3. Cranial Nerves (Dennis) Flashcards
What cranial nerve provides taste sensation to the anterior two thirds of the tongue? Which provides sensation to the posterior one third of the tongue?
Anterior two thirds: facial nerve.
Posterior one third: glossopharyngeal nerve.
What is the function of the spinal accessory nerve?
Motor nerve to the sternocleidomastoid and trapezius.
What is the pathway for the fibers of the optic nerve into the brain?
Retina -> optic canal of the sphenoid bone -> optic chiasm -> optic tract -> thalamus -> optic radiations -> primary visual cortex.
What are the functions of the facial nerve?
Special visceral efferent motor innervation to the muscles of facial expression (pharyngeal arch 2).
General visceral efferent parasympathetic innervation to the lacrimal, and, as well as the submandibular and sublingual salivary glands.
Special visceral afferents bring taste from the anterior two thirds of tongue.
General somatic afferent sensation to the external acoustic meatus.
Where are the cell bodies found for CN IV?
Nucleus of the trochlear n. in the midbrain.
How do you test the oculomotor, trochlear, and abducens nerves?
Pupillary light reflex, accommodation, and extraocular muscle testing – e.g., can the patient move their eye in the motions of the innervated muscles?
What is the function of the trochlear nerve (CN IV)?
General somatic efferent motor innervation to the superior oblique muscle of the eye.
Where are the cell bodies found for CN XII?
Medulla.
Where are the cell bodies found for CN III?
Brainstem nucleus in the midbrain.
Visceral motor nucleus in the Edinger-Westphal nucleus (sends to the ciliary m. and sphincter pupillae m.)
Where are the cell bodies located for CN I?
Sensory nerve bodies in the olfactory epithelium.
Where are the cell bodies found for CN X?
Medulla.
What is the function of the mandibular division of the trigeminal nerve?
Sensation from the skin of the mandible, lower lip side of head (?), Mandibular teeth, TMJ joint, part of oral mucosa, anterior two thirds of tongue, motor innervation to the muscles of mastication (as well as the myelohyoid, anterior belly of the digastric, and the tensor tympani).
What is the function of the vestibulocochlear nerve?
Special somatic afferent senses of hearing and equilibrium.
What are the functions of the glossopharyngeal nerve?
General somatic afferent sensation from the ear and external auditory canal as well as the posterior one third of the tongue.
General visceral afferent from the oropharynx and carotid body.
Special visceral afferents supplying taste to the posterior one third of the tongue.
General visceral efferent parasympathetic’s to the parotid gland.
Special visceral efferent motor to the stylopharyngeus muscles of the pharyngeal arch 3.
Where are the cell bodies found for CN VI?
Nucleus of the abducent in the pons.
Where is the nucleus of the abducens located?
In the pons.
How do you test the trigeminal nerve?
Corneal reflex, check sensation of the cheek, check sensation of the chin, check the motor movements of the muscles of mastication. Click next
Where are the cell bodies found for CN V?
Substance of the pons.
What is the tract of the trochlear nerve?
Exits the dorsal surface of the midbrain -> pierces the dura mater at the margin of the tentorium cerebelli -> runs in the lateral wall the cavernous sinus -> enters the orbit via the superior orbital fissure.
Where are the cell bodies found for CN II?
Sensory nerve cell bodies in the retina.
