Roles and
Actions
Actions
The principal muscle that provides the primary force for a specific action.
What is the prime mover (or agonist)?
The bundle of skeletal muscle fibers wrapped together inside a muscle.
What is a fascicle?
The Latin root meaning "away from" in muscle actions like abduction.
What is ab?
The buttock muscle whose name tells you it is the largest in its group.
What is the gluteus maximus?
The fixed pivot point in a lever system, represented by synovial joints in the body.
What is the fulcrum?
A muscle that opposes or reverses the movement of the prime mover.
What is the antagonist?
The connective tissue layer that directly encloses an entire skeletal muscle.
What is the epimysium?
The Greek root tri-, indicating how many origins the triceps brachii has.
What is three?
The muscle named for covering the frontal bone of the skull.
What is the frontalis?
The tissue connecting muscle to bone that transfers tension to move the skeleton.
What is a tendon?
A muscle that assists the prime mover by adding extra force or stabilizing a bone.
What is a synergist (or fixator)?
A feather-shaped fascicle arrangement where fibers attach obliquely to a central tendon.
What is a pennate muscle?
The Latin root rectus, which describes muscle fibers arranged this way.
What is straight?
In a muscle named after its attachment points, this attachment site is always stated first.
What is the origin?
The viscous fluid with the consistency of egg whites that lubricates synovial joints.
What is synovial fluid?
The attachment point of the movable end of a muscle that pulls during contraction.
What is the insertion?
A spindle-shaped muscle with a large central belly that tapers toward both ends.
What is a fusiform muscle?
The Latin root brevis, indicating this physical dimension of a muscle.
What is short?
The triangular shoulder muscle named after a Greek letter that shares its shape.
What is the deltoid?
In anatomical lever mechanics, this component is supplied by the contracting skeletal muscle.
What is the effort (or applied force)?
The functional role played by an antagonist when holding a limb still or checking rapid motion (such as shadow boxing).
What is maintaining posture/position or controlling rapid movement?
The circular muscle arrangement around body openings, also known by this functional name.
What is a sphincter?
The Latin root ductor, which provides this functional meaning in a muscle name.
What is something that moves (or to move)?
The neck muscle named for its two origins on the chest/collarbone and its insertion behind the ear.
What is the sternocleidomastoid?
An exception to skeletal levers: the internal dome-shaped muscle that changes thoracic volume without moving bones.
What is the diaphragm?