Activity 1:
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Name: Platysma
Origin: Fascia over deltoid and pectoralis major muscles
Insertion: It is inserted through the muscles that surround the angel of the mouth, the mandible or lower jaw, and the skin of the lower face.
Action: Pull down the outer part of the lower lip and backward; this depresses the mandible.
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Name: Mentalis
Origin: Mandible
Insertion: It is inserted through the skin of the chin.
Action: Elevates and protrudes the lower lip and pulls the skin of the chin up like pouting.
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Name: Orbicularis Oris
Origin: muscle fibers that surround the opening of the mouth.
Insertion: It is inserted through the skin at the corner of the mouth.
Action: Orbicularis Oris closes the lips, compresses lips against teeth, protrudes lips, and forms the lips during speech.
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Name: Corrugator supercilli
Origin: medial end of the superciliary arch of the frontal bone.
Insertion: It is inserted in the skin of the eyebrow.
Action: Draws an eyebrow downward, like frowning.
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Name: Orbicularis oculi
Origin: medial wall of orbit.
Insertion: circular path around orbit.
Action: Closes the eye; blinks the eyes.
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Name: Occipitofrontalis (frontal belly)
Origin: Galea aponeurotica (fibrous sheet forming the middle layer of the scalp)
Insertion: skin superior to supraorbital margin.
Action: Pull the scalp forward, raise the eyebrows, and create wrinkles in the skin of the forehead horizontally.
Reference:
Tortora, G. J., & Derrickson, B. (2017). Tortora’s Principles of Anatomy and Physiology John Wiley & Sons, Inc. eBooks https://ci.nii.ac.jp/ncid/BB23861293