Posted on by dp

3. Optic nerve

  1. Is also known as the second cranial nerve. (T/F?)
  2. Is wrapped around with Schwann cells. (T/F?)
  3. Is covered with all three meningeal layers. (T/F?)
  4. Leaves the orbit through superior orbital fissure. (T/F?)
  5. Is not affected with Guillain–Barré syndrome. (T/F?)
  6. Some of its axons terminate in the pretectal nuclei. (T/F?)

  1. T
  2. F
  3. T
  4. F
  5. T
  6. T

  1. The first is the olfactory nerve.
  2. The optic nerve is, actually, a part of the central nervous system because it is developed from the outgrowth of the diencephalon (optic vesicle, optic stalk). It is composed of retinal ganglion cells and glial cells and is covered by myelin produced by oligodendrocytes.
  3. They follow the nerve as it grows from the diencephalon.

    Henry Vandyke Carter [Public domain], via Wikimedia Commons
  4. It goes through the optic foramen and continues through the optic canal.
    Henry Vandyke Carter [Public domain], via Wikimedia Commons
  5. Hmm… GBS is primarily a peripheral demyelinating disease and it should not affect the optic nerve or any other part of CNS, but…
  6. Pretectal nuclei mediate functions like pupillary light reflex, optokinetic reflex and some others.