1. Neuron Function

2. Functional Classifications of Neurons
A. Sensory (afferent) neurons – carry information to the CNS
B. Interneurons – in the CNS, connect sensory neurons to motor neurons
C. Motor (efferent) neurons – carry impulses from the CNS

3. Nerve Impulses
A. Resting potential – at rest, the neuron cell membrane is polarized (more positive outside than inside) to -70mV

4. Depolarization – a stimulus depolarizes the membrane allowing Na+ into the cell.
1. If the impulse is strong enough (reaches the threshold) an Action Potential is generated (goes down the length of the axon)

5. Repolarization – K+ ions rush out of the cell in response to the Na+ coming in
Hyperpolarization – prevents another action potential from starting before one is finished

7. Communication between neurons
Action potential reaches axon terminals of pre-synaptic cell, signals for the release of neurotransmitter into the synapse by exocytosis
Neurotransmitter diffuses across synapse, binds to receptors on post-synaptic cell, opening sodium gates to start an action potential