1. Biological Bases of Behavior
Nervous system and the endocrine system module 4

2. Module Overview Neurons: The Building Blocks of the Nervous System
How Neurons Communicate
The Structure of the Nervous System
The Endocrine System

3. Neurons: The Building Blocks of the Nervous System
Module 04: The Nervous System and the Endocrine System

4. 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

5. Neuron A nerve cell; the basic building block of the nervous system.
Neurons perform three basic tasks
Receive information
Carry the information
Pass the information on to the next neuron

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

7. How Neurons Communicate: The Neural Impulse
Module 04: The Nervous System and the Endocrine System

8. 1. Action Potential
A neural impulse: a brief electrical charge that travels down the axon of a neuron.
Considered an “on” condition of the neuron – the neuron is ready to fire

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

10. The neuron is set and ready to fire
3. 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

11. Resting Potential

12. All-or-None Principle
The principle stating that if a neuron fires, then it always fires at the same intensity;
all action potentials have the same strength.
A neuron always fires at100% each time it fires.

13. How Neurons Communicate: Communication Between Neurons
Module 04: The Nervous System and the Endocrine System

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

15. Neurotransmitters
A chemical messenger that travels across the synapse from one neuron to the next and influences whether a neuron will generate an action potential.

16. Neurotransmitters

18. Neurotransmitters

19. Excitatory Effect/Inhibitory Effect
Neurotransmitters (the chemical messenger between neurons) signal the next neuron to either fire (Excitatory) or not fire (Inhibitory)

20. How Neurons Communicate: The Neural Chain
Module 04: The Nervous System and the Endocrine System

21. Four Types of Nerve Cells in the Neural Chain
Receptor Cells
Sensory Cells
Interneurons
Motor Nerves

22. 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.

23. 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

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

25. 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

26. A Neural Chain

27. Module 04: The Nervous System and the Endocrine System

28. Endocrine System

29. The Structure of the Nervous System
Module 04: The Nervous System and the Endocrine System

30. The Nervous System

31. 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.

32. 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.

33. 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

34. Autonomic Nervous System
The division of the peripheral nervous system that controls the glands and muscles of the internal organs;
its subdivisions are the sympathetic (arousing) division and the parasympathetic (calming) division.
Monitors the autonomic functions
Controls breathing, blood pressure, and digestive processes

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

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

37. Divisions of the Nervous System

38. The Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

39. Studying the Brain: Scanning Techniques
Module 05: The Brain

40. Computerized Axial Tomography (CT or CAT)
Many X-ray photographs - combined into a representation of a slice of the brain or body

41. Magnetic Resonance Imaging (MRI)
A technique that uses magnetic fields and radio waves to produce computer-generated images of the brain

42. Electroencephalogram (EEG)
Amplified recording of the waves of electrical activity that across the brain’s surface
measured by electrodes placed on the scalp -helpful in evaluating brain function.

43. Positron Emission Tomography Scan (PET scan)
A visual display of brain activity.
Injection of a radioactive glucose
Reveals the brain’s functioning

44. Lower-Level Brain Structures: The Brainstem
Module 05: The Brain

45. The oldest part and central core of the brain;
Brainstem
The oldest part and central core of the brain;
begins with the spinal cord and swells as it enters the skull
responsible for automatic survival functions.

46. Brainstem

47. Medulla Located at the base of the brainstem
controls life-supporting functions like heartbeat and breathing.
Damage to this area can lead to death.

48. Medulla

49. Reticular Formation
A nerve network in the brainstem that plays an important role in controlling wakefulness and arousal.
Extending up and down the spinal cord into the brain
Controls an organism’s level of alertness
Damage to this area can cause a coma.

50. Brainstem

51. Thalamus is Greek for “inner chamber.”
The brain’s sensory switchboard, located on top of the brainstem; directs traffic to the sensory receiving areas in the cortex.
Thalamus is Greek for “inner chamber.”

52. Thalamus

53. Thalamus

54. Cerebellum
The “little brain”, attached to the rear of the brainstem; it helps coordinate voluntary movements and balance.
If damaged, the person could perform basic movements but would lose fine coordination skills.

55. Cerebellum

56. Cerebellum

57. Lower-Level Brain Structures: The Limbic System
Module 05: The Brain

58. Limbic System
Ring of structures at the border of the brainstem and cerebral cortex;
Helps regulate functions such as memory, fear, aggression, hunger, and thirst
Includes the hypothalamus, hippocampus, and the amygdala.

59. Hypothalamus
helps regulates the body’s maintenance activities, eating, drinking, body temperature, and is linked to emotion.
Plays a role in emotions, pleasure, and sexual function

60. Hypothalamus

61. Hippocampus
wraps around the back of the thalamus;
it helps processing new memories for permanent storage.
Looks something like a seahorse
Hippo is Greek for “horse.”

62. Amygdala
An almond shaped cluster in the limbic system that controls emotional responses such as fear and anger.

63. Amygdala

64. Cerebral Cortex The wrinkly upper portion of the brain
forms body’s ultimate control and processing center
Divided into four lobes
Covers the brain’s lower level structures
Contains an estimated 30 billion nerve cells

65. Corpus Callosum Longitudinal Fissure
Band of neural fibers connecting the two brain hemispheres
Allows communication between hemispheres
The crevice that divides the cerebral cortex into left and right hemispheres.

66. Frontal Lobes
Portion of the cerebral cortex just behind the forehead: involved in planning and judgment
Also includes the motor cortex: A strip of brain tissue at the rear of the frontal lobes that controls voluntary movement

67. Frontal Lobe: Motor Cortex

68. Parietal Lobes
Portion of the cerebral cortex on the top back portion of the head
Includes the somatosensory cortex At the front of the parietal lobes: registers and processes body sensations.
Regions available for general processing, including mathematical reasoning

69. Parietal Lobe: Somatosensory Cortex

70. Somatosensory Cortex

71. Temporal Lobes
Portion of the cerebral cortex lying roughly above the ears
Includes the auditory (hearing) areas of the brain.
Where sound information is processed

72. Occipital Lobe
Portion of the cerebral cortex lying at the back of the head
it includes the primary visual processing areas of the brain.

73. Differences Between the Brain’s Two Hemispheres
Module 05: The Brain

74. Hemispheric Differences
“Left-brained” and “right-brained” debunked
Brain is divided into two hemispheres but works as a single entity.
Both sides continually communicate via the corpus callosum, except in those with split brains.

75. Differences Between the Two Hemispheres: Language and Spatial Abilities
Module 05: The Brain

76. The Brain’s Left Hemisphere
For most people, language functions are in the left hemisphere.
For a small percentage of people, language functions are in the right hemisphere.

77. Broca’s Area
A brain area of the left frontal lobe that directs the muscle movements involve in speech.
If damaged the person can form the ideas but cannot express them as speech

78. Wernicke’s Area
A brain area of the left temporal lobe involved in language comprehension and expression.
Our ability to understand what is said to us

79. The Brain’s Right Hemisphere
Houses the brain’s spatial abilities
Our spatial ability allows us to perceive or organize things in a given space, judge distance, etc.
Helps in making connections between words

80. Split Brain Research