1. Chapter 10 Lecture PowerPoint
Nervous System I
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2. 10.1: Introduction Cell types in neural tissue: Neurons
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Cell types in neural tissue:
Neurons
Neuroglial cells (also known as neuroglia, glia, and glial)
Dendrites
Cell body
Nuclei of
neuroglia
Axon
© Ed Reschke

3. Nerves are made of many nerve cells
Afferent-sensory nerves carry message to brain
Efferent-motor neurons carry message from brain to muscle

4. Divisions of the Nervous System
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Brain
Central Nervous System (CNS)
Brain
Spinal cord
Peripheral Nervous System (PNS)
Cranial nerves
Spinal nerves
Cranial
nerves
Spinal
cord
Spinal
nerves
(a)

5. Peripheral nervous system
Somatic system
12 pairs cranial nerves
31 pairs spinal nerves
Autonomic
Sympathetic
Fight or flight
Parasympathetic

6. Divisions Nervous System
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Central Nervous System
(brain and spinal cord)
Peripheral Nervous System
(cranial and spinal nerves)
Brain
Cranial
nerves
Sensory division
Sensory receptors
Spinal
cord
Spinal
nerves
Motor division
Somatic
Nervous
System
Skeletal muscle
Autonomic
Nervous
System
Smooth muscle
Cardiac muscle
Glands
(a)
(b)

7. 10.2: General Functions of the Nervous System
The three general functions of the nervous system:
Receiving stimuli = sensory function
Deciding about stimuli = integrative function
Reacting to stimuli = motor function

9. Functions of Nervous System
Sensory Function
Sensory receptors gather information
Information is carried to the CNS
Motor Function
Decisions are acted upon
Impulses are carried to effectors
Integrative Function
Sensory information used to create:
Sensations
Memory
Thoughts
Decisions

10. 10.3: Description of Cells of the Nervous System
Neurons vary in size and shape
They may differ in length and size of their axons and dendrites
Neurons share certain features:
Dendrites
A cell body
An axon

11. Neuron Structure Chromatophilic substance (Nissl bodies) Dendrites
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Chromatophilic
substance
(Nissl bodies)
Dendrites
Cell body
Nucleus
Nucleolus
Neurofibrils
Axonal
hillock
Impulse
Axon
Synaptic knob of
axon terminal
Nodes of Ranvier
Myelin (cut)
Nucleus of
Schwann cell
Axon
Schwann
cell
Portion of a
collateral

12. Classification of Neurons: Functional Differences
Sensory Neurons
Afferent
Carry impulse to CNS
Most are unipolar
Some are bipolar
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Central nervous system
Peripheral nervous system
Cell body
Dendrites
Interneurons
Link neurons
Aka association neurons or internuncial neurons
Multipolar
Located in CNS
Sensory
receptor
Cell body
Axon
(central process)
Axon
(peripheral process)
Sensory (afferent) neuron
Interneurons
Motor (efferent) neuron
Axon
Effector
(muscle or gland)
Motor Neurons
Multipolar
Carry impulses away from CNS
Carry impulses to effectors
Axon
Axon
terminal

13. Types of Neuroglial Cells in the PNS
1) Schwann Cells
Produce myelin found on peripheral myelinated neurons
Speed up neurotransmission

14. 10.5: The Synapse
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Nerve impulses pass from neuron to neuron at synapses, moving from a pre-synaptic neuron to a post-synaptic neuron.
Synaptic
cleft
Impulse
Dendrites
Axon of
presynaptic
neuron
Axon of
postsynaptic
neuron
Axon of
presynaptic
neuron
Cell body of
postsynaptic
neuron
Impulse
Impulse

15. Action Potentials +40 Action potential +20 –20 Resting potential
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+40
Action potential
+20
–20
Resting potential
reestablished
Membrane potential (millivolts)
–40
Resting
potential
–60
–80
Hyperpolarization 1 2 3 4 5 6 7 8
Milliseconds

16. Animation: The Nerve Impulse
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Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at

17. Neurotransmitters

18. Reflex Arc Five components 1. Receptor (sensory cell)
2. Sensory neuron
3. Integration center (association neuron, synapses)
4. Motor neuron
5. Effector (muscle or gland cells)
31 Oct. 2012
Reflexes.ppt

19. REFLEXES
Reflex: Rapid, predictable response to a stimulus. Unlearned, involuntary, "hard-wired" into our neuroanatomy at the cellular & tissue level.
31 Oct. 2012
Reflexes.ppt

21. Protection: 3 meninges: dura mater (outer) arachnoid mater (middle)
Bone
Meninges
CSF (cerebrospinal fluid)
Protection:
3 meninges:
dura mater (outer)
arachnoid mater (middle)
pia mater (inner)
3 potential spaces
epidural: outside dura
subdural: between dura & arachnoid
subarachnoid: deep to arachnoid

22. Spinal nerves continued
Divided based on vertebral locations
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
Cauda equina (“horse’s tail”): collection of nerve roots at inferior end of vertebral canal

23. Examples of Reflexes: Stretch Reflex (Knee jerk)
1. Muscle spindles sense stretch of muscle,
2. Increase rate of sensory impulses to spinal cord
3. One synapse to motor neuron(s)
monosynaptic
4. Motor neurons stimulate muscle to
5. Contract & restore tension.
31 Oct. 2012
Reflexes.ppt

24. Spinal Nerves ALL are mixed nerves (except the first pair)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
ALL are mixed nerves (except the first pair)
31 pairs of spinal nerves:
8 cervical nerves
(C1 to C8)
12 thoracic nerves
(T1 to T12)
5 lumbar nerves
(L1 to L5)
5 sacral nerves
(S1 to S5)
1 coccygeal nerve
(Co or Cc)
Posterior
view C1 C2 C3 C4
Cervical
nerves C5 C6 C7 C8 T1 T2 T3 T4 T5 T6
Thoracic
nerves T7 T8 T9
T10
T11
T12 L1
Cauda equina L2 L3
Lumbar
nerves L4 L5 S1 S2 S3
Sacral
nerves S4 S5 Co
Coccygeal
nerve

25. Disorders of the nervous system
Meningitis- inflammation of the linings of the brain and spinal cord
Encephalitis- inflammation of the brain
Epilepsy-seizure disorder. Excessive discharge from neurons. 1 in 200 suffer. Grand mal or petit mal seizures
Cerebral palsy- disturbance in voluntary muscular action
Parkinson’s –decreased neurotransmitter
MS multiple sclerosis- autoimmune