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
What are conditions that can occur if there is nerve damage in the trochlear nerve?
Paralysis of the superior oblique, strabismus, diplopia
What is the pathway of the abducens nerve?
STarts in the pontine (abducens) of the pons and leaves through the superior orbital fissue and travels to the lateral rectus muscle
What is caused when there is damage to the abducens muscle?
Lateral eye movement is limited
Diplopia
What are the three divisions of the trigeminal nerve?
V1: sensory from the cornea, nose, forehead, and the anterior scalp
V2: sensory from the nasal mucosa, palate, gums, and cheek
V3: sensory from the anterior 2/3 of the tongue, skin of the chin, lower jaw, lower teeth, and one third from teh auricle of the ear
What are the branches that come off of the ophthalmic branch of the trigeminal nerve?
Lacrimal, Frontal, Nasociliary, Meningeal branch
What are the branches that come off of the maxillary branch of the trigeminal nerve?
Zygomatic, Infraorbital, Superior alveolar, Palatine, MEningeal
What are the branches that come off of the mandibular branch of the trigeminal nerve?
Buccal, Lingual, Inferior Alveolar, Auriculotemporal, Meningeal
Describe trigeminal neuralgia
Inflammation of the sensory components of the trigeminal nerve that results in pulsating pain that can last for minutes to hours
Describe Bell’s Palsy
damage to the facial nerve that results in paralysis of the eye muslces; inability to blink, sagging of the corner of the mouth that results in drooling