Term
| The difference in electrical charge inside and outside a cell which is at rest is known as _______________. |
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Definition
| resting membrane potential |
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Term
| Most neurons have a resting membrane potential of ________. |
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Definition
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Term
| How is negative charge maintained inside the neuron? |
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Definition
1. selectively permeable membrane
2. ions moving to equilibrium
3. Na/K pump |
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Term
| ____________ are membrane proteins which allow the passage of certain ions depending on size and charge. |
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Definition
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Term
| Channels are ________ and can be opened or closed. |
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Definition
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Term
| _________ cannot pass through the cell membrane to go outside the cell, causing the intracellular fluid to be negatively charged. |
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Definition
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Term
True or False:
During resting potential, K+ ions passively pass into a cell down its electrostatic gradient. |
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Definition
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Term
True or False:
During resting potential, K+ ions move passively out of the cell due to their concentration gradient. |
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Definition
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Term
| Na+ cations from the extracellular fluid leak through the membrane to go down their electrostatic and concentration gradients (into OR out of) the cell during resting potential. |
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Definition
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Term
True or False:
Na+ ions passively pass outside the cell and are actively pumped back in to maintain resting potential. |
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Definition
| False: the opposite is true |
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Term
| The Na+/K+ Pump exchanges __ Na+ ions for __ K+ ions. |
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Definition
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Term
| The Na+/K+ Pump pumps Na+ ____ the cell and K+ ____ the cell. |
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Definition
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Term
True or False:
Neurons cannot store glucose or oxygen. |
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Definition
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Term
| An action potential is caused by __________ of a membrane past a certain ___________ followed by a ___________. |
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Definition
| depolarization, threshold, repolarization |
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Term
| During ___________, membrane potential becomes less negative compared to resting potential. |
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Definition
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Term
| ___________ is the membrane potential at which an action potential is inevitable. |
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Definition
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Term
| When a cell becomes more negative relative to resting potential after an action potential, the cell is ____________. |
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Definition
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Term
| During a __________, excitable cells are incapable of producing a normal action potential. |
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Definition
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Term
| In ___________, no amount of stimulation can induce an action potential immediately after an action potential. |
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Definition
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Term
| In ____________, very strong stimulation can induce another action potential (not immediately after the action potential, but prior to returning to resting potential). |
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Definition
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Term
| Action potential firing rate increases as _____________ increases. |
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Definition
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Term
| During depolarization, a stimulus (neurotransmitter, drug, electrical stimulus, etc.) results in a slight positive charge, which allows some ____________ to open. |
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Definition
| voltage-gated Na+ channels |
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Term
| If threshold is reached, additional _______________ open causing a rapid change in charge. |
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Definition
| voltage-gated Na+ channels |
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Term
| When an action potential is generated, the intracellular fluid is ___________ charged due to the _____________. |
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Definition
| positively, large influx of Na+ ions |
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Term
| After an action potential is propagated, Na+ channels are inactivated and _________________ open. |
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Definition
| voltage-gated K+ channels |
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Term
| During repolarization, K+ ions move _________ the cell due to the ____________. |
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Definition
| out of, electrical gradient |
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Term
| The opening of voltage-gated K+ channels for repolarization results in _____________. |
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Definition
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Term
| _____________ are located on sensory nerve endings or the axon hillock and have high concentrations of ion channels. |
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Definition
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Term
| Depolarization is initiated at __________. |
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Definition
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Term
True or False:
As an action potential moves down an axon, previous Na+ ion channels remain open. |
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Definition
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Term
| As sodium ions flow down the axon, _____________ open as it moves. |
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Definition
| voltage-gated Na+ channels |
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Term
| Myelin sheath _________ the speed of action potential conduction. |
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Definition
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Term
| ________ is a lipid insulator of neuronal axons. |
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Definition
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Term
| Unmyelinated axons are slower than myelinated axons because ___________. |
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Definition
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Term
True or False:
Myelin covers the entire axons to increase the speed of conduction. |
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Definition
| False: there are nodes of Ranvier |
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Term
| _____________ are concentrated at the nodes of Ranvier. |
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Definition
| Voltage-gated Na+ channels |
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Term
| ___________ is when a nerve impulse jumps from node to node down a myelinated axon. |
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Definition
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