NPTE-PT Neuromuscular and Nervous Systems 5

Question 1

Which neurotransmitter is deficient in myasthenia gravis and what is the mechanism of dysfunction?

Accepted Answer

Acetylcholine; autoimmune destruction of nicotinic receptors

Answer

Myasthenia gravis is caused by autoimmune antibodies against nicotinic acetylcholine receptors at the neuromuscular junction, reducing functional receptor availability.

Question 2

A patient presents with a 'claw hand' deformity with hyperextension at the MCP joints and flexion at the IP joints of the ring and small fingers. Which nerve is injured?

Accepted Answer

Ulnar nerve

Answer

Ulnar nerve injury causes claw hand of the ring and small fingers due to loss of intrinsic muscle function (lumbricals 3 and 4), resulting in unopposed extrinsic extensor and flexor forces.

Question 3

During the swing phase of gait, which muscle group is primarily responsible for foot clearance?

Accepted Answer

Ankle dorsiflexors

Answer

Ankle dorsiflexors (primarily tibialis anterior) lift the foot during swing phase to ensure clearance; weakness results in foot drop and compensatory circumduction or hip hiking.

Question 4

Which of the following is a characteristic feature of Guillain-Barré syndrome (GBS)?

Accepted Answer

Ascending motor weakness with areflexia

Answer

GBS is an acute demyelinating polyneuropathy characterized by ascending, typically symmetric motor weakness and areflexia, often following a respiratory or GI infection.

Question 5

A physical therapist is using PNF techniques with a patient post-stroke. Which PNF technique involves alternating isometric contractions of agonist and antagonist without joint movement?

Accepted Answer

Rhythmic stabilization

Answer

Rhythmic stabilization involves alternating isometric contractions of opposing muscle groups to improve stability, motor control, and cocontractions without movement.

NPTE-PT Test Practice Test

NPTE-PT Test Practice Test

NPTE-PT Neuromuscular and Nervous Systems 5