Transcript How your brain and nervous system work

SMARTER UK – RESOURCES FOR SCHOOLS
Please feel free to use this PowerPoint presentation in the classroom. It is intended to support the KS3 & KS4 curriculum and the
Scottish S3-S4 curriculum.
KEY LEARNING:
The structure of the brain and how the central nervous system works, including information about what happens at a synapse and
information about how our brains adapt and change.
Specific curriculum areas include:
KS4 GCSE Biology Syllabuses
OCR
3.3 Fundamental Scientific Processes. Module B1d – The nervous system
Foundation tier only: low demand
• Name and locate the main parts of the nervous system, to include:
o the central nervous system (CNS) (brain and spinal cord)
o the peripheral nervous system
Both tiers: standard demand
• Name and locate the parts of a motor neurone: cell body, axon and
sheath.
• Recall that the nerve impulse passes along the axon of a neurone.
Higher tier only: high demand
• Recall that the gap between neurones is called a synapse.
• Describe how an impulse triggers the release of a transmitter
substance in a synapse and how it diffuses across to bind with receptor
molecules in the membrane of the next neurone causing the impulse
to continue.
OCR 21st Century Science
MODULE B6: BRAIN AND MIND – OVERVIEW
B6.2 How is information passed through the nervous system? Structure of
motor neurons; transmission of electrical impulses, including synapses.
AQA
11.1 How do human bodies respond to changes inside them
and their environment?
• The nervous system enables humans to react to their
surroundings
• and coordinate their behaviour.
• Information from receptors passes along cells (neurones)
in nerves to the brain. The brain coordinates the response.
• The role of receptors, sensory neurones, motor neurones,
relay neurones, synapses and effectors in simple reflex
actions.
Edexcel
Topic 2: Responses to a changing environment
• 2.19) Recall that the central nervous system consists of the
brain and spinal cord and is linked to sense organs by
nerves
• 2.20) Explain the structure and function of dendrons and
axons in the nervous system
• 2.21) Describe how stimulation of receptors in the sense
organs sends electrical impulses along neurones
• 2.23) Describe the structure and function of sensory, relay
and motor neurones and synapses
Scottish S3-S4 science
Biological Systems - Body systems and Cells
• SCN 2-12a I have explored the structure and
function of organs and organ systems and
can relate this to the basic biological
processes to sustain life.
Scottish Certificate in Education, Standard
Grade Biology. Topic 5: The body in action.
Subtopic c: Coordination
18) Examine the gross structure of the nervous
system of a mammal.
19) Obtain and present information on the flow
of information in the nervous system.
• State that the nerves carry information from
the senses to the central nervous system and
from the central nervous system to the
muscles.
• 20) Obtain and present information on the
three main parts of the brain.
Identify the cerebrum, cerebellum and the
medulla and state their functions in simple
terms.
Your brain and nervous system
How does it work?
your
nervous system
is divided into the central
nervous system (CNS)
Credit Medical Art Service, Munich /, Wellcome Images
spinal cord
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and the
peripheral nervous system
(PNS)
which connects everything
to the brain and spinal cord
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N0022610
Medical Art Service, Munich /, Wellcome Images
which is the brain and
your
brain
interprets the information it gets
though your senses in order to
monitor and regulate your body
as well as being responsible for
Credit: Heidi Cartwright, Wellcome Images
thinking, learning, memory
and emotion
Different parts of
your brain have
different functions…
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different regions have different
Cerebral cortex
functions
Functions include:
planning; reasoning;
language; recognising
sounds and images;
memory.
Corpus
callosum
connects the brain’s
right and left
hemispheres
Brain stem
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Credit: Mark Lythgoe & Chloe Hutton, Wellcome Images
regulates heart
rate, breathing,
sleep cycles
and emotions
Cerebellum
important for
coordination,
precision and timing
of movement
the cells of the nervous system are called
neurones
nerve endings
dendrites
myelin sheath
cell body
nucleus
axon
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structure of a neurone
there are different
types of neurone
dendrites
cell body
direction of
electrical
signal
myelin
sheath
axon
nerve
endings
motor neurone
sends signals to your muscles
to tell them to move
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sensory neurone
sends signals from
your sense organs
relay neurone
connects neurones to
other neurones
communicate with each other using a
mixture of electrical & chemical signals
neurones
dendrites
nerve endings
myelin sheath
But what happens when
the signal
reaches the end of the axon?
cell body
an electrical
signal is
transmitted
along the axon
nucleus
axon
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signals cross between neurones at the
synapse
synapse
dendrites
nerve endings
vesicle
myelin sheath
synaptic cleft
nucleus
cell body
receptor
neurotransmitter
the signal
is transmitted to
another neurone across a
junction called a synapse by
axon
chemicals called
neurotransmitters.
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1
electrical impulse triggers vesicles
to move to the synapse membrane
vesicles fuse with the membrane and
2 release neurotransmitter into the
synaptic cleft
3
neurotransmitter diffuses across
the cleft and binds to receptors
on the other side
synaptic cleft
nucleus
signals cross between neurones at the
synapse
synapse
dendrites
nerve endings
vesicle
myelin sheath
cell body
receptor
4 Once enough receptors have
neurotransmitters bound to
them, the signal is
transmitted…
neurotransmitter
the signal
is transmitted to
another neurone across a
junction called a synapse by
axon
chemicals called
neurotransmitters.
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The point where your muscles and nervous system meet is called the
neuromuscular junction (NMJ)
Signals sent from your central nervous
system to the NMJ tell muscles to move
The synapses at the NMJ
use a neurotransmitter
called
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acetylcholine
Your brain changes and adapts
What happens as our brains mature?
your
brain changes and adapts all the time and all through your life
Credit Marina Caruso, Wellcome Images
your brain learns and
forms memories by
strengthening
synapses that are
used a lot and
weakening those
that are used less
often
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What happens as you
grow?
Between birth and age 3 your
brain makes lots of new synapses
A toddler has 2-3 times more
synapses than an adult
As your brain matures, it prunes
synapses to make it more efficient
During adolescence your brain has a
major tidy-up and gets rid of lots of
connections it isn’t using
This is a critical and delicate process. It is
thought that conditions such as schizophrenia
could be the result of it going wrong
Some evidence suggests that using
drugs can disrupt this process