Cranial nerves & nuclei Flashcards
How many nerves are in the midbrain, pons and medulla? What are they?
2 in Midbrain - Cn 3 & 4
4 in pons - 5,6,7,8
4 in medulla - 9,10, 12 (11 technically in spinal cord)
Where are motor nuclei arranged in the brainstem? Sensory nuclei?
Motor = midline
Sensory = lateral
What functional component does CN 1 use? Which nucleus of origin? Where is it located?
olfactory Mucosa (not a nucleus)
- SVA
- smell!
What type of memory is most prominent? Which part of the brain is responsible for this?
SMELL MEMORY
- hippocampus
What functional component does CN 2 use? Which nucleus of origin? Where is it located?
- SSA
- LATERAL GENICULATE (superior colliculus)
- retina
Where does the optic nerve end up synapsing? Which area is this and in what fissure?
Synapses in the OCCIPITAL CORTEX
- Area 17
- Calcarene Fissure
(optic visual fields are opposite the physical location)
Which fibers (nasal or temporal optic) cross?
NASAl fibers cross
- optic fibers don’t
What does the optic nerve communicate with in the midbrain?
SUPERIOR colliculus & lateral geniculate
attached to back of thalamus
How do auditory fibers communicate to the brain
MEDIAL Geniculate via inferior colliculus
slo aim
What functional component(s) does CN 3 use? Which nucleus(i) of origin? Where is it located in the rostral midbrain?
- GVE & GSE
- GVE = Edinger-Westphal
GSE = Oculomotor - Interpeduncular Fossa
(GVE = sphincter pupillae + accommodate the lens)
Where is the EWN & Oculomotor Nucleus located in the midbrain?
in the middle under the PAG
What is the MLF responsible for?
controlling movement, turning eyes etc
What functional component(s) does CN 4 use? Which nucleus(i) of origin? Where is it located?
- GSE (Superior Oblique)
- Trochlear Nuclei
- DORSAL side of the brain, fibers cross
- CAUDAL midbrain
Which nerve has the longest intracranial exposure?
CN 4
What is a lower motor neuron? Upper?
- synapses in the spinal chord after coming from the brain
- motor neurons in the cerebral cortex or brainstem and carry information TO the lower motor neurons
What are signs of an upper motor neuron lesion? Lower?
Upper:
- Exaggerated Reflexes
- Spasticity
- Hemiplegia
- Babinski
Lower:
- Hyporeflexivity
- Fasciculations
- FLACCID PARALYSIS
What are corticobulbar fibers, upper or lower motor neurons?
UPPER
What is considered the “tee” under the Inferior colliculus (golfball)? What is its function?
Lateral Lemniscus
- HEARING
(TEST)
What nerve sits on top of MLF? What is MLF for?
CN 4!
Coordinates eye movements and head & neck movements w/ vestibular & auditory systems
What functional component(s) does CN 5 use? Which nucleus(i) of origin? Where is it located?
- GSA & SVE
- Mesencephalic
Spinal Nucleus of 5
Principle Sensory - SVE = Motor Nucleus of Nerve 5
- PONS
What are the following nuclei responsible for:
- Mesencephalic
- Spinal Nucleus of 5
- Principle Sensory N.
- Motor Nucleus of 5
- Jaw Jerk reflex
- Pain & temperature (similar to N.Proprius of STT)
- Vibration, prorioception (similar to DCP - N. CUneatus & GRacilus)
- Muscles of Mastication
Wich nucleus of 5 has pseudo-unipolar cells?
Mesencephalic (& Trigeminal ganglion)
What is the order of the nuclei of 5 in the pons?
- mesencephalic
- Principle Sensory N.
- Spinal N. of 5
- Motor of 5 is NEXT to the principle sensory nucleus (more medial)
Which nucleus is used for GSA to the small ear pinna?
Spinal Nucleus of 5
If there was a stroke in the brain & the spinal nucleus was affected, what would be damaged in the face & body?
- IPSILATERAL damage to the face
2. Contralateral damage to the lower body (STT)
Which pathways end up in VPM? VPL?
VPM = Trigeminal Thalamic pathway of 5!!
VPL = DCP & STT
Which nucleus of 5 is like nucleus proprius? Like N. Cuneatus or Gracilus?
- N. Proprius = Spinal Nucleus of 5
(pain & temp to the face) - Principle Sensory N of 5 (proprioception & vibration)
What nucleus of 5 is similar to the Dorsal Root Ganglion? What kind of cells are here? Which reflex does it elicit?
- Mesencephalic
- Pseudo-unipolar
- JAW JERK (masseter muscle)
The Principle sensory nucleus of 5 does what?
Receives info about touch & jaw position
Where do the trigeminal proprioceptive fibers synapse, which is different from DCP & STT? Which area of the brain?
VPM
(the others are VPL)
- AREA 312 (sensory)
What are the following areas responsible for:
312
4
17
- 312 = SENSORY
- 4 = MOTOR (pre-central gyrus)
- Area 17 = VISION (in calcarene fissure)
What nucleus innervates the muscles of mastication?
Trigeminal Motor nucleus of 5
What functional component(s) does CN 6 use? Which nucleus(i) of origin? Where is it located?
- GSE (Lateral Rectus)
- Abducents Nucleus
- Pontomedullary Junction
(pons)
Which nerve forms a GENU around CN 6?
CN 7
Which nerve makes up the Facial Colliculus?
CN 6!!
What functional component(s) does CN 7 use? Which nucleus(i) of origin? Where is it located?
- GVA, SVA, GVE, GSA,SVE
- a) GVA & SVA = Nucleus Solitarius
GVE = Superior Salvitory
GSA = Spinal Nucleus of 5
SVE = Motor Nucleus of 7
Pontomedullary ANGLE
Which is the upper and lower part of Nucleus Solitarius responsible for?
upper = taste
lower = visceral sensation
Which cranial nerves use Nucleus Ambiguous? Which functional component is this responsible for?
9,10
- SVE
(5 & 7 use Motor Nucleus of 5 & 7)
Which nucleus does the muscles of facial expression? The submandibular/sublingual glands?
- SVE –> Motor Nucleus of 7
2. Superior Salvitory Nucleus
Which nucleus is responsible for taste to the anterior 2/3 of the tongue?(SVA)
- Nucleus Solitarius (upper)
What will happen with unilateral corticobulbar damage (upper motor neuron)?
Spare the upper face, since has BILATERAL corticobulbar input to the upper face
- lower face on the opposite side will be affected
What is the difference in symptoms of a stroke in the left Corticobulbar region & a cut in the left CN of 7(Bells Palsy) ?
- Stroke (supra nuclear region)= opposite lower side of face will be affected - RIGHT
- TOTAL left face function will be wiped out- Flaccid Paralysis
Which of the two is up motor neurons and which are lower motor neurons:
- Corticobulbar Cells
- Facial motor Nucleus
- Corticobulbar = UPPER
(opposite side of lower face since BILATERAL representation) - Facial Motor Nucleus = lower
(wipe out same side of face)
What functional component(s) does CN 8 use? Which nucleus(i) of origin? Where is it located?
- SSA
- Cochlear & Vestibular
(cochlear = saddle bags)
cochlear = organ of court
vestibular = Semicircular Canals - MEDULLA–> pontomedullary angle*
Hearing is bilateral. True or false.
TRUE
- it is bilateral and hard to knock out
Where are the vestibular and cochlear nuclei of 8 found in the pons? Which has a peppered look? Which is the saddle bag of ICP?
LATERAL SIDE
- pontomedullary angle
- Vestibular Nucleus = Peppered (more medial)
Cochlear = saddle bags of ICP
What functional component(s) does CN 9 use? Which nucleus(i) of origin? Where is it located?
- GVA, SVA, GVE, GSA, SVE
- GVA= lower Nuc. Solitarius
SVA = upper Nuc. Solitarius
GVE = Inferior Salvitory Nucleus
GSA = Spinal Nuc. of 5
SVE = Nuc. Ambiguus
What are the following nuclei of 9 used for:
- Nucleus Solitarius
- Inferior Salvitory
- Spinal Nuc. of 5
- Nuc. Ambiguus
- Nuc. Solitarius
- upper = taste
- lower = carotid sinus - Inferior Salvitory = PAROTID
- Spinal Nuc of 5 = sensation to ear pinna
- Nuc.Ambiguus = STYLOPHARYNGEUS
What functional component(s) does CN 10 use? Which nucleus(i) of origin? Where is it located?
- GVA, SVA, GVE, GSA, SVE
2. GVA= lower Nuc. Solitarius SVA = upper Nuc. Solitarius GVE =DMX (Dorsal Motor) GSA = Spinal Nuc. of 5 SVE = Nuc. Ambiguus
DORSAL TO OLIVE
What nucleus does 10 use to slow heart and speed digestion? WHERE IS IT LOCATED
GVE
- DORSAL MOTOR NUCLEUS of 10
- located at the top portion of the ROSTRAL medulla
How are nuclei arranged?
In columns according to functional components
What functional component(s) does CN 11 use? Which nucleus(i) of origin? Where is it located?
- SVE
- Accessory Nucleus
- In spinal cord
C1-C5
Which is the only nucleus in the spinal cord?
CN 11
- in the ventral horn
What functional component(s) does CN 12 use? Which nucleus(i) of origin? Where is it located?
- GSE
- Hypoglossal Nucleus
- Ventral to the Olive
(more medial than 10 in the cross section of medulla)
A lesion in CN 12 results in the tongue deviating to or away the lesion?
TO THE LESION
- lick your wounds
What separates the Alar and Basal sections?
Sulcus Limitans
