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Monitors internal and external environment
Integrates sensory information
Coordinates all systems
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Central Nervous System (CNS)
Brain and Spinal Cord
Intelligence, Memory, Emotion
Peripheral Nervous System (PNS)
All neural tissue outside the CNS
Afferent Division
Receptor to CNS
Efferent Division
CNS to muscles and glands
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Somatic Nervous System
Control over skeletal muscle contractions
Autonomic Nervous System
Involuntary regulation
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Cell Body
Large Nucleus
No centrioles (used for division)
Neurons cannot divide
Can divide in nose (for smell) and in
hippocampus (for memory)
Nissl Bodies
Rough ER and free ribosomes
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Several dendrites
Receive signals
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Axon
Usually only one/neuron
Transmits signal
Axon Hillock
Where action potentials start
Collaterals
Branches off axon
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Synaptic terminals
Site where neuron communicates with other
cells
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Multipolar Neuron
Two or more dendrites
One axon
Most common
Control skeletal muscles
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Unipolar
Dendrites and axon continuous
Cell body off to one side
Sensory neurons
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Bipolar neuron
One dendrite
One axon
Sight, smell, hearing
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Sensory Neurons
Receive information from receptors
External receptors—touch, temperature,
pressure and senses
Proprioreceptors—position and movement of
muscles and joints
Visceral (internal) receptors—taste, deep
pressure, pain
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Motor Neurons
CNS to rest of body
Interneurons
Only brain and spinal cord
Coordinate motor activity