1. Biology & Behavior

2. Fact or Falsehood!
1. All behavior is governed by whether or not a neuron, the basic cell of the nervous system, is activated (fires).
2. Strong emotions, like anger, result from more intense firing of neurons.
3. Neurons never actually touch one another.
4. Drugs work either to mimic or mask one of the body’s naturally occurring chemicals, called neurotransmitters.
5. The brain directly processes all sensory information that comes into the body.
6. Your voluntary movements and your involuntary movements (breathing, digestion, heartbeat, etc.) are controlled by two different nervous systems.
7. You have a specialized nervous system that is responsible for calming you down after a stressful situation.
8. The adrenal glands are responsible for telling the rest of the body what hormones to secrete.

3. Answers
1. T
2. F
3. T
4. T
5. F
6. T
7. T
8. F

4. Neuron
The neuron or nerve cell is adapted for receiving and sending signals.
Three major regions of the neuron enable the cell to communicate with other cells.

5. Parts of the Neuron

6. Dendrites
1. The dendrites are branching tubular processes capable of receiving information.

7. Parts of the Neuron - Dendrites
Dendrite – The branching extensions of a neuron that receive information and conduct impulses toward the cell body

8. The Cell Body
2. The cell body (a.k.a. cyton or soma) contains cytoplasm and the nucleus which directs synthesis of such substances as neurotransmitters.

9. Parts of the Neuron - Soma
Soma – The cell body of a neuron, which contains the nucleus and other parts that keep the cell healthy

10. Axon
3. The axon emerges from the cell body as a single conducting fiber (longer than a dendrite) which branches and ends in tips called axon terminals (a.k.a. terminal boutons, terminal buttons, synaptic knobs or end feet).

11. Parts of the Neuron - Axon
Axon – The extension of a neuron through which neural impulses are sent

12. Axon The axon may be covered by an insulating myelin sheath.
Spaces between segments of myelin are called nodes of Ranvier.
(This was on our slide from the play-doh yesterday.)

13. Parts of the Neuron – Myelin Sheath

14. Parts of the Neuron - Terminals
Axon terminals – The endpoint of a neuron where neurotransmitters are stored

15. Thinking time!
Why aren’t we “hard-wired?” In other words, why don’t our nerves actually connect to each other?

16. 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

17. How Neurons Communicate: The Neural Impulse
Module 6: The Nervous System and the Endocrine System
How Neurons Communicate: The Neural Impulse

18. Activity Time! Everyone line up in one long line around the classroom.
Put your hands on the shoulders of the person in front of you and follow my instructions.
Why were the slow times slower and why were the quicker times fast?
First practice with hands on shoulders a couple of times. Then switch to ankles. Then do both hands with squeezing same shoulder. Finally, both hands, squeezing opposite shoulder from what the person behind you did.

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

20. Action Potential

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

22. Refractory Period

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

24. Resting Potential

25. All-or-None Principle
The principle stating that if a neuron fires it always fires 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.

26. How Neurons Communicate: Communication Between Neurons
Module 6: The Nervous System and the Endocrine System

27. 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

28. 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

29. Neurotransmitters

32. Work time!
Complete the diagram.

33. Neurotransmitters

34. Excitatory Effect
A neurotransmitter effect that makes it more likely that the receiving neuron will generate an action potential or “fire”
The second neuron is more likely to fire.

35. Inhibitory Effect
A neurotransmitter effect that makes it less likely that the receiving neuron will generate an action potential or “fire”
The second neuron is less likely to fire.

36. How Neurons Communicate: The Neural Chain
Module 6: The Nervous System and the Endocrine System

37. Receptor Cells
Specialized cells in the sensory systems of the body that can turn other kinds of energy into action potentials (neural impulses) that the brain can process
Receptor cells in the eye turn light into a neural impulse the brain understands.

38. Sensory Nerves
Nerves that carry information from the sensory receptors to the spinal cord and brain.
Connect the sense organs to the brain and spinal cord

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

40. Motor Nerves
Nerves that carry information from the brain and spinal cord to the muscles and glands.
Carries messages from the brain and spinal cord to other parts of your body

46. The Structure of the Nervous System
Module 6: The Nervous System and the Endocrine System

47. The Nervous System

48. Central Nervous System (CNS)
The brain and spinal cord
The brain is the location of most information processing.
The spinal cord is the main pathway to and from the brain.
Also has spinal reflexes

49. Divisions of the Nervous System

50. Peripheral Nervous System (PNS)
The sensory and motor nerves that connect the brain and the spinal cord to the rest of the body
Peripheral means “outer region”
The system is subdivided into the somatic and autonomic nervous systems.

51. Divisions of the Nervous System

52. Somatic Nervous System
The division of the peripheral nervous system that controls the body’s skeletal muscles
Contains the motor nerves needed for the voluntary muscles

53. Divisions of the Nervous System

54. Autonomic Nervous System
The division of the peripheral nervous system that controls the glands and muscles of the internal organs
Monitors the autonomic functions
Controls breathing, blood pressure, and digestive processes
Sub-divided into the sympathetic and parasympathetic nervous systems

55. Divisions of the Nervous System

56. Sympathetic Nervous System
The part of the autonomic nervous system that arouses the body to deal with perceived threats
Fight or flight response

57. Divisions of the Nervous System

58. Sympathetic nervous system
Why does it do this, using our bear example?

59. Parasympathetic Nervous System
The part of the autonomic nervous system that calms the body
Brings the body back down to a relaxed state

60. Divisions of the Nervous System

61. Parasympathetic
Why does it do this, still using our example?

62. Module 6: The Nervous System and the Endocrine System

63. Endocrine System One of the body’s two communication systems
A set of glands that produce hormones-- chemical messengers that circulate in the blood

64. Hormone
Chemical messengers produced by the endocrine glands and circulated in the blood
Similar to neurotransmitters in that they are also messengers
Slower communication system, but with longer lasting effects

65. Pituitary Gland
The endocrine system’s gland that, in conjunction with the brain, controls the other endocrine glands
Called the “master gland”
Located at the base of the brain and connects to the hypothalamus

66. Endocrine System – Pituitary Gland

67. Thyroid Gland
Endocrine gland that helps regulate the energy level in the body
Located in the neck

68. Endocrine System – Thyroid Gland

69. Adrenal Gland
Endocrine glands that help to arouse the body in times of stress
Located just above the kidneys
Release epinephrine (adrenaline) and norepinephrine (noradrenaline)

70. Endocrine System – Adrenal Gland

71. Pancreatic Gland
Regulates the level of blood sugar in the blood

72. Endocrine System – Pancreatic Gland

73. Sex Glands
Ovaries (females) and testes (males) are the glands that influence emotion and physical development.
Testosterone – primary males hormone
Estrogen – primary female hormone
Males and females have both estrogen and testosterone in their systems.

74. Endocrine System – Sex Glands

75. The End!
Thank you for your attention. Go Eagles.