 acetylcholine (ach, pron. ah-seh-til-ko-leen) is an organic molecule that acts as a neurotransmitter in many organisms, including humans. it is an ester of acetic acid and choline, with chemical formula o()2()3 and systematic name 2-acetoxy-n,n,n-trimethylethanaminium. acetylcholine is one of many neurotransmitters in the autonomic nervous system (ans). it acts on both the peripheral nervous system (pns) and central nervous system (cns) and is the only neurotransmitter used in the motor division of the somatic nervous system. acetylcholine is also the principal neurotransmitter in all autonomic ganglia.  in cardiac tissue acetylcholine neurotransmission has an inhibitory effect, which lowers heart rate. however, acetylcholine also behaves as an excitatory neurotransmitter at neuromuscular junctions in skeletal muscle.{{cite book|title=biology|year=2002|publisher=pearson education, inc.|location=san francisco, ca|isbn=0-8053-6624-5|pages=1037|author=campbell, n. a.|edition=6t
Acetate_esters Acetylcholine Choline_esters Quaternary_ammonium_compounds