Transcript Nervous Tissue

Nervous Tissue
Neuron (motor)
Parts of a Neuron
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Nerves – bundles of neurons held
together by connective tissue (found in
PNS)
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Neurons – specialized nerve cells that
make up both the CNS and PNS
- many different types
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Dendrites – extensions of cell body that
conduct nerve impulses toward cell body
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Axons – carries impulse away from cell
body to next nerve cell, muscle or gland
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Myelin – lipid sheath that covers some
axons, provides a thick pad of insulation
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Schwann cells – places on axon covered
with myelin sheath
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Nodes of Ranvier – gaps between
Schwann cells, no myelin at that spot
Neural Circuits
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receptor cells receives
sufficient stimuli
sensory (afferent) neurons
carry info to CNS
Interneurons in CNS
interpret info and
stimulate motor neurons
motor (efferent) neurons
carry info to effectors
(muscles, glands, organs)
response to stimuli is
produced
Reflex Arc
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involuntary & unconscious
stimuli to spinal cord via sensory
interneurons interpret respond via motor (send info to brain
at same time)
effectors activated
prevents damage in cases of emergency
YouTube - The Nervous System ( Animation )