Exam 1: Unit III: CN V; Trigeminal Nerve Flashcards
What CN is known as the “Great Sensory Nerve of the Face”?
Trigeminal N (CN V)
What is the largest CN?
Trigeminal N (CN V)
What type of fibers does the Trigeminal N carry?
Mixed nerve; carries mostly (general) sensory fibers, but also carries motor fibers
What are the three nuclei of termination associated with the Trigeminal Nerve?
- Main sensory nucleus
- Spinal Nucleus
- Trigeminal mesencephalic nucleus
How many nuclei of origin does the Trigeminal have?
One; called Trigeminal motor nucleus
What is the peripheral ganglion ass. with the Trigeminal Nerve called? What type of cell bodies does it contain?
Trigeminal (semilunar) ganglion; contains cell bodies of 1st order sensory neurons
(similar to DRG of a spinal N)
The Trigeminal gets its name from what?
Its three peripheral branches:
- Ophthalmic (V1)
- Maxillary (V2)
- Mandibular (V3)
Where do the three peripheral branches of the Trigeminal Nerve come off?
come off Trigeminal Ganglion, located in PNS (NOT off CNS)
Where do the sensory pathways of the Trigeminal Nerve go?
to the nuclei of termination (main, spinal, mesencephalic)
Where are the cell bodies of the main sensory nucleus and spinal nucleus of the Trigeminal nerve located?
cell bodies located in trigeminal ganglion
For the sensory pathway of the trigeminal nerve, the _______ processes come from the ______ to the ______ ______. Then the _____ processes from there enter the CNS and go to either main or spinal nuclei.
peripheral processes; face to the trigeminal ganglion; central processes (axons)
What type of sensory information is carried to the main trigeminal nucleus?
touch, vibration, joint proprioception (TMJ)
What type of sensory information is carried to the spinal nucleus of the trigeminal nerve?
pain and temperature
What are the cord pathways that would be analogous to info carried to the spinal nucleus of trigeminal nerve?
lateral spinothalamic tract carries pain and temp
(3 neuron pathway)
- 1st neuron enter cord and cross immediately
- 2nd neuron ascends up cord and synapses in thalamus
- 3 neuron goes from thalamus to cerebral cortex
What are the cord pathways that would be analogous to info carried to the main trigeminal nucleus?
Gracilis and Cuneatus carry —–
Anterior spinothalamic tract carries —
???????
What is unique about the neurons going to the trigeminal mesencephalic nucleus?
dendrites from periphery pass THROUGH the trigeminal ganglion, enter CNS, and ascend to nucleus
–there are the ONLY primary sensory neurons that have cell bodies located in the CNS
What type of information is carried to the trigeminal mesencephalic nucleus?
proprioception info form muscles of mastication
What type of neurons are in the motor pathway for the trigmeinal nerve?
since going out into PNS, but be LMNs
What is the only branch of the trigeminal nerve that carries motor fibers?
mandibular branch
Describe the pathway of the axons leaving the motor nucleus of the trigeminal nerve.
Axons from motor nucleus leave CNS and travel THROUGH trigeminal ganglion to be carried in the mandibular branch to supply 8 muscles
What 6 areas does the motor nucleus of the trigeminal nerve receive information from?
- cerebral cortex (both hemispheres)
- reticular formation
- red nucleus
- tectum
- medial longitudinal fasciculus (MLF)
- mesencephalic nucleus (monosynaptic reflex)
Where is the apparent origin of the trigeminal nerve?
lateral aspect of pons
The trigeminal nerve travels _________ over the _____ ___ of the ____ bone, and enters a pouch of dura called the ____ ____.
anteriorward; petrous part of the temporal bone; trigeminal (Meckel’s) cave.
Where is the trigeminal ganglion found?
in a pouch of dura called the trigeminal (Meckel’s) cave
After passing through the trigeminal cave (where trigeminal ganglion is found) the trigeminal nerve moves further into the periphery and then what?
three banches/divisions arise (Ophthalmic, maxillary, mandibular)
What structure does the ophthalmic division enter the orbit through?
superior orbital fissure (same as III, IV, VI)
What type of function does the ophthalmic division (V1) have?
sensory function ONLY
Where does the ophthalmic division (V1) carries sensational information from?
- skin over nose, forehead, and scalp
- mucous membranes in frontal and sphenoid sinuses
- membranes covering nasal septum
What are the 4 branches that the ophthalmic division (V1) gives rise to?
- meningeal nerve, or tentorial branch
- lacrimal nerve
- Frontal nerve
- Nasociliary nerve
(2-4 = the three main ones)
When is the meningeal nerve (or tentorial branch) of the V1 given off? What does it supply?
give off BEFORE opthalmic division leaves the superior orbital fissure
- supplies dura mater lining middle cranial fossa
Which is the smallest of the three main branches of the Ophthalmic nerve?
lacrimal nerve
Describe the path the lacrimal branch of V1 takes.
- travels along superior aspect of lateral rectus
- passes THROUGH lacrimal gland (and supplies it)
- and reaches the skin of the upper eyelid
The lacrimal nerve of V1 carries ______ ______ fibers to the lacrimal gland. These fibers originate in the _______ _____. These fibers reach the lacrimal nerve via the ________ nerve.
postganglionic parasympathetic (secretory) fibers
pterygopalatine ganglion (CN VII)
zygomatic nerve (CN V2)
List in order the path of how the postganglionic parasympathetic fibers reach the lacrimal gland.
- Pterygopalatine ganglion (CN VII)
- zygomatic nerve (V2)
- lacrimal nerve
- lacrimal gland
Which is the largest branch of the ophthalmic division (V1) out of the three main branches?
Frontal nerve
How many branches does the Frontal Nerve (branch of V1) branch into? What are they?
- Supratrochlear nerve
2. Supraorbital nerve
What area does the Supratrochlear nerve (branch of Frontal Nerve of V1) convey sensation from?
medial corner of the eye