Patho Patho #57

Question

How does the nurse describe the pathophysiology of myasthenia gravis?

Answers

  1. A chronic, degenerative neuromuscular disorder caused by antibodies produced by the thymus.
    • Rationale:

      This answer is correct because myasthenia gravis is a disorder that affects the neuromuscular junction. Autoantibodies produced by the thymus attack acetylcholine receptors leading to progressive muscle weakness.

  2. An acute neuromuscular syndrome which causes muscle paralysis with intact cognitive abilities.
    • Rationale:

      This answer choice is not correct because myasthenia gravis is a chronic, not an acute disorder of the neuromuscular system.

  3. A chronic, neurological disorder caused by decreased response to the hormone dopamine.
    • Rationale:

      This answer choice is not correct because the chronic neurological disorder that occurs due to decreased dopamine production/ decreased response to dopamine describes Parkinson rather than myasthenia gravis.

  4. An autoimmune disorder characterized by extreme psychosis and choreiform movements.
    • Rationale:

      This answer choice is not correct because myasthenia gravis is a chronic neuromuscular disorder. There is no associated psychosis or choreiform movements associated with myasthenia gravis.

Overview

The focus of this question is asking the nurse to identify the underlying pathophysiology of myasthenia gravis. Myasthenia gravis is a chronic disorder of the neuromuscular system which causes progressive, descending muscle weakness. Autoantibodies produced by the thymus attack the acetylcholine receptors at the neuromuscular junctions in clients with myasthenia gravis.

Explanation

Learning Outcomes

Myasthenia gravis is an autoimmune disorder in which autoantibodies produced by the thymus attack acetylcholine receptors at the neuromuscular junction. These autoantibodies lead to progressive, descending muscle weakness, and in extreme cases, muscle paralysis. Myasthenic crisis affects the diaphragm and can lead to respiratory failure in affected clients.

Test Taking Tip

Cholinesterase inhibitors such as pyridostigmine and neostigmine are given to clients with myasthenia gravis to enhance communication at the neuromuscular junction.

Video Rationale