Forearm Muscles and Vessels (PDF)

‫بسم الله الرحمن الرحيم‬ ‫سُنِر يِه ْم آَياِتَنا ِف ي اآْل َف اِق َو ِف ي‬ ‫ْل‬ ‫َأ‬ ‫َل‬ ‫َأ‬ ‫نُف ِس ِه ْم َح َّتى َيَتَبَّيَن ُه ْم َّنُه ا َح ُّق‬ ‫ُك‬ ‫َل‬ ‫َّنُه َع ى ِّل َش ْي ٍء‬ ‫َأ‬ ‫َك‬ ‫ْك‬ ‫َل...

‫بسم الله الرحمن الرحيم‬ ‫سُنِر يِه ْم آَياِتَنا ِف ي اآْل َف اِق َو ِف ي‬ ‫ْل‬ ‫َأ‬ ‫َل‬ ‫َأ‬ ‫نُف ِس ِه ْم َح َّتى َيَتَبَّيَن ُه ْم َّنُه ا َح ُّق‬ ‫ُك‬ ‫َل‬ ‫َّنُه َع ى ِّل َش ْي ٍء‬ ‫َأ‬ ‫َك‬ ‫ْك‬ ‫َل‬ ‫َأ‬ ‫َو ْم َي ِف ِبَر ِّب‬ ‫َش ِه يٌد (‪ )53‬فصلت‬ ‫‪Dr. Ahmed Abd Alhamid Albakosh‬‬ ‫‪03:32 PM‬‬  ‫‪Forearm‬‬ ‫د‪.‬أحمد عبدالحميد البكوش‬ ‫ماجستير تشريح وعلم األجنة‬ ‫محاضر مساعد بالكليات الطبية بالجامعات الليبية‬ ‫الطب البشري – الجامعة األسمرية اإلسالمية ‪ -‬زليتن‬ ‫‪Dr. Ahmed Abd Alhamid Albakosh‬‬ ‫‪03:32 PM‬‬  OBJECTIVES  List the names of the Flexors Group of Forearm (superficial & deep muscles).  Identify the common flexor origin of flexor muscles and their innervation & movements.  Identify supination & poronation and list the muscles produced these 2 movements.  List the names of the Extensor Group of Forearm (superficial & deep muscles).  Identify the common extensor origin of extensor musles and their innervation & movements. Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  The forearm extends from Elbow to Wrist.  It contains two bones Radius laterally Ulna medially.  The two bones are connected together by the interosseous membrane (Pronation/Supinatio n ). Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  The forearm is enclosed in a Fascial Compartments of the Forearm sheath of deep fascia, which is attached to the posterior border of the ulna.  This fascial sheath, together with the interosseous membrane & fibrous intermuscular septa, divides the forearm into: 2 compartments, Dr. Ahmed Abd Alhamid Albakosh 03:32 PM Dr. Ahmed Abd Alhamid Albakosh 03:32 PM Ant. Compartment of Forearm Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Anterior compartment 1. Pronator teres m.  Superficial & Deep layers 2. Flex. carpi radialis  Most flexors have 3. Palmaris longus common flexors 4. Flex. carpi ulnaris tendon on medial epicondyle 5. Flex. digitorum superf.  Contains 2 pronators 6. Flex. digitorum All muscles of Ant. Compartment cross Wrist profundus Except 2 pronators 7. Flex. pollicis longus  Innervated by 8. Pronator quadratus Median, Ulnar nerves Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Flexor Group (8 Muscles)  Act on the Elbow & Wrist joints and those of the fingers.  Form fleshy masses in the proximal part and become tendinous in the distal part of the forearm.  Arranged in 4 Superficial 3 groups. Deep 3 From Lat. To Med.  Flexor digitorum  Pronator teres profundus  Flexor pollicis longus  Flexor carpi radialis  Pronator quadratus  Palmaris longus  Flexor carpi ulnaris Intermediate 1  Flexor digitorum Dr. Ahmed Abd Alhamid Albakosh 03:32 PM superficialis  Superficial Flexors  They arise: (more or less) common flexors tendon on medial epicondyle  All are supplied by median nerve except flexor carpi ulnaris by (ulnar).  All cross the wrist joint except one, pronator teres, (PT). Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Pronator Flexor Carpi Palmaris teres Radialis Longus   Insertion: Insertion:  Insertion: into middle of lat. Base of 2nd the flexor surface of metacarpal retinaculum & radius bone palmar  Action:  Action: aponeurosis. pronation & Flexion &  Action: Flexes flexion of abduction of hand & tightens forearm the hand palmer aponeurosis Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Palmaris Longus Common 70 % of population Flexor Origin Palmar Aponeurosis  Tendon of Palmaris Longus Palmar Aponeurosis  Flexor Carpi Ulnaris Flexor Digitorum  Insertion: Superficialis  Insertion: Pisiform, hook of hamate & 5th metacarpal bone base of middle phalanges of  Action: medial 4 fingers Flexion and adduction of the  Action: hand. Flexes middle and proximal phalanges of medial 4 fingers, and the hand Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  flex. digitorum Common flexor superficialis sheath Flexor Digitorum Ring finger Profundus Middle finger Index finger Little finger Relations of Flexor digitorum superficialis flex. digitorum superficialis Flexor Digitorum Profundus Common flexor sheath Flexor Digitorum flex. digitorum Profundus superficialis Perforation in FDS for passage of tendon of FDP  Flexes proximal Assists Flexion of metacarpophalangeal joints interphalangeal joints Innervation: median nerve Action: flexes PIP joints, assists flexion of MCP and wrist joints flex. digitorum superficialis Flexor Digitorum Profundus  Deep Flexors  One above ulna: Flexor Digitorum profundus  One above radius: Flexor pollicis longus  One above the 2 bones: Pronator Quadratus  Notice: All muscles of the deep group are supplied by Anterior interosseous nerve (branch of the median nerve) except medial half of flexor digitoreum profundus which is supplied by the ulnar nerve. Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Flexor Flexor Pollicis Pronator Digitorum Longus Quadratus Profundus  Origin: middle  Origin: lower two 2/4 fourth of ant.  Origin: upper surface of ulna ¾ Ulna Radius   Insertion: distal  Insertion: Insertion: Base of distal fourth of ant. bases of distal surface of radius phalanges of phalanx of thumb  medial 4 digits Action: pronates   Action: flexes forearm Action: Flexes interphalangeal, (primover), helps distal metacarpophalan to hold the bones phalanges of geal & together. medial 4 digits. carpometacarpa l joints of thumb. 03:32 PM  Supination Vs Pronation Occurs Superior & Inferior radioulnar joints Muscles produce supination Biceps brachii. Supinator Muscles produce pronation Pronator quadratus. Pronator teres. Brachioradialis put the forearm in Midprone position Dr. Ahmed Abd Alhamid Albakosh 03:32 PM Supination Pronation Origin Superficial (Humeral) head of Pronator Teres Origin Deep (Ulnar) head of Pronator Teres Pronator Teres Insertion  Pronation and supination Occur at the proximal and distal radioulnar joints and have unequal strengths, with supination being stronger. Supination. The palm faces forward (lateral rotation. Pronation. The radius rotates over the ulna, and thus the palm faces backward (medial rotation Around a longitudinal axis, in which case the shafts of the radius and ulna cross each other. Movements in which the upper end of the radius nearly rotates within the annular ligament. Pos. Compartment of Forearm Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Posterior compartment 1. Brachioradialis M. 2. Ext. carpi radialis longus M. 3. Ext. carpi radialis brevis M. Posterior 4. Ext. carpi ulnaris M. Extensor 5. Extensor digitorum M. Compartment 6. Extensor digiti minimi M. 7. Extensor indicis M. 8. Abd pollicis longus M. Innervated 9. Ext. pollicis longus M. By 10. Ext. pollicis brevis M. Radial nerve 11. Supinator M. 12. Anconeus Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Posterior compartment (3 groups) Superficial Lateral group (2) Deep group (5)  Brachioradialis (3 to  Extensor carpi radialis thumb+ 1 to index + longus Superficial group supinator) (5)  Supinator.  Extensor carpi radialis  Abductor pollicis longus. brevis  Extensor pollicis brevis.  Extensor digitorum  Extensor pollicis longus.  Extensor digiti minimi   Extensor Common indices. Extensor Extensor carpi ulnaris  Anconeus Origin Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Superficial group (from lateral to medial) 1. Brachioradialis (BR). 2. Extensor carpi radialis longus (ECRL). 3. Extensor carpi radialis brevis (ECRB). 4. Extensor digitorum (ED). 5. Extensor digiti minimi (EDM). 6. Extensor carpi ulnaris (ECU). 7. Anconeus (An). Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  All arises from the Superficial extensors common extensor origin (front of lateral epicondyle of the humerus) EXCEPT 2 (BR & ECRL).  All cross the wrist EXCEPT one (Brachioradialis).  All supplied by deep branch of radial nerve, EXCEPT ABE A = Anconeus B = Brachioradialis E = Extensor carpi radialis longus These 3 muscles are supplied by the radial nerve itself. Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Insertions  Extensor carpi radialis brevis base of 3rd metacarpal bone.  Extensor digitorum Extensor expansion of the medial 4 fingers.  Extensor digiti minimi Extensor expansion of the little finger.  Extensor carpi ulnaris Base of the 5th metacarpal bone. Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Dorsal Extensor Expansion  It is formed on the dorsum of medial 4 fingers by: Union of the tendons of: Extensor digitorum, Extensor digiti minimi, Extensor indicis, palmar and dorsal interossei and lumbricals.  All these tendons unite to form one tendon which divides into 3 slips: a median one attached to middle phalanges and 2 lateral attached to the terminal phalanges. Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Extensor Action expansions Middle slip Two collateral slip Extensor expantion Tendon of extensor digitorum Tendons of Tendon of interossei lumbrical  Brachioradialis Extensor Carpi radialis longus  Origin: Lateral Origin: supracondylar ridge of humerus Lateral supracondylar ridge of humerus  Insertion: Base of styloid process of radius Insertion: Posterior surface  Action: of base of 2nd 1. Flexes elbow when metacarpal bone the forearm is in the midprone position.  Action: 2. Rotates forearm to the midprone Extends and position. abducts hand at Dr. Ahmed Abd Alhamid Albakosh wrist joint 03:32 PM  Deep group 5 muscles Supinator 1. Abductor pollicis longus  Origin (APL). Superficial head: 2. Extensor pollicis brevis lateral epicondyle. (EPB). Deep head: supinator 3. Extensor pollicis longus fossa of ulna. (EPL). 4. Extensor indicis (EI).  Insertion: into the posterior, lateral and 5. Supinator. anterior surfaces of upper fourth of the shaft of the radius. All back muscles of forearm supplied by posterior interosseous nerve except ABE by Radial nerve. Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Blood Vessels OF Forearm Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Ulnar artery  It is larger than the radial (passes down the medial side of forearm).  Leaves cubital fossa by passing deep to the pronator teres (between flexor carpi ulnaris and flexor digitorum profundus).  Leaves forearm, enters the hand superficial to the flexor retinaculum of the wrist, and arches over the palm.  Majority blood supply to the medial 3.5 of digits.  Branches: 1. Anterior and posterior ulnar recurrent. 2. Common interosseous artery (anterior and posterior). 3. Palmar carpal branch. 4. Dorsal carpal branch. 5. Superficial terminal branch. 6. Deep terminal branch. 03:32 PM Dr. Ahmed Abd Alhamid Albakosh  Flexor retinaculum ulnar superficial artery palmer arch Deep palmer terminal branch superficial palmer terminal branch  Radial artery  It passes down the lateral side of forearm.  In proximal half is deep to the Brachioradialis.  In the distal part of the forearm, lies on the anterior surface of the radius and is covered only by skin and fascia.  Just above to the Wrist Radial pulse can be felt by gently palpating the radial artery against the underlying muscle and bone.  Branches: 1. Radial recurrent artery. 2. Palmar carpal branch. 3. Superficial palmar branch. 03:32 PM Dr. Ahmed Abd Alhamid Albakosh  Veins of the upper limb Cephalic vein  Formed on the dorsum of the hand by union of lateral end of the dorsal venous arch with the digital vein on the lateral side of the thumb.  It crosses the roof of the anatomical snuff-box and curves around the lateral side of the forearm to reach the anterior compartment.  It ascends in front of the forearm to the level of the cubital fossa where it joins the basilic vein by the median cubital vein.  Then it ascends in the arm on the lateral side of bicips brachii muscle.  It passes in the deltopectoral groove and pierces the clavipectoral fascia to end in the axillary vein. Dr. Ahmed Abd Alhamid Albakosh 03:32 PM  Basilic vein  Formed on the dorsum of the hand by union of medial end of the dorsal venous arch with the digital vein on the medial side of the little finger.  It curves around the medial side of the forearm to reach its front.  It ascends in front of the forearm to the level of the cubital fossa where it joins the cephilic vein by the median cubital vein.   It ascends in the arm on the medial side of bicips brachii muscle.  At the lower border of teres major muscle, it joins the vena commitants of the brachial artery to form the axillary vein. 03:32 PM Dr. Ahmed Abd Alhamid Albakosh  References 1. MOORE Clinically Oriented, Seventh Edition. 2. Clinical Anatomy by Regions Snell, Ninth Edition. 3. Prof. Mohey Hulail. Zagazig University. 4. Lectures of Human Anatomy & Embryology department of Zagazig University. Dr. Ahmed Abd Alhamid Albakosh 03:32 PM