The Probert Encyclopaedia of Medicine

ACETYLCHOLINE

Acetylcholine (Ach) is a chemical that serves as a neurotransmitter, communicating nerve impulses between the cells of the nervous system. It is largely associated with the transmission of impulses across the synapse between nerve and muscle cells, causing the muscles to contract. ACh is produced in the synaptic knob and stored in vesicles until a nerve impulse triggers its discharge across the synapse. When the ACh reaches the membrane of the receiving cell it binds with a specific site and brings about depolarisation - a reversal of the electric charge on either side of the membrane causing a fresh impulse in nerve cells or a contraction in muscle cells. Its action is short-lived because it is quickly destroyed by the enzyme cholinesterase. Anticholinergic drugs have a number of uses in medicine to block the action of ACh, thereby disrupting the passage of nerve impulses and relaxing certain muscles, for example in premedication before surgery.
Research Acetylcholine