UE Axilla, Arm, Forearm, Hand Muscles Flashcards
Axilla boundaries
Apex: 1st rib, clavicle
Base: skin of armpit
Anterior: pectoralis minor
Posterior: scapula, subscapularis muscle
Medial: thoracic wall, serratus anterior
Lateral: Humerus
Axilla contents
Axillary artery, Axillary vein, Axillary lymph nodes, 3 cords of brachial plexus
Anterior compartment of the ARM
Actions: Shoulder & elbow flexion
Musculocutaneous Nerve innervation
Brachial Artery
Posterior compartment of the ARM
Actions: Shoulder & elbow extension
Radial Nerve innervation
Profunda Brachii Artery
Anconeus also in this compartment
Anconeus
Arm muscle
Prox attachment: Lateral epicondyle of humerus
Distal attachment: Lateral surface of the olecranon process
Actions: Elbow extension
Radial Nerve Innervation
Spinal Segments: C7-C8
Biceps brachii (2 heads)
Arm muscle
Prox attachment:
- Short head- coracoid process
- Long head- supraglenoid tubercle of scapula
Distal attachment: Radial tuberosity and deep antebrachial fascia (through bicipital aponeurosis)
Actions: Elbow and shoulder flexion, forearm supination
Musculocutaneous Nerve Innervation
Spinal Segments: C5-C6
Brachialis
Arm muscle
Prox attachment: Distal anterior shaft of humerus & lateral and medial intermuscular septa
Distal attachment: Coronoid process & ulnar tuberosity
Actions: Elbow flexion
Musculocutaneous Nerve Innervation + Small Branch of Radial Nerve
Spinal Segments: C5-C6
Coracobrachialis
Arm muscle
Prox attachment: Coracoid process
Distal attachment: Proximal medial shaft of humerus
Actions: Shoulder flexion and adduction
Musculocutaneous Nerve Innervation
Spinal Segments: C6-C7
Triceps brachii (3 heads)
Arm muscle
Prox attachment:
- Long head- Infraglenoid tubercle of scapula
- Lateral head- proximal posterolateral shaft of humerus
- Medial head- distal posteromedial shaft of the humerus
Distal attachment: Olecranon process of the ulna
Actions: Elbow & shoulder extension
Radial Nerve Innervation
Spinal Segments: C6-T1
Abductor pollicis longus
Forearm muscle
PA: proximal posterior radius, ulna, & interosseous membrane
DA: base of the 1st metacarpal & trapezium
A: abducts & extends the thumb at carpometacarpal joint & abducts hand at wrist (radial deviation)
Radial Nerve Innervation
Spinal Segments C6-C8
Brachioradialis
Forearm muscle
PA: lateral supracondylar ridge of the humerus
DA: distal radius lateral to the styloid process
A: elbow flexion, helps with supination
Radial Nerve Innervation
Spinal Segments C5-C6
Extensor carpi radialis brevis
Forearm muscle
PA: lateral epicondyle of the humerus (common extensor origin)
DA: base of 3rd metacarpal
A: extends & abducts hand at wrist (radial deviation)
Radial Nerve Innervation
Spinal Segments C6-C8
Extensor carpi radialis longus
Forearm muscle
PA: lateral supracondylar ridge of the humerus
DA: base of the 2nd metacarpal
A: extends & abducts hand at wrist (radial deviation) and assists in elbow flexion
Radial Nerve Innervation
Spinal Segments C6-C8
Extensor carpi ulnaris
Forearm muscle
PA: lateral epicondyle of the humerus (common extensor origin)
DA: base of 5th metacarpal
A: extends & adducts hand at wrist (ulnar deviation)
Radial Nerve Innervation
Spinal Segments C6-C8
Extensor digitorum
Forearm muscle
PA: lateral epicondyle of the humerus (common extensor origin)
DA: extensor expansions of digits 2-5
A: extends phalanges (primarily at metacarpophalangeal, secondarily at interphalangeal) & hand at wrist
Radial Nerve Innervation
Spinal Segments C6-C8
Extensor digiti minimi
Forearm muscle
PA: lateral epicondyle of the humerus (common extensor origin)
DA: digital expansion of the 5th digit
A: extends 5th digit (metacarpophalangeal & interphalangeal)
Radial Nerve Innervation
Spinal Segments C7-C8
Extensor indicis
Forearm muscle
PA: posterior surface of the ulna & interosseous membrane
DA: digital expansion of the 2nd digit
A: extends 2nd digit (metacarpophalangeal & interphalangeal)
Radial Nerve Innervation
Spinal Segments C7-C8
Extensor pollicis longus
Forearm muscle
PA: middle 1/3 of the posterior surface of the ulna & interosseous membrane
DA: base of the 1st distal phalanx
A: extends thumb (CMC & metacarpophalangeal & interphalangeal)
Radial Nerve Innervation
Spinal Segments C6-C8
Flexor carpi radialis
Forearm muscle
PA: medial epicondyle (common flexor origin)
DA:palmar aspect of the base of the 2nd metacarpal
A: flexes & abducts hand at wrist (radial deviation) & may assist in pronation of the forearm & flexion of the elbow
Median Nerve Innervation
Spinal Segments C6-C8
Flexor carpi ulnaris
Forearm muscle
PA: medial epicondyle (common flexor origin) of humerus & proximal ulnar shaft
DA: pisiform
A: flexes & adducts hand at wrist (ulnar deviation)
Ulnar Nerve Innervation
Spinal Segments C7-T1
Flexor digitorum profundus
Forearm muscle
PA: anterior proximal 2/3 of the ulna & interosseous membrane
DA: base of the distal phalanges of digits 2-5
A: flexion of digits 2-5 (metacarpophalangeal & distal interphalangeal & proximal interphalangeal), & flexion of hand at wrist
Median (2nd & 3rd digits) & Ulnar (4th & 5th digits) Nerve Innervation
Spinal Segments C7-T1
Flexor digitorum superficialis
Forearm muscle
PA: medial epicondyle (common flexor origin) of the humerus
DA: sides of the middle phalanges of digits 2-5
A: flexion of digits (metacarpophalangeal & proximal interphalangeal) & hand at wrist
Median Nerve Innervation
Spinal Segments C7-T1
Flexor pollicis longus
Forearm muscle
PA: anterior surface of the radius & interosseous membrane
DA: base of the distal phalanx of the thumb
A: flexes thumb (metacarpophalangeal & interphalangeal)
Median Nerve Innervation (anterior interosseous nerve)
Spinal Segments C7-T1
Palmaris longus
Forearm muscle
PA: medial epicondyle of the humerus (common flexor origin)
DA: palmar aponeurosis
A: flexes hand at wrist & tenses palmar fascia
Median Nerve Innervation
Spinal Segments C7-C8
Pronator quadratus
Forearm muscle
PA: anterior surface of the distal ulna
DA: anterior surface of the distal radius
A: pronates the forearm
Median Nerve Innervation (anterior interosseous nerve)
Spinal Segments C8-T1
Pronator teres
Forearm muscle
PA: medial epicondyle & ulnar coronoid process
DA: lateral aspect of the radius
A: pronates & flexes the forearm
Median Nerve Innervation
Spinal Segments C7-C7
Supinator
Forearm muscle
PA: lateral epicondyle of the humerus, radial collateral ligament, & supinator crest of the ulna
DA: lateral surface of the proximal radius
A:supinates forearm
Radial Nerve Innervation
Spinal Segments C5-C6
Abductor digiti minimi
Hand muscle
PA: pisiform
DA: ulnar side of the base of the proximal phalanx of the 5th digit
A: abducts 5th digit (pinky)
Deep branch of Ulnar Nerve Innervation
Spinal Segments C8-T1
Abductor pollicis brevis
Hand muscle
PA: transverse carpal ligament
DA: radial side of the base of the proximal phalanx of the thumb
A: abducts thumb
Recurrent branch of Median Nerve Innervation
Spinal Segments C6-T1
Adductor pollicis
Hand muscle
PA: capitate & 2nd/3rd metacarpals (oblique head) & palmar aspect of the 3rd metacarpal (transverse head)
DA: base of the proximal phalanx of the thumb
A: adducts thumb
Deep branch of Ulnar Nerve Innervation
Spinal Segments C8-T1
Dorsal interossei
Hand muscle
PA: adjacent sides of the metacarpals
DA: proximal phalangeal bases & dorsal digital expansions of digits 2-4
A: abducts (metacarpophalangeal), flexes (metacarpophalangeal) & extends (interphalangeal) digits 2-4
Deep Branch of Ulnar Nerve Innervation
Spinal Segments C8-T1
Flexor digiti minimi brevis
Hand muscle
PA: hamate
DA: ulnar side of the base of the proximal phalanx of the 5th digit
A: flexes (metacarpophalangeal) 5th digit
Deep branch of Ulnar Nerve Innervation
Spinal Segments C8-T1
Flexor pollicis brevis
Hand muscle
PA: transverse carpal ligament & trapezium
DA: radial side of the base of the proximal phalanx of the thumb; deep head blends with opponens pollicis
A: flexes (metacarpophalangeal) thumb
Recurrent branch of the Median Nerve (superficial head) & deep branch of Ulnar Nerve (deep head) Innervation
Spinal Segments: superficial head C6-T1; deep head C8-T1
Lumbricals
Hand muscle
PA: tendons of the flexor digitorum profundus
DA: radial side of dorsal digital expansions of digits 2-5
A: flexes metacarpophalangeal & extends interphalangeal joints of digits 2-5
Deep branch of Ulnar Nerve (3rd & 4th lumbricals C8-T1) and Median Nerve Innervation (1st & 2nd lumbricals C7-8-T1)
Spinal Segments C7-T1
Opponens digiti minimi
Hand muscle
PA: hook of the hamate
DA: ulnar margin of shaft of 5th metacarpal
A: opposition of 5th digit to thumb
Deep branch of Ulnar Nerve Innervation
Spinal Segments C8-T1
Opponens pollicis
Hand muscle
PA: transverse carpal ligament & trapezium
DA: palmar surface of 1st metacarpal
A: opposition of thumb to 5th digit
Recurrent Median Nerve Innervation
Spinal Segments C6-T1
Palmar interossei
Hand muscle
PA: palmar aspects of metacarpals 2, 4, & 5
DA: dorsal digital expansions of digits 2, 4, 5
A: adducts& flexes metacarpophalangeals, extends interphalangeal digits 2, 4, 5.
Deep branch of Ulnar Nerve Innervation
Spinal Segments C8-T1
Extensor pollicis brevis
Forearm muscle
PA: posterior radial surface & interosseous membrane
DA: base of the 1st proximal phalanx
A: extends thumb (metacarpophalangeal) & extends and abducts CMC joint
Radial Nerve Innervation
Spinal Segments C6-C8
Forearm Posterior Compartment
Elbow & hand extension, supination
Radial Nerve Innervation
Radial artery (posterior interosseous)
Cubital Fossa boundaries
from lateral to medial epicondyles
brachioradialis
pronator teres
The bicipital aponeurosis covers and protects the brachial artery and median nerve passing through here.
Forearm Anterior Compartment
Elbow & hand flexion, pronation
Median Nerve Innervation
Ulnar artery (anterior interosseous)
Anterior compartment of forearm superficial layer muscles
Pronator teres
Flexor carpi radialis
Palmaris longus
(all median nerve)
Flexor carpi ulnaris
(ulnar nerve)
Anterior compartment of forearm intermediate layer muscles
Flexor digitorum superficialis
median nerve
Anterior compartment of forearm deep layer muscles
Flexor digitorum profundus (deep)
(medial/ulnar split innervation: digits 2-3 radius, digits 4-5 ulna)
Flexor pollicis longus Pronator quadratus (anterior interosseous nerve from median nerve)
Posterior compartment of forearm superficial layer
6 muscles: Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum Extensor digiti minimi Extensor carpi ulnaris
extension movement
Posterior compartment of forearm deep layer
supinator extensor indicis (index finger)
3 outcropping thumb muscles
abductor pollicis longus
extensor pollicis brevis
extensor pollicis longus (wraps around dorsal tubercle of radius and changes direction to thumb)
