Sponge: Set up Cornell
Notes on pg. 5
10.2 Neuron Structure
2.1 Atoms, Ions,
and Molecules
Topic:
10.2 Neuron Structure
Essential Question: None.
Number your notebook
pages 1-80
Final Group Project Review
• 5 minutes
• Return to Mrs. M
Get Textbook
Synapse
NEURON
nucleus
(gap between
neurons)
Axon
terminals
Action
potential
axon
Schwann
Cells
Myelin sheath
Dendrites
4
Neurotransmitters
(covering)
Cell body
5
Draw and Label on pg. 4-5. Make a “picture bubble
NEURON
map” explaining the function of each part of a
neuron (p.356-361)
Nucleus
Action
potential
Synapse
Axon
terminals
(nerve
impulse)
axon
Schwann Cells
Neurotransmitters
Myelin sheath
Dendrites
(covering)
Cell body
Nodes of
Ranvier
Get out your homework for signature
Synapse
Nucleus
Action
potential
Axon
terminals
(nerve
impulse)
axon
Schwann Cells
Neurotransmitters
Myelin sheath
Dendrites
(covering)
Cell body
NEURON
Nodes of
Ranvier
All Neurons are made up of 4 main parts:
• Dendrites
• A cell body
• Nucleus
• Axon
Dendrites
Cell body
Nucleus
axon
6
Dendrites:
• Usually highly branched
• Receive messages from other cells and provide
receptive surfaces for communication
• Have tiny thorn like spines on their surface which provide
the contact points for other neurons
7
Cell body:
The cells life support center
Contains:
• Cytoplasm
• Mitochondria
• Lysosomes
• Golgi Apparatus
• Microtubles
• Neurofibrils: A network of fine threads that extends into
the axons and supports them
• Nissl bodies: consist mainly of rough endoplasmic
reticulum (E.R.)
• Nucleus with nucleolus
8
Axon:
• Specialized to conduct nerve impulses AWAY from the cell
body to other neurons, muscles, and glands
• Only one axon per neuron
• Slender and cylindrical
9
Axon:
• Myelin sheath- is a layer surrounding the axon that increases
the speed of transmissions
• Schwann cells: found only in the PNS, encase the larger axons
of peripheral neurons
• Gaps between Schwann cells are nodes of Ranvier (Ronvee-ā)
10
Action Potential: Electrical impulse that carries messages down
the axon
Dendrites receive
action potential
(nerve impulse) from
nearby neuron to be
sent to next neuron
Axon terminals: the enlarged endings of a neuron, by which axons
make synaptic contacts with other nerve cells or with effector cells
(muscle/glands)
Neurotransmitters
Synapse: Gaps between neurons that allow signals to be sent from
neuron to neuron
Synapse
Neurotransmitters: Chemical signals released by neurons. Carry
information from neuron to neuron.
Neurotransmitters
15
How Synapses Work 3m15s
16
NEURON
NEURON
NEURON
NEURON
NEURON
NEURON
NEURON
NEURON
NEURON
Dendrites of
next neuron
NEURON
Axon terminal
Synapse
(gap)
Dendrites of
next neuron
Nerves: Bundles of axons
27
Neurons and Neurotransmitters 5m35s
Add info to picture bubble map
28
A Closer Look at Neurons
4m49s
Add info to picture bubble map
29
Sponge: Set up Cornell
Notes on pg. 7
10.2 Three Types of Neurons
2.1 Atoms, Ions,
and Molecules
Topic:
10.2 Three Types of Neurons
Essential Question: None.
Then turn to p. 4/5 for
signature
There are 3 types of neurons:
1) Sensory neurons
2) Interneurons
3) Motor neurons
Three Neuron Functions:
1. Some carry impulses into the brain or spinal cord
2. Others conduct impulses from neuron to neuron
within the brain and spinal cord
3. Others carry impulses out of the brain or spinal cord
Three Types of Neurons 1m59s
33
1. Sensory Neurons:
• Located in PNS
• The dendrites of these neurons act as sensory
receptors
• Most are unipolar, some bipolar
Function: They gather information and carry
impulses TO the brain and spinal cord
Outside:
Light
&
Sound
Intensities
Inside:
Temperature
Oxygen Levels
pH Levels
34
Sensory Neurons
2m59s
35
2)Interneurons:
• Located in CNS
• Multipolar
Function: Receive signals from sensory neurons and relay
them within the brain and spinal cord
• Direct incoming sensory impulses to appropriate
regions for processing and interpreting
36
3)Motor neurons:
• Located in the PNS
• Pass messages from the CNS to the other tissues in
the body
• Multipolar
Function: Carry nerve impulses OUT of the brain or
spinal cord to effectors (muscles and glands)
37
Motor Neurons
59s
38
Key: Motor Neurons
Interneurons
Effectors
Receptors
Sensory Neurons
1._______________
2. ________________
Answer
on p. 7
3.
______________
4. _____________
5._____________
39
1. Receptors
2. Sensory Neurons
3. Interneurons
4. Motor Neurons
5. Effectors
40
Stimuli and Neurons
4m 16s
41
P.6
Types of Neurons Picture TREE MAP
Sensory Neurons
Interneurons
Motor Neurons
• Function
• Location
• Function
• Location
• Function
• Location
As short as possible
As short as possible
As short as possible
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
42
Sponge: Set up Cornell
Notes on pg. 9
10.2 Classification of Neurons and
2.1 Atoms, Ions,
neuroglial cells
and Molecules
Topic:
10.2 Classification of
neurons and neuroglial cells
Essential Question: None.
Then turn to p. 6 for
signature
Classification of Neurons and Neuroglial Cells
Neurons based on structure….(3612/Table 10.1/online)
1. Bipolar Neurons
2. Unipolar Neurons
3. Multipolar Neurons
Neuroglial Cells in CNS (p.364-6/Table
10.2/online)
4. Astrocytes
5. Oligodendrocytes
6. Microglia
7. Ependyma
Neuroglial Cells in PNS (364/Table
10.2/online)
8. Satellite Cells
9. Schwann Cells
•
•
•
•
Title
Illustration
Function
Location
• CNS/PNS
• Specific location?
• Structural
Characteristics
• Shape
• # of processes
•Other important
information
44
Neuron Gallery Walk
• We will go on a
gallery walk to gather
our notes
• 3 mins each (30 mins)
• Use your books to fill
in any missing
information
45
Classification of Neurons –
Structural Differences
1. Bipolar neurons:
• Only 2 processes
• One is an axon/ one is a dendrite
•
Location: Found in PNS sensory neurons
• Eyes, nose, ears
Function: They gather information and carry
impulses into the brain and spinal cord
46
2. Unipolar neurons:
• 1 process extending from its cell body
• Divides into two branches
• One branch enters the brain or spinal
cord
• Location: Found in PNS sensory neurons
• Gather in specialized masses of nerve
tissue called ganglia outside the brain and
spinal cord
Function: They gather information and carry
impulses into the brain and spinal cord
47
3. Multipolar Neurons:
• Many processes
• One is an axon, the rest dendrites
• Location: Found within the CNS
Function: They transmit nerve impulses
between neurons within the brain and spinal
cord
AND conduct nerve impulses out of the brain
and spinal cord to muscles or glands
48
Types of Neuroglial Cells
in the PNS
1. Schwann Cells:
• Location: PNS
Function: Produce myelin that wrap
tightly around the axons of peripheral
neurons and Speed up
neurotransmissions
49
2. Satellite Cells:
• Small cuboidal cells that surround clusters of neuron
cell bodies called ganglia
Function: Support ganglia in the PNS
50
Types of Neuroglial (Neu-rag-lial)
Cells in the CNS
1. Astrocytes:
• Star shaped
• Abundant (many) processes
• Location: Found in CNS between neurons and blood
vessels
Functions:
• Provide support & hold structures together
• Respond to injury of brain tissue and form scar tissue
• Transports substances between blood vessels and
neurons
• Communicate with one another, and with neurons
• Aide in metabolism of certain substances (glucose)
• Regulate the concentrations of important ions
(potassium)
51
52
2. Oligodendrocytes: (Ollie-go-dendro-cytes)
• Fewer processes than Astrocytes
• Occur in rows along myelated axons
• May provide myelin for many axons at one time
Functions:
• Form myelin sheaths within the brain and spinal cord
• Produce nerve growth factors
53
3. Microglia: (My-crog-lia)
• Small
• Have very few processes
• Scattered through the CNS
Functions:
• Support neurons
• Phagocytize bacterial
cells and cellular debris
(immune protection)
• Multiply whenever the
brain or spinal cord is
inflamed due to injury
or disease
54
4. Ependyma: (Eh-pen-di-ma)
• Cuboidal or columnar in
shape
• Found in the inner lining of
the ventricles of the brain
and the central canal of the
spinal cord
Function:
• They form a porous
layer through which
substances diffuse
freely between the
interstitial fluid of the
brain and the
cerebrospinal fluid
within the ventricles
55
56
Crash Course: Nervous System
Part I
9m36s
57