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Set
Cornell Notes on pg.
29.2upNeurons
39
•Topic: 29.2 Nervous
System and Neurons
•Essential Question(s):
1. Draw and label a neuron
on pg. 38 in picture bubble
map format.
Nervous
2.129.2
Atoms,
Ions, System and Neurons
and Molecules
29.2 Neurons
Standard 9.d
Students know the functions of the nervous
system and the role of neurons in
transmitting electrochemical impulses.
Standard 9.e
Students know the roles of sensory neurons,
interneurons, and motor neurons in
sensation, thought, and response.
29.2 Neurons
• The nervous system is a
physically connected network
of cells , tissues, and organs
• Controls thoughts, movement,
and emotion
29.2 Neurons
Ex: Pupils shrinking in
sunlight
When you go out into the sun
your nervous system senses the
bright light coming into your eyes
and tells your pupils to shrink and
let in less light.
Try and come
up with 2
more
examples at
your table
•
•
•
•
•
•
•
Senses
Reflexes
Heart rate
Digestion
Breathing rate
Blinking
Sneezing/coughing
29.2 Neurons
• The nervous system works quickly, using chemical
and electrical signals.
spinal
chord
nerves
29.2 Neurons
– Central nervous system
(CNS) includes the brain
and spinal cord
–interpret messages from
other nerves in the body,
and stores some of these
messages for later use
29.2 Neurons
–Peripheral nervous system
(PNS) network of nerves
that transmit messages to
and from the CNS to other
organs in the body
29.2 Neurons
• Sends signals through a
network of specialized
tissues
• Like cable television
• A physical wire connects your
TV. to the cable provider
29.2 Neurons
SPONGE
1. Why does your body need a communication
system?
2. Which system, the endocrine or the nervous,
controls the rate at which you blink?
3. How might a clogged blood vessel affect the
endocrine system’s ability to deliver signals?
29.2 Neurons
1. Why does your body need a communication system?
• A communication system allows the body to respond
to its environment and maintain homeostasis
2. Which system, the endocrine or the nervous, controls the rate
at which you blink?
• The nervous system controls the rate of blinking
because it controls fast processes.
3. How might a clogged blood vessel affect the endocrine
system’s ability to deliver signals?
• A clogged blood vessel might slow down the delivery
of signals by the endocrine system, but not the
nervous system
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
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
NEURON
Synapse
Synapse: Gaps between neurons
29.2 Neurons
NEURON
Neurotransmitters
Neurotransmitters: Chemical signals released by
neurons. Carry information from neuron to neuron.
29.2 Neurons
NEURON
Dendrites receive
action potential
Action Potential: Electrical impulse that carries
messages
29.2 Neurons
NEURON
29.2 Neurons
NEURON
29.2 Neurons
NEURON
29.2 Neurons
NEURON
29.2 Neurons
NEURON
29.2 Neurons
NEURON
29.2 Neurons
NEURON
29.2 Neurons
NEURON
29.2 Neurons
NEURON
Dendrites of
next neuron
29.2 Neurons
NEURON
Axon terminal
Synapse
(gap)
Dendrites of
next neuron
Axon terminal: releases neurotransmitters (chemical
signals)
29.2 Neurons
Draw and label this neuron on p. 38:
Neurotransmitters
NEURON
Synapse
Cell body
axon
Myelin sheath
Dendrites
Action potential
Axon terminal
29.2 Neurons
• Neurons transmit information in the form of electrical and
chemical impulses
– When a neuron is stimulated, it produces an electrical
signal (action potential) within that neuron
– Before it can move to the next cell it changes into a
chemical signal (neurotransmitter)
– You react
29.2 Neurons
– Electrical Impulse reaches terminal.
terminal
impulse
29.2 Neurons
– Electrical Impulse reaches terminal.
impulse
29.2 Neurons
– Electrical Impulse reaches terminal.
– Neurotransmitters (chemicals) release into synapse.
synapse
impulse
neurotransmitte
vesicles
receptor
29.2 Neurons
– Electrical Impulse reaches terminal.
– Neurotransmitters (chemicals) release into synapse.
– Neurotransmitters stimulate next cell.
synapse
impulse
neurotransmitter
vesicles
receptor
Set
Cornell Notes on pg.
29.2upNeurons
41
•Topic: 29.2 Types of
Neurons
•Essential Question(s):
1. Neuron Picture Tree Map
on pg. 40
1. Function
2. Location
3. Real Example in story
format
4. Picture for each (should
match story)
29.2
Types of Neurons
2.1 Atoms,
Ions,
and Molecules
29.2 Neurons
There are 3 types of neurons:
1) Sensory neurons
2) Interneurons
3) Motor neurons
29.2 Neurons
1. Sensory Neurons:
• The dendrites of these neurons act as sensory
receptors
• Gather information by detecting changes inside
and outside of the body and sends it to the CNS
• Function: They gather information and carry
impulses into the brain and spinal cord
Outside:
Light
&
Sound
Intensities
Inside:
Temperature
Oxygen Levels
pH Levels
37
29.2 Neurons
1) Interneurons:
• Receive signals from sensory neurons and relay them
within the brain and spinal cord
• Process and interpret messages
38
29.2 Neurons
1) Motor neurons:
• Pass messages from the central nervous system to
the other tissues in the body, such as muscles
• Function: Carry nerve impulses out of the brain or
spinal cord to effectors
•Effectors: structures that respond
•ex: muscles and glands
39
29.2 Neurons
Receptors
Sensory Neurons
Interneurons
Motor Neurons
Effectors
40
29.2
LabelNeurons
the parts of this reflex arc:
1
5
3
Spinal Cord
4
2
Key: Effector Motor Neuron
Sensory Neuron
Receptor Interneuron
41
29.2 Neurons
1 Receptor
5 Effector
3 Interneuron
Spinal cord
4 motor
neuron
2 Sensory neuron
42
29.2 NeuronsTypes of Neurons Picture Tree Map
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
43
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
44
29.2 Neurons
Neurons (nerve cells) are cells that can store
information and send and receive messages.
In a paragraph, hypothesize
how drug or alcohol use
might affect neurons?
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.