29.2 Neurons Set up Cornell Notes on pg. 47 Topic: 29.2 Nervous System and Neurons Essential Question(s): 1.Draw and label a neuron on pg. 46 in picture.

29.2 Neurons Set up Cornell Notes on pg. 47•Topic: 29.2 Nervous System and Neurons

•Essential Question(s):

1.Draw and label a neuron on pg. 46 in picture bubble map format.

2.1 Atoms, Ions, and Molecules

29.2 Nervous System and Neurons

KEY CONCEPT The nervous system is composed of highly specialized cells.

29.2 Neurons

KEY CONCEPT The nervous system is composed of highly specialized cells.

29.2 Neurons

Cell body

Dendrites

axon

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)

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

2. dendrites receive messages from neighboring cells

Neurons are highly specialized cells.

• A neuron has three parts.

1. cell body has nucleus and organelles

2 dendrites

29.2 Neurons

3 axon

2. dendrites receive messages from neighboring cells

Neurons are highly specialized cells.

• A neuron has three parts.

1. cell body has nucleus and organelles

3. axon carries messages to other cells

Specialized support cells- such as the myelin sheath- insulate neurons’ axons and helps them send messages

29.2 Neurons

Synapse

Synapse: Gaps between neurons

29.2 Neurons

Neurotransmitters

Neurotransmitters: Chemical signals released by neurons. Carry information from neuron to neuron.

29.2 Neurons

Dendrites receive action potential

Action Potential: Electrical impulse that carries messages

29.2 Neurons

NEURON

29.2 Neurons

NEURON

29.2 Neurons

NEURON

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NEURON

29.2 Neurons

NEURON

29.2 Neurons

NEURON

29.2 Neurons

NEURON

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NEURON

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Dendrites of next neuron

NEURON

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Dendrites of next neuron

Synapse (gap)

Axon terminal

Axon terminal: releases neurotransmitters (chemical signals)

29.2 Neurons

Cell body

Dendrites

Draw and label this neuron on p. 46:

axon

Myelin sheath

Axon terminal

NEURON

Action potential

Neurotransmitters

Synapse

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.

impulse

terminal

29.2 Neurons

– Electrical Impulse reaches terminal.

impulse

29.2 Neurons

– Electrical Impulse reaches terminal.

synapse

receptorvesicles

impulse

neurotransmitter

– Neurotransmitters (chemicals) release into synapse.

29.2 Neurons

– Electrical Impulse reaches terminal.– Neurotransmitters (chemicals) release into synapse.

impulse

synapse

receptorvesicles

neurotransmitter

– Neurotransmitters stimulate next cell.

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.

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Types of Neurons Picture Tree Map

Sensory Neurons Interneurons Motor Neurons

• Function • Location

• Function • Location

• Function • Location

29.2 Neurons

There are 3 types of neurons:

1)Sensory neurons

2)Interneurons

3)Motor neurons

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1. Sensory Neurons:• The dendrites of these neurons act as sensory

receptors• Function: They gather information and carry

impulses into the brain and spinal cord•Located in PNS

Outside:Light &SoundIntensities

Inside:TemperatureOxygen LevelspH Levels

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2)Interneurons:• Receive signals from sensory neurons and relay them within the brain and spinal cord• Function: Process and interpret messages in the CNS

• Located in CNS

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3)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: muscles and glands•Located in the PNS.

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2. ________________

3. ______________

4. _____________

1._______________

5._____________

Key: Motor Neurons Effectors Receptors Sensory Neurons Interneurons

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2. Sensory Neurons

3. Interneurons

4. Motor Neurons

1. Receptors

5. Effectors

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• 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

In a nutshell….

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?