MUSCULAR (HEAD AND NECK)

• MINIMAL/LIMINAL (THRESHOLD) - a smallest amount of stimulus • enough to produce a muscle twitch (a single recordable muscle contraction)
• FRONTALIS - draws scalp anteriorly, raises eyebrows, wrinkling of the forehead horizontally
• Orbicularis Oculi - closes the eyelids, causes the crowsfeet (a name for wrinkles in the outer corner of the eyes as the result of aging)
• ZYGOMATICUS -draws the angle of the mouth upward and outward, as in smiling and laughing
• RISORIUS - draws the angle of the mouth laterally as in sarcastic smile
• BUCCINATOR - major cheek muscle, blowing or kissing (trumpeter’s muscle) muscle, compresses the cheeks as in suckling.
• LEVATOR LABII SUPERIORIS - elevates upper lip
• DEPRESSOR LABII INFERIORIS - depresses lower lip
• DEPRESSOR ANGULI ORIS - depresses angle of the mouth
• MENTALIS - elevates and protrudes lower lip
• ORBICULARIS ORIS - closes lips, protrudes lips, shaped the lips during
• LEVATOR PALPEBRAE ORIS - speech, compresses the lips against teeth
• CORRUGATOR SUPERCILII - elevates the upper eyelid, opens the eye draws the eyebrows inferiorly
• FRONTALIS - raises eyebrow, wrinkles forehead