Upload
mroakes
View
805
Download
1
Tags:
Embed Size (px)
Citation preview
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
www.A6training.co.uk
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