the nervous system b1
TRANSCRIPT
What is this lesson about?
Coordination: The Nervous System
Learning Objectives: - Understand that different cells and tissues
must work together in the nervous system- To know the two systems of coordination in
mammals- Know the structure and function neurones
Learning Flowchart:
Introduction to the two parts of the nervous system
Sensory Neuron function
How the nervous system worksReceptors + Density of touch receptors exp
Effectors in the body
Nerve and Neuron structure/function Video Summary
Picture Quiz
The Nervous System
• Brain• Spinal cord• Nerves
• Enables you to control your body (Coordination)
• Gives you feedback about the world
What does it do?
What are its component parts?
Central Nervous System
Peripheral Nervous System
Look away if you’re squeamish…
A dissected brain, spinal cord and sections of major nerves.
How the nervous system works
STEP 1: ReceptorsReceptors are specialised cells. They can detect
changes in the environment (stimuli) and turn them into electrical impulses.
Receptor Stimuli
Skin
Tongue
Nose
Eye
Ear
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Density of touch receptors Experiment
End
How the nervous system works
STEP 2: A message is carried along a sensory neuron to
the CNS
How the nervous system works
STEP 3: A message is sent from the CNS to an organ
(effector) via a motor neuron to carry out a response
Examples:• a muscle contracting to move the arm • a muscle squeezing saliva from the salivary
gland
The Cells of the Nervous System - Neurones
Nerves and NeuronesNerves are collections of long thin nerve cells
called neurones
Dendrite – Collects information from other cells
Axon – Fibre which carries information
Myelin Sheath – Electrical insulation
Nodes of Ranvier – Allow rapid conduction of impulses
Nerve Impulses
Messages pass along neurons in the form of electrical impulses called action potentials
At the end of each neuron there is a tiny gap which impulses cross in one direction this is called a synapse
A chemical called neurotransmitterdiffuses across the gap
http://www.brainpop.com/health/bodysystems/nervoussystem/
Effector, Receptor or Neurone
Effector, Receptor or Neurone
Effector, Receptor or Neurone
Effector, Receptor or Neurone
Effector, Receptor or Neurone
Effector, Receptor or Neurone