Name the muscle that may cause the following facial expression and write down its origin, insertion, and action.
-
Platysma
-
Origin: Fascia over deltoid and pectoralis major muscles.
-
Insertion: Mandible, blends with muscles around angle of mouth, and skin of lower face.
-
Action: Draws outer part of lower lip inferiorly and posteriorly as in pouting; depresses mandible.
-
-
Mentalis
-
Origin: Mandible.
-
Insertion: Skin of chin.
-
Action: Elevates and protrudes lower lip and pulls skin of chin up, as in pouting.
-
-
Orbicularis oris
-
Origin: Muscle fibers surrounding opening of mouth.
-
Insertion: Skin at corner of mouth.
-
Action: Closes and protrudes lips, as in kissing; compresses lips against teeth; and shapes lips during speech.
-
-
Corrugator supercilii
-
Origin: Medial end of superciliary arch of frontal bone.
-
Insertion: Skin of eyebrow.
-
Action: Draws eyebrow inferiorly and wrinkles skin of forehead vertically as in frowning
-
-
Orbicularis oculi
-
Origin: Medial wall of orbit.
-
Insertion: Circular path around orbit.
-
Action: Closes eye.
-
-
Occipitofrontalis
-
Origin: Epicranial aponeurosis
-
Insertion: Skin superior to supraorbital margin
-
Action: Draws scalp anteriorly, raises eyebrows, and wrinkles skin of forehead horizontally as in look of surprise.
-
REFERENCE:
Tortora, Gerard, and Bryan Derrickson. Principles of Anatomy and Physiology. 15th ed., Wiley, 2016.