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20 Cards in this Set
- Front
- Back
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Water is present in most cells except-? |
Fat cells |
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What is the concentration of water in the cells? |
70-85% |
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List the 5 most important ions in the cell. |
Potassium Magnesium Phosphate Sulphate Bicarbonate |
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Facilitated diffusion is also called? |
Carrier mediated diffusion |
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The extracellular fluid has a large amount of ? But small amount of ? |
Sodium Potassium |
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What cells are capable of generating rapidly changing electrochemical impulses at their membranes? |
Nerve and muscle cells |
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Local changes in membrane potentials activate many of the cell functions in which cells? |
Glandular cells Macrophages Ciliated cells |
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What is the resting membrane potential of large nerve fibres when not transmitting nerve signals? |
-90millivolts |
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Nerve signals are transmitted by ___? |
Action potentials |
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What is depolarization? |
It is due to sodium ion conductance which takes sodium ion into the cell . |
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In what stage is the -90 millivolt neutralized? |
Depolarization stage |
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What is Repolarization stage? |
Rapid diffusion of potassium ions to the exterior re-establishes the normal resting membrane potential. |
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What is the value for threshold of stimulation? |
-65 millivolts |
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The large fibres are ____? The small fibres are____? |
Myelinated Unmyelinated |
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What is the central core of fiber? |
Axon |
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What is the length of node of Ranvier? |
2-3 micrometer |
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What is saltatory conduction? |
When action potentials are conducted from node to node |
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What is the period during which a second action potential cannot be elicited? |
Absolute refractory period |
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High extracellular fluid calcium ion concentration causes ____? |
It decereases membrane permeability to sodium ions and at the same time reduces excitability. Therefore it is a stabilizer |
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What is the meter that responds accurately to the rapid changes in membrane potential? |
Cathode Ray oscilloscope |
