Basal Ganglia: Direct and Indirect Pathways

Question 1

The following structures are components of the direct pathway EXCEPT:

a. Ventral anterior nucleus
b. Globus pallidus externus
c. Putamen
d. Globus pallidus internus

Answer 1

b. Globus pallidus externus

Question 2

Which neurotransmitter helps in modulating the indirect and direct pathways?

a. Dopamine
b. Norepinephrine
c. Glutamate
d. GABA

Answer 2

a. Dopamine

Question 3

The caudate nucleus and putamen are collectively called what?

a. Lentiform nucleus
b. Pars reticularis
c. Striatum
d. Subthalamic nucleus

Answer 3

Striatum

Question 4

In the direct pathway, the globus pallidus internus releases less [neurotransmitter] to the [structure] resulting to its [stimulation/inhibition].

a. Glutamate, globus pallidus externus, inhibition

b. GABA, globus pallidus externus, stimulation

c. Glutamate, thalamus, inhibition

d. GABA, thalamus, stimulation

Answer 4

d. GABA, thalamus, stimulation

Question 5

In the indirect pathway, the striatum releases [neurotransmitter], which [stimulates/inhibits] the [structure].

a. GABA, inhibits, subthalamic nucleus

b. Glutamate, stimulates, subthalamic nucleus

c. GABA, inhibits, globus pallidus externus

d. Glutamate, stimulates, globus pallidus externus

Answer 5

c. GABA, inhibits, globus pallidus externus

Question 6

What is the primary function of the basal ganglia in the brain?

Answer 6

The basal ganglia are involved in motor control, cognition, and emotion.

Question 7

Name two key structures within the basal ganglia.

Answer 7

The striatum (caudate nucleus and putamen) and the globus pallidus are key structures within the basal ganglia.

Question 8

Which neurotransmitter is primarily involved in the direct motor pathway?

Answer 8

The direct motor pathway primarily involves the neurotransmitter dopamine.

Question 9

What is the role of the direct motor pathway in motor control?

Answer 9

The direct motor pathway facilitates voluntary movement and helps initiate and maintain motion.

Question 10

Which neurotransmitter is primarily involved in the indirect motor pathway?

Answer 10

The indirect motor pathway primarily involves the neurotransmitter gamma-aminobutyric acid (GABA).

Question 11

How does the indirect motor pathway influence movement?

Answer 11

The indirect motor pathway inhibits unwanted or inappropriate movements, helping to refine and control motor output.

Question 12

What is the primary function of the direct motor pathway?

Answer 12

The primary function of the direct motor pathway is to facilitate the initiation and execution of voluntary movement.

Question 13

Describe the role of dopamine in the basal ganglia and its impact on the direct and indirect pathways.

Answer 13

Dopamine plays a crucial role in modulating the activity of the direct and indirect pathways. It enhances the function of the direct pathway while inhibiting the indirect pathway, promoting smooth and coordinated movement.

Question 14

Which neurological disorders are associated with dysfunction in the basal ganglia?

Answer 14

Parkinson’s disease, Huntington’s disease, and dystonia are examples of neurological disorders associated with basal ganglia dysfunction.

Question 15

How do the direct and indirect motor pathways interact to regulate movement?

Answer 15

The direct and indirect pathways work in concert to regulate movement. The direct pathway facilitates desired movements, while the indirect pathway inhibits unwanted movements, ensuring that motor output is refined and controlled.

Question 16

A person suffered a CVA (stroke) and now has difficulty moving her right arm, and she also has speech problems. What areas of the brain were damaged by the stroke?

A) Right parietal lobe
B) Left parietal lobe
C) Left frontal lobe
D) Right frontal lobe

Answer 16

C) Left frontal lobe

Damage to the left frontal lobe can lead to weakness or paralysis on the right side of the body (contralateral motor impairment) and speech problems, which are common symptoms of a stroke affecting the left hemisphere.

Question 17

How will a doctor determine whether a patient with facial paralysis is due to lesion to upper motor neuron (stroke) or lower motor neuron (CN VII: facial nerve)? Is it a stroke or facial nerve paralysis (Bell’s palsy)?

Answer 17

**NO FORHEAD MOVEMENT=FACIAL NERVE=BELLS PALSY

Upper Motor Neuron (UMN) Lesion (Stroke):
Typically, only the lower half of the face is affected.
Forehead muscle movement is often preserved due to bilateral cortical innervation.
There may be associated weakness or paralysis of the limbs on the opposite side of the body (contralateral hemiparesis).
Other signs of a stroke may be present, such as speech difficulties, sensory changes, or visual disturbances.

Lower Motor Neuron (LMN) Lesion (Facial Nerve Paralysis/Bell’s Palsy):
Usually, the entire half of the face is affected, including the forehead.
There may be a history of a viral infection (Bell’s palsy is often preceded by a viral illness).
Absence of other signs of stroke, such as limb weakness or sensory deficits.

Question 18

Inhibitory signals in sequence will “cancel out” and allow
activation if there are ______ in sequence:
A) An odd number
B) An even number
C) More than one

Answer 18

Inhibitory signals cancel out and allow activation if there are:

A) An odd number

When inhibitory signals are in sequence, an odd number of them will cancel out, allowing activation to occur. If there is an even number of inhibitory signals in sequence, they will not cancel out, and the overall effect will be inhibition.