Cortical & Brainstem Control Flashcards
3 subareas of motor cortex
primary motor cortex
premotor area
supplementary motor area
mirror neurons
a special class of neurons which become active when a person performs a specific motor task or when he observes the same task performed by others
supplementary motor area
- contractions elicited by this area are mostly bilateral
- these movements are rudiments of hand functions required for climbing
- this area is concerned with body wide altitudinal movements
voluntary eye movement field
- present immediately above brocas area
- controls voluntary eye movements
- it also controls eyelid movements like blinking
motor apraxia
when tumours or lesions develop in motor area for hand skills, hand movements become uncoordinated and non purposeful
motor signals are transmitter directly from the cortex to the spinal cord through?
corticospinal tract aka pyramidal tract
pathway of corticospinal tract
cortex posterior limb of internal capsule brainstem lateral corticospinal tracts inter neurons
ventral corticospinal tracts
control of bilateral postural movements by the supplementary motor cortex
Betz Cells
found in primary motor cortex
give out fibers to corticospinal spinal tracts travel at 70m/s (fastest from brain to spinal cord)
how many betz cell fibers are present in each corticospinal tract?
34000
other fiber pathways from the motor cortex
- collaterals from axons of betz cell fibers
- fibers to caudate nucleus and putamen
- fibers to red nucleus
- fibers to reticular substance and vestibular nuclei of brain
- fibers which synapse in pontile nuclei
- collaterals to inferior olivary nuclei
incoming fibers to the motor cortex
- fibers from adjacent area of cerebral cortex
- fibers that arrive through corpus callosum
- fibers from ventrobasal complex of thalamus (tactile signals
- fibers from ventrolateral and ventroanterior nuclei of the thalamus
- fibers from intralaminar nuclei of thalamus
