Sponge Set up Cornell Notes on pg 5

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 map” explaining the function of each part of a neuron (p. 356 -361) Nucleus Action potential NEURON 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 (Ron-vee -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

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How Synapses Work 3 m 15 s 16

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NEURON Dendrites of next neuron

NEURON Axon terminal Synapse (gap) Dendrites of next neuron

Nerves: Bundles of axons 27

Neurons and Neurotransmitters 5 m 35 s Add info to picture bubble map 28

A Closer Look at Neurons 4 m 49 s 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 1 m 59 s 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 p. H Levels 34

Sensory Neurons 2 m 59 s 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 59 s 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 4 m 16 s 41

P. 6 Types of Neurons Picture TREE MAP Sensory Neurons Interneurons Motor Neurons • Function • Location 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 Draw a picture for each 3. The motor neurons send nerve impulses to your muscles which allow you to answer the phone 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 51 (potassium)

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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

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Crash Course: Nervous System Part I 9 m 36 s 57