Anatomy chapt. 16-17

  1. Name four general characteristic of pathways (sensory & motor)
    • These tracts are paired bilaterally & symetically along the spinal cord.
    • The axons within each tract are grouped according to body region innervated.
    • Processing occurs at several points along the way
    • All tracts involve the brain & spinal cord.
  2. Defne pathways?
    A continous flow of information among the brain, spinal cord and peripheral nerves
  3. How many sensory neurons are apart of the pathway? What are they delivering?
    Millions of sensory neurons are delievering information to processing centers in the CNS
  4. How many motor neurons are apart of the pathway? What do they do?
    Millions of motor neurons are controlling or adjusting the activites or the peripheral effectors.
  5. Define decussation?
    To cross over to the opposite side.
  6. What is true of most cases of decussation?
    The axon of either the 1st, or 2nd order neuron decussates to the opposite side of the spinal cord or brain stem as it decends.
  7. What is the first-order neuron? Where is it's cell body located?
    A sensory neuron that delivers information to the CNS. It's cell body is in the dorsal root ganglion or a cranial nerve ganglion.
  8. What is the 2nd-order neuron? Where is it's cell body located?
    Interneuron upon which the axon of the first order neuron synapses. The second order neuron's cell body may be located in either the spinal cord or the brain stem.
  9. Where is the 3rd-order neuron? Where does it synapse?
    In pathways ending at the cerebral cortex, the 2nd-order neuron synapses on a 3rd-order neuron in the thalamus. The axon of the 3rd-order neuron carries sensory information from the thalamus to the appropiate sensory area of the cerebral cortex.
  10. Define sensation?
    When stimulated a receptor passes information to the form of action potentials in an afferent (sensory) fiber.
  11. What information does the spinocerebellar carry?
    Carries proprioceptive information concerning the position of muscles, tendons, & joints to the cerebellum.
  12. What is the cerebellum reponsible for?
    Fine coordination of body movements
  13. What does the spinothalamic pathway carry?
    Carries sensations of pain, temperature & "crude" sensations of touch & pressure.
  14. What does the posterior column pathway carry?
    Highly localized information from the skin & muscular skeleton system about proprioceptive. Fine touch, pressure, vibration sensations. Carries information about the type of stimulus the exact site of stimulation, & when the stimulus starts & stops.
Card Set
Anatomy chapt. 16-17
Anatomy chapters 16-17 sensory & motor pathways, Visceral motor