The Nervous System Ch 33 AND Ch 34
Electron Micrograph of Neurons
Main Divisions of the Nervous System
Central Nervous System All nerves in the brain & spinal cord (runs from brain to tailbone).
Peripheral Nervous System The PNS, consists of the nerves and neurons that reside or extend outside the central nervous system It is divided into two further divisions: somatic nervous system autonomic nervous system
Organization of the Nervous System
Parts of a Neuron
Neuron Anatomy 1. Dendrites: 2. Cell Body: 3. Axon:
4. Axon Terminals: 5. Myelin Sheath: 6. Synapse:
The Physiology of the Nervous System Resting Potential Action Potential Synapses
Resting Potential
Moving the Impulse- The Action Potential
Channel Gating during an action potential http://www.blackwellpublishing.com/matthews/channel.html
Action Potential- all or none Step 1 Step 2 (Depolarization) Step 3 (Repolarization)
Fig 33.7
Recharging the membrane
Propagation of the action potential. http://www.blackwellpublishing.com/matthews/actionp.html
Synapses
What happens at the axon terminals?