Muscles Flashcards
Pectoralis major
O: anterior medial shaft of clavicle, anterior surface of sternum
I: lateral lip of the intertubercular groove of the humerus
N: Medial and lateral pectoral
A: adduct, medially rotate (extend arm from flexed position)
Pectoralis minor
O: 3rd-5th ribs
I: inferior center of the clavicle
N: medial pectoral
A: stabilize scapula, elevate ribs (respiration)
Subclavius
O: junction of first rib and manubrium
I: inferior center of the clavicle
N: N to the subclavius
A: anchors and depresses the clavicle
Serratus anterior
O: lateral parts of ribs 1-8
I: medial anterior border of scapula
N: long thoracic n
A: protracts, rotates, stabilizes the scapula on the thorax
Deltoid
O: lateral 3rd of clavicle, acromion, scapular spine
I: deltoid tuberosity of humerus
N: axillary n
A: anterior flexes and medially rotates, middle abducts, posterior extends and laterally rotates
Supraspinatus
Rotator cuff
O: supraspinous fossa of scapula
I: superior aspect of greater tubercle of humerus
N: suprascapular n
A: initiations abduction, stabilize joint
Infraspinatus
Rotator cuff O: infraspinatus fossa of scapula I: greater tubercle of the humerus N: suprascapular n A: lateral rotation, stabilization
Teres minor
Rotator cuff O: lateral border of scapula I: greater tubercle of humerus N: axillary n A: lateral rotation, stabilization
Subscapularis
Rotator cuff O: subscapular fossa I: lesser tubercle of humerus N: upper and lower subscapular n A: medial rotation, stabilization
Teres major
O: posterior surface of inferior angle of scapula
I: lesser tubercle of humerus
N: lower subscapular n
A: adduction and medial rotation
Trapezius
O: occipital bone, spinous process C1-T12
I: lateral clavicle, acromion, superior border of scapula
N: Accessory
A: elevate, rotate, retract, depress scapula
Levator scapulae
O: transverse process C1-C4
I: superior angle of scapula
N: dorsal scapular
A: elevate scapula
Rhomboid major/minor
O: spinous process C6-C7/T1-T4
I: medial border of scapula
N: dorsal scapular
A: retract and elevate scapula
Latissimus dorsi
O: spinous process T7-T12, thoracolumbar fascia, iliac crest
I: intertubercular groove of humerus
N: thoracodorsal
A: adduct, extend, medially rotate
Biceps brachii
O: supraglenoud tubercle of scapula, tip of coracoid process
I: radial tuberosity
N: musculocutaneous
A: supinate and flex forearm, assist in shoulder flexion, resist dislocation
Brachialis
O: distal half of anterior humerus
I: coronoid process and ulnar tuberosity
N: musculocutaneous (partially from radial)
A: flex elbow
Coracobrachialis
O: tip of coracoid process of scapula
I: middle 1/3 of medial surface of humerus
N: musculocutaneous
A: flexion, adduction, resists glenohumeral dislocation
Pronator teres
O: medial epicondyle of humerus, proximal ulna
I: lateral midshaft of radius
N: median
A: pronation
Palmaris longus
O: medial epicondyle of humerus
I: palmar aponeurosis
N: median
A: wrist flexion, tense palmar eponeurosis
Flexor carpi radialis
O: medial epicondyle of humerus
I: palmar base of 2nd metacarpal
N: median
A: flex and abduct wrist
Flexor carpi ulnaris
O: medial epicondyle of humerus and olecranon process
I: hook of hamate, pisoform, palmar base of 5th metacarpal
N: ulnar
A: flex and adduct wrist
Flexor digitorum superficialis
O: medial epicondyle of humerus, proximal radius
I: base of intermediate phalanges of 2-5
N: median
A: flex proximal interphalangeal joint, metacarpophalangeal joint, wrist
Flexor digitorum profundus
O: ulnar shaft, interosseous membrane
I: base of distal phalanx of 2-5
N: anterior interosseous (lateral, 2-3), ulnar (medial, 4-5)
A: flex distal interphalangeal joint, PIP, MCP, wrist
Flexor pollicis longus
O: radial shaft, interosseous membrane
I: base of 1st distal phalanx
N: anterior interosseous
A: flex 1st carpometacarpal, MCP, PIP, wrist joints
Pronator quadratus
O: medial aspect of distal ulna
I: lateral aspect of distal radius
N: anterior interosseous
A: pronation
Triceps brachii
O: infraglenoid tubercle of scapula, posterior surface of humerus superior and inferior to humeral groove
I: proximal end of olecranon process
N: radial
A: extension of arm, resists dislocation of arm, extension of forearm
Anconeus
O: lateral epicondyle of humerus
I: lateral surface of olecranon and proximal posterior surface of ulna
N: radial
A: assist in forearm extension, stabilize elbow
Brachioradialis
O: lateral supracondylar ridge of humerus
I: styloid process of radius
N: radial
A: flexion of forearm
Extensor carpi radialis longus
O: lateral supracondylar ridge of humerus
I: dorsal base of 2nd metacarpal
N: radial
A: extend and abduct wrist
Extensor carpi radialis brevis
O: lateral epicondyle of humerus
I: dorsal base of 3rd metacarpal
N: deep branch of radial
A: extend and abduct wrist
Extensor carpi ulnaris
O: lateral epicondyle of humerus
I: dorsal base of 5th metacarpal
N: deep branch of radial
A: extend wrist and adduct
Extensor digitorum
O: lateral epicondyle of humerus
I: extensor expansion of digits 2-5
N: deep branch of radial
A: extend digits 2-5 at all joints, extend wrist
Extensor digiti minimi
O: lateral epicondyle of humerus
I: extensor expansion of digit 5
N: deep branch of radial
A: extend digit 5 at all joints, extend and adduct wrist
Supinator
O: lateral epicondyle of humerus, posterior olecranon process
I: proximo-lateral radius
N: deep branch of radial
A: supination
Abductor pollicis longus
O: posterior ulna, radius, interosseous membrane
I: base of 1st metacarpal
N: posterior interosseous (from deep branch of radial)
A: abduct thumb
Extensor pollicis longus
O: posterior ulna, interosseous membrane
I: base of distal phalanx of pollex
N: posterior interosseous
A: extend pollex at all joints
Extensor pollicis brevis
O: posterior radius, interosseous membrane
I: base of proximal phalanx of pollex
N: posterior interosseous
A: extend pollex at MCP joint
Extensor indicis
O: posterior ulna, interosseous membrane
I: extensor expansion of 2nd digit
N: posterior interosseous
A: extend 2nd digit at all joints, extend wrist
Abductor pollicis brevis
(thenar)
N: recurrent branch of median
A: abduct the thumb
Flexor pollicis brevis
(thenar)
N: recurrent branch of median (deep head is by deep branch of ulnar)
A: flex the thumb
Opponens pollicis
(thenar)
N: recurrent branch of median
A: oppose the thumb
Abductor digiti minimi
(hypothenar)
N: deep branch of ulnar
A: abduct the pinky
Flexor digiti minimi brevis
(hypothenar)
N: deep branch of ulnar
A: flex the pinky
Opponens digiti minimi
(hypothenar)
N: deep branch of ulnar
A: oppose the pinky
Lumbricals
N: medial 2 by deep branch of ulnar, lateral 2 by median
A: flex MCP joints, extend IP joints
Dorsal interossei
N: deep branch of ulnar
A: abduct
Palmar interossei
N: deep branch of ulnar
A: adduct
Adductor pollicis
(not thenar)
N: deep branch of ulnar
A: adduct the thumb
Which muscles have dual innervation?
Flexor digitorum profundus
Lumbricals