acetylcholine
Meaning of acetylcholine: Acetylcholine is a neurotransmitter that relays signals across synapses to nerve, muscle, and gland cells, supporting memory and muscle contraction.
Definition of acetylcholine
Acetylcholine is a chemical messenger, or neurotransmitter, released by certain nerve cells to communicate with other cells across a synapse, the small gap separating a nerve ending from the cell it signals. Target cells include other nerve cells, muscle cells, and gland cells, each responding to acetylcholine in a way suited to its own function.
At the junction between nerve and skeletal muscle, acetylcholine release triggers muscle contraction, making it essential to voluntary movement. Elsewhere in the body, acetylcholine helps regulate involuntary functions carried out by the parasympathetic nervous system, including digestion and heart rate, and it also plays a role in memory and attention within the brain.
Because acetylcholine acts at so many different sites, medications that increase, block, or otherwise alter its activity can affect movement, digestive function, heart rate, or cognitive function, depending on where in the body the medication has its main effect.
Used in a sentence
Medication affecting acetylcholine activity was considered given the patient's muscle weakness pattern.
Good to know
Acetylcholine's effects differ sharply depending on location, since the same chemical stimulates skeletal muscle contraction while slowing the heart rate through its action on the parasympathetic nervous system.
Word origin
Where “acetylcholine” comes from
Formed from acetyl, referring to the acetic acid group attached to the molecule, and choline, from Greek chole, meaning bile, since choline was first identified in bile.