Name the muscle that may cause the following facial expression and write down its origin, insertion and action.
- The muscle that is responsible for this facial expression is the platysma.
- Origin: Fascia over deltoid and pectoralis major muscles.
-
Insertion: Its insertion is in the mandible. It blends with the muscles around the angle of the mouth and skin of the lower face.
-
Action: Pulls the outer part of the lower lip inferiorly and posteriorly as in pouting; it gives force to the mandible.
-
For the facial expression, the muscle responsible is the mentalis.
-
Origin: The origin is the mandible.
-
Insertion: It inserts in the skin of the chin.
-
Action: It elevates and protrudes the lower lip and draws the skin of the chin up, as in pouting.
-
The orbicularis oris is the one responsible for this facial expression.
-
Origin: The muscle fibers encircling the opening of the mouth.
-
Insertion: The skin at the corner of the mouth.
-
Action: It closes and protrudes lips, as in kissing; compresses lips against teeth; and shapes lips during speech.
-
The corrugator supercilii is responsible for this facial expression.
-
Origin: The medial end of the superciliary arch of the frontal bone.
-
Insertion: Skin of eyebrow.
-
Action: The corrugator supercilii draws eyebrows inferiorly and wrinkles the skin of the forehead vertically, like frowning.
-
The orbicularis oculi causes this kind of facial expression.
-
Origin: The origin of this muscle is the medial wall of the orbit.
-
Insertion: Circular path around the orbit.
-
Action: Its action is closing the eye.
-
The muscle responsible is the occipito frontalis.
-
Origin: Its origin is epicranial aponeurosis.
-
Insertion: The skin superior to the supraorbital margin is the insertion.
-
Action: Pulls scalp anteriorly, lifts eyebrows, and wrinkles skin of forehead horizontally as in a look of surprise.
Reference:
Tortora, G. J., Derrickson, B., Burkett, B., Peoples, G., Dye, D., Cooke, J., Diversi, T., McKean, M., Samalia, L., & Mellifont, R. (2022). Principles of anatomy and physiology (3rd ed.). John Wiley & Sons Australia, Ltd.