Lecture 12: Motor Tracts COPY Flashcards
Where are the cell bodies of the UMNs located?
Cerebral cortex or brainstem
What type of motor neurons are the cranial and peripheral nerves?
LMNs
Fibers traveling through the medial corticospinal tract innervate what muscles?
Postural muscles
Fibers traveling through the lateral corticospinal tract innervate what muscles?
Limb muscles
Voluntary motor action is associated with what tract?
Corticospinal
Fractionation of movement is associated with what tract?
Lateral corticospinal tract
What horn do the UMNs and LMNs of the corticospinal tract synapse?
Ventral
What part of the internal capsule do the cell bodies of the corticospinal tract travel through?
Posterior limb
Lesion in the median corticospinal tract would affect what structures? On what side?
Ipsilateral postural muscles
What are the cranial nerves are influenced by the corticobulbar tract?
5, 7, 9, 10, 11, 12
What part of the internal capsule does the corticobulbar tract travel through?
Genu
What is the relationship between the corticobulbar and corticospinal tracts?
Corticobulbar travels medially to corticospinal
If CN IX is being influenced by the corticobulbar tract, what side is being affected?
Ipsilateral
What muscles do the medial LMNs in the ventral horn innervate? Lateral?
Medial project to axial muscles
Lateral project to limbs
What tracts do the medial LMNs receive input from?
Tectospinal
Medial vestibulospinal
Medial reticulospinal
Medial corticospinal
Lateral vestibulospinal
What tracts do lateral LMNs receive input from?
Rubrospinal
Lateral reticulospinal
Lateral corticospinal
Which vestibulospinal tract goes to all spinal levels? What side does it innervate?
Lateral Vestibulospinal tract
Ipsilateral
Where do the medial vestibulospinal fibers terminate?
T2 to T3
(innervate neck and shoulder muscles)