What is primarily affected by myasthenia gravis?

Myasthenia gravis primarily affects the neuromuscular junction, which is the site of communication between nerve cells and skeletal muscles. This autoimmune disorder leads to the production of antibodies that block or destroy the nicotinic acetylcholine receptors at the neuromuscular junction. As a result, the transmission of nerve impulses to the muscles is impaired, leading to weakness and fatigue of voluntary muscles, particularly those involved in activities such as moving the eyes, chewing, swallowing, and breathing.

Although skeletal muscle is involved because it is what becomes weak, the essential problem lies specifically at the neuromuscular junction. The central nervous system and cardiac muscle are not primarily affected by myasthenia gravis; the condition does not originate there and does not alter the functions of those systems in the same way it does with skeletal muscle. Understanding this distinction helps clarify the mechanisms of the disease and how it manifests in symptoms.