1. Platysma
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- Origin: Connective tissue covering the deltoid and pectoralis major muscles.
- Insertion: Jawbone (mandible).
- Action: Pulls the lower lip down and backward, like when pouting, and lowers the jaw.
2. Depressor Labii Inferioris
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- Origin: Jawbone (mandible).
- Insertion: Skin of the lower lip.
- Action: Lowers the bottom lip.
3. Orbicularis Oris
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- Origin: Muscle fibers surrounding the mouth's opening.
- Insertion: Skin at the corner of the mouth.
- Action: Closes and pushes the lips forward; presses the lips against the teeth; shapes the lips during speech.
4. Corrugator Supercilii
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- Origin: Inner part of the brow ridge on the frontal bone.
- Insertion: Skin of the eyebrow.
- Action: Pulls the eyebrows downward and wrinkles the skin of the forehead vertically.
5. Orbicularis Oculi
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- Origin: Medial wall of the eye socket (orbit).
- Insertion: Circular path around the eye socket.
- Action: Closes the eyelids.
6. Occipitofrontalis
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- Origin: Tendinous sheet (epicranial aponeurosis).
- Insertion: Skin just above the eyebrows (supraorbital margin).
- Action: Moves the scalp forward, raises the eyebrows, and creates horizontal wrinkles on the forehead.