Nervous System
About this set
Created by:
wattsrace123 on November 20, 2011
Subjects:
Log in to favorite or report as inappropriate.
Order by
31 terms
Terms | Definitions |
|---|---|
 synapse | junction between a pre-synaptic neuron's axon and a post-synaptic neuron's dendrite or cell body |
| synaptic cleft | space between neurons in which chemical signals called neurotransmitters are released |
| ST 1 | impulse arrives at synapse and triggers Ca+ ion entry |
| ST 2 | Transmitter substance released, diffuses to receptors of post-synaptic membrane |
| ST 3 | Transmitter substance binds, triggering entry of Na+ ions, and action potential in post-synaptic membrane |
| ST 4 | Enzymic inactivation of transmitter |
| ST 5 | Re-formation of transmitter substance vesicles |
| TSC 1 | permeability to Ca+ increases |
| Step Two Transmitter Substance Cycle | release |
| TSC 3 | binding, Na+ channel opening (impulse generated) |
| ST 4 | diffusion and re-entry |
| TSC 5 | re-formation using energy from ATP |
| dendrite | brings impulses towards the cell body |
| axon | carries impulses away from the cell body |
| cell body | contains nucleus and bulk of cytoplasm |
| myelin sheath | supporting cells (called Schwann cells) wrapper around axons which function to increase the speed of transmission of impulses. |
| types of neurons | motor, sensory, relay |
| two systems of neurons | central nervous system, brain and spinal cord |
| impulse | momentary reversal in electrical potential difference in the membrane due to a change in position of charged ions between the inside and outside of the membrane of the nerve fiber |
| RP 1 | After nerve impulse has been transmitted, the resting potential is reestablished = repolarized |
| resting potential | the potential difference across a nerve cell membrane when it is not being stimulated. charge is usually -70 mV |
| RP 2 | Process involves K+ (in) and Na+ (out) being actively transported with help of ATP. No significant change in charge across the membrane |
| RP 3 | Then K+ (many) and Na+ (fewer) are diffused back, making the inside of the membrane more negative to the outside (-70 mV) |
| action potential | the potential difference produced across the plasma membrane of the nerve cell when stimulated, reversing the resting potential from about -70 mV to about +40 mV |
| AP 1 | energy from a stimulus causes a temporary reversal of the resting potential = depolarization |
| Action Potential Step Two | process happens when the energy causes Na+ gates to open in the membrane causing Na+ to enter the cell, down their electrochemical gradient |
| electrochemical gradient | electro- the charged ions flow to their opposite side of the membrane chemical- the ions move down their concentration gradient too |
| Action Potential Step Three | action potential created when the charge changes from -70 mV to +40 mV |
| Action Potential Step Four | this change in charge stimulates the next part of the membrane to create an action potential |
| AP 5 | after action potential passes, the Na+ channels close and K+ channels open, leaving the cell down their electrochemical gradient. the interior becomes less positive again and K+ channels close |
| AP 6 | sodium/potassium pump and facilitated diffusion re-establishes resting potential |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.