Final answer:
The drug of choice for Myasthenia Gravis is Pyridostigmine, as it prevents the breakdown of acetylcholine, increasing its concentration at the neuromuscular junction and countering the dysfunction caused by autoimmune antibodies blocking acetylcholine receptors on muscle cells.
Step-by-step explanation:
The drug of choice for Myasthenia Gravis (MG) is b) Pyridostigmine. This medication works by inhibiting the breakdown of acetylcholine, thereby increasing the concentration of acetylcholine at the neuromuscular junction and improving nerve signal transmission to muscles. Pyridostigmine is preferred in the treatment of Myasthenia Gravis as it directly addresses the impaired muscle contraction capability caused by the autoimmune destruction of acetylcholine receptors.
In Myasthenia Gravis, the body produces autoantibodies against acetylcholine receptors in the synaptic cleft of neuromuscular junctions, as shown in the given figures. These antibodies block the receptors for acetylcholine on muscle cells, resulting in muscle weakness and fatigue. The symptoms of Myasthenia Gravis can range from eye muscle weakness to difficulty in swallowing and slowed speech, and they may worsen under stress or infection.