Texas A&M Biol 319 AOI Lab 5

Pectoralis Major

Action: arm flexion; rotates arm medially; adducts arm

Origin: Sternal end of clavicle; sternum; cartilage of ribs 1-6

Insertion: Intertubercular sulcus & greater tubercle of hummerus

Latissimus dorsi

Action: arm extension; adducts arm; medially rotates arm at shoulder

Origin: Spines of T7-L5; ribs 9-12; iliac crest

Insertion: Intertubercular sulcus of hummerus

Deltoid

Action: Arm abduction; flexion; and medial rotation of humerus; extension/lateral rotation of arm

Origin: Lateral 3rd of clavicle, acromion and spine of scapula

Insertion: Deltiod tuberosity of humerus

Trapezius

Action: Stabilizes, raises, retracts, and rotates the scapula

Origin: Occipital bone; spinous process of C7, and all thoracic vertebrae

Insertion: Acromion and spine of scapula; lateral 3rd of clavicle

Pectoralis Minor

Action: Draws Scapula forward/downward

Origin: Anterior surfaces of ribs 3-5

Insertion: Coracoid process of scapula

External Oblique

Action: Flexes vertebral column; compress abdominal wall; rotating trunk and flexing laterally

Origin: Outer surface of ribs 5-12

Insertion: Linea alba; pubic crest; iliac crest

Brachioradialis

Action: forearm flexion; stabilizes the elbow during rapid flexion and extension

Origin: Lateral supracondylar ridge at distal end of humerus

Insertion: Styloid process of radius

Pronator teres

Action: pronates forearm; weak flexor of elbow

Origin: Medial epicondyle of humerus; coronoid process of ulna

Insertion: Lateral radius

Flexor carpi radialis

Action: Powerful flexor of wrist; abducts hand

Origin: Medial epicondyle of humerus

Insertion: Base of 2nd and 3rd metacarpals

Palmaris longus

Action: tenses skin and fascia of palm during hand movements

Origin: medial epicondyle of humerus

Insertion: Palmar aponeurosis

Flexor carpi ulnaris

Action: wrist flexor; adducts hand

Origin: Medial epicondyle of humerus, olecranon process, and posterior surface of ulna

Insertion: Pisiform, hamate, 5th metacarpal

Extensor carpi radialis longus

Action: Extends and abducts wrist

Origin: lateral supracondylar ridge of humerus

Insertion: Base of 2nd metacarpal

Extensor carpi radialis brevis

Action: Extends and abducts wrist

Origin: lateral epicondyle of humerus

Insertion: base 3rd metacarpal

Extensor digitorum

Action: extension of fingers

Origin: lateral epicondyle of humerus

Insertion: distal phalanges of fingers 2-5

Extensor carpi ulnaris

Action: Extends and abducts wrist

Origin: lateral epicondyle of humerus; posterior border of ulna

Insertion: base of 5th metacarpal

Flexor pollicis longus

Action: flexes distal phalanx of thumb

Origin: anterior surface of radius

Insertion: distal phalanx of thumb

Flexor digitorum profundus

Action: flexes distal interphalangeal joints; wrist flexion

Origin: Coronoid process; anteromedial surface of ulna

Insertion: distal phalanges of fingers 2-5

Abductor pollicis longus

Action: abducts and extends thumb

Origin: posterior surface of radius and ulna

Insertion: Base of 1st metacarpal, trapezium

Extensor pollicis longus

Action: extends the thumb

Origin: dorsal shaft or radius and ulna

Insertion: base of distal phalanx of thumb

Supinator

Action: assists bicep brachii to supinate foreman

Origin: lateral epicondyle of humerus; proximal ulna

Insertion: proximal end of radius

Abductor pollicis brevis

Action: Abducts thumb

Origin: flexor retinaculum

Insertion: lateral base of thumb's proximal phalanx

Flexor pollicis brevis

Action: flexes thumb

Origin: flexor retinaculum

Insertion: lateral side of base of proximal phalanx of thumb

Opponens pollicis

Action: opposition of thumb

Origin: flexor retinaculum; trapezium

Insertion: anterior side of 1 metacarpal

Adductor pollicis

Action: adducts and helps to oppose thumb

Origin: capitate and base of metacarpal 2-4

Insertion: medial side of base of proximal phalanx of thumb

Opponens digiti minimi

Action: Opposition of the 5th metacarpal

Origin: hamate, flexor retinaculum

Insertion: medial side of 5th metacarpal

Lumbricals of the hand

Action: flex fingers at metacarpophalangeal joints; extend fingers at interphalangeal joints

Origin: Lateral side of flexor digitorium profundus

Insertion: proximal phalanx of fingers 2-5

Palmar interossei

Action: adducts fingers

Origin: midaxis side of all metacarpal except the 3rd metacarpal

Insertion: extensor expansion over 1st phalanx of each finger

Dorsal interossei

Action: abducts fingers

Origin: side of metacarpals

Insertion: extensor expansion over proximal phalanx of fingers 2-4