-Motor function: muscles of facial expression, stapedius muscle and part of digastric muscle.
-Parasympathetic function: innervation to lacrimal glands and salivary glands except for parotid
-Visceral sensory function: taste from anterior 2/3 of tongue
-Somatosensory function: touch sensation from region near external auditory meatus.
Label the Diagram ?
Facial Nerve
-
Motor cortex or corticobulbar tract lesions cause?
-Lesions of facial nucleus/nerve cause ?
-contralateral face paralysis/weakness sparing the forehead
-ipsilateral paralysis of whole face.
Upper motor neuron lesions spare what part of the head ? Lower motor neuron lesions cause paralysis in what part of the face ?
Forehead
Upper and lower face.
Describe Bell’s Palsy ?
All divisions of facial nerve are impaired acutely and then gradually recover.
Cause unknown, but viral or inflammatory process suspected.
Unilateral upper and lower face paralysis
Patients often have pain near the ear
Hyperacusis common,
-Dry eye 80% recover fully within 3 weeks
Some have residual weakness
Crocodile tears
Brainstem lesions
Corneal Reflex ?
Lesions of trigeminal, facial nucleus or facial nerve may cause loss of the corneal reflex.
The membranous labyrinth of the cochlea encloses the endolymph-filled what ?
The two compartments of the bony labyrinth, which house the perilymph, are called the ?
Scala media is the receptor organ it is also called the ?
scala media
scalae vestibuli and tympani
Corti
How come there is not unilateral hearing loss if damage is done proximal to the cochlear nerve.
Does more information ascend contralaterally or ipsilaterally
Auditory information ascends bilaterally after leaving the cochlea.
contralaterally
Semicircular canals detect what ?
Saccule and utricle detect what two things ?
angular acceleration around 3 orthogonal axes
linear acceleration and head tilt.
What is the function of the Vestibular System?
Posture
Muscle tone
Eye position in response to head movement
Why are these important
Lateral vestibulospinal tract:
Medial vestibulospinal tract:
Medial longitudinal fasciculus:
-extends throughout spinal cord and functions in balance and extensor tone 2.
-only projects to cervical spinal levels and controls neck and head position muscles
-connects vestibular nuclei and CN nuclei III, IV, and VI; mediates vestibulo-ocular reflex
If you move your head to the left, you will excite which horizontal canal ?
Left
What is the most common tumor for hearing loss is ? Where does it typically originate ?
Acoustic Neuroma -aschwannoma.
Where the 8th cranial nerve enters
Which nerve has no real nucleus to itself ?
Cn:IX Glossopharyngeal
Glossopharyngeal motor neurons are located where ?
nucleus ambiguus
Where are the preganglionic neurons of the Glossopharyngeal neurons ?
inferior salivatory nucleus
Visceral sensory function: Primary sensory neurons in the inferior glossopharyngeal ganglion project to?
Visceral sensory function: chemoreceptors and baroreceptors in carotid body. Primary sensory neurons in the inferior glossopharyngeal ganglion project to ?