Presentation on theme: "Principle Skeletal Muscles 1"— Presentation transcript:
1Principle Skeletal Muscles 1 Muscles of Facial Expression, Muscles that Move the Mandible and Muscles that Move the Eyeballs
2Muscles 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
3Occipitofrontalis 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
5Orbicularis 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
6Zygomaticus Major Origin – zygomatic bone Insertion – Skin at angle of mouth and orbicularis orisAction – Draws corners of mouth outward and upward as in smiling
7Buccinator 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
8Platysma 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
9Orbicularis Oculi Origin – Medial wall of orbit Insertion – Circular path around orbitAction – Closes eye; wrinkles forehead vertically
10Levator Palpebrae Superioris Origin – Roof of OrbitInsertion – Skin of upper eyelidAction - Opens Eye
12Muscles that Move the Mandible Also known as muscles of mastication because they are used for biting and chewing. These muscles also assist in speech.
13Masseter Origin – Maxilla and Zygomatic Arch Insertion – Mandible Action – Elevates and retracts mandible
14Temporalis Origin – Temporal Bone Insertion – Mandible Action – Elevates and retracts mandible
15Medial Pterigoid Origin – Sphenoid bone and maxilla Insertion – MandibleAction – elevates and protracts mandible and moves mandible from side to side
16Lateral Pterygoid Origin – Sphenoid Bone Insertion – TMJ Action – Protracts mandible, depresses mandible and moves mandible from side to side
17Muscles 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.
18Superior 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
20Lateral/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
22Superior/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
29Principle Skeletal Muscles 2 Muscles that act on the abdominal wall, muscles used in breathing and muscles that move the pectoral girdle
30MUSCLES THAT ACT ON THE ANTERIOR ABDOMINAL WALL The anterior abdominal wall is composed of skin, fascia and 4 pairs of muscles.Tendinous Intersections – bands of connective tissue that divides the rectus abdominisLinea Alba – tough fibrous band extending from xiphoid process to pubic symphysis
31Rectus Abdominis Origin – Pubis and Pubic Symphysis Insertion – Costal Cartilage and Xiphoid ProcessAction – Flexes vertebral column and compresses abdomen
40Muscles Used in Breathing These muscles alter the size of the thoracic cavity so that breathing can occur. Inhalation occurs when the thoracic cavity increases in size and exhalation occurs when the thoracic cavity decreases in size
41DiaphragmOrigin – xiphoid process, costal cartilage and lumbar vertebraeInsertion – central tendonAction – increases the vertical dimension of the thoracic cavity resulting in inhalation.
43External and Internal Intercostals Origin – ribsInsertion – ribsAction:External – increases the anteroposterior and lateral dimensions of thoracic cage resulting in inhalationInternal – decreases the antroposterior and lateral dimensions resulting in forceful exhalation
45Muscles that Move the Pectoral Girdle These muscles are divided into anterior (pectoralis minor and serratus anterior) and posterior (trapezius, levator scapulae and rhomboid major) thoracic muscles based on their location.The main action of the muscles is to hold the scapula in place so that is can function as a stable origin for the muscles that move the humerus
46Pectoralis minor Origin – Ribs 3-5 Insertion – Scapula Action – depresses scapula, moves it laterally and forward
48Serratus Anterior Origin – Upper 8 or 9 ribs Insertion – Scapula Action – Moves scapula laterally and forward.AKA: “the boxer’s muscle” because it is important in horizontal arm movements like punching.
65Gluteal Muscles Gluteus Maximus, Minimus and Medius Origin – Ilium Insertion – FemurActions –Maximus: Extends and rotates thigh laterally at hipMedius and Minimus – Abducts and rotates thigh medially at hip