Exam 3 Review:  Chapter 10:  Muscle Actions 

muscle functional group - A set of skeletal muscles located in the same general area and which contribute to the same general set of actions in the movement of a specific body part or parts; each muscle in the set is separated from the next by its epimysium while the entire set is surrounded by a layer of deep fascia.

prime mover = agonist - The principle muscle within a muscle functional group which causes a particular or specified movement.

agonist - (1) The muscle which provides the major force for a particular movement.  (2) A drug, neurotransmitter, hormone or other chemical which can combine with a receptor on a cell to produce or enhance a physiologic reaction in the target cell.

antagonist - (1) The muscle(s) which oppose or reverse a particular movement.  (2) A drug, neurotransmitter, hormone or other chemical substance which interferes with the physiological action of another chemical, especially by combining with and blocking a nerve or effector receptor.

synergist - Any muscle(s) which assist(s) the prime mover muscle in its movement.

fixator - The muscle(s) which contribute to a particular movement by contracting so that the origin of the prime mover muscle providing the major force for the particular movement is immobilized; this action stabilizes a joint supporting the prime mover/agonist when it contracts.

For more information on functional relationships among muscles, visit synergies.

List:

1. Four general functional types or categories of skeletal muscle group actions, i.e., the four different functional roles a skeletal muscle can play within its group, depending on the particular action/movement of the group.

          prime mover = agonist, antagonist, synergist, fixator