8.2 Brain Mechanisms of Movement

Question 1

Primary motor cortex

Answer 1

The precentral gyrus of the frontal cortex, just anterior to the central sulcus; can elicit movements

Question 2

Posterior parietal cortex

Answer 2

Some neurons respond primarily to visual or somatosensory stimuli, Somers fun mostly to current or future movements, and some respond to complicating make sure of the stimulus and the upcoming response; Keeps track of the position of the body relative to the world

Question 3

Prefrontal cortex

Answer 3

Responds mostly to the sensory signals that lead to movement

Question 4

Premotor cortex

Answer 4

Most active during preparations for a movement and less active during the movement itself; response to sensory stimuli, especially to visual stimuli from objects near the hands for the face

Question 5

Supplementary motor cortex

Answer 5

Most active during preparations for a rapid series of movements

Question 6

Dorsolateral tract

Answer 6

The part of the spinal cord that has a set of axons from the primary motor cortex and surrounding areas and from the red nucleus of the midbrain

Question 7

Pyramids

Answer 7

The bulges of the medulla; where the dorsolateral tract crosses from one side of the brain it’s the opposite side of the spinal cord

Question 8

Ventromedial tract

Answer 8

Includes many axons from the primary motor cortex and supplementary motor cortex and also some from many other parts of the cortex; also includes axons that originate from the midbrain tectum, the reticular formation, and the vestibular nucleus; Controls mainly the muscles of the neck, shoulders, and trunk; these movements are necessarily bilateral

Question 9

Vestibular nucleus

Answer 9

The brain area receiving input from the vestibular system

Question 10

Cerebellum

Answer 10

Important for motor control, including learned motor sponsors; contains more neurons than the rest of the brain combined

Question 11

Saccades

Answer 11

Ballistic I movements from one fixation point to another

Question 12

Cerebellar cortex

Answer 12

The surface of the cerebellum

Question 13

Purkinje cells

Answer 13

Very flat cells and sequential planes; found in the cerebellar cortex

Question 14

Parallel fibers

Answer 14

Axons parallel to one another but perpendicular to the planes of the Purkinje cells

Question 15

Nuclei of the cerebellum

Answer 15

Clusters of cell bodies in the interior of the cerebellum

Question 16

Basal ganglia

Answer 16

Applies collectively to a group of large subcortical structures in the forebrain; Includes the caudate nucleus, the putamen, and the globus pallidus; Important for habit learning; active in selecting which response to make or inhibit

Question 17

Caudate nucleus and putamen

Answer 17

Receptive areas; receiving input from sensory areas of the thalamus and the cerebral cortex

Question 18

Globus pallidus

Answer 18

The output area; sends information to the thalamus, which in turn sends it to the motor cortex and the prefrontal cortex