The Hand Flashcards
Thenar muscles (3)
Muscles: opponens pollicis, abductor pollicis brevis, and flexor pollicis brevis
Origin: flexor retinaculum, carpals, and metacarpals
Action: abduction, flexion, and opposition of digit 1
Innervation: recurrent branch of the median nerve
Hypothenar muscles (3)
Muscles: abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi
Origin: the flexor retinaculum and carpals
Action: abduction, flexion, and opposition of the digit 5
Innervation: ulnar nerve branches
Opponens pollicis
Origin: flexor retinaculum, scaphoid, and the trapezium
Insertion: lateral shaft of the 1st metacarpal
Action: opposes the thumb
Innervation: recurrent branch of the median nerve
Abductor pollicis brevis
Origin: flexor retinaculum, scaphoid, and the trapezium
Insertion: lateral base of the proximal phalanx of the thumb
Action: abducts the thumb
Innervation: recurrent branch of the median nerve
Flexor pollicis brevis
Origin: flexor retinaculum, scaphoid, and trapezium
Insertion: lateral base of the proximal phalanx of the thumb
Action: flexes the thumb
Innervation: recurrent branch of the median nerve
Abductor digiti minimi
Origin: pisiform
Insertion: medial base of the proximal phalanx of the 5th digit
Action: abducts the 5th digit
Innervation: deep branch of the ulnar nerve
Flexor digiti minimi brevis
Origin: hook of hamate and the flexor retinaculum
Insertion: medial base of the proximal phalanx of the 5th digit
Action: flexes the 5th proximal phalanx
Innervation: deep branch of the ulnar nerve
Opponens digiti minimi
Origin: the hook of hamate and the flexor retinaculum
Insertion: medial 5th metacarpal
Action: opposes the 5th digit of the thumb
Innervation: deep branch of the ulnar nerve
Tendons of the hand
Tendons of the flexor digitorum superficialis: flexes the PIP
Tendons of the flexor digitorum profundus: flexes the DIP
Adductor pollicis
Origin:
Oblique head: 2nd and 3rd metacarpal bases
Transverse head: 3rd metacarpal shaft
Insertion: medial base of the proximal phalanx of the thumb
Action: adducts the thumb
Innervation: deep branch of the ulnar nerve
Lumbricals
Numbers 1 - 4
Origins: tendons of the flexor digitorum profundus
Insertion: lateral side of the extensor expansions of digits 2-5
Action: flexes the MCP joints and extends the IP joints of digits 2-5
Innervation:
Digits 1 - 2: median nerve
Digits 3 - 4: deep branch of the ulnar nerve
Dorsal interossei
Numbers 1 - 4
Origin: bipennate muscles attach to adjacent metacarpal shafts
Insertion: proximal phalangeal baes and the extensor expansion of digits 2 - 4
Action: abducts digits 2 - 4 from axial line, flex MCP joints and extends IP joints together
Innervation: deep branch of the ulnar nerve
Palmar interossei
Muscles 1 - 3
Origin: unipennate muscles that attach to the palmar surfaces of 2nd, 4th, and 5th metacarpals
Insertion: proximal phalanx bases and the extensor expansions of digits 2 -5
Action: Adduct digits 2 -5 towards axial lines, assists lumbricals with flexing MCP joints and extending IP joints
Innervation: deep branch of the ulnar nerve
Blood supply to the hand
Radial artery: runs through anatomical snuff box and enters the palm
Branches of the radial artery form the deep palmar arch
Branches of the deep palmar arch - palmar metacarpal arteries
Ulnar artery: transverses through the ulnar canal
Terminates as the superficial palmar arch
Branches into the common palmar digital artery and the proper palmar artery
Carpal tunnel
Boundaries
Floor, posterior, medial and lateral walls: carpals
Roof: flexor retinaculum
Contents
1 nerve: median nerve
9 tendons: 4 tendons of FDS, 4 tendons of FDP, and 1 tendon of flexor pollicis longus
