DR4: Hand Flashcards
What tendons border the anatomical snuff box?
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
What muscles make up the thenar eminence?
Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis
What is the origin, insertion and function of abductor pollicis brevis?
Origin: flexor retinaculum and tubercle of scaphoid and trapezium
Insertion: Proximal phalanx of thumb
Function: abduct thumb
What is the origin, insertion and function of flexor pollicis brevis?
Origin: flexor retinaculum and tubercle of trapezium
Insertion: proximal phalanx of thumb
function: flex thumb
What is the origin, insertion and function of opponens pollicis?
Origin: flexor retinaculum and tubercle of trapezium
Insertion: metacarpal I
Function: opposition
What muscles make up the hypothenar eminence?
Abductor digiti minimi
Flexor digiti minimi
Opponens digiti minimi
What is the origin, insertion and function of abductor digiti minimi?
Origin: flexor retinaculum and pisiform
Insertion: proximal phalanx of D5
Function: abduct digit 5
What is the origin, insertion and function of flexor digiti minimi?
Origin: flexor retinaculum and hook of hamate
Insertion: Base proximal phalanx digit 5
Function: flex digit 5
What is the origin, insertion and function of opponens digiti minimi?
Origin: flexor retinaculum and hook of hamate
Insertion: Metacarpal 5
Function: opposition
What muscles are in the central palmar area?
Lumbricals
Dorsal interossei
Palmar interossei
Adductor pollicis
What is the origin, insertion and function of the lumbricals?
Origin: flexor digitorum profundus
Insertion: dorsal Digital expansion
Function: extend interphalangeal joints, flex metacarpophalangeal joints
What is the origin, insertion and function of dorsal interossei?
Origin: sides of metacarpal bones
Insertion: dorsal digital expansion
function: abduct MCP joints
What is the origin, insertion and function of palmar interossei?
Origin: 2, 4, 5th metacarpal
Insertion: dorsal digital expansions
Function: adduct MCP joints
What is the origin, insertion and function of adductor pollicis?
Origin: metacarpal III (transverse head), base metacarpal II, III and carpal bones (oblique head)
Insertion: base proximal phalanx of thumb
Function: adduction
What forms the main part of the superficial palmar arch?
Ulnar artery
What forms the main part of the deep palmar arch?
Radial artery
Describe the path of the median nerve
Travels through carpal tunnel
Divides into digital nerves which supply skin over D1, D2, 1/2 D3
What nerve supplies the thenar muscles?
Recurrent branch of the median nerve
Where is the ulnar nerve in the hand?
On lateral side of pisiform bone
What movements does flexor carpi radialis perform?
flexion and abduction of wrist
What movements does flexor carpi ulnaris perform?
Flexion and adduction of wrist
What is the function of the flexor retinaculum?
Prevent bowing of flexor tendons
What is the function of the five carpi muscles when they contract together?
To form a stable wrist base, which is important for performing fine finger movements, such as during typing or writing.
Which digits have accessory tendons and what are the names of the accessory muscles?
Digit 2 (index finger) – extensor indicis Digit five – extensor digiti minimi
Which muscles insert into the dorsal digital expansion?
The lumbricals and interossei muscles insert into the dorsal digital expansions
What is the clinical significance of the palmer aponeurosis?
Clinically significant because of the common condition which affects it – Dupuytren’s contracture.
A dense fibrosis occurs in the aponeurosis, affecting especially fibres, to, and of, the ring and little fingers. Thickening of the fibrous tissue occurs and a flexion contracture of the metacarpophalangeal joint and proximal interphalangeal joint follow.
Eventually severe deformity may result.
The thickened, contracted aponeurosis has to be surgically released.
What is the nerve supply to the hypothenar muscles?
Ulnar nerve
What is the function of the lumbricals?
On contraction, they put the hand into a precision grip (as in holding a pencil) – they flex at the metacarpophalangeal joint and extend at the interphalangeal joints.
Which structures does the deep branch of the ulnar nerve supply?
Hypothenar muscles
Medial two lumbricals
Dorsal and palmar interossei
Adductor pollicis.
What would be the consequence of an injury to the superficial branch of the ulnar nerve?
Loss of sensation over digits 4 and 5.
What would be the consequence of an injury to the superficial branch of the radial nerve?
Loss of sensation over the dorsolateral aspect of the hand.
Which four carpal bones give attachment to the flexor retinaculum?
On the medial side these are the pisiform and hamate (specifically the hook of the hamate) and on the lateral side these are the scaphoid and trapezium.
The pisiform bone is a sesamoid bone. Which tendon does it sit within?
Flexor carpi ulnaris
