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Chap 12 cont.
nervous
Question | Answer |
---|---|
extracellular fluid is rich in | Na and Cl |
inward flow of ___ cant keep up with outward flow of ___ | na/ K |
graded potentials have _____ and ______ | hyperpolarization and depolarization |
membrane has become more negative | hyperpolarization |
membrane has become more positivit | depolarizaion (goes up) MV |
in ____ the signals are ____, meaning they vary in alplitude (size), depending on the strength of the stimulus and localized | graded |
graded potentials occur most often in the ___ and _____ of a neuron | dendrites and cell body |
_____ stiumulation of membranes with mechanical gated ion channels (pressure) | mechanical |
____ stiumulation of membranes with ligand gated ion channels (neurotrasnmitter) | chemical |
____ or _____ is a sequence of radibly occuring events that increase and eventually reverse the membrane potential (depolarize) and then restore it to the resting state (repolarize) | action potential (AP) |
During an AP, voltaged gated ____ and ____ channels open in sequence | Na and K |
when Na rushes in its | depolarization |
K rushes out it is | repolarization |
in the depolarizing phase of AP the voltaged gated ____ channels open and __ rushes into cell | Na |
depolarizing is an example of | positive feedback process |
when a chem or mech. stimulus caused a graded potentiatl to reach at least -55mV or threshold | depolarization |
when threshold pontential of -55 is reach, voltaged gated K channels open | repolarizing |
in repolarizing ___ channel is much slowing than Na channel opening which caused depolaization | K |