10. Movement (motor control)

Question 1

final common pathway

Answer 1

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

Question 2

somatotopy

Answer 2

topography in the somatosensory and motor system

Question 3

intrafusal fiber

Answer 3

muscle fibers outside the muscle spindle

Question 4

annulospiral ending

Answer 4

terminal of the Ia fiber on the intrafusal fiber

Question 5

miotatic reflex (stretch reflex)

Answer 5

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

Question 6

inverse miotatic reflex (tendon reflex)

Answer 6

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

Question 7

motor unit

Answer 7

collection of muscle fibers innervated by the same motor neuron

Question 8

motoneuron pool

Answer 8

collection of motoneurons innervating muscle units in the same muscle

Question 9

red muscle fiber

Answer 9

muscle fiber characterized by good blood supply, many mitochondria, high myoglobin content and slow fatigue

Question 10

white muscle fiber

Answer 10

muscle fiber charachterized by few mitochondria, low myoglobin content, quick fatigue, but very fast contraction

Question 11

Renshaw neuron

Answer 11

inhibitory neuron in the spinal cord excited by a collateral of the alpha motoneuron and providing negative feedback to the motoneuron

Question 12

decerebrate rigidity

Answer 12

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

Question 13

muscle tone

Answer 13

continous, slight contraction of the skeletal muscles important in the maintenance of the posture

Question 14

Purkinje neuron

Answer 14

GABAenergic inhibitory neuron providing the main output of the cerebellum

Question 15

deep cerebellar nucleus

Answer 15

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

Question 16

vestibulocerebellum (archicerebellum)

Answer 16

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

Question 17

spinocerebellum (paleocerebellum)

Answer 17

consists of the vermis and the intermediate part of the hemispheres, it monitors the execution of motor commands issued by the cortex

Question 18

cerebrocerebellum (neocerebellum)

Answer 18

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

Question 19

basal ganglia

Answer 19

collective name for the neostratium, pallidum, substantia nigra and subthalamic nucleus, subcortical nuclei involved in motor control

Question 20

Parkinson’s disorder

Answer 20

movement disorder caused by the insufficient production and release of dopamine in the neostratium by dopaminergic neurons in the substantia nigra pars compacta; it causes tremor and decreased initiation of movements

Question 21

Huntington’s chorea

Answer 21

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