An individual with the condition of myasthenia gravis is faced with an autoimmune disorder in which the body defenses attack acetylcholine receptors on muscle cells. What would be the expected effect on calcium levels near contractile proteins, following the arrival of an electrical impulse at those neuromuscular junctions?
A) a rapid decrease in concentration due to uptake by sarcoplasmic reticulum
B) a rapid increase in concentration due to release by sarcoplasmic reticulum
C) small or no increases in concentration due to weak responses by acetylcholine receptors
D) a large decrease in concentration that occurs slowly
E) a large increase in concentration that occurs slowly

Question

Quizplus · Accepted Answer

In myasthenia gravis, the autoimmune attack reduces the number of functional acetylcholine receptors, leading to weak muscle responses and thus small or no increases in calcium concentration near contractile proteins.

An Individual with the Condition of Myasthenia Gravis Is Faced