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