1. Slides 1 to 145
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

2. The Nervous System
Two Organ Systems Control All the Other Organ Systems
Nervous system characteristics
Rapid response
Brief duration
Endocrine system characteristics
Slower response
Long duration
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

3. The Nervous System Two Anatomical Divisions
Central nervous system (CNS)
Brain
Spinal cord
Peripheral nervous system (PNS)
All the neural tissue outside CNS
Afferent division (sensory input)
Efferent division (motor output)
Somatic nervous system
Autonomic nervous system
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4. “INPUT” Figure 8-1 2 of 7 PERIPHERAL NERVOUS SYSTEM Receptors
Somatic sensory
receptors (monitor
the outside world
and our position
in it)
Visceral sensory
receptors (monitor
internal conditions
and the status
of other organ
systems)
“INPUT”
Figure 8-1
2 of 7
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5. “INPUT” Figure 8-1 3 of 7 PERIPHERAL NERVOUS SYSTEM Receptors
Sensory information
within
afferent division
Receptors
Somatic sensory
receptors (monitor
the outside world
and our position
in it)
Visceral sensory
receptors (monitor
internal conditions
and the status
of other organ
systems)
“INPUT”
Figure 8-1
3 of 7
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6. “INPUT” Figure 8-1 4 of 7 CENTRAL NERVOUS SYSTEM PERIPHERAL NERVOUS
Information
Processing
PERIPHERAL
NERVOUS
SYSTEM
Sensory information
within
afferent division
Receptors
Somatic sensory
receptors (monitor
the outside world
and our position
in it)
Visceral sensory
receptors (monitor
internal conditions
and the status
of other organ
systems)
“INPUT”
Figure 8-1
4 of 7
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7. “INPUT” “OUTPUT” Figure 8-1 5 of 7 CENTRAL NERVOUS SYSTEM PERIPHERAL
Information
Processing
PERIPHERAL
NERVOUS
SYSTEM
Sensory information
within
afferent division
Motor commands
within
efferent division
Receptors
Somatic sensory
receptors (monitor
the outside world
and our position
in it)
Visceral sensory
receptors (monitor
internal conditions
and the status
of other organ
systems)
“INPUT”
“OUTPUT”
Figure 8-1
5 of 7
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8. “INPUT” “OUTPUT” Figure 8-1 6 of 7 CENTRAL NERVOUS SYSTEM PERIPHERAL
Information
Processing
PERIPHERAL
NERVOUS
SYSTEM
Sensory information
within
afferent division
Motor commands
within
efferent division
includes
Somatic
nervous
system
Receptors
Effectors
Somatic sensory
receptors (monitor
the outside world
and our position
in it)
Visceral sensory
receptors (monitor
internal conditions
and the status
of other organ
systems)
Skeletal
muscle
“INPUT”
“OUTPUT”
Figure 8-1
6 of 7
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9. CENTRAL NERVOUS SYSTEM
Information
Processing
This diagram is on next test. You need to fill in the boxes and know the function of each branch.
PERIPHERAL
NERVOUS
SYSTEM
Sensory information
within
afferent division
Motor commands
within
efferent division
includes
Somatic
nervous
system
Autonomic
nervous system
Parasympathetic
division
Sympathetic
division
Receptors
Effectors
Smooth
muscle
Figure 8-1
7 of 7
Somatic sensory
receptors (monitor
the outside world
and our position
in it)
Visceral sensory
receptors (monitor
internal conditions
and the status
of other organ
systems)
Skeletal
muscle
Cardiac
muscle
Glands
Adipose
tissue
“INPUT”
“OUTPUT”

10. Nervous System Overview
Red = CNS
Blue = PNS

11. The Autonomic Nervous System
Branch of nervous system that coordinates cardiovascular, digestive, excretory, and reproductive functions
Should the lower text be 30 pt?
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12. Autonomic Nervous System

13. Neural Tissue Organization
Two Classes of Neural Cells
Neurons
For information transfer, processing, and storage
Neuroglia
Supporting framework for neurons
Phagocytes = eat up microbes
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14. Neural Tissue Organization
Neuroglia in the CNS
Figure 8-4

15. Neural Tissue Organization
Three Classes of Neurons
Sensory neurons
Deliver information to CNS
Motor neurons
Stimulate or inhibit peripheral tissues
Interneurons (=association neurons)
Located between sensory and motor neurons
Analyze inputs, coordinate outputs
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16. Neural Tissue Organization
Neuron Anatomy
Cell body
Nucleus
Mitochondria, RER, other organelles
Dendrites
Several branches
Signal reception and transmission toward cell body
Axon
Signal propagation Away from cell body
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17. Neural Tissue Organization
Anatomy of a Motor Neuron
This diagram is on next test. You need to label the parts.
Figure 8-2

18. Neural Tissue Organization
Two Types of Neuroglia in the PNS
Satellite cells
Surround cell bodies
Schwann cells
Surround all peripheral axons
Form myelin sheath on myelinated axons
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19. Neural Tissue Organization
Schwann Cells and Axons of Peripheral Neurons
Figure 8-5

20. Neural Tissue Organization
Key Note
Neurons perform all of the communication, information processing, and control functions of the nervous system. Neuroglia outnumber neurons and have functions essential to preserving the physical and biochemical structure of neural tissue and the survival of neurons.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

21. Neuron Function The Membrane Potential
Resting Membrane Potential (RMP)
Excess negative charge inside the neuron. Excess positive charge outside.
Maintained by Na+/K+ ion pump (uses ATP)
Negative voltage (potential) inside
-70 mV (0.07 Volts)
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22. Neuron Function The Cell Membrane at the Resting Potential
This diagram is on next test. You need to label each item in this diagram. There will be a checklist of parts to assist you.
Figure 8-7

23. Neuron Function Changes in Membrane Potential
Result from changes in ion movement
Ions move thru trans-membrane channels
Some membrane channels can open or close.
Some membrane channels are always open (=“leak channels.”)
If Na+ channels open  positive charges enter cell  membrane potential becomes more (+). (This is called depolarization.)
If K+ channels open  positive charges leave cell  membrane potential becomes more (-). (This is called hyperpolarization.)
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

24. Neuron Function Key Note
A membrane potential exists across the cell membrane because (1) the cytosol and the extracellular fluid differ in their ionic composition, and (2) the cell membrane is selectively permeable to these ions. The membrane potential can quickly change, as the ionic permeability of the cell membrane changes, in response to chemical, pressure, light, sound, etc stimuli.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

25. Neuron Function Generation of Action Potential
Gradual depolarization of membrane until it reaches the threshold
Rapid opening of voltage-gated Na+ channels
Na+ entry causes rapid depolarization (spike in graph)
Then voltage-gated K+ channels open
K+ ions exit causing rapid repolarization
Refractory period ends as membrane restores the RMP, thanks to the Na+/K+ pumps.
An action potential is all-or-none!

26. Transmembrane potential (mV)
Depolarization to threshold
Sodium ions
Local
current
+30
DEPOLARIZATION
Transmembrane potential (mV) _
Threshold 60 _ 1 70
Resting
potential 1 2 3
Time (msec)
Figure 8-8
2 of 5
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27. Transmembrane potential (mV)
Activation of voltage-
regulated sodium channels
and rapid depolarization
Depolarization to threshold
Sodium ions
Local
current
Potassium ions
+30
DEPOLARIZATION 2
Transmembrane potential (mV) _
Threshold 60 _ 1 70
Resting
potential 1 2 3
Time (msec)
Figure 8-8
3 of 5
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28. Transmembrane potential (mV)
Activation of voltage-
regulated sodium channels
and rapid depolarization
Depolarization to threshold
Sodium ions
Local
current
Potassium ions
Inactivation of sodium
channels and activation of
voltage-regulated
potassium channels
+30
DEPOLARIZATION
REPOLARIZATION 3 2
Transmembrane potential (mV) _
Threshold 60 _ 1 70
Resting
potential 1 2 3
Time (msec)
Figure 8-8
4 of 5
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29. Transmembrane potential (mV)
Activation of voltage-
regulated sodium channels
and rapid depolarization
Depolarization to threshold
Sodium ions
Local
current
Potassium ions
Inactivation of sodium
channels and activation of
voltage-regulated
potassium channels
This graph is on the second test. You need to know what is occurring during each phase of the graph and why it is occurring.
+30
DEPOLARIZATION
REPOLARIZATION 3 2
Transmembrane potential (mV)
The return to normal
permeability and resting state _
Threshold 60 _ 1 70 4
Resting
potential
REFRACTORY PERIOD
Figure 8-8
5 of 5 1 2 3
Time (msec)
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30. Neuron Function Propagation of an Action Potential
“Continuous” propagation
Involves entire membrane surface
Proceeds in series of small steps (so it’s slower)
Occurs in unmyelinated axons
“Saltatory” (= leaping/hopping) propagation
Involves patches of membrane exposed at nodes (spaces between myelin sheath)
Proceeds in series of large steps (so it’s faster)
Occurs in myelinated axons

31. Neuron Function
The Propagation of Action Potentials over Unmyelinated Axons
Figure 8-9(a)

32. Neuron Function
The Propagation of Action Potentials over Myelinated Axons
Figure 8-9(b)

33. Neuron Function Key Note
“Information” travels within the nervous system primarily in the form of propagated electrical signals known as action potentials. The most important information (e.g., vision, balance, movement), is carried by myelinated axons.
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34. Neural Communication Synapse Basics Intercellular communication
Axon terminal
Input to next cell
Chemical signaling
Neurotransmitter release
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35. Neural Communication Structure of a Synapse Presynaptic components
Axon terminal
Synaptic knob
Synaptic vesicles
Synaptic cleft
Postsynaptic components
Neurotransmitter receptors
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36. The Structure of a Typical Synapse
Neural Communication
The Structure of a Typical Synapse
Figure 8-10

37. Neural Communication Synaptic Function and Neurotransmitters
Cholinergic synapses
Release neurotransmitter acetylcholine
Enzyme in synaptic cleft (acetylcholinesterase) breaks it down
Adrenergic synapses
Release neurotransmitter norepinephrine
Dopaminergic synapses
Release neurotransmitter dopamine
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38. Figure 8-11 2 of 5 An action potential arrives and
depolarizes the synaptic knob
PRESYNAPTIC
NEURON
Action potential
Synaptic vesicles
EXTRACELLULAR
FLUID ER
Synaptic
knob
AChE
POSTSYNAPTIC
NEURON
CYTOSOL
Figure 8-11
2 of 5
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39. Figure 8-11 3 of 5 An action potential arrives and
depolarizes the synaptic knob
Extracellular Ca2+ enters the synaptic
cleft triggering the exocytosis of ACh
PRESYNAPTIC
NEURON
Action potential
Synaptic vesicles
EXTRACELLULAR
FLUID
ACh ER
Synaptic
knob
Synaptic
cleft
Ca2+
Ca2+
AChE
Chemically regulated
sodium channels
POSTSYNAPTIC
NEURON
CYTOSOL
Figure 8-11
3 of 5
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

40. Figure 8-11 4 of 5 An action potential arrives and
depolarizes the synaptic knob
Extracellular Ca2+ enters the synaptic
cleft triggering the exocytosis of ACh
PRESYNAPTIC
NEURON
Action potential
Synaptic vesicles
EXTRACELLULAR
FLUID
ACh ER
Synaptic
knob
Synaptic
cleft
Ca2+
Ca2+
AChE
Chemically regulated
sodium channels
POSTSYNAPTIC
NEURON
CYTOSOL
ACh binds to receptors and depolarizes
the postsynaptic membrane
Initiation of
action potential
if threshold
is reached
Na2+
Receptor
Na2+
Na2+
Na2+
Na2+
Figure 8-11
4 of 5
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41. Figure 8-11 5 of 5 An action potential arrives and
depolarizes the synaptic knob
Extracellular Ca2+ enters the synaptic
cleft triggering the exocytosis of ACh
PRESYNAPTIC
NEURON
Action potential
Synaptic vesicles
EXTRACELLULAR
FLUID
ACh ER
Synaptic
knob
Synaptic
cleft
Ca2+
Ca2+
AChE
Chemically regulated
sodium channels
POSTSYNAPTIC
NEURON
CYTOSOL
ACh is removed by AChE
(acetylcholinesterase)
ACh binds to receptors and depolarizes
the postsynaptic membrane
Initiation of
action potential
if threshold
is reached
Propagation of
action potential
(if generated)
Na2+
Receptor
Na2+
Na2+
Na2+
Na2+
Figure 8-11
5 of 5
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42. Neural Communication Key Note
A synaptic terminal releases a neuro-transmitter that binds to the postsynaptic cell membrane. The result is a brief, local change in the permeability of the postsynaptic cell. Many drugs affect the nervous system by stimulating neurotransmitter receptors and thus produce complex effects on perception, motor control, and emotions.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

43. Neural Tissue Organization
Anatomic Organization of CNS Neurons
Nucleus—A center with a discrete anatomical boundary
Gray matter covering of brain portions. Made up of neuron cell bodies
White matter—Bundles of axons (tracts) that share origins, destinations, and functions
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

44. Neural Tissue Organization
Anatomic Organization of PNS Neurons
Ganglia—Groupings of neuron cell bodies
Nerve—Bundle of axons supported by connective tissue
Spinal nerves
To/from spinal cord
Cranial nerves
To/from brain
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45. Neural Tissue Organization
The Anatomical Organization of the Nervous System
Figure 8-6

46. The Central Nervous System
Meninges—Layers that surround and protect the brain and spinal cord (CNS)
Dura mater (“tough mother”)
Tough, fibrous outer 2 layers. Dural sinus between them contains CSF.
Epidural space above dura of spinal cord
Arachnoid (“spidery”)
Subarchnoid space
Cerebrospinal fluid
Pia mater (“delicate mother”)
Thin inner layer
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47. The Central Nervous System
The Cranial Meninges
Figure 8-13(a)

48. The Central Nervous System
The Spinal Meninges
Figure 8-13(b)

49. The Central Nervous System
Spinal Cord Basics
Relays information to/from brain
Processes some information on its own
Divided into 31 segments
Each segment has a pair of:
Dorsal root ganglia
Dorsal roots
Ventral roots
Gray matter appears as horns
White matter organized into columns
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50. The Central Nervous System
Gross Anatomy of the Spinal Cord
Figure 8-14(a)

51. The Central Nervous System
Gross Anatomy of the Spinal Cord
Red rectangles indicate structures to memorize.
Figure 8-14(b)

52. The Central Nervous System
Functional Anatomy of the Spinal Cord
Figure 8-15(a)

53. The Central Nervous System
Sectional Anatomy of the Spinal Cord
Figure 8-15(b)

54. The Central Nervous System
Key Note
The sensory and motor nuclei (gray matter) of the spinal cord surround the central canal. Sensory nuclei are dorsal, motor nuclei are ventral. A thick layer of white matter consisting of ascending and descending axons covers the gray matter. These axons are organized into columns of axon bundles with specific functions. This highly organized structure can enable a clinician to predict the impact of a particular injury.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

55. The Central Nervous System
Brain Regions
Cerebrum
Midbrain
Pons
Medulla oblongata
Cerebellum
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56. The Central Nervous System
Superior View of Brain
Figure 8-16(a)

57. The Central Nervous System
Lateral View of Brain
Figure 8-16(b)

58. The Central Nervous System
Mid-sagittal Section of Brain
Figure 8-16(c)

59. The Central Nervous System
Brain Ventricles —The four hollow chambers in the center of the brain filled with cerebrospinal fluid (CSF)
CSF circulates
From ventricles and central canal
To subarachoid space
Accessible by lumbar puncture
To blood stream
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60. The Central Nervous System
The Ventricles of the Brain
Figure 8-17

61. The Central Nervous System
Functions of the Cerebrum
Conscious thought
Intellectual activity
Memory
Origin of complex patterns of movement
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62. The Central Nervous System
Anatomy of Cerebral Cortex
Highly folded surface (increases S.A.)
Elevated ridges (gyri) = “hills”
Shallow depressions (sulci) = “valleys”
Cerebral Hemispheres
Longitudinal fissure
Central sulcus (very impt landmark)
Boundary between frontal and parietal lobes
Lateral sulcus – separates temporal lobe.
Other lobes (temporal, occipital)
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63. The Central Nervous System
Functions of the Cerebral Cortex
Hemispheres serve opposite body sides
Primary motor cortex (pre-central gyrus)
Directs voluntary movement
Primary sensory cortex (post-central gyrus)
Receives somatic sensation (touch, pain, pressure, temperature)
Association areas
Interpret sensation
Coordinate movement
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64. The Central Nervous System
The Surface of the Cerebral Hemispheres
Figure 8-19

65. The Central Nervous System
Hemispheric Lateralization
Left hemisphere
General interpretative and speech centers
Language-based skills
Right hemisphere
Spatial relationships
Logical analysis
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66. The Central Nervous System
Hemispheric Lateralization
Figure 8-20

67. The Central Nervous System
Brain Waves
(Electroencephalogram)
Figure 8-21

68. The Central Nervous System
Anatomy and Function of the Cerebellum
Oversees postural muscles (these are the muscles that maintain posture and correct body position in different situations.)
Stores patterns of movement
Fine tunes most movements/balance
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69. The Central Nervous System
Functions of the Medulla Oblongata
Controls crucial organ systems by reflex
Cardiovascular centers (regulation of heart rate)
Respiratory rhythmicity centers (regulation of breathing rate)
very important for overall homeostasis
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70. The Central Nervous System
Key Note
The brain, a large mass of neural tissue, contains internal passageways and chambers filled with CSF. The six major regions of the brain have specific functions. As you ascend from the medulla oblongata to the cerebrum, those functions become more complex and variable. Conscious thought and intelligence are provided by the cerebral cortex.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

71. The Peripheral Nervous System
PNS Basics
Links the CNS with the body
Carries all sensory information and motor commands
Axons bundled in nerves
Cell bodies grouped into ganglia
Includes cranial nerves (12 pairs) and spinal nerves (31 pairs)
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72. The Peripheral Nervous System
The Cranial Nerves
Someday you may have to learn these names.
Figure 8-25(a)

73. The Peripheral Nervous System
Key Note
The 12 pairs of cranial nerves are responsible for the special senses of smell, sight, and hearing/balance, and control movement of the eye, jaw, face, tongue, and muscles of the neck, back, and shoulders. They also provide sensation from the face, neck, and upper chest and autonomic innervation to thoracic and abdominopelvic organs.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

74. The Peripheral Nervous System
Dermatomes
very important!
each shaded region corresponds to a specific spinal nerve
diagram enables diagnosing problems in a specific nerve or nerve root
A dermotome = a region of the body surface monitored by a pair of spinal nerves
Left side of picture = anterior view
Right side of picture = posterior view
Figure 8-27

75. The Peripheral Nervous System
Reflex—An automatic involuntary motor response to a specific stimulus
The 5 steps in a reflex arc
Arrival of stimulus and activation of receptor
Activation of sensory neuron
CNS processing of information
Activation of motor neuron
Response by effector (muscle or gland)
See the next 5 slides for examples of these.
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76. Arrival of stimulus and activation of receptor Stimulus Figure 8-27
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77. Dorsal root Arrival of stimulus and activation of receptor
Activation of a
sensory neuron
Receptor
Stimulus
KEY
Sensory neuron
(stimulated)
Figure 8-27
3 of 6
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78. Sensation relayed to the brain by collateral Dorsal root
Arrival of
stimulus and
activation of
receptor
Activation of a
sensory neuron
Receptor
Stimulus
Information
processing
in CNS
KEY
Sensory neuron
(stimulated)
Excitatory
interneuron
Figure 8-27
4 of 6
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79. Sensation relayed to the brain by collateral Dorsal root Arrival of
stimulus and
activation of
receptor
Activation of a
sensory neuron
REFLEX
ARC
Receptor
Stimulus
Ventral
root
Information
processing
in CNS
Activation of a
motor neuron
KEY
Sensory neuron
(stimulated)
Excitatory
interneuron
Motor neuron
(stimulated)
Figure 8-27
5 of 6
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80. Sensation relayed to the brain by collateral Dorsal root Arrival of
stimulus and
activation of
receptor
Activation of a
sensory neuron
REFLEX
ARC
Receptor
Stimulus
Effector
Ventral
root
Information
processing
in CNS
Response
by effector
Activation of a
motor neuron
KEY
Sensory neuron
(stimulated)
Excitatory
interneuron
Motor neuron
(stimulated)
Figure 8-27
6 of 6
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81. The Peripheral Nervous System
Examples of Reflexes
touching hot stove (a “withdrawal” reflex)
“stretch reflex” - regulates muscle length and tension (example: patellar reflex aka “knee jerk reflex”)
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82. Stretching of muscle tendon stimulates muscle spindles Muscle spindle
(stretch receptor)
Stretch
Spinal
cord
Figure 8-29
2 of 3
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83. Stretching of muscle tendon stimulates muscle spindles Muscle spindle
(stretch receptor)
Stretch
Spinal
cord
REFLEX
ARC
Contraction
Activation of motor
neuron produces reflex
muscle contraction
Figure 8-29
3 of 3
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84. The Peripheral Nervous System
The Flexor Reflex, a Type of Withdrawal Reflex
Figure 8-30

85. The Peripheral Nervous System
Key Note
Reflexes are rapid, automatic responses to stimuli that “buy time” for the planning and execution of more complex responses that are often consciously directed.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

86. The Autonomic Nervous System
Divisions of the ANS
Sympathetic division
Preganglionic neurons in the thoracic and lumbar segments of the spinal cord
“Fight or flight” system
Parasympathetic division
Preganglionic neurons in the brain and sacral segments
“Rest and digest” system
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87. The Autonomic Nervous System
Key Note
The two divisions of the ANS operate largely without our awareness. The sympathetic division increases alertness, metabolic rate, and muscular abilities; the parasympathetic division reduces metabolic rate and promotes visceral activities such as digestion.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

88. The Autonomic Nervous System
The Somatic and Autonomic Nervous Systems
The Organization of the Somatic and Autonomic Nervous System
Figure 8-33(b)

89. The Autonomic Nervous System
The Sympathetic Division
Figure 8-34

90. The Autonomic Nervous System
Effects of Sympathetic Activation
Generalized response in crises
Increased alertness
Feeling of euphoria and energy
Increased cardiovascular activity
Increased respiratory activity
Increased muscle tone
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

91. The Autonomic Nervous System
The Parasympathetic Division
Figure 8-35

92. The Autonomic Nervous System
Effects of Parasympathetic Activation
Relaxation
Food processing
Energy absorption
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

93. The Autonomic Nervous System
Relationship between the Two Divisions
Sympathetic division reaches visceral and somatic structures throughout the body
Parasympathetic division reaches only visceral structures via cranial nerves or in the abdominopelvic cavity
Many organs receive dual innervation
In general, the two divisions produce opposite effects on the their target organs
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings