Upper Limb Muscles | Functions, Innervation, Vasculature

Deltoid

• arm abduction, flexion, and extension.

• innervated by axillary nerve, supplied by posterior circumflex humeral artery

Supraspinatus

• arm abduction and stabilization of the shoulder joint.

• innervated bysuprascapular nerve, supplied by suprascapular artery.

Infraspinatus

• Laterally rotates, transversely abducts and stabilizes arm at glenohumeral (shoulder) joint.

• Suprascapular Nerve (C5-C6). Arterial Supply: Circumflex scapular and suprascapular arteries.

Teres Minor

• Laterally rotates, transversely abducts and stabilizes arm at glenohumeral (shoulder) joint.

• Axillary nerve (C5-C6).

• Circumflex scapular and

  osterior circumflex humeral arteries.

Teres Major

• Adducts and medially rotates arm at glenohumeral (shoulder) joint.

• Lower subscapular nerve (C5-C7).

• Arterial Supply: Circumflex scapular, subscapular, and posterior circumflex humeral arteries.

Subscapulari

• Medially rotates and stabilizes arm at glenohumeral (shoulder) joint.

• Innervation: Upper and lower subscapular nerves (C5-C7).

• Arterial Supply: Subscapular, suprascapular, and lateral thoracic arteries.

Pectoralis Major

• Adducts, medially rotates, and transversely adducts arm at glenohumeral (shoulder) joint;

• Innervation: Medial and lateral pectoral nerves (C5-T1).

• Arterial Supply: Pectoral branches of thoracoacromial artery, perforating branches of internal thoracic artery, superior and lateral thoracic arteries.

Pectoralis Mino

• Protracts and downwardly rotates pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints.

• Innervation: Medial and lateral pectoral nerves (C5-T1)

• Arterial Supply: Pectoral and deltoid branches of thoracoacromial artery, superior and lateral thoracic arteries.

Serratus Anterio

• Protracts and upwardly rotates pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints.

• Innervation: Long thoracic nerve (C5-C7).

• Arterial Supply: Superior and lateral thoracic, thoracodorsal arteries.

Latissimus Dorsi

• Adducts, medially rotates, and extends arm at glenohumeral (shoulder) joint.

• Innervation: Thoracodorsal nerve (C6-C8).

• Arterial Supply: Thoracodorsal artery, dorsal branches of ninth to eleventh posterior intercostal, subcostal and first to third lumbar arteries.

Trapezius

• Elevates, depresses, retracts, and upwardly rotates the pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints; extends and laterally flexes head and neck.

• Innervation: Accessory nerve, anterior rami of third and fourth cervical nerves.

• Arterial Supply: Occipital, transverse cervical, and dorsal scapular arteries.

Levator Scapulae

• Elevates and downwardly rotates pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints; extends and laterally flexes neck at cervical vertebral joints.

• Innervation: Anterior rami of third and fourth cervical nerves, dorsal scapular nerve (C5).

• Arterial Supply: Transverse cervical, ascending cervical, and vertebral arteries.

Rhomboid Major

• Retracts and downwardly rotates pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints.

• Innervation: Dorsal scapular nerve (C4-C5).

• Arterial Supply: Dorsal scapular artery, dorsal branches of upper posterior intercostal arteries.

Rhomboid Mino

• Retracts and downwardly rotates pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints.

• Innervation: Dorsal scapular nerve (C4-C5).

• Arterial Supply: Dorsal scapular artery, dorsal branches of upper posterior intercostal arteries.

Biceps Brachii

• Supinates forearm; flexes forearm at elbow joint, most effectively when the forearm is supinated.

• Innervation: Musculocutaneous nerve (C5-C6).

• Arterial Supply: Brachial and anterior circumflex humeral arteries

Brachialis

• Flexes forearm at elbow joint.

• Innervation: Musculocutaneous (C5-C6) and radial (C7) nerves.

• Arterial Supply: Brachial, radial recurrent, and superior ulnar collateral arteries.

Coracobrachialis

• Adducts and flexes arm at glenohumeral (shoulder) joint.

• Innervation: Musculocutaneous nerve (C5-C7).

• Arterial Supply: Brachial and anterior circumflex humeral arteries.

Triceps Brachii

• Extends forearm at elbow joint.

• Innervation: Radial nerve (C6-C8).

• Arterial Supply: Deep brachial, superior ulnar collateral, and posterior circumflex humeral arteries.

Anconeus

• Extends forearm at elbow joint. -

• Innervation: Radial nerve (C7-C8).

• Arterial Supply: Recurrent interosseous artery.

Pronator Teres

• Pronates forearm at radioulnar joints.

• Innervation: Median nerve (C6-C7).

• Arterial Supply: Anterior branch of ulnar recurrent artery, inferior ulnar collateral, common interosseous, ulnar, and radial arteries.

Flexor Carpi Radialis

• Flexes hand at radiocarpal (wrist) joint; abducts hand at radiocarpal and midcarpal joints.

• Innervation: Median nerve (C6-C7).

• Arterial Supply: Radial artery and posterior branch of ulnar recurrent artery.

Palmaris Longus

• Flexes hand at radiocarpal (wrist) joint; stabilizes palmar aponeurosis.

• Innervation: Median nerve (C7-C8).

• Arterial Supply: Median artery and anterior branch of ulnar recurrent artery.

Flexor Carpi Ulnaris

• Flexes and adducts hand at radiocarpal (wrist) joint.

• Innervation: Ulnar nerve (C7-T1).

• Arterial Supply: Ulnar artery and posterior branch of ulnar recurrent artery.

Flexor Digitorum Superficiali

• Flexes index, middle, ring, and little fingers.

• Innervation: Median nerve (C7-T1).

• Arterial Supply: Anterior branch of ulnar recurrent artery, ulnar and radial arteries.

Flexor Digitorum Profundus

• flexes index, middle, ring, and little fingers.

• Innervation: Medial part: ulnar nerve (C8-T1); Lateral part: anterior interosseous branch of median nerve (C8-T1).

• Arterial Supply: Ulnar artery; inferior ulnar collateral artery; ulnar recurrent artery; anterior interosseous artery.

Flexor Pollicis Longus

• Flexes thumb.

• Innervation: Anterior antebrachial interosseous nerve (C7-T1).

• Arterial Supply: Anterior interosseous and radial arteries.

Pronator Quadratus

• Pronates forearm at radioulnar joints.

• Innervation: Anterior antebrachial interosseous nerve (C7-C8).

• Arterial Supply: Anterior interosseous artery.

Brachioradialis

• Flexes forearm at elbow joint.

• Innervation: Radial nerve (C5-C6).

• Arterial Supply: Radial recurrent, radial collateral, and radial arteries.

Extensor Carpi Radialis Longu

• Extends hand at radiocarpal (wrist) joint; abducts hand at radiocarpal and midcarpal joints.

• Innervation: Radial nerve (C6-C7).

• Arterial Supply: Radial recurrent, radial collateral, and radial arteries.

Extensor Carpi Radialis Brevi

• Extends hand at radiocarpal (wrist) joint; abducts hand at radiocarpal and midcarpal joints.

• Innervation: Deep branch of radial nerve (C7-C8) and posterior antebrachial interosseous nerve (C7-C8).

• Arterial Supply: Radial recurrent and radial arteries.

Extensor Digitoru

• Extends index, middle, ring, and little fingers.

• Innervation: Posterior antebrachial interosseous nerve (C7-C8).

• Arterial Supply: Radial recurrent, anterior and posterior interosseous arteries.

Extensor Digiti Minim

• Extends little finger.

• Innervation: Posterior antebrachial interosseous nerve (C7-C8).

• Arterial Supply: Radial recurrent, anterior and posterior interosseous arteries.

Extensor Carpi Ulnari

• Extends and adducts hand at radiocarpal (wrist) joint.

• Innervation: Posterior antebrachial interosseous nerve (C7-C8).

• Arterial Supply: Radial recurrent and posterior interosseous arteries

Supinator

• supinates forearm at radioulnar joints.

• Innervation: Posterior antebrachial interosseous nerve (C6-C7).

• Arterial Supply: Radial recurrent, posterior interosseous, and recurrent interosseous arteries

Abductor Pollicis Longus

• Abducts and extends thumb at first carpometacarpal joint.

• Innervation: Posterior antebrachial interosseous nerve (C7-C8).

• Arterial Supply: Anterior and posterior interosseous arteries.

Extensor Pollicis Brevis

• Extends thumb.

• Innervation: Posterior antebrachial interosseous nerve (C7-C8).

• Arterial Supply: Anterior and posterior interosseous arteries.

Extensor Pollicis Longus

• Extends thumb.

• Innervation: Posterior antebrachial interosseous nerve (C7-C8).

• Arterial Supply: Anterior and posterior interosseous arteries.

Extensor Indicis

• Extends index finger.

• Innervation: Posterior antebrachial interosseous nerve (C7-C8).

• Arterial Supply: Anterior and posterior interosseous arteries.

Lumbricals

• intrinsic muscles in the hand. These muscles mainly act to simultaneously flex the metacarpophalangeal joints and extend the interphalangeal joints of the fingers.

Palmar Interossei

• adduct the index, ring, and little fingers at their metacarpophalangeal joints;

• simultaneously flex the metacarpophalangeal joints and extend the interphalangeal joints of the index, ring, and little fingers.

Dorsal Interosse

• abduct the index, middle, and ring fingers at their metacarpophalangeal joints

• simultaneously flex the metacarpophalangeal joints and extend the interphalangeal joints of the index, middle, and ring fingers.

Abductor Pollicis Brevi

• Abducts thumb at its carpometacarpal joint.

• Innervation: Recurrent branch of median nerve (C8-T1).

• p Arterial Supply: Superficial palmar branch of radial artery.

Flexor Pollicis Brevi

• flexes thumb.

• Innervation: Superficial head: recurrent branch of median nerve (C8-T1); Deep head: deep branch of ulnar nerve (C8-T1).

• Arterial Supply: Superficial palmar branch of radial artery and princeps pollicis artery.

Opponens Pollici

• Opposes thumb towards other fingers.

• Innervation: Recurrent branch of median nerve (C8-T1).

• Arterial Supply: Superficial palmar branch of radial artery and princeps pollicis artery.

Adductor Pollici

• Adducts thumb at its carpometacarpal joint.

• Innervation: Deep branch of ulnar nerve (C8-T1).

• Arterial Supply: Radialis indicis and princeps pollicis arteries, deep palmar arch.

Abductor Digiti Minim

• Abducts little finger at its metacarpophalangeal joint.

• Innervation: Deep branch of ulnar nerve (C8-T1).

• Arterial Supply: Deep palmar branch of ulnar artery and superficial palmar arch.

Flexor Digiti Minimi Brevi

• Flexes little finger at its metacarpophalangeal joint.

• Innervation: Deep branch of ulnar nerve (C8-T1).

• Arterial Supply: Deep palmar branch of ulnar artery and superficial palmar arch.

Opponens Digiti Minim

• Opposes little finger towards thumb.

• Innervation: Deep branch of ulnar nerve (C8-T1).

• Arterial Supply: Deep palmar branch of ulnar artery and deep palmar arch.