Quiz 4: Sidman (Ch 25, 28, & 29)

Question 1

The basal nuclei plays an important role in helping to initiate and terminate _____ movements. The primary function of the basal nuclei is to provide feedback to the _____ to control motor responses.

Answer 1

voluntary; cortex

Question 2

Much of the output of the basal nuclei is funneled through the _____. The basal nuclei _____ the excitatory inputting the cortex. Hyperactivity of the basal nuclei results in _____er movements, whereas lesions of basal nuclei produce _____ movements at rest.

Answer 2

thalamus; reduce; slower; involuntary (excessive)

Question 3

The cerebral _____ and _____ nuclei provide crude motor commands that descend to the brainstem and the spinal cord. Control mechanisms in the _____um, _____stem and _____ cord serve to fine-tune descending pathways to ensure smooth coordinated movement.

Answer 3

cortex; basal; cerebellum; brainstem; spinal cord

Question 4

The basal nuclei and cerebellum control different aspects of _____ activity and are considered together as control circuits. They both receive input from the _____ and send info back to it through the _____.

Answer 4

motor; cortex; thalamus

Question 5

Basal nuclei are concerned with activation and inhibition of _____ commands, whereas the _____um plans and executes coordinated movements, adjusts motor performance, and is involved in learning motor tasks.

Answer 5

motor; cerebellum

Question 6

The cerebellum compares motor commands with actual execution of movement, functioning to detect errors. Cerebellar inputs are sideloops of paths from the motor _____, _____ nuclei, and spinal _____.

Answer 6

cortex, basal, cord

Question 7

Cerebellum receives _____ input from tendons, joints, and auditory, vestibular, and visual systems. The cerebellum receives output from the _____ cortex, _____ nuclei, and _____. Cerebellar efferents descend to exert an inhibitory influence on the pyramidal and _____ pyramidal paths.

Answer 7

sensory; motor; basal; brainstem; extrapyramidal

Question 8

The cerebellum corrects motor performance through output to _____ nuclei via red nucleus, vestibular nuclei, superior colliculus, and reticular formation. The cerebellum also projects to the cortex through the ventral lateral nucleus of the _____.

Answer 8

brainstem; thalamus

Question 9

The motor cortex sends projections to brainstem that run outside the corticospinal (pyramidal) tract to regulate lower motor neurons in the spinal cord. These extrapyramidal paths originate in the red _____ , _____ colliculus, vest_____ nuclei, and reticular formation. All of these areas also receive input from the cerebellum and are involved in the maintenance of posture, muscle tone, and coordination.

Answer 9

nucleus; superior; vestibular

Question 10

Output from the basal nuclei through the thalamus functions to _____ the excitatory input to the motor cortex. Basal nuclei disturbances result in motor disturbances.

Answer 10

reduce

Question 11

There are both direct and indirect connections from the _____ nuclei to the thalamus. The direct pathway modulates the output of the basal nuclei to the _____ _____ to release thalamic inhibition of the cortex. This sequence of events facilitates movement.

Answer 11

basal; globus pallidus

Question 12

The _____ pathway uses the globus pallidus to _____ voluntary movements.

Answer 12

direct; facilitate

Question 13

The indirect pathway involves cortical activation of the basal nuclei, which inhibits the subthalamus. The subthalamus activates the globus pallidus. The global pallidus _____ the thalamus, reducing motor cortical activation.

Answer 13

inhibits

Question 14

The indirect pathway _____ motor cortex, whereas the direct pathway _____ motor cortex.

Answer 14

inhibits; activates

Question 15

Malfunctioning of the basal nuclei results in movement disorders, known as dyskinesias. Dys refers to abnormal, and kinesia refers to _____.

Answer 15

movement

Question 16

Dyskinesias, or abnormal movements, manifest in one of two ways: as either negative or positive symptoms. Negative signs (_____kinetic symptoms) involve the inability of a patient to perform a movement (lack of movement), whereas positive signs (_____kinetic symptoms) evoke unwanted motor activities (excessive movements).

Answer 16

hypokinetic; hyperkinetic

Question 17

Negative signs are characterized by the _____ ability to initiate movement. These signs include akinesia (lack of movement) and bradykinesia (slowness of movement) with increased muscle tone.

Answer 17

impaired

Question 18

Negative signs, or _____ dyskinesia, results from reduced excitation of the direct pathway. Increased inhibition of the _____ reduces motor activity

Answer 18

hypokinetic; thalamus

Question 19

Positive signs are characterized by excessive involuntary movements and reduced muscle tone, resulting from diminished activation of the _____ pathway.

Answer 19

indirect

Question 20

Reduced inhibition of the thalamus leads to _____ motor activity, characteristic of _____kinetic dyskinesias.

Answer 20

excessive; hyperkinetic

Question 21

Note that dyskinesia is not equivalent to paralysis (muscle _____) or apraxia (inability to plan a _____), which are cortical problems.

Answer 21

weakness; movement

Question 22

Hypokinetic dyskinesias involve _____ of movement, whereas hyperkinetic dyskinesias are characterized by _____ movement.

Answer 22

lack; excessive

Question 23

Parkinson’s disease is a _____kinetic movement disorder in which patients exhibit resting tremor, muscle rigidity, and bradykinesia.

Answer 23

hypokinetic

Question 24

In Parkinson’s disease, substantia nigral neurons degenerate, producing less dopamine. This affects both the direct and _____ paths of the basal nuclei. Replacement therapy involves administering the dopamine precursor, L-DOPA, to patients. Dopamine is ineffective when administered exogenously because it cannot cross the blood-_____ barrier.

Answer 24

indirect; brain

Question 25

Huntington’s chorea is an example of a _____kinetic dyskinesia. Chorea literally means “to dance,” and these patients exhibit uncontrolled dance-like movements of the limbs.

Answer 25

hyperkinetic

Question 26

Huntington’s chorea affects the striatum, whereas Parkinson’s disease targets the _____ _____.

Answer 26

substantia nigra

Question 27

Like Huntington’s chorea, hemiballism is a _____kinetic disorder of the basal nuclei. Patients with hemiballismus often suffer from subthalamic nuclear stroke and exhibit b_____istic movements of the limbs.

Answer 27

hyperkinetic; ballistic

Question 28

Damage to the subthalamic nucleus results in _____ of the contralateral extremities. The subthalamic nucleus reduces _____ output of the globus pallidus, facilitating thalamic activation of the motor cortex.

Answer 28

hemiballismus; inhibitory

Question 29

Athetosis is similar to chorea, except the aberrant movements of the extremities are slow and writhing rather than _____. Like other dyskinesias, athetosis is caused by a lesion of the basal _____.

Answer 29

ballistic; nuclei

Question 30

Dystonia is a variant of athe_____ and involves sustained muscle contractions of the limbs, trunk, and neck, resulting in abnormal posture.

Answer 30

athetosis

Question 31

Tardive dyskinesia primarily affects muscles of the tongue and face. It differs from other dyskinesias in that it is not induced by lesions but, instead, by antipsychotic drugs that block dop_____ transmission.

Answer 31

dopamine

Question 32

Match the appropriate classification on the right with the pathologies listed on the left.
A. Hyperkinetic disorder
B. Hypokinetic disorder

_____ Hemiballism
_____ Parkinson’s disease
_____ Athetosis
_____ Tardive dyskinesia
_____ Huntington’s disease

Answer 32

A. Hemiballism
B. Parkinson’s disease
A. Athetosis
A. Tardive dyskinesia
A. Huntington’s disease