Trigeminal Pathway Flashcards Preview

Neuro Block 2 > Trigeminal Pathway > Flashcards

Flashcards in Trigeminal Pathway Deck (17):

The trigeminal nerve and galgnion are to the head what the spinal nerves and ___ are to the body as far as transmission of sensory informaiton is concerned.



Where are the cell bodies of the primary afferent fibers for the trigeminal pathway?

in the trigeminal ganglion


How many nuclei does the trigeminal pathway have and what info do they hold?


three are sensory and 1 is motor


What are some common pain syndromes involving trigeminal dermatomes?

TMJ, earaches, headaches, toothaches, sinus pain, trigeminal neuralgia


What areas of the body receive afferent supply from the trigeminal pathway?


top of head


anterior 2/3 of tongue = touch NOT taste

proprioceptors for the jaw


Three areas that are innervated only receive pain sensation regardless of the stimulus. What are they?

teeth, cornea, and eardrum


Where does efferent motor output go in the trigeminal pathway?

muscles of mastication and the tensor tympani


What are the three trigeminal sensory nuclei called?


main sensory

spinal trigeminal


What would be the impact of damage to the motor nucleus of the trigeminal nerve and its efferent fibers on muscles of mastication?

 - paralysis of the contralateral mastication muscles

sensitivity to noise

mouth muscles would atrophy, so mouth would devidate to the affected side.


What type of information do the second order neurons int he SPINAL TRIGEMINAL NUCLEUS carry? THrough what tract?

mostly nociceptive (but some tactile) through the ventral trigeminothalamic tract


What type of receptors giev the major amount of input to the main sensory nucleus of the trigmeinal pathway?



What tract do the main sensory nucleus second order axons join to reach the VPM?

the ventral trigeminothalamic tract


What is the special situation for  information related to intraoral mechanoreception?

A small component of the secondary axons from the main sensory nucleus project ot the IPSILATERAL VPM via the corsal trigeminothalamic tract instead of going contralateral with the ventral trigeminothalamic tract



How is the somatotopic organization of the VPM?

the face projections are positioned laterally in the nucleus, taste is medial and intraoral is betwen them


Here's an important exception!!

Where are the cell bodies (pseudounipolar neurons) of the neurons that synapse on the mesencephalic trigeminal nuclei?

They're located in the pons and midbrain! Not the trigeminal gnalgion!

it's a developmental quirk


Describe the jaw jerk reflex....

the pseudounipolar neurons with cell bodies in the mesencephalic trigeminal nucleus receive stretch input from the peridontium and muscles of mastication

axons project to the motor nucleus of the trigeminal pathway

motor fibers running back down to the muscles of mastication are activated in the jaw jerk reflex