Download presentation
Presentation is loading. Please wait.
1
The nervous system
2
Learning objectives Identify the key parts of the central nervous system (CNS) Explain the function of each part of the CNS Explain how the CNS helps humans to react to there surroundings
3
The nervous system The nervous system is made up of three main parts:
the brain,the spinal cord and nerve fibres. It detects stimuli such as light,temperature, sound, pressure, pain,movement, touch and chemicals (for example, food) and co-ordinates the body’s response. If you smell something burning your nose sends a message to your brain, and it co-ordinates your response. Q1) Look at photograph:Explain, in detail what happens the moment the starter fires the gun.
4
Answer Q1
5
Diagram of nervous system
6
The nervous system - Receptors
Receptors are sensors on the body that detect stimuli. Information from these passes along nerve fibres to the brain. Nerve fibres are made from lots of nerve cells, called neurones. The information passes along them as electrical signals called impulses.
7
A Neurone
8
Types of Neurone Sensory neurones Relay neurones Motor neurones
An effector can be a muscle that is made to contract (tighten) or a gland that releases (secretes) a chemical (for example, a hormone).
9
Task 2: Label the function of each part of the nervous system
10
Takes impulses from the sense organ to the relay neurone.
Where the relay neurones are found. Receives impulses from the spinal cord and sends out new impulses. Takes impulses to the brain and from the brain. The muscle that receives the impulse from motor neurone Takes impulses from the relay neurone to the effector. Senses stimuli from our surroundings.
11
Task 3: Write down the path of the impulse from when the athlete hears the starting pistol
12
Reflexes; The Grabbing Game
Who is the best? Why are they the best? What stimuli is making you react? What do we call the time it takes to grab the paper?
13
Reflex Action
14
Describe a reflex action
15
Pupil in the eye shrinks
Reflexes are automatic actions that we cannot control.They are used to protect our body from injury. Complete the table below by filling in the missing boxes. Reflex Protection given to eye stops us from choking Sneezing Pupil in the eye shrinks
16
Learning objectives – What have I learnt
Identify the key parts of the central nervous system (CNS) Explain the function of each part of the CNS Explain how the CNS helps humans to react to there surroundings
17
Diagram of nervous system
18
Types of Neurone Sensory neurones carry impulses from the receptor to the spinal cord. Relay neurones carry impulses through the spinal cord and up to the brain and from the brain back along the spinal cord. Motor neurones take impulses from the spinal cord to an effector. An effector can be a muscle that is made to contract (tighten) or a gland that releases (secretes) a chemical (for example, a hormone).
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.