Muscles of the Upper Limb Quiz PDF

Quiz about Muscles of the upper limb - Ligaments of the metacarpal joint are rather simple, as they connect the 8 bones that constitute the metacarpal bone complex (in lateromedial direction, first row and second row: scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capit...

Quiz about Muscles of the upper limb - Ligaments of the metacarpal joint are rather simple, as they connect the 8 bones that constitute the metacarpal bone complex (in lateromedial direction, first row and second row: scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate) directly indicating the name of the two bones involved, for instance the scapho-lunate ligament is a horizontal ligament that connects the medial aspect of the scaphoid bone with the lateral aspect of the lunate bone. - **Muscles from trunk to shoulder girdle** - Serratus anterior: - Originates from 1^st^ to 9^th^ rib - Inserts into medial border of the scapula - Performs abduction and upward rotation of scapula - Trapezius: - 3 components: descending, transverse, ascending trapezius - Originates from occipital bone and spinous processes of C7 through T12 - Inserts into acromion and spine of the scapula - Performs adduction, downward-upward rotation, and elevation-depression of the scapula - Rhomboid minor and major: - Originate from spinous process and nuchal ligament of C5 to T4 - inserts into medial border of the scapula - Perform adduction, downward rotation, and elevation of the scapula - Pectoralis minor: - Originates from the second to fifth rib - Inserts into the coracoid process of the scapula - Performs depression and ventral tilt of the scapula, and elevation of the second to fifth ribs - Levator scapulae: - Originates from the transverse process of the upper cervical vertebrae - Inserts into the superior medial border (above the rhomboid minor and major) of the scapula - Performs elevation and downward rotation of the scapula, and ipsilateral rotation and flexion of the head - **Muscles from shoulder girdle to humerus** - Deltoid: - 3 components - Originates from the spine of the scapula, acromion process, and acromial end of the clavicle - Inserts as a single tendon into the deltoid tuberosity, located medially on the shaft of the humerus - Performs abduction of glenohumeral joint. Clavicular part performs flexion and spinal part performs extension of glenohumeral joint - Supraspinatus: - Originates from the supraspinal fossa - Inserts into uppermost facet of greater tubercle - Performs abduction of glenohumeral joint - Infraspinatus: - Originates from the infraspinous fossa - Inserts into the middle facet of the greater tubercle - Performs external rotation of the glenohumeral joint - Teres minor: - Originates from the lateral border of the scapula - Inserts into the lower facet of the greater tubercle - Performs external rotation of the glenohumeral joint - Subscapularis: - Originates from the subscapular fossa - Inserts into the lesser tubercle - Performs internal rotation (also adduction, extension, and flexion depending on arm position) of the glenohumeral joint - Teres major: - Originates from the inferior angle of the scapula - Inserts into the crest of the lesser tubercle - Performs internal rotation, adduction, and extension of the glenohumeral joint - Pectoralis major: - Originates from the second to seventh rib, sternal end of the scapula, and sternum - Inserts into the crest of the greater tuberosity of the humerus - Performs adduction and internal rotation of the glenohumeral joint. Clavicular head also performs flexion - Latissimus dorsi: - Originates from spinous process of T6 to the crest of the ilium - Inserts into the crest of the lesser tubercle, proximal to teres major - Performs external rotation, extension, and adduction of the glenohumeral joint (also performs scapular depression) - Motor muscles of supination: - Supinator muscle - Biceps brachii - Motor muscles of pronation: - Pronator quadratus - Pronator teres - Tendons of most flexor muscles are kept in place by the palmar carpal ligament and the transverse carpal ligament (flexor retinaculum), all located on the palmar side of the - **Flexor-pronator muscles** - Superficial layer: - Pronator Teres - Palmaris longus - Flexor carpi radialis - Flexor carpi ulnaris - All muscles originate from the medial epicondyle of the humerus (through the common flexor attachment tendon). The order in lateromedial direction is pronator teres, flexor carpi radialis, palmaris longus, and flexor carpi ulnaris. - Insertions and actions: - Pronator teres: lateral middle surface of the radius; performs pronation and flexion of the arm. - Flexor carpi radialis: base of the second metacarpal bone; flexes and abducts the wrist. - Palmaris longus: distal half of flexor retinaculum and palmar aponeurosis; flexes the wrist and tenses the aponeurosis. - Flexor carpi ulnaris: pisiform bone, hook of the hamate bone, and fifth metacarpal bone; flexes and adducts the wrist. - Intermediate layer: - Flexor digitorum superficialis - This is the single muscle that consists this intermediate layer. - Originates from the medial epicondyle and coronoid process of the humerus - Inserts into the shafts of the middle phalanges of the four digits (excluding the thumb) - Performs flexion of the middle phalanges at the proximal interphalangeal joint, also flexing the proximal phalanges to the metacarpophalangeal joint. Has an effect on wrist flexion as well - Deep layer: - Flexor digitorum profundus - Originates from anterior and medial aspects of the proximal ulna superior ¾ of the shaft of the ulna (close to the coronoid process), and interosseous membrane - Inserts into the base of the distal phalanges of the second through fifth digits - Performs flexion of the distal interphalangeal joint - Flexor pollicis longus - Originates from the anterior surface of the radius and adjacent interosseous membrane - Inserts into the base of the distal phalanx of the first digit - Performs phalanx flexion of the first digit - Pronator quadratus - Originates from the anterior aspect of the distal quarter of the ulna - Inserts into the anterior aspect of the distal quarter of the radius - Performs pronation of the forearm, superimposing the radius on top of the ulna - Extensor-supinator muscles are located, differently from flexor-pronator muscles, on the posterior aspect of the forearm, and have the main functions of extension and supination of the forearm (and also perform abduction and adduction, depending on their insertion). Extensors that insert into the radius are primarily abductors, and extensors that insert into the ulna are primarily adductors. - Extensor-supinator muscles are kept in place by the presence of the extensor retinaculum, that has the same role as the palmar carpal ligament (indeed it is a dorsal continuation of the palmar carpal ligament) and the flexor retinaculum, with the difference that extensor tendons are kept in place in this single area. - **Extensor muscles** - Superficial layer: - Brachioradialis - Originates from the proximal 2/3^rds^ of the lateral supracondylar ridge of the humerus - Inserts into the lateral distal portion of the radius, proximal to the styloid process - Performs flexion of the forearm - Extensor carpi radialis longus - Originates from the lateral supracondylar ridge of the humerus - Inserts into the dorsal aspect of the base of the second metacarpal bone (index finger) - Performs extension and abduction of the hand at the wrist joint - Extensor carpi radialis brevis - Originates from the lateral epicondyle of the humerus - Inserts in the dorsal aspect of the base of the third metacarpal bone - Performs extension and abduction of the hand at the wrist joint - Extensor digitorum - Originates from the lateral epicondyle of the humerus - Inserts into the distal phalanges of the second through fifth digits - Performs extension of the digits at the metacarpophalangeal and interphalangeal joints - Extensor digiti minimi - Originates from the lateral epicondyle of the humerus - Inserts into the distal phalanx of the fifth digit - Performs extension of the fifth digit at the metacarpophalangeal and interphalangeal joints - Extensor carpi ulnaris - Originates from the lateral epicondyle of the humerus - Inserts into the dorsal base of the fifth metacarpal bone - Performs extension and adduction the hand at the wrist joint - Deep layer: - Supinator - Originates from the lateral epicondyle of the humerus, crest of the ulna, and supinator fossa - Inserts into the lateral, posterior, and anterior surfaces of the proximal third of the radius - Performs supination of the forearm - Extensor indicis - Originates from the posterior surface of the distal third of the ulna and interosseous membrane - Inserts into the dorsal base of the distal phalanx of the index finger - Performs independent extension of the second digit and helps with hand extension - Abductor pollicis longus - Originates from the posterior surfaces of the proximal halves of the ulna, radius, and interosseous membrane - Inserts into the dorsal base of the first metacarpal bone - Performs independent abduction of the thumb - Extensor pollicis longus - Originates from the posterior surface of the middle third of the ulna and interosseous membrane - Inserts into the dorsal base of the distal phalanx of the first digit - Performs individual extension of the thumb at the metacarpophalangeal and interphalangeal joints - Extensor pollicis brevis - Originates from the posterior surface of the distal third of the radius and interosseous membrane - Inserts into the dorsal base of the proximal phalanx of the first digit - Performs individual extension of the thumb at the metacarpophalangeal joint and the carpometacarpal joint