In which condition is muscle weakness and fatigability primarily due to destruction of acetylcholine receptors?

Myasthenia gravis is characterized by muscle weakness and fatigability primarily due to the autoimmune destruction of acetylcholine receptors at the neuromuscular junction. In this condition, the body's immune system produces antibodies that block or destroy these receptors, leading to impaired transmission of nerve impulses to the muscles. This results in significant weakness, particularly in skeletal muscles that control eye and eyelid movements, facial expressions, and swallowing. Symptoms may worsen with activity and improve with rest, which is a classic hallmark of the disorder. Understanding this pathophysiology is crucial for recognizing and managing myasthenia gravis effectively.