Welcome it is a great day to learn about the Brain

1. Welcome it is a great day to learn about the Brain

2. What does the Brain do? • Stand up • Walk around – every person you pass – tell them a different function the brain performs • Do this until you are told to stop

3. Why do we study the Brain? • Back at your tables – report back what you learned about what the brain does… did you learn anything new?

4. We are going to start small and go big

5. Neurons: The Building Blocks of the Nervous System Module 7: Neural and Hormonal Systems

6. Nervous system Neurons Dendrites Soma Axon Terminal branches of Axon Myelin Sheath What are the primary parts of a typical neuron?

7. Nervous System • The electrochemical communication system of the body • Sends messages from the brain to the body for movement • Brings information to the brain from the senses

8. Neuron • The basic building block of the nervous system -- a nerve cell • Neurons perform three basic tasks • Receive information • Carry the information • Pass the information on to the next neuron

9. Neurons • Neurons “fire” -- send an impulse down their length -- or they don’t “fire” • Neurons come in a variety of shapes, sizes, etc.

10. Parts of the Neuron

11. Parts of the Neuron - Dendrites

12. Parts of the Neuron - Soma

13. Parts of the Neuron - Axon

14. Parts of the Neuron – Myelin Sheath

15. Parts of the Neuron - Terminals

16. Time to Move • Locate the person furthest from you • Go to that person • Introduce yourself

17. Pick an A and D A = Axon D= Dendrite With your partner explain the relationship between neurons

18. Neuron

19. Neuron

20. Neural Communication: The Neural Impulse

21. Action Potential • A brief electrical charge that travels down the axon of the neuron. • A neural impulse • Considered an “on” condition of the neuron

22. Refractory Period • The “recharging phase” when a neuron, after firing, cannot generate another action potential • Once the refractory period is complete the neuron can fire again

23. Resting Potential • The state of a neuron when it is at rest and capable of generating an action potential • The neuron is set and ready to fire

27. Neuron firing like a Toilet • Like a Neuron, a toilet has an action potential. When you flush, an “impulse” is sent down the sewer pipe

28. Neuron firing like a Toilet 2. Like a neuron, a toilet has a refractory period. There is a short delay after flushing when the toilet cannot be flushed again because the tank is being refilled

29. Neuron firing like a Toilet • Like a Neuron, a toilet has a resting potential. The toilet is “charged” when there is water in the tank and it is capable of being flushed again • Like a Neuron, a toilet operates on the all-or-none principle – it always flushes with the same intensity, no matter how much force you apply to the handle

30. All-or-None Principle • The principle that if a neuron fires it will always fire at the same intensity • All action potentials are of the same strength. • A neuron does NOT fire at 30%, 45% or 90% but at 100% each time it fires.

31. Communication Between Neurons Module 7: Neural and Hormonal Systems

32. Synapse • The tiny, fluid filled gap between the axon terminal of one neuron and the dendrite of another neuron • The action potential cannot jump the gap

33. Neurotransmitters • A chemical messenger that travels across the synapse from one neuron to the next • Can influence whether the second neuron will generate an action potential or not

34. Neurotransmitters

38. Excitatory Effect • A neurotransmitter effect that makes it more likely that the receiving neuron will generate an action potential (impulse) • The second neuron is more likely to fire.

39. Inhibitory Effect • A neurotransmitter effect that makes it less likely that the receiving neuron will generate an action potential (impulse) • The second neuron is less likely to fire.

40. Neural Communication: The Neural Chain Module 7: Neural and Hormonal Systems

41. Receptor Cells • Specialized cells in the sensory systems of the body that can turn other kinds of energy into action potentials that the nervous system can process • Receptor cells in the eye turn light into a neural impulse the brain understands.

42. Sensory Nerves • Nerves that carry information to the central nervous system • Connect the sense organs to the brain and spinal cord

43. Interneurons • Nerve cells in the brain and spinal cord responsible for processing information related to sensory input and motor output

44. Motor Nerves • Nerves that carry information from the central nervous system • Carries messages from the brain and spinal cord to other parts of your body

45. A Neural Chain

46. A Neural Chain

47. A Neural Chain

48. A Neural Chain

49. A Neural Chain

50. The Structure of the Nervous System Module 7: Neural and Hormonal Systems