Another name for the SENSORY DECUSSATION
Decussation of the Medial Lemniscus
Epicritic Pathway and crossing in what region of the medulla
Decussation of the Epicritic Pathway carrying -2 point tactile discrimination -conscious proprioception -vibration sense occurs in the caudal third of the medulla.
Dorsal Column contents and cell body location
ascending axons carrying Epicritic information are located in the Dorsal Columns of the spinal cord (cell bodies in the DRG)
Dorsal Column Divisions
Fasciculus Gracilus which controls the Lower Body and Fasciculus Cuneatus which controls the Upper Body
The fate of Dorsal Columns axons
Dorsal columns axons enter the medulla and synapse on cell bodies in the Nucleus Gracilis and Nucleus Cuneatus
What happens at the Medial Lemniscus ?
axons from the nucleus gracilus and cuneatus DECUSSATE and ascend as the MEDIAL LEMINISCUS
Fate of the Medial Lemniscus
Medial Lemniscus terminates in the VPL nucleus of the THALAMUS
In reference to the Motor Component what happens in the Caudal Third of the Medulla ?
Decussations of the majority of fibers in the Pyramidal Pathway
What occurs at the level of the pyramids ?
Fibers whose cell bodies are in the Cerebra Cortex descend through the brainstem into the Pyramid of the medulla.
Motor Fiber crossing in the medulla
In the caudal medulla 85% of the fibers Decussate and descend into the spinal cord as the Lateral Corticospinal Tract. [remaining 15% of the fibrers in the pyramid do not cross but continue on the same side into the spinal cord as the anterior corticospinal tract]
Occulomotor Nerve has two Fiber components:
GSE- Occulomotor Nerve GVE- Edinger Westphal Nuc. (Accesory Occulomotor Nuc.)
Spinal Trigeminal Tract Recieves information from which cranial nerves ?
CN 5, CN 7 , CN 9, CN 10
What is viewed in the caudal medulla in reference to the pyramids ?
The pyramids are migrating out to the lateral funiculus as they descend.
What is unique about the Spinal Trigeminal Tract?
It is a descending sensory tract and all other descending tracts are motor in function.