Nerve Impulse - PowerPoint PPT Presentation

1 / 11
About This Presentation
Title:

Nerve Impulse

Description:

Nerve Impulse - both an electric ... charges on either side of the axon membrane Polarization Both sides of the axon membrane with opposing charges Resting Membrane ... – PowerPoint PPT presentation

Number of Views:159
Avg rating:3.0/5.0
Slides: 12
Provided by: WestM154
Category:

less

Transcript and Presenter's Notes

Title: Nerve Impulse


1
Nerve Impulse
  • - both an electric and chemical experience

2
Nerve Impulse
  • Stimuli causes a change in both the chemical and
    electrochemical properties in a neuron
  • consumes oxygen and ATP
  • changes axon membrane permeability to sodium
    (Na) and potassium (K) ions

3
A Nerve impulse is run by the...
  • SODIUM - POTASSIUM PUMP
  • active transport
  • at rest
  • Na pumped out - 3
  • K pumped in - 2
  • ? producing opposing (relative) charges on either
    side of the axon membrane

4
Polarization
  • Both sides of the axon membrane with opposing
    charges
  • Resting Membrane Potential is before the impulse
    in introduced

5
Impulse
  • Stimulation causes axon membrane to become
    permeable to Na
  • ? at the point of stimulation polarization is
    lost
  • DEPOLARIZED

6
Action Potential
  • Wave of depolarization from the dendrite to the
    axon (terminal knobs)
  • All or None Response - either experiences action
    potential or not
  • Threshold Stimuli - amount to trigger impulse /
    the minimum

7
Refractory Period
  • Time it takes for the sodium-potassium pump to
    reestablish polarization
  • during the refractory period it can NOT accept
    another impulse

8
Transfer of Impulse over the Synapse
  • Neurotransmitters
  • carry impulse over the synapse
  • at the terminal knobs of the axons SYNAPTIC
    VESICLES store neurotransmitters

9
Upon Impulse
  • Makes synaptic vesicles move towards synapse
    until it releases neurotransmitter into the
    synapse

10
On the dendrite of the adjacent neuron.
  • Neurotransmitter is accepted by RECEPTOR PROTEINS
    causing an action potential to be established on
    the next neuron

11
Types of Neurotransmitters
  • CHOLINESTERASE
  • enzyme that breaks down acetylcholine
  • ACETYLCHOLINE
  • transfers the impulse in the motor neurons of the
    skeletal muscles

NORADRENALINE / NORESPINEPHRINE - causes body to
go into STRESS conditions increasing heart rate
gland secretions
Write a Comment
User Comments (0)
About PowerShow.com