1. Neuron Anatomy

2. The nervous system also allows you to react to a stimulus.
A stimulus is a change in the environment.
Example: A hot stove
Or… tripping over a rock

3. Structure of a Vertebrate Neuron

5. Anatomy of a Neuron Cell body: functional portion
Dendrites: short extensions that receive signals
Axon: long extension that transmits impulses away

6. Myelinated Neurons
Many vertebrate peripheral neurons have an insulating sheath around the axon called myelin which (white matter) is formed by Schwann cells.
Myelin sheathing allows these neurons to conduct nerve impulses faster than in non-myelinated neurons (gray matter)
Node of Ranvier is the location where nervous impulses are conducted.

7. Basic Tasks of the Nervous System
Sensory Input: Monitor both external and internal environments.
Integration: Process the information and often integrate it with stored information.
Motor output: If necessary, signal effector organs to make an appropriate response.

8. Messages carried throughout the body by nerves.
Nerve Impulse
Messages carried throughout the body by nerves.

9. Saltatory Conduction in Myelinated Axons
Myelin sheathing has bare patches of axon called nodes of Ranvier
Action potentials jump from node to node
Fig

10. •At rest, the membrane maintains an electrical polarization called the resting membrane potential.
–the inside of the membrane is slightly negative with respect to the outside. (approximately -70 millivolts)
The Nerve Impulse

11. Depolarization – influx of Na+ ions

12. Repolarization – outflux of K+ ions

14. Nerve Impulse - The Action Potential
Threshold potential will trigger an action potential or nerve impulse
The action potential is an all-or-none response

15. INTEGRATION WITHIN THE CENTRAL NERVOUS SYSTEM
The nervous system gathers and processes information from the external and internal environments and then relays a response to the necessary areas of the body.

16. REFLEX ARC
Neurons allow the nervous system to relay sensory information to the brain and spinal cord for integration, and to produce a response, as needed, by the effectors.

17. How does a signal move from one neuron to another?
A synapse separates 2 neurons
The action potential will not move across the synapse
Neurotransmitters
Released by the signal cell to the receiver cell
Move by diffusion

19. Types of chemical neurotransmitters
Excitatory: helps to initiate a response, making the cell membrane receptors more permeable
Acetylcholine: neuromuscular junctions, glands, brain and spinal cord
Norepinepherine: affects brain regions concerned with emotions, dreaming

20. Inhibitory neurotransmitters: is able to breakdown the excitatory neurotransmitters to prevent further action potentials from occuring. Cholinesterase: breaks down acetylcholine.

21. Central Nervous System
The Central Nervous System is made of the brain and the spinal cord.
The Central Nervous System controls everything in the body.

22. The Outer Nervous System is made of the nerves and the sense organs.

23. The Central Nervous System

24. The Central Nervous System
* The Central Nervous System controls all of the body’s activities.
* The Central Nervous System is made of two main organs.
1. The brain
2. The spinal cord

25. The Spinal Cord
* The spinal cord sends messages to the brain.
* The spinal cord is the part of the nervous system that connects the brain to the rest of the nervous system.

26. The Brain
* The brain controls everything in the body.
* The brain is made of more than 10 billion nerves!
* The brain is divided into three parts and is protected by the skull.

27. The Three Parts of the Brain
* The Brain has three main parts…
1. The Cerebrum
2. The Cerebellum
3. The Brain Stem

28. * The Cerebrum is the largest part of the brain.
1. The cerebrum controls your thinking.
2. The cerebrum controls your memory.
3. The cerebrum controls your speaking.
4. The cerebrum controls your movement and identifies the information gathered by your sense organs.

30. The right and left halves of the cerebral cortex (cerebrum) are made of four pairs of lobes, each of which is associated with particular functions:
FRONTAL lobes (conscious thought and movements, speech),
PARIETAL lobes (touch, taste),
TEMPORAL lobes (hearing and speech),
OCCIPITAL lobes (vision).

31. * The cerebellum is below and to the back of the cerebrum.
1. The cerebellum controls you balance.
2. The cerebellum controls your posture.

33. The Brain Stem
* The Brain Stem connects the brain to the spinal cord.
* The nerves in the brain stem control your heartbeat, breathing, and blood pressure (MEDULLA OBLONGATA and HYPOTHALAMUS).

35. The Vertebrae
* The vertebrae are the many bones that protect the nerves in the spinal cord.

36. The Outer Nervous System

37. Outer Nervous System
* The outer nervous system carries messages between the central nervous system and the rest of the body.
* The Outer Nervous System’s job is to connect the Central Nervous System to the rest of the body.

38. * The outer nervous system is made of the nerves and the sense organs.
Eye
Tongue
Ear
Nerves
Skin

39. * An automatic reaction that happens without thinking about it.
Reflex
* An automatic reaction that happens without thinking about it.
* A reflex happens quickly in less than a second.

41. Automatic Nervous System
* The outer nervous system controls the body’s activities that you don’t think about.
* The outer nervous system controls activities in your small intestine, your breathing, and your heartbeat.
controls

44. Sense Organs
Sense organs carry messages about the environment to the central nervous system.

45. The eyes, ears, nose, tongue, and skin are examples of sense organs.
The sense organs gather information (light, sound, heat, and pressure) from the environment.

46. The environment is everything outside the body.
The sense organs gather information from outside the body, then send the messages to the brain.

47. Vision is your ability to see.
Vision involves the eye and the brain.

49. Parts of the Eye Detectors on the Fovea
Rods
light intensity and motion sensitive
Cones
color sensitive
The blind spot for the eye is cause by the optic nerve.

52. Myopia (Near-Sightedness)
People with near-sightedness cannot see clearly at distance.

53. Hyperopia (Farsightedness)
People with far-sightedness cannot see clearly up close

54. When a sound is made, the air around the sound vibrates.
Hearing
Hearing starts when some of the sound waves go into the ear.

55. Parts of the Ear
There are nine main parts of the ear.
1. Pinna
5. Anvil
2. Ear canal
6. Stirrup
3. Ear drum
7. Cochlea
4. Hammer
8. Eustachian tube
9. Auditory nerve

56. The pinna is the part of the ear that you can see.
The ear canal is the tube between the outside of the ear and the ear drum.
The ear drum is in the middle ear. It vibrates when sound waves hit it.

57. The stirrup passes the vibrations to the inner ear.
Parts of the Ear
The three smallest bones in the body, the hammer, the anvil, and the stirrup, are in the middle ear.
The hammer gets the vibrations from the eardrum, then sends them to the anvil.
The anvil passes the vibrations to the stirrup.
The stirrup passes the vibrations to the inner ear.

58. The inner ear is made of the cochlea and liquid.
The Eustachian tube controls the amount of pressure in the ear.
The inner ear is made of the cochlea and liquid.
The cochlea is in the inner ear. The cochlea looks like a shell.
The auditory nerve carries the hearing information to the brain and the brain tells us what we heard.

59. The ear works with the brain to control your balance.
The Ear and Balance
The ear works with the brain to control your balance.
All of your movements are controlled by balance and muscles.
The liquid in your inner ear is responsible for your balance.
The liquid in your ear moves when we move. The liquid movement sends information to the brain to tell it how we are moving.

61. The sense of touch is located in the skin.
The nerves in the skin allow us to feel texture, pressure, heat, cold, and pain.
Texture is how something feels.

62. The nose is able to smell 80 different kinds of smells.
The nose controls your sense of smell.
Smell
The nose is able to smell 80 different kinds of smells.

63. Your sense of taste comes from the taste buds in the tongue.
Taste buds are the parts on the tongue that allow us to taste.
The four kinds of taste buds are sweet, sour, bitter, and salty.

65. Tastes and smells work together to make flavors.
Flavors are the tastes of food and drinks.

66. Addictive Drug Use: Tobacco, Alcohol, & Illicit Drugs
Dr. Robert B. Coambs
Psy333
November, 2002

67. Pharmacology of Addictive Drugs
All addictive drugs produce:
Short-term pleasure to some degree
Long-term negative consequences
Tolerance & physical dependence
A withdrawal syndrome
Activation of dopamine neurons in the Nucleus Accumbens

68. Transmission Across the Synapse
Source: Gray

69. How Drugs Become Addictive

70. Detail of Axon Terminal

71. Detail of the Synapse Itself
Neurotransmitter
molecules
(e.g., Acetylcholine
or Dopamine)
Postsynaptic
membrane

72. How binding sites work
Binding site

73. Neurotransmitter re-uptake helps keep binding sites clear

74. Cocaine inhibits the re-uptake of dopamine producing effects such as increased heart rate and blood pressure

75. Nicotine fills & activates acetylcholine binding sites producing effects such as increased heart rate and blood pressure

76. What is Addiction?
All definitions describe behaviour which produces positive sensations in the short term, but negative consequences in the long term
A straightforward definition:
Compulsive use
Loss of control
Use despite harm
* Portnoy

77. How People Start Using Drugs
Genetics
Predisposing risk factors:
Age for onset
Primitive character structures
Especially Conduct Disorder
Peer influence
Parental influence
Smoking and alcohol use
Constricted temporal focus?

78. Nicotine Use is Associated With Other Drug Use
Kozlowski, Coambs, et al., 1989

79. Some People Never Start
Factors which reduce risk:
Age 35+
Nuanced character structures
No Peer influence
No Parental drug use history
No other smoking or alcohol abuse
E.G., the SISAP

80. Basic Treatment For Addiction
Treat the urges directly, if possible
Establish why the person uses the drug
What needs are being fulfilled by that drug?
Find methods to fulfil those needs without the drug

81. How People Quit Drug Abuse
Most quit on their own (cold turkey)
Most use no medication
Probably those people who can quit easily do so
Clinicians tend to see the difficult cases
Ambivalence is normal
Most quit by age 40

82. Relapse Prevention Plan for relapse: Abstinence Violation Effect
Relapse is common: it is not failure!
Repeated relapse is associated with success in quitting
Learn from it in next attempt
Find a way to control urges