Descending tracts- Corticospinal tract Flashcards
Where does the CST start?
UMN in precentral gyrus
Where do the fibers of UMN first go?
To the posterior limb of internal capsule
What artery when occluded can damage the posterior limb of internal capsule and ultimately damage the CST?
Lenticulostriate artery
As the CST is descending from the posterior limb of internal capsule where does it enter?
Crus cerebri of cerebral peduncles
Where does the CST travel past after entering the cerebral peduncles?
Pontine nuclei of anterior pons
Where does the CST travel past after passing the pontine nuclei of anterior pons?
To the medullary pyramids
What happens to the CST at the pyramids?
They decussate (cross)
What fibers are decessating at the pyramids and descending to the lateral white column and what fibers are staying ipsilateral and enter the anterior white column?
Lateral CST cross while Anterior CST stays ipsilateral
Where do they LCST synapse at after descending through lateral white column?
Ventral gray horn with the LMN which then go to the distal limb muscle
LSCT deals with what type of movements?
Fine and precise movements of distal limbs
If UMN is lesioned what are the symptoms?
Hyperreflexia and hypertonia (Clonus)
If LMN is lesioned what are the symptoms?
Hyporeflexia and hypotonia
