Lec 7 Flashcards
Anterior cortico-spinal tract
control what muscles?
Where originate?
What level does it cross at?
Control muscles ipsilaterally, bilateral, or contralateral?
where does it terminate?
axial muscles
Originate at motor cortex
cross and divide at cervical spinal level but not decussate
control bilaterally
terminate at cervical and upper thoracic cord
Cotrico-bulbar tract
where does the UMN synapse with LMN? What is that nerve called?
control what muscles?
What level does it cross at?
Control muscles ipsilaterally, bilateral, or contralateral
What condition can affect this area
Upper motor neuron synapse with lower motor neuron in pons. - called the facial nerve (CN VII)
facial muscles
crosses at pons
Upper face receives upper motor neuron control
from both brain hemispheres. Lower face receive from one side. Therefore, if whole face is affected, can assume that it is a lower motor neuron lesion, if only lower, can assume was upper motor neuron lesion.
Bell’s palsy can affect.
How does the organization of the corticospinal and corticobulbar tracts look as they travel through the CNS
Follows same organization of the homunculus of the brain (where feet are most medial and face is most lateral)
Additionally, as they enter the spinal cord, the facial nerves are the most anterior and the legs and feet are most posterior.
(must ask in office hours, I think they cross over between medial and lateral but not flip in terms of which is anterior/posterior.
Name the 7 tracts that we covered in class
Lateral Corticospinal Tract - primary motor pathway for voluntary limb movement
Anterior corticospinal tract - axial muscs
corticobulbar - facial muscs
rubrospinal tract - facilitate flexor muscle tone, inhibit extensor tone
reticulospinal tract - reflexes and tone
vestibulospinal tract - lateral tract facilitate extensor muscle tone, medial tract goes bilaterally and facilitate balance + posture
tectospinal tract - reflexive head and eye movements
