The diagnosis of myasthenia gravis when acetylcholine bites the receptors on the muscle cells it causes them to contract and produce movement true or false
The correct answer and explanation is:
False
Explanation:
The statement “when acetylcholine bites the receptors on the muscle cells it causes them to contract and produce movement” accurately describes the normal physiological process at the neuromuscular junction. Acetylcholine (ACh) is a neurotransmitter released by nerve cells. When it binds to (not “bites”) acetylcholine receptors on the surface of muscle fibers, it triggers a series of events that lead to muscle contraction and, consequently, movement. This is how our voluntary muscles work in healthy individuals.
However, the statement is presented in the context of diagnosing myasthenia gravis (MG). Myasthenia gravis is an autoimmune disease where the body’s own immune system attacks and destroys or blocks the acetylcholine receptors on the muscle cells. Because these receptors are damaged or blocked, acetylcholine released by the nerve cannot effectively bind to them and initiate a muscle contraction.
Therefore, in a person with myasthenia gravis, even though acetylcholine is released, it fails to effectively stimulate enough receptors to cause normal muscle contraction. This leads to the characteristic muscle weakness and fatigue seen in MG patients. The diagnosis of myasthenia gravis is based on recognizing this failure of normal neuromuscular transmission – the inability of acetylcholine to cause proper contraction due to receptor issues – not the successful contraction described in the statement. So, while the statement describes normal function, it is false in the context of representing the functional state of the neuromuscular junction in an untreated MG patient, which is what the diagnosis addresses.