characteristics used to name muscles

• directional terms used to describe orientation of muscle fibers to body midline

  • rectus - parallel to midline

  • transverse - perpendicular to midline

  • oblique - diagonal to midline

• size - relative size of the muscle

  • maximus - largest

  • minimus - smallest

  • longus - long

  • brevis - short

  • latissimus - widest

  • longissimus - longest

  • magnus - large

  • major - larger

  • minor - smaller

  • vastus - great

• shape - relative shape of the muscle

  • deltoid- triangular

  • trapezius - trapezoid

  • serratus - saw-toothed

  • rhomboideus - diamond shaped

  • orbicularis - circular

  • pectinate - comb like

  • piriformis - pear shaped

  • platys - flat

  • quadratus - square

  • gracilis - slender

• action

  • flexor - decreases joint angle

  • extensor - increases joint angle

  • abductor - moves bone away from midline

  • adductor - moves bone toward midline

  • levator - produces superior movement

  • depressor - produces inferior movement

  • supinator - turns palm superiorly or anteriorly

  • pronator - turns palm inferiorly or posteriorly

  • sphincter - decreases size of opening

  • tensor - makes a body part rigid

  • rotator - moves bone around longitudinal axis

• number of origins

  • biceps - two origins

  • triceps - three origins

  • quadriceps - four origins

• location

  • ex frontalis

• origin and insertion

  • ex sternocleidomastoid

important terms of muscle action

• origin

• insertion

• agonist or prime mover

• synergist

• antagonist

muscles of facial expression

• epicranius

  • frontalis and occipitalis

• orbicularis oculi (eye)

• orbicularis oris (mouth)

• buccinator (moves the mandible, purses the lips)

• zygomaticus

  • major and minor

• platysma