Myasthenia gravis is caused by a disruption in the communication between nerves and muscles.
Essentially, myasthenia gravis is an autoimmune disease where the body's immune system mistakenly attacks the neuromuscular junction. This is where nerve cells (neurons) communicate with the muscles they control. This attack disrupts the normal transmission of nerve signals to muscles, leading to muscle weakness and fatigue.
Here's a more detailed breakdown:
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The Neuromuscular Junction: This is the point where a nerve ending meets a muscle fiber.
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Acetylcholine: When a nerve impulse reaches the neuromuscular junction, the nerve releases a neurotransmitter called acetylcholine.
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Acetylcholine Receptors: Acetylcholine travels across the junction and binds to acetylcholine receptors on the muscle fiber. This binding triggers muscle contraction.
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The Problem in Myasthenia Gravis: In myasthenia gravis, the immune system produces antibodies that block, alter, or destroy the acetylcholine receptors at the neuromuscular junction. This prevents acetylcholine from effectively binding to the receptors and triggering muscle contraction.
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Resulting Muscle Weakness: Because of the reduced number of available acetylcholine receptors or their impaired function, muscles receive fewer signals, resulting in weakness and fatigue that worsen with activity and improve with rest.
Therefore, the root cause of myasthenia gravis is an autoimmune attack on the acetylcholine receptors at the neuromuscular junction, hindering nerve-muscle communication.
