Term
| What is the capacitance of the plasma membrane? What is the resistance of the membrane? |
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Definition
| 1 uF/cm2, 10^9 (ohm)(cm2) |
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Term
| Which ion has the greatest difference in transmembrane concentration? |
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Definition
| Calcium (the difference is 20,000 fold!) |
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Term
| List the following from fastest to slowest: channels, diffusion, transporters |
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Definition
| diffusion>channels>>transporters |
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Term
| When chloride ions flow in, what kind of current is this? |
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Definition
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Term
| Where is the "CatSPer" calcium channel expressed? |
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Definition
| In sperm tails. This is an example of localized expression of an ion channel. |
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Term
| What job does the narrow selectivity filter have? |
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Definition
| He acts like a bouncer, standing by the door (ie: the extracellular side or the pore) and determines who can come in (ie: what ion the channel is selective for) |
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Term
| What are the roles of L-Type calcium channels? What blocks them? Why do we care? |
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Definition
| EC coupling in heart and skeletal muscle. Blocked by verapamil. Treats hypertension (targeting smooth muscle) and cardiac arrhythmia (targeting AV node). |
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Term
| What are the roles of T-Type calcium channels? What blocks them? |
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Definition
| Phasic firing of Neurons. Blocked by mebifradil. |
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Term
| What are the roles of N-Type calcium channels? What blocks them? Why do we care? |
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Definition
| in NS. Transmitter release at nerve terminals. Blocked by conotoxin. Used to treat severe pain (ie: cancer). |
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Term
| What are the roles of P-Type calcium channels? What blocks them? |
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Definition
| In NS. Transmitter release. Blocked by Agatoxin. |
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Term
| The voltage sensor contains which amino acids? |
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Definition
| Positively charged lysine or arginine. |
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Term
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Definition
| By blocking axonal, voltage-gated sodium channels. |
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Term
| What happens if you block the rapid delayed rectifier K current? What medication unknowingly did this? |
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Definition
| Causes prolonged QT interval, long action potentials, increasing risk of ventricular arrhythmia. The antihistamine terfenadine did this. |
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Term
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Definition
| Cystic fibrosis and long QT syndrome. |
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Term
| What is Primary Erythermalagia? |
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Definition
| It it a gain of function mutation in Nav1.7 channels in peripheral neurons. Results in burning, pain, swollen limbs... |
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