A 56-year-old teacher complains to her family physician that she has been having trouble reading and correcting papers, as her eyes quickly become tired; she has also noticed that lately she has had some difficulty swallowing and she has been unable to exercise because she feels “weak.” After a month or so the conditions seem to be worsening, as she is losing strength and control of her skeletal muscles. Discuss: On the basis of the circumstances and the symptoms, discuss the probable disease from which this patient is suffering. Discuss the cause of the disease and its mechanism of action.