Deck 9: Sensory Receptors and the Peripheral Nervous System

Question 1

Lesions rostral to the red nucleus result in which of the following?

A) Lower extremity weakness
B) Upper limb flexion and lower limb extension
C) Loss of pain and temperature sensation
D) Deviation of the tongue on protrusion
E) Weakness of the masticatory muscles

Answer 1

B

Question 2

A 58-year-old woman complains of left hand weakness that she noticed while planting flowers in her garden. Neurological examination indicates weak wrist and finger flexion and extension. She also has weakness when abducting, adducting, and opposing her thumb. All other motor and sensory tests are normal. The combined deficits in this patient can most accurately be attributed to a lesion in which of the following?

A) Left precentral gyrus
B) Left postcentral gyrus
C) Right postcentral gyrus
D) Right precentral gyrus
E) Superior frontal gyrus

Answer 2

D

Question 3

A 24-year-old woman is brought to the emergency department from the scene of a motor vehicle collision. A neurological examination reveals that her tongue deviates to the left on protrusion and that she is unable to raise the right corner of her mouth when asked to smile. In addition, she is unable to move the entire right side of her body. Which of the following represents the most likely location of a lesion?

A) Right anterior limb of the internal capsule
B) Pontine tegmentum
C) Left posterior limb of the internal capsule
D) Right precentral gyrus
E) Pyramidal decussation

Answer 3

C

Question 4

A 32-year-old woman visits her dermatologist several days before her wedding for botulinum toxin injections around her eyes. What effect does this toxin have on the neuromuscular junction?

A) Blocks release of acetylcholine
B) Stimulates muscarinic cholinergic receptors
C) Depletes norepinephrine
D) Enhances release of acetylcholine esterase
E) Stimulates nicotinic cholinergic receptors

Question 5

A 53-year-old man complains to his family physician of cramping, twitching, and weakness in his lower limbs. The man states that the weakness in his lower limbs has progressively worsened over the past 4 months, making it difficult for him to climb stairs and stand from a seated position. He has also begun to notice that his upper limbs have become weak. What is the most likely cause of this patient's weakness?

A) Myasthenia gravis
B) Syringomyelia
C) Charcot-Marie Tooth disease
D) Spinocerebellar ataxia
E) Amyotrophic lateral sclerosis

Question 6

A 35-year-old roofer is examined in the emergency department after falling two stories and landing abdomen first on a barrel. Examination reveals weakness and loss of pain and temperature sensation in the left and right lower limbs. A magnetic resonance image indicates thrombosis of an artery in the abdomen. Which of the following arteries is most likely involved?

A) Anterior spinal
B) Abdominal aorta
C) Anterior radicular
D) Posterior spinal
E) Posterior radicular

Question 7

A 52-year-old woman unable to move her left leg visits your office. Sensory modalities in all of her limbs are retained and there appears to be no sign of weakness in any of her other limbs. In which of the following structures are the cell bodies of lower motor neurons innervating the lower limb located?

A) Lamina I-VI
B) Lamina VIII, IX
C) Lamina X
D) Lamina I, II
E) Lamina III, IV