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29.2 Neurons
SPONGE 3
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
Quick
Includes
CNS and
PNS
Send
signals
Slower
disconnected
Respond to
stimuli
Connected Nervous
Endocrine
network
system
system
Controls
thoughts and
movement
Electrical
Signals
Maintain
homeostasis
Chemical
Signals
Controls
growth and
development
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
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
3
axon
29.2 Neurons
Draw and label this neuron:
Cell body
axon
Myelin sheath
neurotransmitter
Dendrites
29.2 Neurons
Sponge 4
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.
29.2 Neurons
There are 3 types of neurons:
1)Sensory neurons: detect stimuli and transmit signals
to the brain and the spinal cord
2)Interneurons: receive signals from sensory neurons
and relay them within the brain and spinal cord
3)Motor neurons: pass messages from the nervous
system to the other tissues in the body, such as
muscles
* Specialized support cells- such as the myelin
sheath- insulate neurons’ axons and helps them send
messages
29.2 Neurons
• Neurons transmit information in the form of electrical and
chemical impulses
– When a neuron is stimulated, it produces an electrical
signal within that neuron
– Before it can move to the next cell it changes into a
chemical signal
– 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