Sponge: Set up Cornell Notes on pg. 5 Topic: 10.2 Neuron Structure Essential Question: None. 2.1 Atoms, Ions, and Molecules 10.2 Neuron Structure Number your notebook pages 1-80

Final Group Project Review 5 minutes Return to Mrs. M Get Textbook

Cell body Dendrites axon Myelin sheath (covering) Axon terminals NEURON Action potential Neurotransmitters Synapse (gap between neurons) nucleus Schwann Cells 4 5

Cell body Dendrites axon Myelin sheath (covering) Axon terminals Action potential (nerve impulse) Neurotransmitters Synapse Nucleus Schwann Cells Nodes of Ranvier Draw and Label on pg Make a “picture bubble map” explaining the function of each part of a neuron (p ) NEURON

Cell body Dendrites axon Myelin sheath (covering) Axon terminals Action potential (nerve impulse) Neurotransmitters Synapse Nucleus Schwann Cells Nodes of Ranvier Get out your homework for signature NEURON

6 All Neurons are made up of 4 main parts: Dendrites A cell body Nucleus Axon Dendrites Cell body Nucleus axon

7 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

8 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

9 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

10 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)

Dendrites receive action potential (nerve impulse) from nearby neuron to be sent to next neuron Action Potential: Electrical impulse that carries messages down the axon

Neurotransmitters Axon terminals: the enlarged endings of a neuron, by which axons make synaptic contacts with other nerve cells or with effector cells (muscle/glands)

Synapse Synapse: Gaps between neurons that allow signals to be sent from neuron to neuron

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

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How Synapses Work 3m15s 16

NEURON

Dendrites of next neuron NEURON

Dendrites of next neuron NEURON Synapse (gap) Axon terminal

27 Nerves: Bundles of axons

28 Neurons and Neurotransmitters 5m35s Add info to picture bubble map

29 A Closer Look at Neurons 4m49s Add info to picture bubble map

Sponge: Set up Cornell Notes on pg. 7 Topic: 10.2 Three Types of Neurons Essential Question: None. 2.1 Atoms, Ions, and Molecules 10.2 Three Types of Neurons 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

34 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

35 Sensory Neurons 2m59s

36 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

37 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)

38 Motor Neurons 59s

39 2. ________________ 3. ______________ 4. _____________ 1._______________ 5._____________ Key: Motor Neurons Effectors Receptors Sensory Neurons Interneurons Answer on p. 7

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

41 Stimuli and Neurons 4m 16s

Give a real life example (Tell a story) Draw a picture for each 42 Types of Neurons Picture TREE MAP Sensory Neurons Interneurons Motor Neurons 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 Function Location Function Location Function Location P.6 As short as possible

Sponge: Set up Cornell Notes on pg. 9 Topic: 10.2 Classification of neurons and neuroglial cells Essential Question: None. 2.1 Atoms, Ions, and Molecules 10.2 Classification of Neurons and neuroglial cells Then turn to p. 6 for signature

44 Classification of Neurons and Neuroglial Cells Neurons based on structure….(361- 2/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

Neuron Gallery Walk 45 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

46 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 Classification of Neurons – Structural Differences

47 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

48 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

49 1.Schwann Cells: Location: PNS Function: Produce myelin that wrap tightly around the axons of peripheral neurons and Speed up neurotransmissions Types of Neuroglial Cells in the PNS

50 2. Satellite Cells: Small cuboidal cells that surround clusters of neuron cell bodies called ganglia Function: Support ganglia in the PNS

51 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) Types of Neuroglial (Neu-rag-lial) Cells in the CNS

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53 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

54 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

55 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

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Crash Course: Nervous System Part I 9m36s 57