In the disease myasthenia gravis, the body produces antibodies against receptors for acetylcholine (ACh). As a result, not all ACh can find a receptor. Based on your knowledge of how muscle contraction occurs, what key symptoms would you expect to see and why?

Question

Quizplus · Accepted Answer

Muscle contraction occurs when ACh binds to its receptor, triggering an influx of calcium ions and resulting in muscle fiber contraction. In myasthenia gravis, not all ACh can find a receptor due to the antibodies against the receptors. Therefore, there is poor nerve transmission and weakness in the muscles. Paralysis (A) would occur if none of the ACh could bind to receptors, and tetany (B) would occur if there was excessive firing of the muscle fiber. Muscle spasms (D) would not occur because ACh does not irritate receiving nerves, it is the buildup of lactic acid that causes spasms.

In the Disease Myasthenia Gravis, the Body Produces Antibodies Against