What happens to hemoglobin with pH changes? |
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Definition
- Lower pH (acidic)= hemoglobin gives up more oxygen
- Activity causes more acid production & activity needs more oxygen
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Term
| What happens to hemoglobin with DPG? |
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Definition
- DGP= hemoglobin gives up more oxygen
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Term
| What happens to hemoglobin with CO2 changes? |
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Definition
- High CO2= hemoglobin gives up more oxygen
- Active tissues produce heat, acid, & CO2, and those same tissues need more oxygen
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Term
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Definition
- Enhances unloading of oxygen
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Term
| What is stagnant hypoxia? |
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Definition
- Blood is flowing slower
- Oxygen is just pouring out, so by the time you get to venous blood its exhausted
- Much bigger AV difference in oxygen saturation than normal
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Term
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Definition
- Not enough oxygen is available (like breathing in a gas will little oxygen)
- Not enough oxygen gets to the alveoli
- Start with less oxygen in the arterial blood & blood goes back venously with less blood
- However, tissues will still try to take the normal amount of oxygen, so the AV difference will be normal
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Term
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Definition
- Oxygen is available but there isn't enough hemoglobin to carry it
- Less oxygen transport due to lack of hemoglobin
- Tissues will still try to take what they need, so AV difference remains normal
- Can't rely on partial pressure to tell you the animal really needs oxygen
- Carbon monoxide can cause hypoxic hypoxia by tying up hemoglobin
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Term
| What is circulatory (escemic) hypoxia? |
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Definition
- Blood flow problem to the tissues
- Oxygen is available, but can't get to where it needs to go
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Term
| What is histotoxic hypoxia? |
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Definition
- Biochemical problem where oxygen is available but not being used by the tissues b/c of some problem
- Venous blood comes back more saturated than normal b/c the tissues are not using the oxygen
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Term
| What are the types of hypoxia? |
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Definition
- Stagnant hypoxia
- Hypoxic hypoxia
- Anemic hypoxia
- Circulatory (escemic) hypoxia
- Histotoxic hypoxia
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Term
| How is the majority of CO2 transported in the blood? |
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Definition
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Term
| What is it called when CO2 is transported as bound to hemoglobin? |
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Definition
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Term
| Explain CO2 transport in the venous periphery. |
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Definition
- CO2 comes out of the cell into the plasma down a partial pressure gradient
- Now its transported as dissolved CO2
- CO2 diffuses into the RBC
- In RBC, some will combine with hemoglobin & be transported as carbaminohemoglobin
- This acts as a buffer to keep CO2 from making an acid.
- Or CO2 can combine with water (catalyzed by carbonic annhydrase) to form carbonic acid
- Carbonic acid dissociates into bicarbonate & hydrogen ions (H+ changes pH)
- H+ can attach to hemoglobin (which is again acting as a buffer)
- Bicarbonate will build up until it moves down a concnetration gradient out into the plasma
- Chloride will move into the RBC to take the place of bicarbonate (chloride shift)
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Term
| Explain CO2 transport in the lungs. |
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Definition
- O2 attaches to hemoglobin
- CO2 dettaches from hemoglobin & moves out of the RBC into the dissolved state
- Because there is more CO2 in the venous blood than in the alveoli, it will move into the alveoli
- Bicarbonate will move into the RBC to produce more CO2, which has a place to go in the alveoli
- As bicarbonate moves into the RBC, chloride moves back out
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Term
| How does the body react to acidosis? |
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Definition
- Buffer
- Kidney reabsorption of bicarbonate
- Increase in respiratory minute volume
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Term
| Describe hemoglobin binding of CO2 and O2. |
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Definition
- Hemoglobin can bind both O2 and CO2
- They do not bind to the same site (unlike CO)
- When CO2 binds to hemoglobin, it diminishes the affinity of hemoglobin for O2 and it will give up more oxygen
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Term
| What is the normal amount of oxygen transported in 100 ml of whole blood? |
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Definition
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Term
| How much oxygen is transported in the dissolved state? |
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Definition
- 0.3 mL/100 mL of whole blood
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Term
| How much carbon dioxide is transported in the dissolved state? |
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Definition
- 2.8 mL/100 mL whole blood
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Term
| What is the normal pCO2 in the arteries? |
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Definition
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Term
| What is the normal pCO2 in the veins? |
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Definition
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Term
| What is the normal pO2 in the arteries? |
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Definition
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Term
| What is the normal pO2 in the veins? |
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Definition
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