Prime Movers/Agonists
-muscles responsible for producing a particular movement
Anatagonists
muscles that oppose or reverse a movement
Synergists
-aid sthe action of agonists either by assisting with the same movement or by reducing undesirable or unnecessary movement
Fixators
-immobilize the origin of a prime mover so that all the tension is exerted at the insertion
-specialized synergists
Rectus
-any straight muscle
Transverse
- at right angles to the axis
Oblique
- in a slanted position
Maximus
largest
Minimus
smallest
Longus
long
Brevis
short
Deltoid
triangular
Orbicularis Oculi
-muscle of eyelids
ORIGIN: frontal and maxillary bones and ligaments around orbit
INSERTION: encircles orbit and inserts in tissue of the eyelid
ACTION: closes eyes, blinking, squinting
Zygomaticus (major and minor)
-extends diagonally from the corner of mouth to cheekbone
ORIGIN: zygomatic bone
INSERTION: skin and muscle at corner of mouth
ACTION: raises lateral corners of mouth upward (smiling muscle)
Orbicularis Oris
-multilayered muscle of lips with fibers that run in many different directions
Buccinator
-principal muscle of cheek; runs horizontally deep into the masseter