Chapter 8 Study Guide: The Nervous System

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Chapter 8 Study GuideThe Nervous System

• Anatomy Bowl Prep

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Organs and Divisions of the Nervous System
(understand)

• Central Nervous System (CNS)
• Brain
• Spinal Cord
• Peripheral Nervous System (PNS)
• Cranial Nerves
• Spinal Nerves
• Autonomic Nervous System (ANS) Involuntary
• Sympathetic
• Parasympathetic

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CNS vs. PNS

• Two types of cells found in the nervous system
• Neurons and glial cells
• Neurons conduct impulses, whereas glial cells are
  for support
• Each neuron consist of a cell body, dendrites,
  and an axon

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Nerves

• A nerve is a group of peripheral nerve axons
  bundled together like the strands of a cable
• Because nerves usually have myelin sheath and
  myelin is white, nerves are called white matter
  in the PNS
• Bundles of axons are called tracts, and may be
  myelinated and thus form this system of white
  matter
• Dendrites is called gray matter because of its
  characteristic grey appearance
• Understand that myelinated nerves have faster
  conduction velocity
• Which means that they are able to carry a signal
  much faster than nonmyelinated fibers

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Reflex Arc (understand concept)

• Brain is not consciously involved pathway of
  nerve fibers and does not ascend to communicate
  with the neurons of the brain after stimulus is
  applied.
• Sensory (afferent) impulse
• Sensory neuron cell bodies housed in the Dorsal
  Root Ganglion (DRG)
• Motor (efferent) impulse
• Motor neuron cell bodies housed in the Ventral
  (Anterior) Horn of the Gray Matter of Spinal Cord
• Interneurons may be involved if the reflex arc is
  polysynaptic
• Polysynaptic vs. Monosynaptic

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Neurotransmission (understand)

• Propagated action potential (AP) causes release
  of a neurotransmitter (NT)
• Over 30 NTs identified
• NTs are docked in vesicles at the axon terminus
• NTs are released into the synaptic cleft
• Bind to complementary receptors
• Binding is either stimulatory or inhibitory to
  post-synaptic cell
• Post-synaptic cell is either an effector cell
  (skeletal muscle or glandular cell) or another
  neuron

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Divisions of the Brain(structure and function)

• Cerebrum
• Diencephalon
• Thalamus
• Hypothalamus
• Cerebellum
• Brainstem
• Midbrain
• Pons
• Medulla Oblongata

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Spinal Cord(structure and function)

• Dont worry about different spinothalamic
  tracts!!!
• Understand that grey mater is found in the center
  of the spinal cord
• White mater is found around the outer portion of
  the spinal cord
• Meninges are protective tissue layers that
  enclose the brain and spinal cord. The three
  layers are
• Dura
• Arachnoid
• Pia
• There are spaces in between the meningeal layers.
  
• Ex epidural layer, sub dural layer

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Clinical Applications

• Herpes Zoster or Shingles
• Is a unique viral infection that almost always
  affects the skin of a single dermatome
• A dermatome is a pathway that a nerve travels to
  innervate the skin
• The result is that a patient would experience a
  painful eruption of red, swollen, plaques of
  vesicles on their skin