8 Control Of Movement

Question 0

Flexion

Answer 0

A movement of the limbs that tends to bend its joints; the oppocite of extension.

Question 1

Skeletal muscle

Answer 1

One of the striated muscles attached to the bones.

Question 2

Extension

Answer 2

Movement of a limb that tends to straighten its joints; opposite of flexion.

Question 3

Extrafusal muscle fiber

Answer 3

One of the muscle fibers that are responsible for the force exerted by contracting of a skeletal muscle.

Question 4

Alpha motor neuron

Answer 4

Neuron whose axons forms synapses with extrafusal muscles fibers of a skeletal muscle; activation contract the muscle fibers.

Question 5

Intrafusal muscle fiber

Answer 5

A muscle fiber that functions as a stretch receptor, arrange parallel to the extrafusal muscle fibers, just detecting changes in muscle length.

Question 6

Gamma motor neuron

Answer 6

Neuron whose axons form synapses with intrafusal muscle fibers.

Question 7

Motor unit

Answer 7

Motor neuron and its associated muscle fibers.

Question 8

Myofibril

Answer 8

Element of muscle fibers that consist of overlapping strands of actin and myosin; responsible for muscular contractions.

Question 9

Actin

Answer 9

One of the proteins (with myosin) that provide the physical basis for muscular contraction.

Question 10

Myosin

Answer 10

One of the proteins (with actin) that provides the physical basis for muscular contraction.

Question 11

Striated muscle

Answer 11

Skeletal muscle; muscle that contains striations.

Question 12

Neuromuscular junction

Answer 12

Synapse between the terminal buttons of an axon and a muscle fiber.

Question 13

Motor endplate

Answer 13

Postsynaptic membrane of the neuromuscular junction.

Question 14

Endplate potential

Answer 14

Postsynaptic potential that occurs in the motor endplate in response to release of acetylcholine by the terminal button.

Question 15

Golgi tendon organ

Answer 15

Receptor organ at the junction of the tendon and muscle that is sensitive to stretch.

Question 16

Monosynaptic stretch reflex

Answer 16

Reflects in which a muscle contracts in response to its being quickly stretched; involves a sensory neuron and a motor neuron, with one synapse between them.

Question 17

Decerebrate

Answer 17

Describes an animal whose brainstem has been transected.

Question 18

Decerebrate rigidity

Answer 18

Simultaneous contraction of agonistic and antagonistic muscles; caused by the cerebration or damage to the particular formation.

Question 19

Clasp-knife reflex

Answer 19

Reflects that occurs when force is applied to flex or extend the limb of an animal showing decerebrate rigidity; resistance is replaced by sudden relaxation.

Question 20

Somatotopic organization

Answer 20

Topographically organized mapping of parts of the body that are represented in a particular region of the brain.

Question 21

Supplementary motor area (SMA)

Answer 21

Region of motor association cortex of the dorsal and dorsomedial frontal lobe, rostral to the primary motor cortex.

Question 22

Premotor cortex

Answer 22

Region of motor association cortex of the lateral frontal lobe, rostral to the primary motor cortex.

Question 23

Lateral group

Answer 23

Corticospinal tract
Corticobulbar tract
Rubrospinal tract

Question 24

Ventromedial group

Answer 24

Vestibulospinal tract Tectospinal tract Reticulospinal tract Ventral corticospinal tract

Question 25

Corticospinal tract

Answer 25

System of axons that originates in the motor cortex and terminates in the ventral gray matter of the spinal cord.

Question 26

Pyramidal tract

Answer 26

Portion of the corticospinal tract on the ventral border of the medulla.

Question 27

Lateral corticospinal tract

Answer 27

System of axons that originates in the motor cortex and terminates in the contralateral ventral gray matter of the spinal cord; controls movements of the distal limbs.

Question 28

Ventral corticospinal tract

Answer 28

System of axons that originates in the motor cortex and terminates in the ipsilateral eventual gray matter of the spinal cord; controls movements of the upper legs and trunk.

Question 29

Corticobulbar tract

Answer 29

Bundle of axons from the motor cortex to the fifth, seventh, ninth, 10th, 11th, and 12 cranial nerves; controls movements of the face, neck, tongue, and parts of the extraocular eye muscles.

Question 30

Rubrospinal tract

Answer 30

System of axons that travels from the red nucleus to the spinal cord; controls independent limb movements.

Question 31

Corticorubral tract

Answer 31

System of axons that travels from the motor cortex to the red nucleus.

Question 32

Vestibulospinal tract

Answer 32

Bundle of axons that travels from the vestibular nuclei to the gray matter of the spinal cord; controls postural movements in response to information from the vestibular system.

Question 33

Tectospinal tract

Answer 33

Bundle of axons that travels from the tectum to the spinal cord, coordinates head and trunk movements with eye movements.

Question 34

Reticulospinal tract

Answer 34

Bundle of axons a travel from the reticular formation to the gray matter of the spinal cord; controls the muscles responsible for postural movements.

Question 35

Mirror neurons

Answer 35

Neurons located in the ventral premotor cortex and inferior parietal lobule that respond when the individual makes a particular movement or sees another individual making that movement.

Question 36

Parietal reach region

Answer 36

Region in the medial posterior parietal cortex that plays a critical role in control of pointing or reaching with the hands.

Question 37

Apraxia

Answer 37

Difficulty in carrying out purposeful movements, in the absence of paralysis or muscular weakness.

Question 38

Constructional apraxia

Answer 38

Difficulty in drawing pictures or diagrams or in making geometrical constructions of elements such as building blocks or stick; caused by damage to the right parietal lobe.

Question 39

Caudate nucleus

Answer 39

Telencephalic nucleus, one of the input nuclei of the basal ganglia; involved with control of voluntary movement.

Question 40

Putamen

Answer 40

Telencephalic nucleus; one of the input nuclei of the basal ganglia; involved with control of voluntary movement.

Question 41

Globus pallidus

Answer 41

Telencephalic nucleus; primary output nucleus of the basal ganglia; involved with control of voluntary movement.

Question 42

Ventral anterior nucleus (of thalamus)

Answer 42

Thalamic nucleus that receives projections from the basal ganglia and sends projections to the motor cortex.

Question 43

Ventrolateral nucleus (of thalamus)

Answer 43

Thalamic nucleus that receives projections from the basal ganglia and send projections to the motor cortex.

Question 44

Subthalamic nucleus

Answer 44

Nucleus located ventral to the thalamus, an important part of the subcortical motor system that includes the basal ganglia, a target of deep-brain stimulation for treatment of Parkinson's disease.

Question 45

Direct pathway (in basal ganglia)

Answer 45

Pathway that includes the caudate nucleus and putamen, the internal division of the globus pallidus, and ventral anterior/ventrolateral thalamic nuclei; has an excitatory effect on movement.

Question 46

Indirect pathway (in basal ganglia)

Answer 46

Pathway that includes the caudate nucleus and putamen, the external division of the globus pallidus, the subthalamic nucleus, the internal division of the globus pallidus, and the ventral interior/ventrolateral thalamic nuclei; has an inhibitory effect on movement.

Question 47

Hyperdirect pathway

Answer 47

Excitatory pathway from that pre-SMA to the subthalamic nucleus that increases the activity of the GPi and appears to play a role in preventing or quickly stopping movements that are being initiated by the direct pathway.

Question 48

Huntington's disease

Answer 48

Fatal inherited disorder that causes degeneration of the caudate nucleus and putamen; characterized by uncontrollable jerking movements, riveting movements, and dementia.

Question 49

Flocculonodular lobe

Answer 49

Region of the cerebellum; involved in control of postural reflexes.

Question 50

Vermis

Answer 50

Portion of the cerebellum located at the midline; receive somatosensory information and helps to control the vestibulospinal and reticulospinal tracks through its connections with the fastigial nucleus.

Question 51

Interposed nuclei

Answer 51

Set of deep cerebellar nuclei; involved in the control of the rubrospinal system.

Question 52

Pontine nucleus

Answer 52

Large nucleus in the pons that serves as an important source of input to the cerebellum.

Question 53

Dentate nucleus

Answer 53

Deep cerebellar nucleus; involved in the control of rapid, skilled movements by the cortical spinal and rubrospinal systems.

Question 54

Mesencephalic locomotor region

Answer 54

A region of the reticular formation of the midbrain whose stimulation causes alternating movements of the limbs normally seen during locomotion.