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Masseter
- Origin: Zygomatic arch
- Insertion: Lateral surface of mandibular ramus
- Action: Elevates mandible and closes the jaws
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Temporalis
- Origin: Along the temporal lines of skull
- Insertion: Coronoid process of mandible
- Action: Elevates mandible
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Sternocleidomastoid
- Origin: Two bellies: clavicular head attaches to sternal end of clavicle; sternal head attaches to manubrium
- Insertion: Mastoid region of the skull and lateral portion of superior nuchal line
- Action: Together, they flex the neck; alone, one side bends head toward shoulder and turns face to opposite side
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Pectoralis major
- Origin: Cartilages of ribs 2-6, body of sternum, and inferior, medial portion of clavicle
- Insertion: Crest of greater tubercle and lateral lip of intertubercular groove of humerus
- Action: Flexion, adduction, and medial rotation at shoulder
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Biceps brachii
- Origin: Short head from the coracoid process; long head of the supraglenoid tubercle (both on the scapula)
- Insertion: Tuberosity of radius
- Action: Flexion at elbow and shoulder; supination
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Flexor carpi radialis
- Origin: Medial epicondyle of humerus
- Insertion: Bases of second and third metacarpal bones
- Action: Flexion and abduction at wrist
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Flexor carpi ulnaris
- Origin: Medial epicondyle of humerus; adjacent medial surface of olecranon and anteromedial portion of the ulna
- Insertion: Pisiform, hamate, and base of fifth metacarpal bone
- Action: Flexion and adduction at wrist
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Rectus abdominus
- Origin: Superior surface of pubis around symphysis
- Insertion: Inferior surfaces of costal cartilages (ribs 5-7) and xiphoid process
- Action: Depresses ribs, flexes vertebral column, compresses abdomen
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Adductor longus
- Origin: Inferior ramus of pubis anterior to adductor brevis
- Insertion: Linea aspera of femur
- Action: Adduction, flexion, and medial rotation at hip
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Rectus femoris
- Origin: Anterior inferior iliac spine and superior acetabular rim of ilium
- Insertion: Tibial tuberosity via patellar ligament
- Action: Extension at knee; flexion at hip
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Vastus lateralis
- Origin: Anterior and inferior to greater trochanter of femur and along linea aspera (proximal half)
- Insertion: Tibial tuberosity via patellar ligament
- Action: Extension at knee
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Vastus intermedius
- Origin: Anterolateral surface of femur and linea aspera (distal half)
- Insertion: Tibial tuberosity via patellar ligament
- Action: Extension at knee
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Vastus medialis
- Origin: Entire length of linea aspera of femur
- Insertion: Tibial tuberosity via patellar ligament
- Action: Extension at knee
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Tibialis anterior
- Origin: Lateral condyle and proximal shaft of tibia
- Insertion: Base of first metatarsal bone and medial cuneiform bone
- Action: Flexion (dorsiflexion) at ankle; inversion of foot
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Extensor hallucis longus
- Origin: Anterior surface of fibula
- Insertion: Superior surface, distal phalanx of great toe
- Action: Extension at joints of great toe
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Extensor digitorum longus
- Origin: Lateral condyle of tibia, anterior surface of fibula
- Insertion: Superior surfaces of phalanges, toes 2-5
- Action: Extension at joints of toes 2-5
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