2. Cranial Nerves Flashcards
What is the pathway of the first cranial nerve?
Receptors of the olfactory mucosa in the nasal cavity–> foramina in the cribiform plate in the ethmoid bone–> synapses in the olfactory bulbs
Which of the cranial nerves is capable of regenerating neural tissue?
Olfactory
What is the pathway of the optic nerve?
Left and right are separate–> goes through the optic foramen of the sphenoid bone –> synapses in teh optic chiasm–> lateral geniculate nucleus of the thalamus–> to the occipital lobe
What happens if there is a lesion at number 1?
Total right eye blindness
What happens if there is a lesion at number 2?
Right nasal hemianopia due to lesion in the perichiasmal area
What happens if there is a lesion at number 3?
Bipolar hemianopia
What happens if there is a lesion at number 4?
Left homonymous hemianopia
What happens if there is a lesion at number 5?
Left homonymous inferior quadrantanopia
What happens if there is a lesion at number 6?
Left homonymous superior quadrantanopia
What happens if there is a lesion at number 7?
Left homonymous
Describe the innervations of the muscles of the eye
CN III: all the muscles of the eye except for superior oblique and lateral rectus
CN IV: superior oblique
CN VI: Lateral rectus
What is the path of the oculomotor nerve?
Starts in the oculomotor and Edinger Westphal nuclei–> leaves through the superior orbital fissure–> travels to the eyelid and the eye
What are conditions that are caused by damage to the oculomotor nerve?
Ptosis, paralysis of the eye muscles, strabismus (eyes not parallel), diplopia
What happens when there is nerve damage to the optic nerve?
Visual defects
What is the path of the trochlea nerve?
Starts in the trochlear nucleus and leaves in the superior orbital fissure to the superior oblique muslce