Upper Limb - Muscles Flashcards
Pectoralis minor
Origin - 3rd-5th ribs near their costal cartilages
Insertion - coracoid process of scapula
Innervation - medial pectoral nerve
Action - depresses the shoulder
Serratus anterior
Origin - lateral parts of ribs 1-8
Insertion - anterior surface of the medial surface of the scapula
Innervation - long thoracic nerve
Action - protracts the scapula and holds it against thoracic wall. Rotates scapula allowing arm to be raised above 90 degrees.
Pectoralis major
Origin - clavicle (clavicular head). Sternum and ribs (sternocostal head)
Insertion - intertubercular groove of humerus
Innervation - medial and lateral pectoral nerves
Action - adduct and medically rotate the humerus. Clavicular head can perform flexion.
Biceps brachii
Origin - supraglenoid tubercle (long head) and coracoid process (short head) of the scapula.
Insertion - radial tuberosity
Innervation - musculocutaneous nerve
Action - supination of the forearm (main), flexion of elbow and flexion of shoulder.
Brachialis
Origin - Distal half of anterior surface of humerus
Insertion - coronoid process and tuberosity of ulna
Innervation - musculocutaneous nerve and small lateral portion is radial nerve
Action - main flexor at the elbow
Coracobrachialis
Origin - Coracoid process of scapula
Insertion - medial surface of the humerus at the level of the deltoid tuberosity
Innervation - musculocutaneous nerve
Action - flexion at the shoulder, resists dislocation of shoulder
Triceps brachii
Origin - infraglenoid tubercule of scapula (long head), posterior surface of humerus inferior to radial groove (medial head) and posterior surface of humerus superior to radial groove (lateral head)
Insertion - olecranon of ulna
Innervation - radial nerve
Action - chief extension of forearm. Long head resist dislocation of humerus during adduction
Anconeus
Origin - lateral epicondyle of the humerus
Insertion - lateral surface of the olecranon
Innervation - radial nerve
Action - moves the ulna during pronation and extends the elbow joint
Supraspinatus
Origin - supraspinous fossa of the scapula
Insertion - greater tuberosity of the humerus
Innervation - Suprascapular nerve
Action - adducts the arm 0-15 degrees then assists the deltoid 15-90 degrees
Infraspinatus
Origin - infraspinous fossa of the scapula
Insertion - greater tubercule of the humerus
Innervation - Suprascapular nerve
Action - laterally rotates the arm
Subscapularis
Origin - subscapular fossa of scapula
Insertion - lesser tubercule of the humerus
Innervation - upper and lower subscapular nerves
Action - medially rotates the arm
Teres minor
Origin - middle part of lateral border of scapula
Insertion - greater tubercule of the humerus
Innervation - axillary nerve
Action - laterally rotates the arm
Deltoid
Origin - lateral third of clavicle, acromion and spine of scapula
Insertion - deltoid tuberosity of the humerus
Innervation - axillary nerve
Action - anterior part flexes arm, middle part abducts arm and posterior part extends arm.
Teres major
Origin - posterior surface of the interior angle of the scapula
Insertion - Intertubercular groove of humerus
Innervation - lower subscapular nerve
Action - adducts and medially rotates the arm
Trapezius
Origin - external occipital protuberance of skull, nuchal ligament and spinous processes of C7-T12 vertebrae
Insertion - lateral third of clavicle, acromion and spine of scapula
Innervation - accessory nerve
Action - superior part elevates scapula, middle part retracts scapula, inferior part depresses scapula. Superior and inferior parts work together to rotate the scapula, elevating the glenoid cavity.
Trapezius
Origin - external occipital protuberance of skull, nuchal ligament and spinous processes of C7-T12 vertebrae
Insertion - lateral third of clavicle, acromion and spine of scapula
Innervation - accessory nerve
Action - superior part elevates scapula, middle part retracts scapula, inferior part depresses scapula. Superior and inferior parts work together to rotate the scapula, elevating the glenoid cavity.
Latissimus dorsi
Origin - spinous process of T7-12 vertebra, iliac crest, thoraco-lumbar fascia and inferior 3 ribs.
Insertion - floor of Intertubercular groove of humerus
Innervation - thoracodorsal nerve
Action - extends, adducts and medially rotates the arm
Levator scapulae
Origin - transverse processes of C1-4 vertebrae
Insertion - superior part of the medial border of the scapula
Innervation - dorsal scapula nerve
Action - elevates scapula and rotates the glenohumeral cavity inferiorly.
Rhomboid minor
Origin - spinous processes of C7 & T1 vertebrae
Insertion - medial border of the scapula, at the level of the spine
Innervation - dorsal scapula nerve
Action - retract and rotate scapula, depressing the glenoid cavity
Rhomboid major
Origin - spinous processes of T2-5 vertebrae
Insertion - medial border of scapula, inferior to spine
Innervation - dorsal scapula nerve
Action - retract and rotate scapula, depressing the glenoid cavity
Pronator teres
Origin - medial epicondyle and coronoid process of ulna (two heads)
Insertion - lateral side of shaft of radius
Innervation - median nerve
Action - pronation
Flexor carpi radialis
Origin - medial epicondyle
Insertion - base of 2nd and 3rd metacarpals
Innervation - median nerve
Action - flexion and abduction at the wrist
Palmaris longus
Origin - medial epicondyle
Insertion - flexor retinaculum and palmar aponeurosis
Innervation - median nerve
Action - flexion at the wrist
Flexor carpi ulnaris
Origin - medial epicondyle and along the ulna
Insertion - pisiform, hook of hamate and 5th metacarpal
Innervation - ulnar nerve
Action - flexion and adduction of the wrist
Flexor digitorum superficialis
Origin - medial epicondyle and radius (two heads)
Insertion - shaft of middle phalanges of the 4 fingers
Innervation - median nerve
Action - flexion at the MCP joints, PIP joints and wrist
Flexor digitorum profundus
Origin - ulna and interosseous membrane
Insertion - bases of the distal phalanges of the 4 fingers
Innervation - medial half (4th and 5th digits) is ulnar nerve. Lateral half is median nerve.
Action - flexes at the distal interphalangeal joints, as well as the PIPJ, MCPJ and the wrist.
Flexor pollicis longus
Origin - anterior surface of radius and interosseous membrane
Insertion - base of the distal phalanx of the thumb
Innervation - median nerve
Action - flexion at the IP and MCP joint of the thumb
Pronator quadratus
Origin - anterior surface of the distal ulna
Insertion - anterior surface of the distal radius
Innervation - median nerve
Action - primates the forearm
Brachioradialis
Origin - proximal aspect of the supra-epicondylar ridge of the humerus
Insertion - lateral surface of distal end of radius
Innervation - radial nerve
Action - flexion at the elbow - strongest when forearm is half pronated
Extensor carpi radialis longus
Origin - supra-epicondylar ridge of humerus
Insertion - dorsal aspect of base of metacarpal 2
Innervation - radial nerve
Action - extension and abduction at the wrist
Extensor carpi radialis brevis
Origin - lateral epicondyle of the humerus
Insertion - dorsal aspect of base of 3rd metacarpal
Innervation - deep branch of radial nerve
Action - extension and abduction at the wrist
Extensor digitorum
Origin - lateral epicondyle of the humerus
Insertion - extensor expansions of medial four digits
Innervation - deep branch of radial nerve
Action - extension at the MCP and IP joints of the medial 4 fingers
Extensor digiti minimi
Origin - lateral epicondyle of the humerus
Insertion - extensor expansion of 5th digit
Innervation - deep branch of radial nerve
Action - extension at the MCP and IP joint of 5th digit
Extensor carpi ulnaris
Origin - lateral epicondyle of the humerus
Insertion - dorsal aspect of the base of the 5th metacarpal bone
Innervation - deep branch of radial nerve
Action - extension and adduction at the wrist
Supinator
Origin - lateral epicondyle of the humerus and posterior surface of the ulna (two heads)
Insertion - lateral surface of proximal radius
Innervation - deep branch of radial nerve
Action - supinate the forearm
Abductor pollicis longus
Origin - interosseous membrane and adjacent posterior surfaces of the radius and ulna
Insertion - lateral side of the base of the first metacarpal
Innervation - posterior interosseous nerve, continuation of deep branch of radial nerve
Action - abduction of the thumb
Extensor pollicis brevis
Origin - interosseous membrane and posterior surface of the distal radius
Insertion - dorsal aspect of base of proximal phalanx of thumb
Innervation - posterior interosseous nerve, continuation of deep branch of radial nerve
Action - extends at the metacarpophalangeal and carpometacarpal joints of the thumb
Extensor pollicis longus
Origin - posterior surface of the ulna and interosseous membrane
Insertion - distal phalanx of the thumb
Innervation - posterior interosseous nerve, continuation of the deep radial nerve
Action - extends all the joints of the thumb
Extensor indicis
Origin - posterior surface of the ulna and interosseous membrane, distal to extensor pollicis longus
Insertion - extensor expansion of 2nd digit
Innervation - posterior interosseous nerve, continuation of deep branch of radial nerve
Action - extends the index finger
Opponens pollicis
Origin - flexor retinaculum and tubercule of the trapezium
Insertion - lateral side of 1st metacarpal
Innervation - recurrent branch of the median nerve
Action - opposes thumb by medially rotating and flying the metacarpal on the trapezium.
Abductor pollicis brevis
Origin - flexor retinaculum and tubercules of the scaphoid and trapezium
Insertion - lateral side of the proximal phalanx
Innervation - recurrent branch of the median nerve
Action - abducts the thumb
Flexor pollicis brevis
Origin - flexor retinaculum and tubercule of the trapezium
Insertion - base of the proximal phalanx of the thumb
Innervation - recurrent branch of the median nerve
Action - flexes the thumb at the MCP and CMC joints
Opponens digiti minimi
Origin - hook of hamate and flexor retinaculum
Insertion - medial border of 5th metacarpal
Innervation - deep branch of ulnar nerve
Action - rotates the 5th metacarpal towards the palm, producing opposition
Abductor digiti minimi
Origin - pisiform
Insertion - medial side of base of the proximal phalanx of the little finger
Innervation - deep branch of ulnar nerve
Action - abducts 5th digit
Flexor digiti minimi brevis
Origin - hook of hamate and flexor retinaculum
Insertion - medial side of base of the proximal phalanx of the 5th finger
Innervation - deep branch of the ulnar nerve
Action - flexion at the MCP and CMC joints.
1st and 2nd lumbricals
Origin - lateral two tendons of flexor digitorum profundus, as uni pennate muscles
Insertion - lateral sides of extensor expansions of the 2nd and 3rd digits
Innervation - median nerve
Action - flex MCP and extend IP joints
3rd and 4th lumbricals
Origin - medial 3 tendons of the flexor digitorum profundus, as bipennate muscles
Insertion - lateral sides of extensor expansions of the 3rd and 4th digits
Innervation - deep branch of the ulnar nerve
Action - flexs MCP and extends at the IP joints
Dorsal interossei
Origin - adjacent sides of two metacarpals, as bipennate muscles
Insertion - bases of the proximal phalanges and extensor expansions of 2nd-4th digits
Innervation - deep branch of ulnar nerve
Action - abduct 2nd-4th digits from axial line (DAb)and assist lumbricals
Palmar interossei
Origin - palmar surface of 2nd, 4th and 5th metacarpals, as uni pennate muscles
Insertion - extensor expansion and base of proximal phalanx of same finger
Innervation - deep branch of ulnar nerve
Action - adduct 2nd, 4th and 5th digits towards the axial line (PAd) and assist lumbricals
Adductor pollicis
Origin - capitate and metacarpals II and III (oblique head). Anterior surface of shaft of 3rd metacarpal (transverse head)
Insertion - medial side of base of proximal phalanx of thumb
Innervation - deep branch of ulnar nerve
Action - adducts thumb
Palmaris brevis
Origin - medial border of palmar aponeurosis
Insertion - skin of medial border of the hand
Innervation - ulnar nerve
Action - wrinkles the skin of the hypothenar eminence and deepens the curvature of the hand, improving grip
