Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
34 Cards in this Set
- Front
- Back
|
does the olfactory nerve have a thalamic relay?
|
-no
|
|
|
what can primary taste sensation convey about food?
|
-sweet, sour, salty or bitter
-none of the character of foods |
|
|
what are the three major projections of CN 1?
|
-stria medullaris
-stria terminalis -medial forebrain bundle |
|
|
how do we test CN 1 function?
|
-with essential oils or other obvious smells
-only tested if anosmia is a complaint of the patient |
|
|
do rods or cones have higher sensitivity to light?
|
-rods
|
|
|
info from what half of the retinas cross at the optic cup?
|
-the medial half
|
|
|
what part of the visual field does meyers loop carry fibers for?
|
-the superior field
|
|
|
what part of the visual field does the parietal radiation carry fibers for?
|
-inferior field
|
|
|
what part of the retina does a central scotoma effect?
|
-the macula
|
|
|
what is the pupillary light reflex pathway?
|
-optic tract synapses at the pretectal area
-then synapses in the EW nucleus (III) -these parasymp fibers travel to ciliary ganlion -then to short ciliary nerves |
|
|
what presents when someone has an afferent lesion in the pupillary reflex?
|
-less light is detected on the lesioned side leading to dec constriction in both eyes
|
|
|
what happens in an efferent lesion of the pupillary light reflex?
|
-get normal constriction in contralateral eye
-but no constriction of the eye on the affected side |
|
|
what is the near reflex (eyes)?
|
-pupils constrict when focusing on an object that is close to the person
|
|
|
what are the motor innervations of CN III?
|
-all mm of the eye except for SO and LR
-parasymp to constrictor pupillae and ciliary muscle via ciliary ganglia |
|
|
where do the parasympathetics from III originate?
|
-edinger westphal nuc
|
|
|
what are the typical presentations of a patient with a left IIIrd nerve lesion?
|
-left eye is looking "down and out" due to unopposed LR and SO
-also left ptosis and dilated left pupil |
|
|
what are the motor innervations of IV?
|
-contralateral SO
|
|
|
what two characteristics are exclusive to IV?
|
-only CN to exit from dorsum on BST
-only CN in which all fibers decussate |
|
|
what are the typical presentations of a peripheral trochlear nerve lesion?
|
-ipsilateral effects
-extorsion of eye -diplopia -loss of downgaze in medial position -patients tilt head toward unaffected side to compensate |
|
|
what are the typical presentations of a central IVth nerve lesion?
|
-contralateral effects
-extorsion of eye -diplopia -loss of downward gaze in medial position -head tilts toward the side that the BST lesion is on |
|
|
what ganlion houses the sensory CBs of V?
|
-tigeminal ganglia
|
|
|
what are the motor innervations of V?
|
-mm of mastication
-tensor tympani/veli palatini -mylohyoid -ant digastric |
|
|
where does V exit the BST?
|
-ventrolateral pons
|
|
|
where do V1 V2 and V3 exit the skull?
|
-V1 at sup orbital fissure
-V2 at foramen rotundum -V3 at foramen ovale |
|
|
what does the mesencephalic nuc of V house?
|
-primary sensory neurons from from the mm which V innervates
-mediates proprioception for reflex control of chewing |
|
|
what does the pontine nuc of V house?
|
-secondary sensory neurons for the face
|
|
|
what does the nuc of the spinal tract of V house?
|
-pain and temp info for face
|
|
|
what happens in UMN and LMN lesions of V?
|
-UMN nothing happens due to bilateral cortical innervation
-LMN you get ipsilateral paralysis of mm of mastication |
|
|
what are the presentations of a VIth nerve lesion?
|
-ipsilateral LR weakness and diplopia on lateral gaze
-medial deviation of eye (unopposed MR) |
|
|
where is the VIth nerve nucleus?
|
-dorsal pons, near midline
|
|
|
what is strabismus?
|
-inability to direct both eyes simultaneously to one target
|
|
|
what are the rules of diplopia?
|
-the false image is always the outer one
-false image always comes from the affected eye |
|
|
where is lateral gaze initiated?
|
-in the FEF (brodmans 8)
|
|
|
what is the lateral gaze pathway?
|
-originates in FEF
-fibers cross in pons and innervate PPRF -excitatory inputs to ipsilateral VIth nuc -excitatory inputs to contralateral IIIrd nuc -fibers run in MLF |
