1. Structure and Physiology of Neurons
Nervous System Lecture 2

2. Neurons (Nerves)
Specialized cells to transmit nerve impulses from one part of body to another
3 main parts
Dendrite (conducts electrical current towards cell body)
Cell body
Axon (conducts electrical current away from cell body)

3. Synapses
junction between two neurons where messages are passed on by neurotransmitters

4. Resting neuron structure
Contain potassium (K+) ions inside neuron
Sodium (Na+) ions are outside plasma membrane and don’t normally pass inward

5. Polarized neuron Inactive (not sending an impulse)
Inside of neuron negatively charged to compared to outside

6. Stimulated neuron- Depolarization
Na+ gates in membrane open and Na+ rushes into cell causing inside to be more positive than outside of cell which activates neuron to transmit an action potential

7. Action potential
nerve impulse which causes the axon to release a neurotransmitter into synapse that binds to next neuron stimulating it

8. Cell Repolarization After action potential
K+ rushes out of cell causing the inside to become negative again
Must occur before neuron can send another nerve impulse

9. After repolarization Na+/K+ pump
Pumps K+ into cell and Na+ out to restore cell to make it polarized again