Nervous System I

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Chapter 10

• Nervous System I

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Functions of the Nervous System

• Nervous tissue is composed of nerve cells or
  ___________ and neuroglia.
• Neurons react to their environment.

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Functions of the Nervous System

• ______________ receive input.
• __________ carry information away from the cell.
• Information is carried across the _______ (the
  space between neurons) by neurotransmitters.

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Functions of the Nervous System

• ________ nervous system brain, spinal cord
• __________ nervous system cranial and spinal
  nerves
• Three functions _________________________________
  _______________

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Functions of the Nervous System

• Peripheral nervous system has ____________ and
  _________branches
• Somatic sensing and conscious activities
• Autonomic controls unconscious activities

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Parts of the Neuron

• The _________________ contains granular
  cytoplasm, organelles, and microtubules
• Neurofibrils support fibers in the soma
• Chromatophilic substance in cytoplasm
• ____________ are branched receptive structures
• Axons arise from ________________ and have
  branches. Axons end in a synaptic knob at the
  terminal, separated from another receptive
  surface by the synaptic cleft

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Figure 10.3
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Neuron Structure

• Schwann cells are neuroglial cells that produce
  the _____________, a lipid-rich covering of the
  axon.
• A neurilemma surrounds the myelin sheath.

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Neuron Structure

• Nodes of _______________ are gaps in the sheath.
• Fibers with myelin sheaths are myelinated nerve
  fibers (___________ matter).
• Fibers without myelin are unmyelinated nerve
  fibers (___________ matter).

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Neuron Classification

• ______________ neurons two processes from the
  cell body. These are found in sense organs.

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Neuron Classification

• ___________ neurons one process from the cell
  body. These are found in sense organs.
• ___________ neurons many processes extend from
  the cell body, one axon and many dendrites. These
  are found in the brain and spinal cord.

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Figure 10.7
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Neuron Classification

• Sensory (___________________) neurons carry
  impulses from the body to brain or spinal cord.

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Neuron Classification

• ___________________ (association neurons) lie
  within brain and spinal cord. They form links
  with other neurons.
• Motor (_______________) neurons carry nerve
  impulses out of the brain or spinal cord to
  effectors, muscles or glands.

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Neuroglia Classification

• __________ star-shaped cells regulate
  environment around neurons and aid in healing
  brain injury.
• Oligodendrocytes form myelin in the
  ________________________________

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Neuroglia Classification

• ____________ support neurons and phagocytize
  bacteria and cell debris.
• Ependyma regulate the composition of
  cerebrospinal fluid.

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Nerve Fiber Regeneration

• Mature neurons do not __________ so neurons are
  not replaced in response to injury.
• Damaged _____________ may regenerate.
• The distal portion deteriorates and is
  phagocytized. The _______________ end grows in
  response to nerve growth factors.
• ____________ cells regenerate the myelin sheath.

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Figure 10.10
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Cell Membrane Potential

• The cell membrane is polarized, the inside is
  negatively charged with respect to the outside.
  This is due to ion distribution.
• ____ is the major intracellular cation, ____ is
  the major extracellular cation.
• The ___________ pump actively pumps ____ out of
  and ____ into the cell.