Matters
What is a ganglion?
In the PNS
Gray Matter
Groups of neuron cell bodies
What is the electrical nature of a neuron?
Graded Potential and Action Potential
What is action potential?
An electrical wave that travels down the axon
What is depolarization?
Makes the electrical potential less negative (toward zero)
What is "saltatory" conduct?
Fast method of conduction
goes from node to node
What is a nucleus?
In the CNS
Gray Matter
Groups of neuron cell bodies
Where is graded potential?
in the neuron cell body and dendrite area
What triggers action potential?
Depolarization to -55mv
"All-or-none"- never varies in intensity
What is hyperpolarization?
makes the electrical potential more negative (away from zero)
What conducts impulses faster?
Thick and myelinated axons
What is the Central Nervous System?
2 Organs: Brain & Spinal Cord
What is graded potential?
Variable in intensity
Weakens over distance
Mainly in dendrites
Nothing
the gates are ready to be open
What is repolarization?
Returns electrical potential to resting state after depolarization
What is a synapse?
Connections between 2 neurons
messages move slow throughout the synapse, fast through axons
What is the Peripheral Nervous system?
Nerves
What are graded potentials deviations of?
Deviations from the -70mv
What happens at action potential during depolarization phase?
Inside becomes more positive
Na+ gate is open
K+ gate is resting/closed
What is a voltage-gated ion channel?
* voltage trigger it
K+ Open- Ions move through
K+ Closed- No ions move through, can respond to voltage
Na+ Inactivated- No ions move through, cannot respond to voltage
What is a voltage-gated Ca++ channel?
Allow calcium to go in
What is Resting Potential?
Electrical state of a neurons membrane
Where does action potential occur?
In the axon
What happens at action potential during repolarization phase?
Returns back to negative on the inside
Na+ gate is inactivated/blocked
K+ gate is open
What is a sodium-potassium pump?
maintains the difference
ATP driven
3 sodium out for 2 potassium in
What do neurotransmitters do?
Bind to receptors
Diffuse against the synaptic cleft