1. The Nervous System
Development and Basics

2. The Human Nervous System
3. Nervous System
Enteric
Sensory (afferent) System transmits impulses from organs to CNS
Sympathetic
Peripheral Nervous System
Central Nervous System
Somatic (controls voluntary muscles)
Autonomic (involuntary nervous system)
Parasympathetic
Motor (efferent) System transmits impulses from CNS to peripheral organs to cause an affect or action
Human Nervous System Components
4. The Neuron
5. The Neuron: The Universe Inside You
6. Neurons vs. Other Cells
Neurons have dendrites and axons to carry information back and forth.
Neurons can communicate with other neurons.
Neurons have specialized structures, like synapses and chemicals.
7. Classification of Neurons
8. Neurons Work Electrochemically
Ions are the electrically charged chemicals in neurons.
The most common ions are:
Sodium
Potassium
Calcium
Chloride
Ions can be negatively (-) or positively (+) charged.
Ions can be outside or inside a neurons membrane.
9. A Neurons Potential Depends on the Charge of the Ions
The charge of the ions determines the type of potential a neuron has.
This animated graph shows the sequence: resting potential, action potential, and back to resting potential.
10. Polarized/Depolarized Neurons
Resting neurons are polarized. When they become depolarized, an action potential occurs.
Depolarization
Resting state
11. Animations to Review
Propagation of the action potential
http://www.blackwellpublishing.com/matthews/actionp.html
Click the blue circles on the left to play.
Channel gating during an action potential
http://www.blackwellpublishing.com/matthews/channel.html
Click the Begin Depolarization gold circle to start.
12. Conduction Velocity
Conduction velocity is the speed of a nerve impulse and is measured in meters per second (msec).

The wave on this animated graph represents the amount of time it takes for the nerve impulse to travel from the beginning to the end of the time line.
13. Variations in Conduction Velocity
Factors that can affect conduction velocity:
Temperature
Myelination
Width of axon
lower the temperature, the slower the conduction velocity
wider the axon, thefaster the conduction velocity
moremyelination, the
faster the conduction velocity
Salutatory conduction example:http://www.brainviews.com/abFiles/AniSalt.htm
14. The Big Picture
Sensory Neurons
Sensory Neurons
Motor Neurons
Motor Neurons
Internal Environment
External Environment
Central Nervous System