Term
The _____ is primarily important for movements requiring a high degree of conscious, voluntary attention & for spontaneous acts of will |
|
Definition
|
|
Term
The corticospinal tract is also known as the _____ |
|
Definition
|
|
Term
Corticospinal tract fibers from the frontal lobe originate both from the _____ (area 4) & the _____ (area 6) |
|
Definition
primary motor cortex; premotor cortex (PMC) |
|
|
Term
The more superior & medial part of the premotor cortex is the _____ |
|
Definition
supplementary motor area (SMA) |
|
|
Term
Fibers leaving the cortex enter the _____ en route to the internal capsule, where most travel in the posterior limb |
|
Definition
|
|
Term
Fibers split into longitudinal bundles that course through the _____ gray matter before reuniting in the medulla to form the pyramids |
|
Definition
|
|
Term
Corticospinal fibers maintain a relative _____, with fibers destined for upper parts of the body running medially & those innervating lower body parts running laterally |
|
Definition
|
|
Term
______ pathways to the brainstem travel near corticospinal axons in the internal capsule & innervate cranial nerve nuclei controlling movements of the face, tongue, pharynx, & larynx |
|
Definition
|
|
Term
At the _____, most corticospinal fibers cross to the opposite side in the pyramidal decussation |
|
Definition
|
|
Term
The _____ corticospinal tract travels through the lateral column & innervates neurons that control distal muscles |
|
Definition
|
|
Term
Most _____ fibers travel in the ventral column |
|
Definition
|
|
Term
Most pyramidal tract fibers influence _____ & _____ indirectly via interneurons |
|
Definition
A alpha & A gamma motor neurons |
|
|
Term
Through a _____ descending pathway, corticoreticular fibers modify reticulospinal projections & provide an alternate route for voluntary motor control |
|
Definition
|
|
Term
The caudal _____ division of the red nucleus is the origin of the rubrospinal tract |
|
Definition
|
|
Term
_____ circuits involve feedback from the basal ganglia & cerebellum that the cortex uses to assist in planning |
|
Definition
|
|
Term
_____ & _____ of the movement is commanded by the primary motor cortex |
|
Definition
|
|
Term
Error correction is accomplished by portions of the ______ |
|
Definition
|
|
Term
Electrical stimulation of area 6 evokes _____ |
|
Definition
coordinated contractions of muscles at multiple joints |
|
|
Term
Area 6 lesions do not produce weakness or paralysis but ______ (difficulty in executing complex movements such as those requiring coordination of both hands) |
|
Definition
|
|
Term
The premotor areas contain ______ that fire either when complex movements are performed or witnessed |
|
Definition
|
|
Term
Imaging studies in humans indicate that increased blood flow occurs in area 6 only when _____ performed & whenever the movements are mentally _____ |
|
Definition
complex movements; rehearsed |
|
|
Term
Increased blood flow occurs in area 4 only when _______ |
|
Definition
movement is performed & not rehearsed |
|
|
Term
Neurons in are 4 begin to fire ______ |
|
Definition
before contraction of the relevant muscle begins |
|
|
Term
______ of area 4 neuronal firing codes for the amount of force that is needed in the muscle |
|
Definition
|
|
Term
______ of area 4 neurons code for the direction of movement, with individual neurons having a "preferred" direction for which they are most active |
|
Definition
|
|
Term
Brain injury often reveals that the net effect of supraspinal pathways on motor neurons is ______ |
|
Definition
|
|