Download 2.1 Resonding for change

Title: Responding to Change
Learning
Objectives
Why do you
need a
nervous
system?
Starter:
 Complete the following past exam
question:
What is a
receptor?
How do you
respond to
changes in
your
surroundings?
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs
The Nervous System
Learning
Objectives
Why do you
need a
nervous
system?
• The primary goal of the nervous system
is to enable you to react to your
surroundings and co-ordinate your
behaviour.
What is a
receptor?
How do you
respond to
changes in
your
surroundings?
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs
The Nervous System
Learning
Objectives
Why do you
need a
nervous
system?
• Changes in your surroundings (stimuli)
are picked up by cells known as receptors
What is a
receptor?
How do you
respond to
changes in
your
surroundings?
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs
The Nervous System
Learning
Objectives
Why do you
need a
nervous
system?
• Receptor cells are clustered together in
special sense organs, like your eyes or
skin.
What is a
receptor?
How do you
respond to
changes in
your
surroundings?
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs
The Nervous System
Learning
Objectives
Why do you
need a
nervous
system?
What is a
receptor?
How do you
respond to
changes in
your
surroundings?
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs
How Your Nervous System Works
Learning
Objectives
Why do you
need a
nervous
system?
• Once a sensory receptor detects a
stimulus, the information is sent in the
form of an electrical impulse along cells
known as neurons.
What is a
receptor?
How do you
respond to
changes in
your
surroundings?
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs
How Your Nervous System Works
Learning
Objectives
Why do you
need a
nervous
system?
• Neurons are usually arranged in bundles
of round a thousand, known as a nerve.
What is a
receptor?
How do you
respond to
changes in
your
surroundings?
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs
How Your Nervous System Works
Learning
Objectives
Why do you
need a
nervous
system?
• The impulse travels along the nerve until
it reaches the central nervous system
(CNS)
What is a
receptor?
How do you
respond to
changes in
your
surroundings?
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs
How Your Nervous System Works
Learning
Objectives
Why do you
need a
nervous
system?
What is a
receptor?
How do you
respond to
changes in
your
surroundings?
• Sensory Neurons carry
nerve impulses from
receptors in the body
to the CNS.
• Motor Neurons carry
nerve impulses from
the CNS to the rest of
the body
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs
How Your Nervous System Works
Learning
Objectives
Why do you
need a
nervous
system?
What is a
receptor?
• Impulses that travel along motor
neurones cause effector organs like
muscles or glands to respond.
• Muscles contract and glands secrete
chemical substances.
How do you
respond to
changes in
your
surroundings?
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs
Task
Learning
Objectives
Why do you
need a
nervous
system?
What is a
receptor?
How do you
respond to
changes in
your
surroundings?
1. Your ........ system carries fast.......
impulses. Changes in the .............. are
picked up by your................
2. Complete:
Receptor  ___  CNS  ___ Effector
3. Explain what happens in your nervous
system when you see a piece of
chocolate and eat it.
Key Words: stimuli, receptors, impulses, sense organs, CNS,
neurons, nerves, secretory organs