ACTIVITY 1
Name the muscle that may cause the following facial expression and write down its origin, insertion and action.
|
No. |
Name of Muscle |
Origin |
Insertion |
Action |
|
1. |
PLATYSMA |
Fascia over deltoid and pectoralis major muscles. |
Mandible, blends with muscles around angle of mouth, and skin of lower face. |
Draws outer part of lower lip inferiorly and posteriorly as in pouting; depresses mandible (against resistance). |
|
2. |
MENTALIS |
Mandible |
Skin of chin (mentolabial sulcus) |
Elevates and protrudes lower lip and pulls skin of chin up, as in pouting. |
|
3. |
ORBICULARIS ORIS |
Muscle fibers surrounding opening of mouth. |
Skin at corner of mouth |
Closes and protrudes lips, as in kissing; compresses lips against teeth; and shapes lips during speech |
|
4. |
CORRUGATOR SUPERCILII |
Medial end of superciliary arch of frontal bone. |
Skin of eyebrow |
Draws eyebrow inferiorly and wrinkles skin of forehead vertically as in frowning |
|
5. |
ORBICULARIS OCULI |
Medial wall of orbit |
Circular path around orbit |
Closes eyelids; palpebral part does so gently; orbital part tightly (winking) |
|
6. |
OCCIPITOFRONTALIS (Frontal Belly) |
Epicranial aponeurosis |
Skin superior to supraorbital margin |
Draws scalp anteriorly, raises eyebrows, and wrinkles skin of forehead horizontally as in look of surprise |
REFERENCE: Tortora, G. & Derrickson, B. (2014). Principles of Anatomy and Physiology (14th ed.). New Jersey, NJ: Wiley