Hand Anatomy PDF

Hand Dr Sapna Shevade, Asst Professor Objectives Identify the thenar and hypothenar eminences Describe the movements and nerve supply of the muscles of the hand Muscles of the hand ✓Muscles of the thumb – Thenar eminence ✓Muscles of the little finger – Hypothenar eminence ✓Lumbricals ✓Inteross...

Hand Dr Sapna Shevade, Asst Professor Objectives Identify the thenar and hypothenar eminences Describe the movements and nerve supply of the muscles of the hand Muscles of the hand ✓Muscles of the thumb – Thenar eminence ✓Muscles of the little finger – Hypothenar eminence ✓Lumbricals ✓Interossei Thenar Eminence Abductor pollicis brevis. Flexor pollicis brevis Opponens pollicis Adductor pollicis  Adductor pollicis: Movements of the thumb Abduction and adduction occur in a plane perpendicular to the other 4 fingers. Extension and flexion occur in a plane parallel to the other 4 fingers Hypothenar Eminence Abductor digiti minimi Flexor digiti minimi Opponens digiti minimi Palmaris bevis Palmaris brevis: superficial muscle lies under the skin ✓Nerve supply : Ulnar N ✓Action : helps in gripping by making hypothenar eminence prominent ✓Improves the grip of the hand Lumbricals 4 small muscles ✓Origin : tendon of flexor digitorum profundus Nerve supply : 1st & 2nd – Median nerve 3rd & 4th – Ulnar Nerve Action: Flexion at MCP joint extension at interphalangeal joints (writing position) Interrossei Dorsal interossei and Palmar interossei :4 small muscles between the metacarpal bones Palmar Interrossei ✓Nerve supply: Ulnar N ✓Action: PAD Dorsal Interrossei : all are bipinnate ✓Origin : Metacarpal bones ✓Nerve supply : Ulnar N ✓Action : DAB References Netter's Clinical Anatomy. Hansen, John T. Elsevier; 2019 4th Edition. ISBN: 978-0-323-53188-7 https://www-clinicalkey- com.gmulibrary.com/#!/content/book/3-s2.0- B978032353188700007X?scrollTo=%23hl0002447 Nerve injuries-Upperlimb Brachial Plexus injuries Winging of scapula ?? Musculocutaneous nerve From the lateral cord (C5,6,7) Penetrates coracobrachialis muscle. Passes between the biceps brachii and brachialis muscles. Lateral to the tendon of the biceps penetrates deep fascia > superficial & continues as the lateral cutaneous nerve of forearm. It supplies coracobrachialis, biceps and brachialis muscles & the skin of lateral forearm Axillary nerve From the posterior cord of the brachial plexus. Exits the axilla by passing through the quadrangular space with the posterior circumflex humeral vessels. Related to the surgical neck of the humerus posteriorly. It innervates the deltoid and teres minor muscles. It gives superior lateral cutaneous nerve of the arm, which carries sensation from the skin over the deltoid muscle. Median nerve Origin?? In the ARM Is lateral to the axillary artery. Is anterior to the elbow joint. In the FOREARM Passes between the 2 heads of the pronator teres muscle. Then on the deep surface of the flexor digitorum superficialis muscle. It enters the palm of the hand by passing through the carpal tunnel deep to the flexor retinaculum. Branches of the median N No branches in the arm In the Forearm Muscular branches in the to the pronator teres, flexor carpi radialis, palmaris longus, and flexor digitorum superficialis. Articular branches to the elbow joint. Anterior interosseous nerve- deep branch Palmar cutaneous branch: superficial to flexor retinaculum Hand : 1st& 2nd lumbrical Thenar eminence accept adductor pollicis Palmar cutaneous branch Arises proximal to the flexor retinaculum It supplies the lateral 2/3 of the skin of the palm of the hand It is not affected in carpal tunnel syndrome because it passes into the hand superficial to the flexor retinaculum of the wrist.  At the wrist : Recurrent neve supplies the supplies the thenar muscles. Palmar digital branches supply the palmar surface of the lateral 3 and half fingers reaching the dorsal aspect of their distal phalanges + the lateral 2 lumbricals.  Ulnar nerve Origin: ?? In the ARM Medial to the axillary artery. Passes posterior to the medial epicondyle of the humerus. In the Forearm passes between the 2 heads of the flexor carpi ulnaris muscle.  Passes between the flexor carpi ulnaris and the flexor digitorum profundus muscles. Wrist At wrist, it lies lateral to the tendon of flexor carpi ulnaris & superficial to the flexor retinaculum (the dangerous position, at which it can be injured). Branches of ulnar nerve Arm : No branches Forearm Muscular branches to the flexor carpi ulnaris and to the medial 1/2 of the flexor digitorum profundus. Palmar branch: supplies skin on the medial 1/3 of the palm. Dorsal branch: supplies the skin of the medial 1/3 of the dorsal surfaces of the hand & the medial 1 ½ fingers. Hand: Superficial branch supplies palmaris brevis muscle skin on the palmar surface of the medial 1 ½ fingers. Deep branch supplies all the interossei, adductor pollicis, and the 2 medial lumbricals Radial nerve Origin ?? Arm: Accompanies the profunda brachii artery, in the lower triangular space. Crosses the radial groove from medial to lateral. Appears the forearm between the brachialis and the brachioradialis muscles. Divides into deep (motor) and superficial (cutaneous) branches. The deep branch pierces supinator to enter the back of forearm. The radial nerve supplies the lateral part of brachialis, triceps , anconeus, brachioradialis and extensor carpi radialis longus. Branches of radial nerve : In the axilla: Muscular branches to the triceps. Posterior cutaneous nerve of the arm which supplies the skin of back of arm. In the arm : in the radial groove Muscular branches to the triceps and to anconeus. Lower lateral cutaneous nerve of the arm supplies the skin over the anterolateral aspect of the lower part of the arm. Posterior cutaneous nerve of forearm supplies the skin of back of forearm In the forearm : Emerges between the 2 heads of supinator as posterior interosseous nerve and supplies the remaining extensor muscles of the forearm The superficial branch of the radial nerve Supplies the the skin of the lateral 2/3 of the dorsal surface of the hand and the skin of the dorsal surface of the lateral 3½ fingers except the distal phalanges which are supplied by median nerve. Branches of radial nerve References Describe the course, branches of the major nerves of the upper limb. Gray's Anatomy for Students. Drake, Richard L. 4th edition. Saunders Elsevier; 2020. ISBN: 978-0-323-61104-6. https://www.clinicalkey.com/#!/content/book/3-s2.0- B9780323393041000117 Carpal tunnel syndrome Wrist drop Ape thumb deformity Claw hand Nerve involved? Muscles affected? Deformity