Nervous system 2

kshinsky's version from 2017-08-01 23:26


Question Answer
types of gated channelschemical, voltage, mechinal
depolarizationgates open up for K to come out, membrane becomes less negative
repolarationK released, returns to resting membrane potential
hyperpolarizationmore negative than the resting potential
exictatorycausing depolarization
inhibitoryhyperpolarization, makes a resting potential, making it more negative,
sodium channels openexictatory
potassium channels openinhibatory
action polarizationaleffects entire membrane
initial stimulusresting membrane potential = -70 mv, threshold potential = -55 mv
all or noneeither the action potential is triggered or its not
myelincauses a faster impulse
propagationconduction across the entire axon
continuous propagationunmyelated axon nodes
saltitory propagationmyelated axons. travels over internode, through extracellular fluid, increases speed
three groups of axonstype a, type b, type c
type Amyelinated, large, high speed 140 m/sec, carry information to/from CNS, ex: position, balance
type Bsmaller diameter, myelinated, medium speed 18 m/sec, ex: sensory information, peripheal effectors
type Csmall, unmyelinated, slow 1 m/sec, ex: smooth, cardiac, vasocontriction, glandular secretions
chemical synapsesneuron to another cell
effect of neurotransmitterdepends on receptor
acetycholinedepends on laction
inhibitory for cardiacacetycholine
excitatory for muscularacetycholine
protein neurotransmittersamino acids, neuropeptides, dissolved gases
common neurotransmittersnorepinephrine, dopamine, serotonin, GABA
dopaminecocaine use, lack of dopamine = parkinsons
GABAmost prevalent inhibitory
opiodsendorphins, enkephalins, endomorphins, dynorphins
summationtriggers an action potential, EPSP, 1 EPSP is not enough
temporal summationmultiple stimuli, rapid, one neuron fires off multiple times
spatial summationmultiple locations, many stimuli arrive at multiple synapses, multiple neurons firing off

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