<prompt> Which receptors are blocked in Myasthenia Gravis.Ach receptorsCalcium receptorsSodium receptorsOpioid receptors  <response>: Ref. Guyton. 13th edition. Page. 96Myasthenia gravis is an autoimmune disease characterized by autoantibodies against the acetylcholine ACh receptor of the neuromuscular junction, result- ing in muscular weakness predominantly affecting the facial muscles. Females are affected more frequently than males.Extra ocular muscle weakness may lead to ptosis and diplopia; the weakness worsens with repeated contractions.Respiratory muscle involvement may lead to death. There is an association with thymic hyperplasia and thymomas.Treatment is anticholinesterase agents, steroids, and thymectomy. 