Trigeminal Pathways Flashcards
What are the three regions where there is only pain sensation?
Teeth, cornea, and eardrum
Is trigeminal sensory ipsilateral or contra lateral?
Ipsilateral
What do the motor output of the trigeminal nerve do?
Muscles of mastication
Tensor tympani
How many sensory ganglia are there in CN V?
3
Mesencephalic - properiception in jaw
Main (principal or chief) - normal touch
Spinal (descending) trigeminal - pain and temp (like spinal thalamic tract)
Where does the mesencephalic tract axons have their cell bodies of their primary neurons?
In the CNS
Where are most primary sensory cell bodies?
Outside the CNS
Where is the chief sensory nucleus of CN V?
The pons
What is unique about the sensory inform to the oral cavity?
It is bilateral
What side is pain?
It is ipsilateral
What do we call the face, oral, and pain/temp nerves going to the thalamus and what does it carry?
The ventral trigeminothalamic tract
Have sensory to the face, oral cavity, and pain to the face
What is contained in the DTT dorsal trigeminothalamic tract?
Sensory to the oral cavity
At what level is the trigeminal ganglion?
Midpons
What end of the pons is closed?
A little more caudal
What is the ventral basal nuclei made of?
VPM
VPL
What is the orientation of the VPM?
Face most laterally Intraoral cavity in the middle Taste most medically Face and taste is contralateral Oral is both ipsilateral and contralateral
What nucleuses of the trigeminal are involved in the jaw jerk reflex?
The mesencephalic trigeminal nucleus and the Motor nucleus. It is a two neuron reflex
What side is motor neurons of the motor nucleus of the trigeminal nerve?
Ipsilateral
What is the one exception of primary sensory neurons being in the CNS?
The mesencephalic nucleus of CN V
Involved in the jaw jerk reflex
What is the afferent supply of the trigeminal?
Ipsilateral to face, top of head, eardrum, 2/3 of tongue, proprioceptors for the jaw
What is the major input to the main sensory nucleus from?
Mechanoreceptors
Is the main sensory nucleus ipsilateral or contralateral?
Contra to the VPM joins the VTT
BUT a small part is bilateral to the mouth
Where are the cell bodies of the mesencephalic nucleus?
The pons and medulla NOT the trigeminal ganglion
Pseudounipolar
What area involves the jaw jerk reflex?
The mesencephalic nucleus
