335 4.1 Neuroanatomy Part 4

  1. nerves definition
    whitish cordlike structure composed of one or more bundles of fibers, courrsing outside the CNS by which stimuli are transmitted from the CNS to a part of the body or vice versa
  2. PNS
    • part of the nervous system located outside the bony confines of the skull and vertebral column
    • includes 12 pairs of cranial nerves and 31 pairs of spinal nerves
  3. Anatomy of PNS and CNS
    all structures made up of neurons or a nerve cell
  4. nuerons are made up of
    • soma
    • dendrite
    • axon
    • synaptic cleft
    • myoneural junction
  5. soma
    cell body
  6. dendrite
    branches off soma which receives info from other neurons and brings it TOWARD the soma
  7. axon
    longest process from the soma which transmits info AWAY from the soma
  8. synaptic cleft
    space between neurons across which a nerve impulse is transmitted by a neurotransmitter
  9. myoneural junction
    synapse with a motor neuron and a muscle fiber
  10. axon hillock
    all information in the cell body is pooled together from dendrites and comes here
  11. myelin sheath
    fatty covering over axons which helps speed up movement of electrical activity down axon
  12. node of ranvier
    gaps in the myelin sheath
  13. telodendria
    long, thin projections are the end of an axon
  14. neurotransmitters
    compounds responsible for activation of the next neuron
  15. 2 types of neurons
    presynaptic v. postsynaptic
  16. neurons information pathway
    • info comes from the cerebral cortex
    • is relayed by neurons referred to as 'somatic motor pathways'
    • infor goes out the cerebrum, down the brainstem and/or spinal cord, out to muscles of the body (outside the central nervous system)
  17. somatic motor pathways consist of
    motor neurons
Card Set
335 4.1 Neuroanatomy Part 4
CDO 335