1. 29.2 Nervous System and Neurons
Set up Cornell Notes on pg. 47
Topic: 29.2 Nervous System and Neurons
Essential Question(s):
Draw and label a neuron on pg. 46 in picture bubble map format.
29.2 Nervous System and Neurons
2.1 Atoms, Ions, and Molecules
KEY CONCEPT The nervous system is composed of highly specialized cells.

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

3. Make up an information network (Like the internet)
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
neurotransmitter
Dendrites

4. Neurons are highly specialized cells.
A neuron has three parts.
1. cell body has nucleus and organelles 1
Cell body

5. 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

6. 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 sheath- insulate neurons’ axons and helps them send messages 3
axon

7. Synapse: Gaps between neurons

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

9. Action Potential: Electrical impulse that carries messages
Dendrites receive action potential

10. NEURON

11. NEURON

12. NEURON

13. NEURON

14. NEURON

15. NEURON

16. NEURON

17. NEURON

18. NEURON
Dendrites of next neuron

19. Axon terminal: releases neurotransmitters (chemical signals)
Synapse (gap)
Axon terminal
Dendrites of next neuron

20. NEURON Draw and label this neuron on p. 46: Neurotransmitters Synapse
Cell body
axon
Myelin sheath
Dendrites
Axon terminal
Action potential

21. 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

22. Electrical Impulse reaches terminal.

23. Electrical Impulse reaches terminal.

24. Electrical Impulse reaches terminal.
Neurotransmitters (chemicals) release into synapse.
synapse
impulse
neurotransmitter
vesicles
receptor

25. Electrical Impulse reaches terminal.
Neurotransmitters (chemicals) release into synapse.
Neurotransmitters stimulate next cell.
synapse
impulse
neurotransmitter
vesicles
receptor

26. How does the structure of a neuron make it effective in carrying out the functions of the nervous system?

27. 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.

28. Types of Neurons Picture Tree Map
Sensory Neurons Interneurons Motor Neurons
Function
Location
Function
Location
Function
Location

29. There are 3 types of neurons:
Sensory neurons
Interneurons
Motor neurons

30. The dendrites of these neurons act as sensory receptors
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
&
Sound
Intensities
Inside:
Temperature
Oxygen Levels
pH Levels

31. 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

32. 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.

33. Key: Motor Neurons Effectors Receptors Sensory Neurons Interneurons
1._______________
2. ________________
3. ______________
4. _____________
5._____________

34. 2. Sensory Neurons 3. Interneurons 4. Motor Neurons 1. Receptors
5. Effectors

35. 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

36. 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?