Transcript 29.2 Neurons - Cloudfront.net

Set
Cornell Notes on pg.
29.2upNeurons
31
Nervous
2.129.1-2
Atoms,
Ions, System and Neurons
and Molecules
•Topic: 29.2 Nervous
System and Neurons
•Essential Question(s):
1. Draw and label a neuron
on pg. 46 in picture bubble
map format.
KEY CONCEPT
The nervous system provides the
means by which organ systems
communicate and is composed of
highly specialized cells.
29.2 Neurons
KEY CONCEPT
The nervous system provides one of the means by
which organ systems communicate.
29.2 Neurons
• The nervous system controls thoughts, movement, and
emotion as well as simpler life processes such as
swallowing
29.2 Neurons
• The nervous system works quickly, using chemical
and electrical signals.
– interconnected network of cells (hardwired)
– signals move through cells (neurons)
– divided into central nervous system (CNS) and
peripheral nervous system (PNS)
- CNS- brain and spinal cord
- PNS-network of nerves that transmit messages to and from the
PNS to the CNS
spinal
chord
nerves
29.2 Neurons
KEY CONCEPT
The nervous system is composed of highly specialized
cells.
29.2 Neurons
Neurons (aka nerve cells) are cells that can
store information and send and receive
messages within the nervous system.
• Make up an information network
(Like the internet)
Cell body
axon
Dendrites
neurotransmitter
29.2 Neurons
A Closer Look at Neurons
(4m53s)
29.2 Neurons
Neurons are highly specialized cells.
• A neuron has three parts.
1. cell body has nucleus and organelles
1
Cell body
29.2 Neurons
Neurons are highly specialized cells.
• A neuron has three parts.
1. cell body has nucleus and organelles
2. dendrites receive messages from neighboring cells
2
dendrites
29.2 Neurons
Neurons are highly specialized cells.
• A neuron has three parts.
1. cell body has nucleus and organelles
2. dendrites receive messages from neighboring cells
3. axon carries messages to other cells
Specialized support cells- such as the myelin sheathinsulate neurons’ axons and helps them send messages
3
axon
29.2 Neurons
Directions: Please make a picture bubble map of this neuron. Use p. 876-879 in your book to help you. Label
all major parts of a neuron (cell body, dendrites, axon, myelin sheath, axon terminals, action potential,
synapse, neurotransmitters). Once all parts are labeled, you need to describe the function of each.
29.2 Neurons
Synapse: Gaps between neurons
Synapse
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Neurotransmitters: Chemical signals released by
neurons. Carry information from neuron to neuron.
Neurotransmitters
29.2 Neurons
Action Potential: Electrical impulse that carries
messages
Dendrites receive
action potential
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NEURON
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NEURON
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NEURON
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NEURON
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NEURON
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NEURON
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NEURON
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NEURON
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NEURON
Dendrites of
next neuron
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Axon terminal: releases neurotransmitters (chemical
signals)
Synapse
(gap)
Axon terminal
Dendrites of
next neuron
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Check your labels:
Neurotransmitters
NEURON
Synapse
Cell body
axon
Myelin sheath
Dendrites
Action potential
Axon terminal
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Neurons transmit information in the form of electrical and
chemical impulses
1. When a neuron is stimulated, it produces an electrical
signal (action potential) within that neuron
- Electrical Impulse reaches axon terminal
29.2 Neurons
2. Before it can move to the next cell it changes into a
chemical signal (neurotransmitter)
3. Neurotransmitters (chemicals) release into synapse.
4. Neurotransmitters stimulate next cell.
synapse
neurotransmitte
vesicles
receptor
29.2 Neurons
Neurons and Sensory Neurons (2m59s)
29.2 Neurons
How does the structure of a neuron
make it effective in carrying out the
functions of the nervous system?
29.2 Neurons
How does the structure of a neuron
make it effective in carrying out the
functions of the nervous system?
Neurons have long extensions called
axons, which allow messages to be
carried long distances without having
to pass the signal to another cell.
Set
Cornell Notes on pg.
29.2upNeurons
33
•Topic: 29.2 Types of
Neurons
•Essential Question(s):
1. None.
29.2
Types of Neurons
2.1 Atoms,
Ions,
and Molecules
29.2 Neurons
How the Nervous System Works (1m59s)
29.2 Neurons
There are 3 types of neurons:
1) Sensory neurons
2) Interneurons
3) Motor neurons
29.2 Neurons
1. Sensory Neurons: (Think Senses)
• Function: Sensory receptors gather information
from external/ internal environment and carry
impulses along sensory neurons to the CNS
• NO INTERPRETATION
• Located in PNS
Outside:
Light
&
Sound
Intensities
Inside:
Temperature
Oxygen Levels
pH Levels
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29.2 Neurons
2)Interneurons:
• Function: Receives signals from sensory neurons and
processes and interprets these messages within the
CNS
• Makes decisions on what needs to be done
• Sends messages/instructions to motor neurons
• Located in CNS
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29.2 Neurons
3)Motor neurons:
• Function: Carry nerve impulses out of the brain
or spinal cord to effectors
•Effectors: muscles and glands will execute a
specific task
• Located in the PNS.
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29.2 Neurons
Motor Neurons (57s)
29.2 Neurons
Key: Motor Neurons
Interneurons
Effectors
Receptors
Sensory Neurons
Draw/label
2. ________________
on p. 33
1._______________
3.
______________
4. _____________
5._____________
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29.2 Neurons
Key: Motor Neurons
Effectors
Receptors
Sensory Neurons
Interneurons
1. Receptors
2. Sensory Neurons
3. Interneurons
4. Motor Neurons
5. Effectors
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29.2 Neurons
Key: Motor Neurons
Effectors
Receptors
1.
Sensory Neurons
2.
3.
5.
4.
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Interneurons
29.2 Neurons
Stimuli and Neurons (4m 16s)
29.2 Neurons
In a nutshell….
• The nervous system can:
• Detect changes in the body
• Make decisions based on the info received
• Stimulate muscles and/or glands to respond
• Counteract changes to maintain homeostasis
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Types of Neurons “Story” Tree Map (P. 32)
29.2 Neurons
Sensory Neurons
Interneurons
Motor Neurons
• Function
• Location
• Function
• Location
• Function
• Location
Give a real life example (Tell a story)
1. The phone rings. The
sensory neurons in your
ear gather the sound
information and send it to
the CNS
2. Your brain interprets this
information and identifies
the sound as the phone
ringing. This info is sent to
the motor neurons
3. The motor neurons
send nerve impulses to
your muscles which
allow you to answer the
phone
Draw a picture for each
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