Download Transmission across a Synapse

TRANSMISSION ACROSS A
SYNAPSE
Do you remember???
 Synapse
 Small empty space
between 2 neurons
 Between the synaptic
knob and dendrite
Overview
 Impulses must cross
synapse to reach next
neuron
 Uses chemicals
 Neurotransmitters
 Stored in vesicles within
synaptic knobs
In Synaptic Knob
 Impulse reaches synaptic knob
 Synaptic vesicles move toward pre-synaptic
membrane (on synaptic knob)
 Fuse with membrane using exocytosis
In Synapse
 Neurotransmitters
 Released from synaptic vesicles into synapse
 Diffuse across synapse
 Toward dendrite of adjacent neuron
Adjacent Neuron
 Neurotransmitters bind to a receptor site on
post –synaptic membrane (on dendrite)
 Sodium channels open
 Impulse continues down neuron
 NOTE: A stronger stimulus causes impulses to arrive
faster so more neuron transmitters are released
Back in Synapse
 Unused neurotransmitter must be removed
from synapse
 Either:
 Re-enters synaptic knob
 Removed by enzyme
Review Time!!!
 Complete “Student Worksheet”
 Bring it to Mrs. Pheifer once you completed for
the correct answers
 Complete in class assignment on Synapse
 Must be handed in at the end of class to be graded