subcortical control of movement Flashcards
what are reflexes
spinal reflexes eg stretch reflexes, and water in a cup. rapid autonomic control, like the stretch is simple but others like swallowing are complicated
what part of the brainstem is responsible for reflexes
the medulla
describe the function of the reticular formation in the pons
reticulospinal tracts originate here, they are responsible for maintaining balance and posture, the brain predicts postural consequences of planned movements and acts to prevent loss of balance.
describe the function of the vestibular system of the pons
sensory system that provides a sense of balance and spatial orientation for the purpose of coordinating movement with balance
what is the red nucleus?
roughly spherical collection of cell bodies in the midbrain, it is called the red nucleus because there are lots of blood vessels
describe the function of the rubrospinal tract
rubrospinal fibers originate in the red nucleus and cross the midline as soon as they leave it. they terminate in the cervical and lumbar enlargements of the spinal cord which contains motor neurons for fore and hind limbs. controls reach to grasp movements
describe some features of the cerebellum
highly conserved, highly folded, 10% of brain volume, more neurons than cortex. input to output connections ratio 40:1.
describe some features of the superior cerebellar peduncle
efferent pathway to nucleus and cortex
describe some features of the inferior cerebellar peduncle
carries information to and from the spinal cord
describe some features of the middle cerebellar peduncle
most fibres originate in the pons, input from sensory, visual vestibular and motor systems, largest input is from the cortex
describe some features of the basal ganglia
movement regulation, skill learning, habit formation, reward systems, selection of appropriate behaviors, 2 pathways.
name the 2 pathways into the basal ganglia
direct - runs through the basal ganglia, excitatory effect, net effect is pro-movement
indirect - takes a longer loop, inhibitory effect, net effect is anti-movement. both finish in cortex
what is the relationship between BG and cerebellum
damage to BG produces states where there is too much or too little movement
damage to the cerebellum produces states where movements can be made but they are uncoordinated.