The Upper Limb--Muscles Flashcards
Pectoralis major
Proximal Attach (origin): -Clavicular head -sternocostal head Distal Attach (insertion): -Lateral lip of intertubercular sulcus of humerus Innervation: -Lateral and medial pectoral nerves -clavicular head (C5, C6) -Sternocostal head (C7, C8, T1) Action: -Adducts and medially rotates humerus -draws scapula anteriorly and inferiorly
Pectoralis minor
Proximal Attach: 3rd-5th ribs near their costal cartilages
Distal Attach: medial border and superior surface of coracoid process of scapula
Innervation: Medial pectoral nerve (C8, T1)
Action: Stabilizes scapula by drawing it inferiorly and anteriorly against thoracic wall
Subclavius
Proximal Attach: Junction of 1st rib and its costal cartilage
Distal Attach: Inferior surface of middle third of clavicle
Innervation: Nerve to subclavius (C5, C6)
Action: Anchors and depresses clavicle
Serratus anterior
Proximal Attach: External surfaces of lateral parts of 1st-8th ribs
Distal Attach: Anterior surface of medial border of scapula
Innervation: Long thoracic nerve (C5, C6, C7)
Action: Protracts scapula and holds it against thoracic wall; rotates scapula
Trapezius
Proximal Attach: -Medial third of superior nuchal line -External occipital protuberance -Nuchal ligament -Spinous process of C7-T1 Distal Attach: -Lateral third of clavicle -Acromion and spine of scapula Innervation: -Spinal accessory nerve (CN XI) motor fibers -C3, C4 spinal nerves (pain and proprioceptive fibers) Action: -Descending part elevates -Ascending part depresses -Middle part (or all parts together) retract scapula -Descending and ascending parts act together to rotate glenoid cavity superiorly
Latissimus dorsi
Proximal Attach: -Spinous processes of inferior 6 thoracic vertebrae -thorocolumbar fascia -iliac crest -Inferior 3 or 4 ribs Distal Attach: -Floor of intertubercular sulcus of humerus Innervation: -thoracordorsal nerve (C6, C7, C8) Action: -Extends, adducts, and medially rotates humerus -Raises body toward arms during climbing
Levator scapulae
Proximal Attach:
-Posterior tubercles of transverse processes of C1-C4 vertebrae
Distal Attach:
-Medial border of scapula superior to root of scapular spine
Innervation:
-Dorsal scapular (C4, C5) and
-Cervical (C3, C4) nerves
Action: Elevates scapula and rotates its glenoid cavity inferiorly by rotating scapula
Rhomboid minor
Proximal Attach:
-Nuchal ligament
-Spinous processes of C1-C4 vertebrae
Distal Attach:
-Smooth triangular area at medial end of scapular spine
Innervation: Dorsal scapular nerve (C4, C5)
Action:
-Retract scapula and rotate its glenoid cavity inferiority
-Fix scapula to thoracic wall
Rhomboid major
Proximal Attach: Spinous processes of T2-T5 vertebrae
Distal Attach: Medial border of scapula from level of spine to inferior angle
Innervation: Dorsal scapular nerve (C4, C5)
Action: -Retract scapula and rotate its glenoid cavity inferiority
-Fix scapula to thoracic wall
Infraspinatus
Proximal Attach:Infraspinous fossa of scapula
Distal Attach:Middle facet of greater tubercle of humerus
Innervation: Suprascapular nerve (C5, C6)
Action: Laterally rotates arm and acts with rotator cuff muscles
Teres minor
Proximal Attach:Middle part of lateral border of scapula
Distal Attach: Inferior facet of greater tubercle of humerus
Innervation: Axillary nerve (C5, C6)
Action: Laterally roates arms and acts with rotator cuff muscles
Teres major
Proximal Attach: Posterior surface of inferior angle of scapula
Distal Attach: Medial lip of intertubercular sulcus of humerus
Innervation: Lower subscapular nerve (C5, C6)
Action: Adducts and medially rotates arm
Subscapularis
Proximal Attach: Subscapular fossa
Distal Attach: Lesser tubercle of humerus
Innervation: Upper and lower subscapular nerves (C5, C6, C7)
Action:
-Medially rotates arm
- Helps hold head of humerus in glenoid cavity
Deltoid
Proximal Attach:
-Lateral third of clavicle
-Acromion and spine of scapula
Distal Attach: Deltoid tuberosity of humerus
Innervation: Axillary nerve (C5, C6)
Action:
-Clavicular (anterior) part: flexes and medially rotates arm
-Acromial (middle) part: abducts arm
-Spinal (posterior) part: extends and laterally rotates arm
Supraspinatus
Proximal Attach: Supraspinous fossa of scapula
Distal Attach: Superior facet of greater tubercle of humerus
Innervation: Suprascapular nerve (C4, C5, C6)
Action: Initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles
Infraspinatus
Proximal Attach: Infraspinous fossa of scapula
Distal Attach: Middle facet of greater tubercle of humerus
Innervation: Suprascapular nerve
Action:
-Laterally rotates arm
-Acts with rotator cuff muscles
Teres minor
Proximal Attach: Middle part of lateral border of scapula
Distal Attach: Inferior facet of greater tubercle of humerus
Innervation: Axillary nerve (C5, C6)
Action:
-Laterally rotates arm
-Acts with rotator cuff muscles
Teres major
Proximal Attach: Posterior surface of inferior angle of scapula
Distal Attach: Medial lip of intertubercular sulcus of humerus
Innervation: Lower subscapular nerve (C5, C6)
Action: Adducts and medially rotates arm
Subscapularis
Proximal Attach: Subscapular fossa
Distal Attach: Lesser tubercle of humerus
Innervation: Upper and lower subscapular nerves
Action:
-Medially rotates arm; as part of rotator cuff
-helps hold head of humerus in glenoid cavity
Biceps brachii
Proximal Attach:
-Short head: tip of coracoid process of scapula
-Long head: supraglenoid tubercule of scapula
Distal Attach:
Tuberosity of radius
-Fascia of forearm via bicipital aponeurosis
Innervation: Musculotaneous nerve (C5, C6, C7)
Action:
-Supinates forearm
-Flexes forearm
-Short head resists dislocation of shoulder
Coracobrachialis
Proximal Attach: Tip of coracoid process of scapula
Distal Attach: Middle third of medial surface of humerus
Innervation: Musculotaneous nerve (C5, C6, C7)
Action:
-Helps flex and adduct arm
-Resists dislocation of shoulder
Brachialis
Proximal Attach: Distal half of anterior surface of humerus
Distal Attach: Coronoid process and tuberosity of ulna
Innervation: Musculocutaneous nerve (C5, C6) and radial nerve
Action: Flexes forearm in all positions
Triceps brachii
Proximal Attach:
-Long head: infraglenoid tubercule of scapula
-Lateral head: posterior surface of humerus, superior to radial groove
-Medial head: posterior surface of humerus, inferior to radial groove
Distal Attach: Proximal end of olecranon of ulna and fascia of forearm
Innervation: Radial nerve (C6, C7, C8)
Action:
-Chief extensor of forearm
-Long head resists dislocation of humerus
-Adduction
Anconeus
Proximal Attach: Lateral epicondyle of humerus
Distal Attach: Lateral surface of olecranon and superior part of posterior surface of ulna
Innervation: Radial nerve (C7, C8, T1)
Action:
-Assists triceps in extending forearm
-Stabilizes elbow joint
-May abduct ulna during pronation
Pronator teres
ANT FOREARM, Superficial
Proximal Attach:
-Ulnar head: coronoid process
-Humeral head: medial epicondyle of humerus
Distal Attach: Middle of convexity of lateral surface of radius
Innervation: Median nerve (C6, C7)
Action: Pronates and flexes arm at elbow
Flexor carpi radialis
ANT FOREARM, Superficial Proximal Attach: Medial epicondyle of humerus Distal Attach: Base of 2nd metacarpal Innervation: Median nerve (C6, C7) Action: Flexes and abducts hand
Palmaris longus
ANT FOREARM, Superficial
Proximal Attach: Medial epicondyle of humerus
Distal Attach: Distal half of flexor retinaculumand apex of palmar aponeurosis
Innervation: Median nerve (C7, C8)
Action:
-Flexes hand at wrist
-Tenses palmar aponeurosis
Flexor carpi ulnaris
ANT FOREARM, Superficial Proximal Attach: -Humeral head: Medial epicondyle of humerus -Ulnar head: Olecranon and posterior border of ulna Distal Attach: -Pisiform -Hook of hamate -5th metacarpal Innervation: Ulnar nerve Action: Flexes and adducts hand at wrist
Flexor digitorum superficialis
ANT FOREARM, Intermediate
Proximal Attach:
-Humero-ulnar head: medial epicondyle
-Radial head: Superior half of anterior border of radius
Distal Attach: Shafts of middle phalanges of medial four digits
Innervation: Median nerve (C7, C8, T1)
Action:
-Flexes middle phalanges at proximal interphalangeal joints of middle 4 digits
-Flexes proximal phalanges at metacarpophalangeal joints
Flexor digitorum profundus
ANT FOREARM, Deep
Proximal Attach: Proximal three-quarters of medial and anteriro surfaces of ulna and interosseous membrane
Distal Attach:
-Medial part: bases of distal phalanges of 4th and 5th digits
-Lateral part: bases of distal phalanges of 2nd and 3rd digits
Innervation:
-Medial part: ulnar nerve
-Lateral part: Anterior interosseous nerve, from median nerve
Action:
-Medial part: flexes distal phalanges 4 and 5 at distal interphalangeal joints
-Lateral part: flexes distal phalanges 2 and 3 at distal inter phalangeal joints
Flexor pollicis longus (FPL)
ANT FOREARM, Deep
Proximal Attach:
-Anterior surface of radius
-Adjacent interosseous membrane
Distal Attach: Base of distal phalanx of thumb
Innervation: Anterior interosseous nerve, from median nerve
Action: Flexes phalanges of 1st digit
Pronator quadratus
ANT FOREARM, Deep
Proximal Attach: Distal quarter of anterior surface of ulna
Distal Attach: Distal quarter of anterior surface of radius
Innervation: Anterior interosseous nerve, from median nerve
Action: pronates forearm; deep fibers bind radius and ulna together
Brachioradialis
POST FOREARM, Superficial
Proximal Attach: Proximal two-thirds of supra-epicondylar ridge of humerus
Distal Attach: Lateral surface of distal end of radius proximal to styloid process
Innervation: Radial nerve (C5, C6, C7)
Action: Weak flexion of forearm (this is an exception)
Extensor carpi radialis longus
POST FOREARM, Superficial
Proximal Attach: Lateral supra-epicondylar ridge of humerus
Distal Attach: Dorsal aspect of base of 2nd metacarpal
Innervation: Radial nerve (C6, C7)
Action: Extend and abduct hand at wrist joint
Extensor carpi radialis brevis
POST FOREARM, Superficial
Proximal Attach: Lateral epicondyle of humerus
Distal Attach: Dorsal aspect of base of 3rd metacarpal
Innervation: Deep branch of radial nerve (C7, C8)
Action: Extend and abduct hand at wrist joint (same action as extensor carpi radialis longus)
Extensor digitorum
POST FOREARM, Superficial
Proximal Attach: Lateral epicondyle of humerus
Distal Attach: Extensor expansions of medial 4 digits
Innervation: Deep branch of radial nerve (C7, C8)
Action: Extends medial 4 digits primarily at metacarpophalangeal joint, secondarily at interphalangeal joints
Extensor digiti minimi
POST FOREARM, Superficial
Proximal Attach: Lateral epicondyle of humerus
Distal Attach: Extensor expansion of 5th digit
Innervation: Deep branch of radial nerve (C7, C8)
Action: Extends 5th digit primarily at metacarpophalangeal joint; secondarily at interphalangeal joints
Extensor carpi ulnaris
POST FOREARM, Superficial
Proximal Attach:
-Lateral epicondyle of humerus
-Posterior border of ulna via a shared aponeurosis
Distal Attach: Dorsal aspect of base of 5th metacarpal
Innervation: Deep branch of radial nerve (C7, C8)
Action: Extends and adducts hand at wrist joint (same action as extensor carpi radialis longus & brevis)
Supinator
POST FOREARM, Deep
Proximal Attach:
-Lateral epicondyle of humerus
-Radial collateral and anular ligaments
-Supinator fossa
-Crest of ulna
Distal Attach: Lateral, posterior, and anterior surfaces of proximal third of radius
Innervation: Deep branch of radial nerve (C7, C8)
Action:
-Supinates forearm
-Rotates radius to turn palm anteriorly or superiorly
Extensor indicis
POST FOREARM, Deep
Proximal Attach: Post surface of distal third of ulna and interosseous membrane
Distal Attach: Extensor expansion of 2nd digit
Innervation: Posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
Action:
-Extends 2nd digit, enabling its independent extension
-Helps extend hand at wrist
Abductor pollicis longus
POST FOREARM, Outcropping muscles of Deep Layer
Proximal Attach: Post surface of proximal halves of ulna, radius, and interosseous membrane
Distal Attach: Base of 1st metacarpal
Innervation: Post interosseous nerve(C7, C8), continuation of deep branch of radial nerve
Action: Abducts thumb and extends it at carpometacarpal joint
Extensor pollicis longus
POST FOREARM, Outcropping muscles of Deep Layer
Proximal Attach: Post surface of middle third of ulna and interosseous membrane
Distal Attach: Dorsal aspect of base of distal phalanx of thumb
Innervation: Post interosseous nerve (C7, C8), continuation of deep branch of radial nerve
Action:
-Extends distal phalanx of thumb at interphalangeal joint
-Extends metacarpophalangeal and carpometacarpal joints
Extensor pollicis brevis
POST FOREARM, Outcropping muscles of Deep Layer
Proximal Attach: Post surface of distal third of radius and interosseous membrane
Distal Attach: Dorsal aspect of base of proximal phalanx of thumb
Innervation: Post interosseous nerve (C7, C8), continuation of deep branch of radial nerve
Action:
-Extends proximal phalanx of thumb at metacarpophalangeal joint
-Extends carpometacarpal joint