Illustration of a how a neuromuscular synapse functions in a healthy person (top) : Acetylcholine attaches to receptors and information (nerve impulse) is sent to the muscle cell which contracts. At the bottom, neuromuscular synapse function in a person suffering from myasthenia (neuromusculaire disease which leads to muscle weakness and fatigability) : there are less acetylcholine receptors and the synaptic cleft structure is modified. The body produces antibodies which latch on to the receptors instead of the acetylcholine doing so and, as a result, the nerve impulse doesn't take place and the muscle cell cannot contract.