Functional hierarchy of the motor system Flashcards
four systems that control movement
descending control pathways
basal ganglia
cerebellum
local spinal cord/ brain circuits
the spinal cord receives descending input via the brainstem and direct cortical input via the
corticospinal (pyramidal) tract
stretch reflex follows a sharp
tap to an inelastic tendon
sensory nerves activated in muscle spindles (after stretch reflex) increases the number of …… in afferent nerves projecting through the dorsal horn to the spinal cord
APs
monosynaptic reflex
no interneurons are involved
causes rapid contraction of the AGONIST muscle
when the agonist muscle contracts, the antagonist muscle
relaxes (stretches)
when the agonist muscle contracts, the antagonist muscle relaxes. what is this called?
reciprocal inhibition
the primary motor cortex is in the
pre-central gyrus
parkinson’s is a …… ……. disorder
basal ganglia
parkinsons is caused by what?
caused by degeneration of neurones in substantia nigra
huntingtons disease involves hyperkinesia with
dementia and personality disorders
the knee jerk (or patellar reflex) is an example of what kind of reflex?
stretch
what is the golgi-tendon organ reflex?
inverse stretch reaction
(antagonist muscle is activated)
(agonist muscle is inhibited)
(you drop a really heavy load so to not damage the muscle)
what is the flexor reflex?
withdrawal reflex!
withdraws part of body subjected to painful stimulus
if the load is too heavy - the load is dropped (muscle relaxes) - what reflex is this?
golgi tendon organ reflex
