Corticobulbar Tract Flashcards
What is the function of the corticobulbar tract
Motor information to the head and neck
Voluntary movement of the skeletal muscle
Which part of the internal capsule does the fibres pass through in the corticobulbar tract
The genu
The LMN in the corticobulbar tract is always which kind of nerve
A cranial nerve
Do cranial nerves innverated by UMN have a sensory or a motor function
They have a motor function
Each UMN connects bilaterally to a cranial nerve, which two cranial nerves are the exception to this rule?
The facial nerve (to lower face) and hypoglossal nerves
Which cranial nerves does the nucleas ambigious relate to in the corticobulbar tract
Glossopharnygeal and vagus
What is pseudobulbbar palsy
A lesion to most cranial nerves UMNs will NOT produce facial paralysis of the muscles of the face and the neck.
Instead mild form of weakness occur in the affected muslces - this is because of the bilateral innervation of nerves - contralateral side more dominant
There is a lesion on the UMN neuron on the facial nerve what will the symptoms be and why does this happen?
A lesion on the UMN has consequences for the LMN( facial nerve) leaving lower facial nucleas paralysed on the contralateral side.
Contralateral lower facial paralysis but sparing of the upper facial muscles
What happens when there is a lesion on the LMN (facial nerve) and why does this happen
If there is a lesion on the LMN of the facial nerve then there will be paralysis on one side of the face completely.
This is because the lower motor neurone is the facial nerve itself
Which muscle is responsible for sticking out the tongue and how does it do this?
The genioglossus, the left and right muscles work together pushing against one another to bring tongue out
What is unique about the innervation of the hypoglossal nerve in the corticobulbar tract
It is single contralateral innveration to a nucleas
Whereas most others are bilateral innervation
What is the problem with the hypoglossal nerve only having single contralateral innveration
This means that this nerve cannot get pseudobulbar palsy - there is no backup innveration
Lesion on the UMN of the hypoglossal nerve, what happens?
Deviation of tongue upon protrusion to the contralateral side
What happens when there is a lesion on the LMN ( the hypoglossal nerve)
Deviation of tongue upon protrusion to ipsilateral ( same) side
A lesion to most cranial nerves UMNs will not cause paralysis of muscles of face and head what will it instead do
Pesudobulbar palsy
