Muscles of the arm Flashcards
What are the two superficial extrinsic muscles of the shoulder?
Trapezius and latissimus dorsi
What are the ORIGINS of the TRAPEZIUS?
Skull, nuchal ligament and spinous processes of C7-T12
What are the ATTACHMENTS of the TRAPEZIUS?
Clavicle, acromion and spine of the scapula
What is the INNERVATION of the TRAPEZIUS?
Motor innervation - accessory nerve
It also receives proprioceptor fibres from C3 and C4 spinal nerves
What are the ACTIONS of the TRAPEZIUS?
The upper fibres elevate and rotate the scapula during abduction of the arm
The middle fibres retract the scapula
The lower fibres pull the scapula inferiorly
What are the ORIGINS of the LATISSIMUS DORSI?
The spinous processes of T7-T12, the iliac crest, thoracolumbar fascia and the inferior three ribs
What are the ATTACHMENTS of the LATISSIMUS DORSI?
The fibres converge into a tendon that attaches to the intertubercular sulcus of the humerus
What is the INNERVATION of the LATISSIMUS DORSI?
Thoracodorsal nerve
What are the ACTIONS of the LATISSIMUS DORSI?
Extends, adducts and medially rotates the upper limb.
What are the three deep extrinsic muscles of the shoulder?
The levator scapulae, and the two rhomboids (major and minor)
What are the ORIGINS of the LEVATOR SCAPULAE?
The transverse processes of the C1-C4 vertebrae
What are the ATTACHMENTS of the LEVATOR SCAPULAE?
Medial border of the scapula
What is the INNERVATION of the LEVATOR SCAPULAE?
The dorsal scapular nerve
What are the ACTIONS of the LEVATOR SCAPULAE?
Elevates the scapula
What are the ORIGINS of the RHOMBOID MAJOR?
The spinous processes of T2-T5 vertebrae
What are the ATTACHMENTS of the RHOMBOID MAJOR?
the medial border of the scapula, between the scapula spine and inferior angle
What is the INNERVATION of the RHOMBOID MAJOR?
Dorsal scapular nerve.
What are the ACTIONS of the RHOMBOID MAJOR?
Retracts and rotates the scapula
What are the ORIGINS of the RHOMBOID MINOR?
The spinous processes of C7-T1 vertebrae
What are the ATTACHMENTS of the RHOMBOID MINOR?
The medial border of the scapula, at the level of the spine of scapula.
What is the INNERVATION of the RHOMBOID MINOR?
Dorsal scapular nerve
What are the ACTIONS of the RHOMBOID MINOR?
Retracts and rotates the scapula
What does EXTRINSIC muscle of the shoulder mean?
The muscles originate from the torso and attach to bones of the shoulder (clavicle, scapula or humerus)
What does INTRINSIC muscle of the shoulder mean?
The muscles originate from the scapula and/or clavicle and attach to the humerus
What are the six intrinsic muscles of the shoulder?
the deltoid, teres major, and the four rotator cuff muscles (supraspinatus, infraspinatus, subscapularis and teres minor)
What are the ORIGINS of the DELTOID?
the scapula and clavicle
What are the ATTACHMENTS of the DELTOID?
the deltoid tuberosity on the lateral surface of the humerus
What is the INNERVATION of the DELTOID?
The axillary nerve
What are the ACTIONS of the DELTOID?
Anterior fibres – flexion and medial rotation.
Posterior fibres – extension and lateral rotation.
Middle fibres – the major abductor of the arm (takes over from the supraspinatus, which abducts the first 15 degrees).
What are the ORIGINS of the TERES MAJOR?
the posterior surface of the inferior angle of the scapula
What are the ATTACHMENTS of the TERES MAJOR?
the medial lip of the intertubercular groove of the humerus
What is the INNERVATION of the TERES MAJOR?
Lower subscapular nerve
What are the ACTIONS of the TERES MAJOR?
Adducts at the shoulder and medially rotates the arm
What are the four muscles that make up the rotator cuff?
Teres minor, supraspinatus, subscapularis and infraspinatus.
What are the ORIGINS of the SUPRASPINATUS?
the supraspinous fossa of the scapula
What are the ATTACHMENTS of the SUPRASPINATUS?
greater tubercle of the humerus
What is the INNERVATION of the SUPRASPINATUS?
Suprascapular nerve
What are the ACTIONS of the SUPRASPINATUS?
Abducts the arm 0-15deg, and assists deltoid for 15-90deg
What are the ORIGINS of the INFRASPINATUS?
the infraspinous fossa of the scapula
What are the ATTACHMENTS of the INFRASPINATUS?
the greater tubercle of the humerus
What is the INNERVATION of the INFRASPINATUS?
suprascapular nerve
What are the ACTIONS of the INFRASPINATUS?
Laterally rotates the arm.
What are the ORIGINS of the SUBSCAPULARIS?
the subscapular fossa, on the costal surface of the scapula
What are the ATTACHMENTS of the SUBSCAPULARIS?
the lesser tubercle of the humerus
What is the INNERVATION of the SUBSCAPULARIS?
Upper and lower subscapular nerves.
What are the ACTIONS of the SUBSCAPULARIS?
Medially rotates the arm
What are the ORIGINS of the TERES MINOR?
the posterior surface of the scapula, adjacent to its lateral border
What are the ATTACHMENTS of the TERES MINOR?
the greater tubercle of the humerus
What is the INNERVATION of the TERES MINOR?
Axillary nerve
What are the ACTIONS of the TERES MINOR?
Laterally rotates the arm
What are the muscles of the upper arm?
Three in the anterior compartment - the biceps brachii, brachialis, coracobrachialis
One in the posterior compartment - triceps brachii
What are the ORIGINS of the BICEPS BRACHII?
Long head originates from the supraglenoid tubercle of the scapula, and the short head originates from the coracoid process of the scapula
What are the ATTACHMENTS of the BICEPS BRACHII?
Both heads insert distally into the radial tuberosity and the fascia of the forearm via the bicipital aponeurosis
What is the INNERVATION of the BICEPS BRACHII?
Musculocutaneous nerve
What are the ACTIONS of the BICEPS BRACHII?
Supination of the forearm. It also flexes the arm at the elbow and at the shoulder
What are the ORIGINS of the CORACOBRACHIALIS?
the coracoid process of the scapula
What are the ATTACHMENTS of the CORACOBRACHIALIS?
the medial side of the humeral shaft, at the level of the deltoid tubercle
What is the INNERVATION of the CORACOBRACHIALIS?
Musculocutaneous nerve
What are the ACTIONS of the CORACOBRACHIALIS?
Flexion of the arm at the shoulder, and weak adduction
What are the ORIGINS of the BRACHIALIS?
the medial and lateral surfaces of the humeral shaft
What are the ATTACHMENTS of the BRACHIALIS?
the ulna tuberosity, just distal to the elbow joint
What is the INNERVATION of the BRACHIALIS?
Musculocutaneous nerve, with contributions from the radial nerve
What are the ACTIONS of the BRACHIALIS?
Flexion at the elbow
What are the ORIGINS of the TRICEPS BRACHII?
Long head – originates from the infraglenoid tubercle.
Lateral head – originates from the humerus, superior to the radial groove.
Medial head – originates from the humerus, inferior to the radial groove
What are the ATTACHMENTS of the TRICEPS BRACHII?
the heads converge onto one tendon and insert into the olecranon of the ulna
What is the INNERVATION of the TRICEPS BRACHII?
Radial nerve
What are the ACTIONS of the TRICEPS BRACHII?
Extension of the arm at the elbow
what are the compartments of the forearm?
anterior and posterior
What are the categories of muscles in the anterior compartment?
superficial, intermediate and deep
What are the general functions of the anterior compartment of the forearm?
flexion at the wrist and fingers, and pronation
What are the superior muscles of the anterior compartment of the forearm?
flexor carpi ulnaris, palmaris longus, flexor carpi radialis and pronator teres
What are the ORIGINS of the FLEXOR CARPI ULNARIS?
the medial epicondyle with the other superficial flexors, and the ulna
What are the ATTACHMENTS of the FLEXOR CARPI ULNARIS?
passes into the wrist, and attaches to the pisiform carpal bone
What is the INNERVATION of the FLEXOR CARPI ULNARIS?
ulnar nerve
What are the ACTIONS of the FLEXOR CARPI ULNARIS?
Flexion and adduction at the wrist.
What are the ORIGINS of the PALMARIS LONGUS?
medial epicondyle
What are the ATTACHMENTS of the PALMARIS LONGUS?
the flexor retinaculum of the wrist
What is the INNERVATION of the PALMARIS LONGUS?
Median nerve
What are the ACTIONS of the PALMARIS LONGUS?
Flexion at the wrist
What are the ORIGINS of the FLEXOR CARPI RADIALIS?
medial epicondyle
What are the ATTACHMENTS of the FLEXOR CARPI RADIALIS?
the base of metacarpals II and III
What is the INNERVATION of the FLEXOR CARPI RADIALIS?
Median nerve
What are the ACTIONS of the FLEXOR CARPI RADIALIS?
Flexion and abduction at the wrist
What are the ORIGINS of the PRONATOR TERES?
The medial epicondyle, and the coronoid process of the ulna
What are the ATTACHMENTS of the PRONATOR TERES?
laterally to the mid-shaft of the radius
What is the INNERVATION of the PRONATOR TERES?
Median nerve
What are the ACTIONS of the PRONATOR TERES?
Pronation of the forearm
What muscles are in the intermediate category of the anterior compartment?
flexor digitorum superficialis
What are the ORIGINS of the FLEXOR DIGITORUM SUPERFICIALIS?
the medial epicondyle of the humerus, the radius
What are the ATTACHMENTS of the FLEXOR DIGITORUM SUPERFICIALIS?
The muscle splits into four tendons at the wrist, which travel through the carpal tunnel, and attaches to the middle phalanges of the four fingers
What is the INNERVATION of the FLEXOR DIGITORUM SUPERFICIALIS?
Median nerve
What are the ACTIONS of the FLEXOR DIGITORUM SUPERFICIALIS?
Flexes the metacarpophalangeal joints and proximal interphalangeal joints at the 4 fingers, and flexes at the wrist
What are the muscles of the deep anterior forearm?
flexor digitorum profundus, flexor pollicis longus, and pronator quadratus
What are the ORIGINS of the FLEXOR DIGITORUM PROFUNDUS?
the ulna and associated interosseous membrane
What are the ATTACHMENTS of the FLEXOR DIGITORUM PROFUNDUS?
At the wrist, it splits into four tendons, that pass through the carpal tunnel and attach to the distal phalanges of the four fingers
What is the INNERVATION of the FLEXOR DIGITORUM PROFUNDUS?
The medial half (acts on the little and ring fingers) is innervated by the ulnar nerve. The lateral half (acts on the middle and index fingers) is innervated by the anterior interosseous branch of the median nerve.
What are the ACTIONS of the FLEXOR DIGITORUM PROFUNDUS?
It is the only muscle that can flex the distal interphalangeal joints of the fingers. It also flexes at metacarpophalangeal joints and at the wrist
What are the ORIGINS of the FLEXOR POLLICIS LONGUS?
the anterior surface of the radius, and surrounding interosseous membrane
What are the ATTACHMENTS of the FLEXOR POLLICIS LONGUS?
The base of the distal phalanx of the thumb
What is the INNERVATION of the FLEXOR POLLICIS LONGUS?
Median nerve (anterior interosseous branch)
What are the ACTIONS of the FLEXOR POLLICIS LONGUS?
Flexes the interphalangeal joint and metacarpophalangeal joint of the thumb
What are the ORIGINS of the PRONATOR QUADRATUS?
the anterior surface of the ulna
What are the ATTACHMENTS of the PRONATOR QUADRATUS?
the anterior surface of the radius
What is the INNERVATION of the PRONATOR QUADRATUS?
Median nerve (anterior interosseous branch)
What are the ACTIONS of the PRONATOR QUADRATUS?
Pronates the forearm
What are the layers of the posterior compartment of the forearm?
superficial and deep
what is the general function of the muscles in the posterior compartment?
produce extension at the wrist and fingers
What are the superficial muscles of the posterior forearm?
Brachioradialis, extensor carpi radialis longus and brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, anconeus
What are the ORIGINS of the BRACHIORADIALIS?
the proximal aspect of the lateral supracondylar ridge of humerus
What are the ATTACHMENTS of the BRACHIORADIALIS?
the distal end of the radius, just before the radial styloid process
What is the INNERVATION of the BRACHIORADIALIS?
Radial nerve
What are the ACTIONS of the BRACHIORADIALIS?
Flexes at the elbow
What are the ORIGINS of the EXTENSOR CARPI RADIALIS LONGUS AND BREVIS?
The ECRL originates from the supracondylar ridge, while the ECRB originates from the lateral epicondyle
What are the ATTACHMENTS of the EXTENSOR CARPI RADIALIS LONGUS AND BREVIS?
metacarpal bones II and III
What is the INNERVATION of the EXTENSOR CARPI RADIALIS LONGUS AND BREVIS?
Radial nerve
What are the ACTIONS of the EXTENSOR CARPI RADIALIS LONGUS AND BREVIS?
Extends and abducts the wrist
What are the ORIGINS of the EXTENSOR DIGITORUM?
the lateral epicondyle
What are the ATTACHMENTS of the EXTENSOR DIGITORUM?
The tendon continues into in the distal part of the forearm, where it splits into four, and inserts into the extensor hood of each finger
What is the INNERVATION of the EXTENSOR DIGITORUM?
Radial nerve (deep branch)
What are the ACTIONS of the EXTENSOR DIGITORUM?
Extends medial four fingers at the MCP and IP joints
What are the ORIGINS of the EXTENSOR DIGITI MINIMI?
the lateral epicondyle of the humerus
What are the ATTACHMENTS of the EXTENSOR DIGITI MINIMI?
with the extensor digitorum tendon, into the extensor hood of the little finger
What is the INNERVATION of the EXTENSOR DIGITI MINIMI?
Radial nerve (deep branch)
What are the ACTIONS of the EXTENSOR DIGITI MINIMI?
Extends the little finger, and contributes to extension at the wrist
What are the ORIGINS of the EXTENSOR CARPI ULNARIS?
the lateral epicondyle of the humerus
What are the ATTACHMENTS of the EXTENSOR CARPI ULNARIS?
the base of metacarpal V
What is the INNERVATION of the EXTENSOR CARPI ULNARIS?
Radial nerve (deep branch)
What are the ACTIONS of the EXTENSOR CARPI ULNARIS?
Extension and adduction of wrist
What are the ORIGINS of the ANCONEUS?
the lateral epicondyle
What are the ATTACHMENTS of the ANCONEUS?
the posterior and lateral part of the olecranon
What is the INNERVATION of the ANCONEUS?
Radial nerve
What are the ACTIONS of the ANCONEUS?
Extends and stabilises the elbow joint. Abducts the ulna during pronation of the forearm
What are the muscles in the deep posterior forearm?
the supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus and extensor indicis
What are the ORIGINS of the SUPINATOR?
the lateral epicondyle of the humerus and the posterior surface of the ulna
What are the ATTACHMENTS of the SUPINATOR?
together into the posterior surface of the radius
What is the INNERVATION of the SUPINATOR?
Radial nerve (deep branch)
What are the ACTIONS of the SUPINATOR?
Supinates the forearm
What are the ORIGINS of the ABDUCTOR POLLICIS LONGUS?
the interosseous membrane and the adjacent posterior surfaces of the radius and ulna
What are the ATTACHMENTS of the ABDUCTOR POLLICIS LONGUS?
the lateral side of the base of metacarpal I
What is the INNERVATION of the ABDUCTOR POLLICIS LONGUS?
Radial nerve (posterior interosseous branch)
What are the ACTIONS of the ABDUCTOR POLLICIS LONGUS?
Abducts the thumb
What are the ORIGINS of the EXTENSOR POLLICIS BREVIS?
The posterior surface of the radius and interosseous membrane
What are the ATTACHMENTS of the EXTENSOR POLLICIS BREVIS?
the base of the proximal phalanx of the thumb
What is the INNERVATION of the EXTENSOR POLLICIS BREVIS?
Radial nerve (posterior interosseous branch)
What are the ACTIONS of the EXTENSOR POLLICIS BREVIS?
Extends at the metacarpophalangeal and carpometacarpal joints of the thumb
What are the ORIGINS of the EXTENSOR POLLICIS LONGUS?
The posterior surface of the ulna and interosseous membrane
What are the ATTACHMENTS of the EXTENSOR POLLICIS LONGUS?
the distal phalanx of the thumb
What is the INNERVATION of the EXTENSOR POLLICIS LONGUS?
Radial nerve (posterior interosseous branch)
What are the ACTIONS of the EXTENSOR POLLICIS LONGUS?
Extends all joints of the thumb: carpometacarpal, metacarpophalangeal and interphalangeal.
What are the ORIGINS of the EXTENSOR INDICIS PROPRIUS?
the posterior surface of the ulna and interosseous membrane, distal to the extensor pollicis longus
What are the ATTACHEMENTS of the EXTENSOR INDICIS PROPRIUS?
the extensor hood of the index finger
What is the INNERVATION of the EXTENSOR INDICIS PROPRIUS?
Radial nerve (posterior interosseous branch)
What are the ACTIONS of the EXTENSOR INDICIS PROPRIUS?
Extends the index finger
What are the two groups of muscles in the hand?
extrinsic and intrinsic muscles
What are the extrinsic muscles of the hand?
located in the anterior and posterior compartments of the forearm. They control crude movements and produce a forceful grip.
What are the intrinsic muscles of the hand?
located within the hand itself. They are responsible for the fine motor functions of the hand
what are the thenar muscles?
three short muscles located at the base of the thumb. The muscle bellies produce a bulge, known as the thenar eminence. They are responsible for the fine movements of the thumb.
what are the three thenar muscles?
opponens pollicis, abductor pollicis brevis and flexor pollicis brevis
What are the ORIGINS of the OPPONENS POLLICIS?
the tubercle of the trapezium, and the associated flexor retinaculum
What are the ATTACHMENTS of the OPPONENS POLLICIS?
the lateral margin of the metacarpal of the thumb (i.e. the first metacarpal)
What is the INNERVATION of the OPPONENS POLLICIS?
Median nerve
What are the ACTIONS of the OPPONENS POLLICIS?
Opposes the thumb, by medially rotating and flexing the metacarpal on the trapezium.
What are the ORIGINS of the ABDUCTOR POLLICIS BREVIS?
the tubercles of the scaphoid and trapezium, and from the associated flexor retinaculum
What are the ATTACHMENTS of the ABDUCTOR POLLICIS BREVIS?
lateral side of proximal phalanx of the thumb
What is the INNERVATION of the ABDUCTOR POLLICIS BREVIS?
Median nerve
What are the ACTIONS of the ABDUCTOR POLLICIS BREVIS?
Abducts the thumb.
What are the ORIGINS of the FLEXOR POLLICIS BREVIS?
the tubercle of the trapezium and from the associated flexor retinaculum
What are the ATTACHMENTS of the FLEXOR POLLICIS BREVIS?
The base of the proximal phalanx of the thumb
What is the INNERVATION of the FLEXOR POLLICIS BREVIS?
Median nerve. The deep head is innervated by the deep branch of the ulnar nerve.
What are the ACTIONS of the FLEXOR POLLICIS BREVIS?
Flexes the metacarpophalangeal (MCP) joint of the thumb
What are the hypothenar muscles?
produce the hypothenar eminence – a muscular protrusion on the medial side of the palm, at the base of the little finger.
What are the three hypothenar muscles?
Opponens digiti minimi, Abductor Digiti Minimi and Flexor Digiti Minimi Brevis
What are the ORIGINS of the OPPONENS DIGITI MINIMI?
The hook of hamate and associated flexor retinaculum
What are the ATTACHMENTS of the OPPONENS DIGITI MINIMI?
the medial margin of metacarpal V
What is the INNERVATION of the OPPONENS DIGITI MINIMI?
Ulnar nerve
What are the ACTIONS of the OPPONENS DIGITI MINIMI?
It rotates the metacarpal of the little finger towards the palm, producing opposition
What are the ORIGINS of the ABDUCTOR DIGITI MINIMI?
The pisiform and the tendon of the flexor carpi ulnaris
What are the ATTACHMENTS of the ABDUCTOR DIGITI MINIMI?
The base of the proximal phalanx of the little finger
What is the INNERVATION of the ABDUCTOR DIGITI MINIMI?
Ulnar nerve
What are the ACTIONS of the ABDUCTOR DIGITI MINIMI?
Abducts the little finger
What are the ORIGINS of the FLEXOR DIGITI MINIMI BREVIS?
The hook of hamate and adjacent flexor retinaculum
What are the ATTACHMENTS of the FLEXOR DIGITI MINIMI BREVIS?
The base of the proximal phalanx of the little finger
What is the INNERVATION of the FLEXOR DIGITI MINIMI BREVIS?
Ulnar nerve
What are the ACTIONS of the FLEXOR DIGITI MINIMI BREVIS?
Flexes the MCP joint of the little finger
What are the Lumbricals?
there are four in each hand, each associated with a finger
What are the ORIGINS of the LUMBRICALS?
Each lumbrical originates from a tendon of the flexor digitorum profundus
What are the ATTACHMENTS of the LUMBRICALS?
They pass dorsally and laterally around each finger, and inserts into the extensor hood
What is the INNERVATION of the LUMBRICALS?
The lateral two lumbricals (of the index and middle fingers) are innervated by the median nerve. The medial two lumbricals (of the little and ring fingers) are innervated by the ulnar nerve
What are the ACTIONS of the LUMBRICALS?
The flex at the MCP joint, and extend at the interphalangeal (IP) joints of each finger
What are the two groups of interossei muscles?
Dorsal and palmar
What are the ORIGINS of the DORAL INTEROSSEI?
Each interossei originates from the lateral and medial surfaces of the metacarpals
What are the ATTACHMENTS of the DORSAL INTEROSSEI?
the extensor hood and proximal phalanx of each finger
What is the INNERVATION of the DORSAL INTEROSSEI?
Ulnar nerve
What are the ACTIONS of the DORSAL INTEROSSEI?
Abduct the fingers at the MCP joint.
What are the ORIGINS of the PALMAR INTEROSSEI?
Each interossei originates from a medial or lateral surface of a metacarpal
What are the ATTACHMENTS of the PALMAR INTEROSSEI?
the extensor hood and proximal phalanx of same finger as it originates
What is the INNERVATION of the PALMAR INTEROSSEI?
Ulnar nerve
What are the ACTIONS of the PALMAR INTEROSSEI?
Adducts the fingers at the MCP joint.
What is the What are the ORIGINS of the PALMAR INTEROSSEI?
a small, thin muscle, found very superficially in the subcutaneous tissue of the hypothenar eminence.
What are the ORIGINS of the PALMARIS BREVIS?
the palmar aponeurosis and flexor retinaculum
What are the ATTACHMENTS of the PALMARIS BREVIS?
the dermis of the skin on the medial margin of the hand
What is the INNERVATION of the PALMARIS BREVIS?
Ulnar nerve
What are the ACTIONS of the PALMARIS BREVIS?
Wrinkles the skin of the hypothenar eminence and deepens the curvature of the hand, improving grip
What is the ADDUCTOR POLLICIS?
large triangular muscle with two heads. The radial artery passes anteriorly through the space between the two heads, forming the deep palmar arch
What are the ORIGINS of the ADDUCTOR POLLICIS?
One head originates from metacarpal III.
The other head originates from the capitate and adjacent areas of metacarpals II and III
What are the ATTACHMENTS of the ADDUCTOR POLLICIS?
Both heads into the base of the proximal phalanx of the thumb.
What is the INNERVATION of the ADDUCTOR POLLICIS?
Ulnar nerve
What are the ACTIONS of the ADDUCTOR POLLICIS?
Adductor of the thumb