Agonist

Definition

In the context of anatomy and physiology, an agonist is a muscle that causes or facilitates movement when it contracts, working as the primary mover. It plays a crucial role in the muscular system by interacting with skeletal muscles to produce specific movements.

Related terms

Antagonist: A muscle that opposes the action of an agonist by relaxing or lengthening, helping to regulate or modulate motion.

Synergist: A muscle that assists an agonist by adding extra force to enhance the movement or by reducing undesirable movements.

Neuromuscular junction: The site where a motor neuron communicates with a muscle fiber, triggering muscle contraction and enabling movement