Term
| (04-20) What does the Oxygen-hemoglobin dissociation curve graph look like? |
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Definition
| X-axis is PO2 in mmHg, Y-axis is percent oxygen saturaion of Hb. A positive slope that levels out to a plateau around 100 mmHg and 98% saturation |
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Term
| (04-20) On an oxygen-Hb dissociatin curve, what is the percent oxygen saturation and the pressure of oxygen in a resting cell |
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Definition
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Term
| (04-20) Oxygen-Hb dissociation curve: What happens if we shift it to the right? What is favored? |
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Definition
| The plateau of hemoglobin saturation is the same as normal (about 98%), but the resting cell (around 40 mmHg), has a reduced percentage of oxygen. This favors oxygen unloading in tissues |
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Term
| (04-20) Oxygen-Hb dissociation curve: What happens if the curve is shifted to the left? What does it favor? |
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Definition
| The plateau remains the same (about 98% at 100 mmHg), but the resting cell has a higher saturation of oxygen. This favors oxygen loading (hemoglobin holds onto oxygen even tighter) |
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Term
| (04-20) What happens to a hemoglobin molecule when one oxygen binds to it? What's the outcome? What type of binding is this? |
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Definition
| Hb undergoes a conformational change, revealing the other heme groups and allowing more oxygen to bond quicker. This binding is cooperative. |
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Term
| (04-20) What are other factors that affect the oxygen-Hb dissociation curve? |
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Definition
| Temperature, carbamino effect (CO2), Bohr effect (pH), 2,3-DPG (molecule that can bind to Hb instead of oxygen) |
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Term
| (04-20) How do lower temperatures affect the oxygen-Hb dissociation curve? Higher temperatures? |
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Definition
| Lower temperatures move the curve to the left (oxygen is not delivered to the tissues). Higher temperaures shift the curve to the right (causes oxygen unloading in the tissues) |
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Term
| (04-20) What is the carbamino effect? how does an increase affect the oxygen-Hb curve? A decrease? |
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Definition
| Carbamino: increases partial pressure of carbon dioxide. An increase shifts the curve to the right (favors unloading of oxygen in the tissues). A decrease shifts the curve to the left (oxygen is not unloaded in the tissues) |
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Term
| (04-20) What happens to the oxygen-Hb curve when you exercise? Why? |
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Definition
| You increase the carbamino effect and temperature, which shifts the curve to the right (favors the unloading of oxygen) |
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Term
| (04-20) What is the Bohr effect? How does it affect the oxygen-Hb curve? |
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Definition
| Bohr effect: decreased pH decreases Hb's affinity for oxygen. A decrease in pH (increase in H+), shifts the curve to the right (favors unloading of oxygen in the tissues). An increse in pH shifts the curve to the left (does not favor unloading) |
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Term
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Definition
| 2,3-diphoshpoglycerate It can bind to Hb, changing its conformation and decreasing its affinity for oxygen. |
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Term
| (04-20) What does an increase in 2,3-DPG do to an oxygen-Hb curve? A decrease? |
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Definition
| An increase shifts the curve to the right (favors unloading oxygen in the tissues). A decrease shifts the curve to the left (does not favor unloading) |
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Term
| (04-20) What can alter the levels of 2,3-DPG in the blood? |
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Definition
| Low oxygen (altitude, anemia) can trigger an increase in 2,3-DPG |
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Term
| (04-20) What does hemoglobin prefer to bind to: oxygen or carbon monoxide? How can you treat carbon monoxide poisoning? |
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Definition
| carbon monoxide. By a crazy amount: roughly 240x higher affinity than oxygen. You can't really treat it; you can't unbind CO from Hb. You just provide a high amount of oxygen and hope the CO doesn't kill you first. |
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Term
| (04-20) What type of genetic anomaly causes sickle cell anemia? What is the effect of the change? |
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Definition
| A single nucleotide polymorphism (A to T) leads to a single amino change -- valine (hydrophobic) instead of glutamate (hydrophilic). This changes the beta subunit of hemoglobin. |
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Term
| (04-20) What allele is present if you have sickle cell anemia? |
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Definition
| RR=normal, Rr=unaffected carrier, rr=sickle cell |
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Term
| (04-20) What does sickle cell anemia do to RBC? |
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Definition
| The mutation that causes sickle cell anemia forms long polymers that cause the RBCs to become jagged and sickle-shaped, often leading to lysis. |
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Term
| (04-20) How much carbon dioxide do your tissues produce? |
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Definition
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Term
| (04-20) What are the three ways our body gets rid of carbon dioxide? What are the approximate amounts of CO2 transported /L? |
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Definition
| dissolved in plasma (around 29 mL/L), bound to Hb (around 30 mL/L) bound as HCO3 (bicarbonate) in plasma (around 450 mL/L) |
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Term
| (04-20) What are the steps of carbon dioxide transport? |
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Definition
| 1) CO2 dissolves into plasma 2) diffuses down [ ] gradient from tissues to RBCs (some binds to Hb) 3) Reacts w/ H2O --> H2CO3 4) dissociates to HCO3- &H+ 5) exchanges for Cl- 6) H+ binds to Hb |
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Term
| (04-20) Where does the first step of carbon dioxide transport occur? |
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Definition
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Term
| (04-20) What is the main reaction for carbon dioxide transport? In which direction does it proceed? |
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Definition
| CO2 + H2O <--> H2CO3 <--> H+ + HCO2-; This is a reversible reaction |
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Term
| (04-20) What are the two types of control of respiration? |
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Definition
| Involuntary and voluntary control |
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Term
| (04-20) What drives breathing? |
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Definition
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Term
| (04-20) Where is regulated breathing generated? What does it trigger? |
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Definition
| In the central pattern generator (CPG) in the medulla, perhaps with input with the pons. It stimulates motor neurons that innervate inspiratory muscles |
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Term
| (04-20) What are the peripheral chemoreceptors? |
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Definition
| they are chemoreceptors in the carotid sinus that responds to change in the pressure of oxygen and carbon dioxide, and changes in pH |
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