What is the impact of myasthenia gravis on muscle function?

Myasthenia gravis is an autoimmune neuromuscular disorder characterized by weaknesses in the skeletal muscles, which are responsible for voluntary movements. The condition primarily affects the communication between the nerves and the muscles. Specifically, antibodies produced by the immune system mistakenly attack the acetylcholine receptors at the neuromuscular junction, where nerve cells communicate with muscles. This disruption leads to reduced transmission of nerve signals to the muscle fibers, resulting in muscle weakness.

The impact of this impairment is particularly noticeable during repetitive movements or after prolonged activity, as the muscles may become increasingly weak with continued use. Therefore, the primary effect of myasthenia gravis is the impairment of communication between nerves and muscles, leading to fluctuating muscle weakness and fatigue, especially in the eyes, face, throat, and limb muscles, rather than strengthening or involuntary contraction of muscles, stiffness, or rigidity.