does it matter which ions flow into the cell?
DESCRIPTION
Does it matter which ions flow into the cell? . Sodium (Na + ). Calcium (Ca 2+ ). Chloride ( Cl - ). Positive. Positive. Negative. Opening Voltage-Gated Na + Channels. Threshold – Voltage at which Na + channels o pen. - PowerPoint PPT PresentationTRANSCRIPT
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Does it matter which ions flow into the cell?
Sodium (Na+) Calcium (Ca2+) Chloride (Cl-)
Positive Positive Negative
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Opening Voltage-Gated Na+ Channels
Inhibitory Postsynaptic potentials (IPSP) caused by entry of negative ions
Threshold – Voltage at which Na+ channels open
Excitatory Postsynaptic potentials (EPSP) caused by entry of positive ions
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Excitatory and Inhibitory SynapsesExcitatory Synapse:Neurotransmitters open Na+ channels producing EPSPs.
Inhibitory Synapse:Neurotransmitters open Cl- channels producing IPSPs.
Axon hillock reaches threshold and action potential is fired.
IPSPs encounter EPSPs. Threshold is not reached and no action potential is fired.
-
-
+
+
+
+
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But why would you ever want to prevent an action potential from firing?
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Getting Pain to the Brain
First Pain Synapse:Pain Receptors
Second Pain Synapse:Spinal Cord
Third Pain Synapse:Cerebral Cortex
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Why do we instinctively apply pressure to something that is painful?
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Projection Neuron
Interneuron
Pressure neuron
Pain neuron
Build the Circuit in the Spinal Cord
To the Brain
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Interneuron
Projection neuron
To Brain
Build the Circuit in the Spinal Cord
-
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Pain neuron
Projection neuron
To BrainInterneuron
Add the Pain Neuron
- - +PainX
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Pain neuron
Pressure neuron
Projection neuron
To BrainInterneuron
Add the Pressure Neuron
- - +
+ X PainPain
-