1.
The cranial motor nuclei which receive innervation only from the contralateral corticobular tract are:
Correct Answer
C. Facial and hypoglossal
Explanation
The cranial motor nuclei that receive innervation only from the contralateral corticobular tract are the facial and hypoglossal nuclei. The trigeminal and vagus nuclei receive innervation from both ipsilateral and contralateral corticobular tracts. The vagus and glossopharyngeal nuclei receive innervation from both ipsilateral and contralateral corticobular tracts. The facial and glossopharyngeal nuclei receive innervation from both ipsilateral and contralateral corticobular tracts.
2.
Lesion of lateral column will lead to the following motor deficit:
Correct Answer
A. Paralysis of fine movement muscles on the same side of the lesion
Explanation
A lesion of the lateral column refers to damage or injury to the lateral column of the spinal cord. The lateral column contains motor fibers that control voluntary movements of the body. Therefore, if there is a lesion in this area, it will result in paralysis of the fine movement muscles on the same side of the lesion. This means that the muscles responsible for precise and delicate movements on the same side as the lesion will be unable to function properly.
3.
Regarding the difference between pyramidal and extrapyramidal tracts, which is true:
Correct Answer
C. Pyramidal functions later on in life
Explanation
The statement "pyramidal functions later on in life" is the correct answer because it accurately reflects the difference between pyramidal and extrapyramidal tracts. The pyramidal pathway, which involves the corticospinal tract, is responsible for voluntary motor movements and develops later in life. In contrast, the extrapyramidal tracts are involved in involuntary movements and are present from birth. The other options in the question are not accurate explanations of the difference between the two tracts.
4.
Functions of the Extrapyramidal system include all of the following except:
Correct Answer
D. Type writing
Explanation
The extrapyramidal system is responsible for controlling muscle tone, swinging of the arms during walking, and maintaining posture and equilibrium. However, it is not involved in the specific motor skills required for typing, such as fine motor control and coordination of finger movements. Therefore, the correct answer is type writing.
5.
Stroke of precentral gyrus will cause:
Correct Answer
B. Loss of fine movements
Explanation
A stroke affecting the precentral gyrus, which is responsible for motor control, can result in the loss of fine movements. This is because the precentral gyrus contains the primary motor cortex, which controls voluntary movements of the body. When damaged, it can lead to difficulties in executing precise and coordinated movements, such as writing, buttoning a shirt, or picking up small objects. Other symptoms of a stroke in this area may include weakness or paralysis on one side of the body, difficulty with speech or swallowing, and changes in muscle tone.
6.
Primary motor area (area 4) characterized by all of the following except:
Correct Answer
B. Cortical representation of any part of the body in area 4 is directly proportional to its size
Explanation
The primary motor area (area 4) is characterized by the following: the body is represented in an inverted manner, it is an area of high excitability, and it facilitates the spinal reflexes such as the stretch reflex. However, the cortical representation of any part of the body in area 4 is not directly proportional to its size.
7.
Premotor area 6, which is false:
Correct Answer
D. Shares together with the cerebellum in initiation of automatic associated involuntary movements
Explanation
The premotor area 6 is not involved in the initiation of automatic associated involuntary movements. This area is actually involved in the selection of appropriate motor plans for voluntary movements. It is responsible for planning and organizing movements, rather than controlling involuntary movements.