Physiology EXAM 1 Lecture 8 Flash Cards

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Title: Physiology EXAM 1 Lecture 8
Description: phys exam one lecture eight
Number of Cards: 60
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Author: susilli67211
Created: 2009-02-21
Tags: eight lecture phys
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    • Question
    • Answer
    • Side 3
    • electrons ignals occur via two mechanims... they are
    • graded potentials
      action potentials
    • are graded potentials important for signaling over short or long distances
    • short
    • are actions potentials important for signaling over long or short distances
    • long
    • is the resting membrane potential "polarized, depolarized, or repolarized"
    • polarized
    • definition. membrane potential becomes less negative than the resting potentials
    • deploarization
    • definition. a reversal in the membrane potential where the inside of the cell becomes postivie relative to the outside
    • overshoot
    • definition. return to the polarized potentiasl
    • repolarizaiton
    • definition. when the membrane potential is more negative than the resting potential
    • hyperpolarization
    • what are the three types of graded potentials
    • synatpic
      receptor
      pacemaker
    • definition. a potential change of variable amplitude and duration that iss conducted decrementally. has no threshold or refractory period
    • graded potential
    • deifniton. a brief all or none depolarization of the membrane reversing polirity in neurons. it has a threshold and refractory period and is conducted without decrement
    • action potential
    • what is meant by graded
    • the magnitude of these changes in a graded membrane potential can vary
    • what does decremental mean
    • die with distance
    • what does decremental apply to
    • graded membrane potentials. remember... graded potentials are best for short distances
    • can graded membrane potentials be depolarzing hyperpoliarizing or both
    • BOTH
    • what does hyperpolarizing mean
    • inhibit action potential
    • why is it that a graded potential is decremental
    • because of leaky channels
    • does higher magnitude menan higher intensity
    • yes
    • in a depolarizing graded potential is the flow of ions in or out
    • into the cell
    • are action potentials confined to nerve cells
    • no
    • deifniton. a brief all or none depolarization of the membrane reversing polirity in neurons. it has a threshold and refractory period and is conducted without decrement
    • action potential
    • what is meant by graded
    • the magnitude of these changes in a graded membrane potential can vary
    • what does decremental mean
    • die with distance
    • what does decremental apply to
    • graded membrane potentials. remember... graded potentials are best for short distances
    • can graded membrane potentials be depolarzing hyperpoliarizing or both
    • BOTH
    • what does hyperpolarizing mean
    • inhibit action potential
    • why is it that a graded potential is decremental
    • because of leaky channels
    • does higher magnitude menan higher intensity
    • yes
    • in a depolarizing graded potential is the flow of ions in or out
    • into the cell
    • are action potentials confined to nerve cells
    • no
    • what are action potentials dependent on
    • voltage gated ion channels
    • are Na channels in voltage gated channels fast or slow
    • fast that's why they need the ball and chain
    • are K channels in voltage gated channels fast or slow
    • slow they are leaky
    • does depolarization become a ostive or negative feedback loop
    • positive
    • in return to the resting membrane potential is the closing voltage gated K channels go through a negative or positive feedback system
    • negative
    • the rapid opening of voltage gated Na channels explains the rapid _____- phase at the beginning of the actinon potential
    • depolarization
    • the slower opening of votage gated K channels explains what
    • repolarization
    • is sodium associated wiht positive or negative feedback
    • sodium is positive
    • is K associated with negative or positive feedback
    • negative
    • this occurs during the period when the voltage gated Na channels are eiher open or inactiving
    • absolute refractory period
    • this follows and absolute refractory peirod
    • relative refractory period
    • in this period a second action potential can be produce dbut only if the stimulus is stronger than normal
    • relative refractory period
    • during a refractory period can another action potential be fired
    • NO
    • what does one way propagation mean
    • that the action potential can only go one way
    • does myelin increase or decrease metabolic cost
    • decrease
    • the bigger the diamete of the axon the faster or slower the action potential due to increased surface
    • faster
    • what is the "best case scenario" for an axon
    • myelinated large diameter
    • does amplitude of an action potential vary
    • NO, but graded potentials can
    • can action potentials be summed
    • no, but graded potentials can
    • do graded potentials have a threshold
    • no, action potentials do
    • do actyion potentiasl have a refractory period
    • yes but graded do not
    • are graded or action potentials decremental
    • graded
    • does duration of graded or action vary
    • graded
    • which action or graded is only a depolarization
    • action
    • is graded or action inititaed by a graded potential
    • action
    • which action or graded is initiated by environnmntal stimulus by neurotrans or spontaneously
    • graded
    • action or graded. mechanism depnds on voltage gated channels
    • action
    • graded or action. mechanism depends on ligand gated channels or other chemical or physical changes
    • graded
    • grade or action. can be summer
    • graded
    • action or graded can be depolarizing or hyperpolarizingn
    • graded