Hands Flashcards
Proximal row of carpal bones
Lateral to medial when viewed anteriorly Scaphoid Lunate Triquetrum Pisiform (sesamoid bone in FCU - articulates with anterior surface of triquetrum)
Scaphoid and lunate articulate with radius to form wrist joint
Distal row of carpal bones
Lateral to medial when viewed anteriorly Trapezium - articulates with metacarpal of thumb trapezoid capitate - largest of carpal bones hamate
Carpal tunnel borders
lateral - scaphoid and trapezium
medial - pisiform and hook of hamate
Anterior - flexor retinaculum
Wrist joint
Synovial joint between distal end of radius and ulna and scaphoid lunate and triquetrum
Contents of carpal tunnel
4 tendons of FDP 4 tendons of FDS Tendon of FPL Median nerve (anterior to tendons)
FCR passes through flexor retinaculum
ulnar artery, ulnar nerve and palmaris longus passes anterior to flexor retinaculum
Extensors at wrist
Posterior surface has 6 compartments defined by an extensor retinaculum
ECU and EDM have their own synovial sheaths
ED and EI share a synovial sheath on posterior surface of wrist
palmar aponeurosis
apex continuous with palmaris longus
Palmaris brevis
Overlies the hypothenar muscle, ulnar artery and superficial branch of the ulnar nerve at medial side of palm.
Innervated by superficial branch of ulnar nerve
Anatomical snuffbox
Medial border - EPL
lateral border - APL and EPB
Floor - scaphoid and trapezium + distal ends of ECRL and ECRB
Radial artery passes through deep to extensor tendons of thumb
Terminal parts of superficial branch of radial nerve + origin of cephalic vein passes subcutaneously over snuffbox
Intrinsic muscles of hands
Palmaris brevis Interossei Adductor pollicis - radial artery comes out anteromedially between the two heads to form deep palmar arch Hypothenar Thenar Lumbricals
All innervated by deep branch of ulnar nerve
Interossei
Between and attached to metacarpals
Insert into proximal phalanx of each digit and into extensor hood.
Radial artery pass between two heads of first dorsal interossei
Thenar muscles
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
All originate from tubercle of trapezium
All innervated by recurrent branch of median nerve
Opponens pollicis deep to the other 2
APB is proximal to FPB, both insert onto extensor hood of thumb
Hypothenar muscles
Flexor digiti minimi brevis
Opponens digiti minimi
Abductor digiti minimi
Opponens lies deep to the other 2. Base is penetrated by deep branch of ulnar nerve and ulnar artery
ADM is medial to FDMB
Lumbricals
Medial 2 are bipennate
lateral 2 are unipennate
Pass dorsally around lateral side of each finger and insert into extensor hood.
Tendons are anterior to deep transverse metacarpal ligaments
Arteries to hands
Radial artery - thumb and lateral side of index finger
Ulnar artery - remaining digits and medial side of index
Ulnar artery
Lies between palmaris brevis and flexor retinaculum and is lateral to ulnar nerve and pisiform bone.
Forms superficial palmar arch (superficial to long flexor tendons of digits and just deep to palmar aponeurosis)
Branches into deep palmar arch and anatastomose with deep palmar arch derived from radial artery
Radial artery
Passes between 2 heads of 1st dorsal interosseous and then 2 heads of adductor pollicis to form deep palmar arch
Ulnar nerve
Divides into deep branch (mainly motor) and superficial branch (mainly sensory) distal to pisiform
Lateral to pisiform and medial to ulnar artery when it enters hand
Deep branch of ulnar nerve lies in Guyon’s canal between hook of hamate and flexor tendons.
Superficial branch of ulnar nerve supplies palmaris brevis and cutaneous to medial half of hand
How to distinguish damage to ulnar nerve at wrist or site proximal to wrist
Evaluate function of dorsal branch of ulnar nerve, which supplies dorsal surface of medial side of hand. As this branches from distal regions in forearm.
Median nerve
After carpal tunnel branches into recurrent branch and palmar digital branches (superficial to flexor retinaculum)
Recurrent - three thenar muscles. Passes between PFB and APB.
Palmar digital - Cutaneous and lateral two lumbricals
Radial nerve in hand
Only part of radial nerve that enters hand is superficial branch. Passes over anatomical snuffbox.
Cutaneous supply
