Biceps Brachii
Origin: coracoid process, tubercle above glenoid cavity of scapula, anterior surface of humerus
Insertion: radial tuberosity
Action: flexes, supinates arm and forearm
Brachialis
Origin: anterior surface of humerus
Insertion: coronoid process of ulna
Action: flexes, pronated foramen
Brachioradialis
Origin: distal lateral end of humerus
Insertion: surface of radius proximal to styloid process
Action: flexes, supinates forearm
Buccinator
Origin: outer surfaces of maxilla and mandible
Insertion: orbicularis oris muscle
Action: compresses cheeks inward as when blowing air out, retracts corner of mouth
Coracobrachialis
Origin: coracoid process of scapula
Insertion: medial surface of humerus
Action: flexes, adducts upper arm; rotates upper arm medially
Deltoid
Origin: acromion process and spine of scapula, clavicle
Insertion: deltoid tuberosity of humerus
Action: abducts, flexes, extends upper arm
Diaphragm
Origin: xiphoid process, ribs 7-12, lumbar verebrae
Insertion: central tendon
Action: enlarges thorax by depressing floor of thoracic cavity during inhalation
Epicranius
Origin: occipital bone
Insertion: skin and muscles around eyebrows and above nose
Action: raises eyebrows (as when surprised)
Extensor Carpi Radialis (group)
Origin: lateral surface and lateral epicondyle of humerus
Insertion: proximal end of second, third metacarpals
Action: extends, abducts hand at wrist
Extensor Carpi Ulnaris
Origin: lateral epicondyle of humerus, ulna
Insertion: proximal end of fifth metacarpal
Action: extends, adducts hand at wrist
External Intercostals
Origin: inferior border of ribs
Insertion: superior border of ribs
Action: elevates rib during inhalation
Flexor Carpi Radialis
Origin: medial epicondyle of humerus
Insertion: proximal end of metacarpals 1-3
Action: flexes, abducts hand at wrist
Flexor Carpi Ulnaris
Origin: medial epicondyle of humerus, olecranon process of ulna
Insertion: 5th metacarpal, carpals
Action: flexes, adducts hand at wrist
Infraspinatus
Origin: infraspinous fossa
Insertion: greater tubercle of humerus
Action: extends upper arm, rotates upper arm
Internal Intercostals
Origin: superior border of ribs
Insertion: inferior border of ribs
Action: depresses ribs during exhalation
Latissimus Dorse
Origin: spinous processes of lower 6 T, all L and S vertebrae, iliac crest, ribs
Insertion: intertubercular groove of humerus
Action: extens, adducts upper arm; rotates arm medially; pulls shoulder downward, back
Levator Scapulae
Origin: transverse processes of C1-C4
Insertion: superior medial border of scapula
Action: elevates, retracts scapula
Masseter
Origin: zygomatic arch, maxilla
Insertion: lateral surface of mandible
Action: elevates mandible
Orbicularis Oculi
Origin: maxilla, frontal bone
Insertion: skin around orbit of eye
Action: closes eye (as in blinking or squinting)
Orbicularis Oris
Origin: muscles near mouth, maxilla, mandible, nasal septum
Insertion: skin of central lip
Action: draws lips together (as in kissing)
Pectoralis Major
Origin: clavicle, sternum, and ribs 2-6
Insertion: intertubular groove of humerus
Action: flexes, adducts upper arm; rotates upper arm medially
Pectoralis Minor
Origin: sternal end of ribs 3-5
Insertion: coracoid process of scapula
Action: depresses shoulder, rotates scapula forward, raises ribs
Rhomboideus (Group)
Origin: spinous processes C7, T1-T5
Insertion: medial border of scapula
Action: raises, adducts, rotates scapula
Serratus Anterior
Origin: outer surface of first 8 or 9 ribs
Insertion: ventral surface of scapula
Action: pulls scapula forward, down; assists in elevating ribs
Sternocleidomastoid
Origin: sternum, sternal end of clavicle
Insertion: mastoid process of temporal bone
Action: pulls head to one side, flexes neck (bows head), elevates sternum
Supraspinatus
Origin: supraspinous fossa
Insertion: greater tubercle of humerus
Action: abducts upper arm
Subscapularis
Origin: subscapular fossa
Insertion: lesser tubercle of humerus
Action: extends upper arm, rotates upper arm medially
Temporalis
Origin: temporal bone
Insertion: coronoid process, ramus of mandible
Action: elevates mandible
Teres Major
Origin: lateral and medial borders of scapula
Insertion: intertubercular groove and lesser tubercle of humerus
Action: extends, adducts, upper arm; rotates upper arm medially
Teres Minor
Origin: lateral and medial borders of scapula
Insertion: greater tubercle of humerus
Action: rotates upper arm laterally
Trapezius
Origin: occipital bone, spinous processes of C and T vertebrae
Insertion: spine, acromion process of scapula; acromial end of clavicle
Action: shrugs shoulders, rotates and adducts scapula
Triceps Brachii
Origin: tubercle below glenoid fossa, posterior surface humerus
Insertion: olecranon proces of ulna
Action: extends arm at elbow
Zygomatiucs (group)
Origin: zygomatic bone
Insertion: orbicularis oris muscle
Action: retracts, raises corner of mouth (as when smiling)