Download L1 Nervous System Neurons File

L1: Outline
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Notes on
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Video:
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Neuron structure, types of neurons, and reflex arcs
Simple Reflex arc in claymation
Reflex arc video
ActivityLink: Reflex Timing
L1: What is the Nervous System
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A collection of specialized cells called neurons that
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connect your 5 senses to your brain
make up your brain and allow thought
connect to your muscles and allow movement
L1: Main parts of a Neuron
Cell body: each neuron
is a single cell
Myelin sheath: insulates
axon to speed up the
message
Dendrites: receives
impulses (messages)
Axon: sends messages
away
L1: Dendrites and Axons
Dendrites:
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Bring information to the cell body
Rough Surface (dendritic spines)
Usually many dendrites per cell
No myelin insulation
Branch near the cell body
Axons:
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Take information away from the cell body
Smooth Surface
Generally only 1 axon per cell
Can have myelin
Branch further from the cell body
L1: 3 Neuron Types
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Sensory neurons: carry messages from the
senses to the brain/spinal cord
Interneurons: in the brain and spinal cord,
process the messages
Motor neurons: carry messages to muscles
L1: Reflex Arc
A nerve pathway designed to react quickly to painful/
motor stimuli. Consists of..
Ouch!!!
Sensory neurons
interneurons in the
spinal cord
Motor neurons
L1: Neuron Structure Quick Quiz
dendrites
nucleus
Myelin sheath
axon
axon endings
Cell body
L1: Assignment
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Read pages 372-376
  Define
the terms
 afferent
 efferent
 innervate
Do reflex activity.
  Work on Major Lab Project
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Reflex Activity
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Watch videos on
  Deep
leg reflex
  Plantar
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Do reflex activity on above plus retinal