Presentation on theme: "Principle Skeletal Muscles 1"— Presentation transcript:
1 Principle Skeletal Muscles 1 Muscles of Facial Expression, Muscles that Move the Mandible and Muscles that Move the Eyeballs
2 Muscles of Facial Expression The muscles of facial expression provide humans with the ability to express a wide variety of emotions. The muscles themselves lie within the layers of superficial fascia. The origins are generally in the fascia or bones of the skull and insertions into the skin of the face
3 Occipitofrontalis Front and Occipital Bellies Front Belly:Origin – Epicranial AponeurosisInsertion – Skin superior to orbitAction – Draws scalp forward, raises eyebrows and wrinkles skin of forehead horizontallyOccipital BellyOrigin – Occipital and Temporal BonesInsertion – Epicranial AponeurosisAction – Draws scalp backwards
5 Orbicularis Oris Origin – muscle fibers surrounding opening of mouth Insertion – Skin at corner of mouthAction – Closes and protrudes lips, compresses lips against teeth and shapes lips during speech
6 Zygomaticus Major Origin – zygomatic bone Insertion – Skin at angle of mouth and orbicularis orisAction – Draws corners of mouth outward and upward as in smiling
7 Buccinator Origin – Maxilla and Mandible Insertion – Orbicularis Oris Action – presses cheeks against teeth and lips, as in whistling; draws corner of mouth laterally, assists in chewing be keeping food between teeth
8 Platysma Origin – Fascia over deltoid and pectoralis major muscles Insertion – Mandible, muscles around mouth and skin of lower faceAction – Draws outer part of lower lip downward and backward as in pouting; depresses mandible
12 Muscles that Move the Mandible Also known as muscles of mastication because they are used for biting and chewing. These muscles also assist in speech.
13 Masseter Origin – Maxilla and Zygomatic Arch Insertion – Mandible Action – Elevates and retracts mandible
14 Temporalis Origin – Temporal Bone Insertion – Mandible Action – Elevates and retracts mandible
15 Medial Pterigoid Origin – Sphenoid bone and maxilla Insertion – MandibleAction – elevates and protracts mandible and moves mandible from side to side
16 Lateral Pterygoid Origin – Sphenoid Bone Insertion – TMJ Action – Protracts mandible, depresses mandible and moves mandible from side to side
17 Muscles that Move the Eyeballs Movement of the eyeballs are controlled by three pairs of extrinsic muscles. These are among the fastest contracting and most precisely controlled skeletal muscles of the body.
18 Superior Rectus/Inferior Rectus Origin – Tendinous ring attached to bony orbit around the optic foramenInsertion – Superior and central part of the eyeballAction – Moves eyeball upward and medially and rotates its mediallyInferior:Origin - Tendinous ring attached to bony orbit around the optic foramenInsertion – Inferior and central part of the eyeballAction – Moves eyeball downward and medially and rotates it laterally
20 Lateral/Medial Rectus Origin – Tendinous ring attached to bony orbit around the optic foramenInsertion – Lateral Side of EyeballAction – Moves eyeball laterallyMedial:Insertion – Medial Side of EyeballAction – Moves eyeball medially
22 Superior/Inferior Oblique Origin – Tendinous ring attached to bony orbit around the optic foramenInsertion – Eyeball between superior and lateral rectiAction – moves eyeball downward, laterally and rotates mediallyInferior:Origin – MaxillaInsertion – eyeball between inferior and lateral rectiAction – moves eyeball upward and laterally and rotates it laterally
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