AP06 Topography of Major Motor Systems Flashcards
From where do pyramidal tracts originate and what is their function?
cerebral cortex
voluntary control of body and facial musculature
From where do extrapyramidal tracts originate and what is their function?
brainstem
involuntary control of all musculature
What are the 2 pyramidal tracts?
corticospinal tracts
Corticobulbar tracts
What is the rough function of the corticospinal tracts?
supply body musculature
What is the rough function of the corticobulbar tracts?
supply head and neck musculature
Where does the corticospinal tract receive input from?
primary motor cortex premotor cortex
supplementary motor area
somatosensory area
pyramidal cells of Bertz
Where do the neurones of the corticospinal tract converge and descend?
What pathology is associated with this?
internal capsule
capsular stroke
What part of the midbrain does the corticospinal tract pass through?
crus cerebri
Where does the corticospinal tract split?
medulla
What does the corticospinal tract split into?
lateral corticospinal tract
anterior corticospinal tract
what is the pathway of the lateral corticospinal tract?
decussates and descends into the spinal cord, terminating in the ventral horn
What is the pathway of the anterior corticospinal tract?
remains ipsilateral, descending into the spinal cord
decussates and terminates in the ventral horn of cervical and upper thoracic layers (axial control)
From where do the crticobulbar tracts originate?
arise frrom lateral primary motor cortex (receive same inputs)
5th layer of cerebral cortex (giant cells of Bertz)
Which part of the internal capsule do the corticobulbar tracts pass through?
corona radiata (genu of internal capsule)
Where do the corticobulbar tracts terminate?
motor nuclei of cranial nerves
