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

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. The Basic Parts of a Neuron

11. Parts of the Neuron

12. A. Dendrites
Thin, branching fibers lined with receptors at which the dendrite receives information from other neurons.

13. Parts of the Neuron - Dendrites

14. B. Cell Body/Soma
Contains the (C) nucleus and other parts of the cell needed to sustain life

15. Parts of the Neuron - Soma

16. C. Axon
Carries the message across the neuron

17. Parts of the Neuron - Axon

18. D. Myelin Sheath
An insulating, fatty covering around the axon that speeds neural transmissions. Axons that are myelinated appear white. Known as “white matter.”

19. Parts of the Neuron – Myelin Sheath

20. E. Axon Terminal Buttons
The branched end of the axon that contains neurotransmitters

21. Parts of the Neuron - Terminals

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

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

24. Neuron

25. Neuron

26. Neural Transmission

28. Neural Communication: The Neural Impulse

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

30. 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

31. 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

35. 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

36. 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

37. 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

38. 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.

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

40. Synapse
The space between the terminal buttons on one neuron and dendrites of the next neuron

42. Neurotransmitters
Chemicals contained in the terminal buttons that enable neurons to communicate. Neurotransmitters fit into receptor sites on the dendrites of neurons like a key fits into a lock.

43. Neurotransmitters

44. 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

49. 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.

50. 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.

51. Neurotransmitters

52. Acetylcholine (ACh)
Enables muscle action, REM sleep, and memory
Undersupply, as ACh-producing neurons deteriorate, marks Alzheimer’s disease

53. Dopamine Reward and Motivation, Motor Control over Voluntary Movements
Excessive dopamine receptor activity is linked to schizophrenia; a lack of dopamine produces the tremors and lack of mobility of Parkinson’s disease

54. Serotonin Affects mood, hunger, sleep, and arousal
Undersupply is linked to depression; Prozac and other anti-depressants raise serotonin levels

55. Helps to control alertness and arousal
Norepinephrine
Helps to control alertness and arousal
Undersupply can depress mood

56. GABA
Muscular movement; inhibition of brain activity
Undersupply linked to seizures, tremors, and insomnia
Anxiety disorders

57. Glutamate Involved in memory
Oversupply can overstimulate the brain, producing migraines or seizures

58. Endorphins
Natural opiates that are released in response to pain and vigorous exercise

59. Adrenaline Burst of Energy (small amounts in brain)
Epinephrine
Adrenaline Burst of Energy (small amounts in brain)

60. Drugs and Chemical Interactions with Neural Transmission

61. Prozac blocking the re-uptake of Serotonin

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

63. 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.

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

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

66. 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

67. A Neural Chain

68. A Neural Chain

69. A Neural Chain

70. A Neural Chain

71. A Neural Chain

72. Most information travels from the body, up the spinal cord, is processed by the brain, sent back down the spinal cord, and then back to the body with behavior instructions. The exception to this general pathway is reflexes.

73. Reflexes are controlled by the spinal cord without any conscious effort on behalf of the brain. Reflexes serve as primitive responses that protect our bodies from danger and help us adjust to our surroundings.

74. Reflex
We cough, for example, when an irritant enters our windpipe and we need to expel it through our mouth. We sneeze when we need to clear our nasal air passages of irritants and allergens. We blink when danger threatens the sensitive tissues of the eye and when we need to moisten and clean the cornea. (This reflex occurs 900 times an hour!) We yawn when nerves in the brain stem find there's too much carbon dioxide in the blood.

75. Reflex
Spinal Cord