Locate and identify the cut ends of the 12 cranial nerves which are indicated in the
dissection. NOTE: CN I is composed of numerous nerve fibers
dispersed through the cribiform plate and the rootlets are too small to identify.
Identify the three cranial fossae (anterior,
middle and posterior) and each of the openings related to all branches of the
cranial nerves and vessels. For example, CN II passes through the optic canal and shares that space
with the ophthalmic artery. NOTE: You may not be able to distinguish individual nerves in those
cases where more than one nerve enters an opening.
Identify CN III by its relavely large size where it
protrudes from the wall of the cavernous sinus, which it enters.
Attempt to identify the trochlear nerve (CN IV) (very small), and branches of CN V
(ophthalmic, maxillary and mandibullar nerves) in the middle cranial
fossa. The abducens nerve (CN VI) is small but will enter the dura in the posterior cranial
fossa. Find CN VII and CN VIII entering the internal auditory meatus
in the posterior cranial fossa, CN IX, X and XI (exiting via the jugular
foramen in the posterior cranial fossa) and finally CN XII
entering the hypoglossal canal just above foramen magnum in the
posterior cranial fossa.
