Motor control

Question 1

final common pathway

Answer 1

skeletal muscles can only be reached through the spinal or brainstem motloneuron

Question 2

somatotopy

Answer 2

topography in the somatosensory and motor system

Question 3

intrafusal fiber

Answer 3

modified muscle fiber in the muscle spindle

Question 4

extrafusal fiber

Answer 4

muscle fiber outside the muscle spindle

Question 5

annulospiral ending

Answer 5

terminal of the la fiber on the intrafusual fiber

Question 6

miotatic reflex (stretch reflex)

Answer 6

monosynaptic reflex starting from the muscle spindle and causing contraction of the muscle on stretching

Question 7

inverse miotatic reflex (tendon reflex)

Answer 7

bisynaptic reflex starting from the tendon organ: it protects the muscle and tendon by relaxing the muscle, when extreme tension develops

Question 8

motor unit

Answer 8

collection of muscle fibers innervated by the same motoneuron

Question 9

motoneuron pool

Answer 9

collection of motoneurons innervating muscle units in the same muscle

Question 10

red muscle fibre

Answer 10

muscle fiber characterizied by good blood supply, many mitrochondria, high myoglobin content and slow fatigue

Question 11

white muscle fiber

Answer 11

muscle fiber characterizied by few mitrochondria, low myoglobin content, quick fatigue but very fast contraction

Question 12

renshaw neuron

Answer 12

inhibitory neuron in the spinal cord exited by collateral the alpha motoneuron and providing negative feedback to the motorneuron

Question 13

decerebrate rigidity

Answer 13

increase of the muscle tone caused by the transection of the brain stem above the Deiter´s nucleus

Question 14

muscle tone

Answer 14

continous, slight contraction of the skeletal muscles, important for maintaining the posture

Question 15

purkinje neuron

Answer 15

GABAergic inhibitory neutron providing the main output of the cerebellum

Question 16

deep cerebellar nucleus

Answer 16

most of the cerebellar Purkinje cells project through these nuclei to other parts of the brain

Question 17

Vestibulocerebellum (archicerebellum)

Answer 17

the most ancient part of the cerebellum (flocculonodular lobe), its input comes from the vestibular organ, and its main function is keep posture and balance

Question 18

Spinocerebellum (palecerebellum)

Answer 18

consists of the vermis an the intermediate part of the hemispheres, it monitors the execution of motor commands issue by the cortex

Question 19

cerebrocerebellum (neocerebellum)

Answer 19

the newest part of the cerebellum, consists of the lateral part of the hemispheres, its role is the learning, starting and stopping movements

Question 20

basal ganglia

Answer 20

collective name for the neostriatum, pallidum, substantia nigra and sub thalamic nucleus, subcortical nuclei involved in motor control

Question 21

Parkinson´s disorder

Answer 21

movement disorder caused by the insufficient production and release of dopamine in the neostriatum by dopamineric neurons in the substantia nigra pars compact; it causes tremor and decreased initiation of movements

Question 22

huntington´s chorea

Answer 22

genetic neurological disorder leading to loss of GABAergic cells in the neostriatum leading to jerky, random, uncontrollable movements