Understanding Neuron Structure: Parts and Functions

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

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

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

4. NEURON Draw and Label on pg. 4-5. Make a “picture bubble map” explaining the function of each part of a neuron (p.356-361) Synapse Nucleus Action potential (nerve impulse) Axon terminals axon Schwann Cells Neurotransmitters Myelin sheath (covering) Dendrites Cell body Nodes of Ranvier

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

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

12. 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

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

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

16. How Synapses Work 3m15s

17. NEURON

18. NEURON

19. NEURON

20. NEURON

21. NEURON

22. NEURON

23. NEURON

24. NEURON

25. NEURON Dendrites of next neuron

26. NEURON Synapse (gap) Axon terminal Dendrites of next neuron

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

30. 10.2 Three Types of Neurons 2.1 Atoms, Ions, and Molecules Sponge: Set up Cornell Notes on pg. 7 Topic: 10.2 Three Types of Neurons Essential Question: None. Then turn to p. 4/5 for signature

31. There are 3 types of neurons: • Sensory neurons • Interneurons • Motor neurons

32. Three Neuron Functions: • Some carry impulses into the brain or spinal cord • Others conduct impulses from neuron to neuron within the brain and spinal cord • Others carry impulses out of the brain or spinal cord

33. Three Types of Neurons 1m59s

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

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

41. Stimuli and Neurons 4m 16s

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

43. 10.2 Classification of Neurons and neuroglial cells 2.1 Atoms, Ions, and Molecules Sponge: Set up Cornell Notes on pg. 9 Topic: 10.2 Classification of neurons and neuroglial cells Essential Question: None. Then turn to p. 6 for signature

44. Classification of Neurons and Neuroglial Cells • Neurons based on structure….(361-2/Table 10.1/online) • Bipolar Neurons • Unipolar Neurons • 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

45. 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

46. 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

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

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