ACTIVITY 1

DAVID, Patricia Khae S.

DAVID, Patricia Khae S.

by Patricia Khae David -
Number of replies: 0

 

Name the muscle that may cause the following facial expression and write down its origin, insertion and action.

  1. 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. 

 

  1. 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.

 

  1. 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.

 

  1. 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.

 

  1. 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.

 

  1. 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.