8.4: MODELS- Head and Neck and Torso
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Name |
Action |
Origin |
Insertion |
|
Muscles of facial expression |
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Frontalis (epicranius) |
Raises eyebrows , wrinkles forehead |
Frontal Bone |
Skin of the brow |
|
Occipitalis (epicranius) |
Pull scalp posteriorly |
Occipital bone |
Aponeurosis connecting to frontalis |
|
Orbicularis oris |
Closes mouth |
Maxillae and Mandible |
Lips |
|
Zygomaticus (major/minor) |
smile |
Zygomatic Bone |
mouth |
|
Orbicularis oculi |
Closes eye |
Margin of Orbit |
Eyelid |
|
Masseter |
Elevates mandible |
Zygomatic Arch |
Mandible |
|
Temporalis |
Elevates mandible |
Temporal Bone |
Mandible |
|
Buccinator |
Presses cheek inward |
Maxillae and Mandible |
orbicularis oris |
|
Muscles of the head, vertebral column and abdominal wall |
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Splenius capitis |
extend + laterally flex head |
upper spine |
Temporal & occipital |
|
Sternocleidomastoid |
Flexes + rotates neck (also elevates ribs) |
Sternum & Clavicle |
Mastoid Process |
|
Scalenes |
Flexes neck (also elevates ribs) |
Cervical Vertebrae |
1st Two Ribs |
|
Rectus abdominus |
Flexes vertebral column , compresses abdomen |
Pubis |
Lower Ribs and Xiphoid |
|
External oblique |
Flexes + rotates vertebral column, compresses abdomen |
Lower Ribs |
Linea alba and Ilium |
|
Internal oblique |
Flexes + rotates vertebral column, compresses abdomen |
Lumbar Vertebrae & Ilium |
Lower Ribs, Linea alba, Sternum |
|
Transverse abdominus |
Compresses abdomen |
Lower Ribs, Ilium, Lumbar Vertebrae |
Linea Alba & Pubis |
|
Erector spinae group |
Extends vertebral column |
Ilium, Sacrum, Ribs, Vertebrae |
Ribs, Vertebrae, Base of Skull |
|
Levator scapulae |
Extends neck (also elevates scapula) |
Cervical Vertebrae |
Scapula |
|
Name |
Action |
Origin |
Insertion |
|
Thoracic & shoulder muscles |
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Pectoralis major |
Flexes, adducts + medially rotates arm at shoulder |
Sternum & Clavicle |
Humerus |
|
Pectoralis minor |
Elevates ribs (also moves scapula anterior and inferior) |
Ribs |
Scapula |
|
External intercostals |
Elevates ribs |
Inferior Rib |
Superior rib |
|
Internal intercostals |
Depresses ribs |
Superior rib |
Inferior Rib |
|
Diaphragm |
Increases thoracic volume |
Xiphoid Process, Ribs, Lumbar Vertebrae |
Central Tendinous Sheet |
|
Arm movers |
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Serratus anterior |
Moves and fixes scapula anteriorly |
Ribs |
Scapula |
|
Trapezius |
Elevates, retracts, depresses+ rotates scapula upward (also extends neck) |
Occipital Bone & Thoracic Vertebrae |
Scapula |
|
Rhomboids (major & minor) |
Elevates + adducts scapula |
Cervical & Thoracic Vertebrae |
Scapula |
|
Latissimus dorsi |
Extends, adducts + medially rotates arm at shoulder |
Thoracic, Lumbar Vertebrae, Ribs |
Humerus |
|
Deltoid |
Abducts arm at shoulder (also anterior fibers flex + posterior fibers extend arm at shoulder) |
Clavicle & Scapula |
Humerus |
|
Teres major |
Medially rotate arm |
Scapula |
Humerus |
|
Rotator cuff (SITS) |
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Infraspinatus |
Laterally rotates shoulder |
Scapula |
Humerus |
|
Supraspinatus |
Abducts shoulder |
Scapula |
Humerus |
|
Subscapularis |
Medially rotates shoulder |
Scapula |
Humerus |
|
Teres minor |
Laterally rotates shoulder |
Scapula |
Humerus |