acetylcholín

Acetylcholine is a neurotransmitter, a chemical messenger that transmits signals between nerve cells and also between nerve cells and muscles or glands. It is a vital component of the parasympathetic nervous system, which controls functions like digestion, heart rate, and pupil constriction. Acetylcholine plays a crucial role in various bodily processes, including muscle contraction, memory formation, and learning. It is synthesized in the presynaptic neuron from choline and acetyl-CoA. Once released into the synaptic cleft, acetylcholine binds to specific receptors on the postsynaptic membrane, triggering a response. There are two main types of acetylcholine receptors: nicotinic and muscarinic. Nicotinic receptors are found in the neuromuscular junction, where they mediate muscle contraction, and also in the central nervous system. Muscarinic receptors are primarily located in the parasympathetic nervous system and the central nervous system, influencing a wide range of physiological functions. The action of acetylcholine is terminated by an enzyme called acetylcholinesterase, which breaks it down into choline and acetic acid, allowing the nerve cell to reset for the next signal. Disruptions in acetylcholine signaling are implicated in various neurological and neuromuscular disorders, such as Alzheimer's disease and myasthenia gravis.