Movement

Question 1

Final common pathway

Answer 1

Skeletal muscles can only be reached through the spinal or brainstem motor neuron.

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 fibers outside the muscle spindle.

Question 5

Annulospiral ending

Answer 5

Terminal of the la fiber on the intrafusal 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

Biosynaptic 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 motorneuron.

Question 9

Motorneuron pool

Answer 9

Collection of motorneurons innervating muscle units int he same muscle.

Question 10

Red muscle fiber

Answer 10

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

Question 11

White muscle fiber

Answer 11

Muscle fiber characterized by a few mitochondria, low myoglobin content, quick fatigue, but very fast contraction.

Question 12

Renshaw neuron

Answer 12

Inhibitory neuron in the spinal cord excited by a collateral of the alpha motorneuron and providing negative feedback to the motorneuron.

Question 13

Decerebrate rigidity

Answer 13

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

Question 14

Muscle tone

Answer 14

Continuous, slight contraction of the skeletal muscles important in the maintenance of the posture.

Question 15

Purkinje neuron

Answer 15

GABAergic inhibitory neuron 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 (flocculondular lobe) its input comes from the vestibular organ, and its main function is to keep posture and balance.

Question 18

Spinocerebellum (paleocerebellum)

Answer 18

Consists of the vermis and the intermediate part of the hemispheres, it monitors the execution of motor commands issued 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 in the learning, starting and stopping movements.

Question 20

Basal ganglia

Answer 20

Collective name for the neostriatum, pallidu, substabtia nigra and subthalamic nucleus, subcortical nuclei involved in motor control.

Question 21

Parkinson’s disorder

Answer 21

Movement disorder caused ny the insufficient production and release of dopamine in the neostriatum by dopaminergic neurons in the substantia nigra pars compacta; it causes tremor and decreased intiation of movements.

Question 22

Huntington’s chorea

Answer 22

Genetic neurological disorder leading to loss of GABAergic and cholinergic cells in the neostriatum leading to jerky, random, uncontrollable movements.