Anatomy of the hand Flashcards
Name the bones found in the hand
Carpals
Metacarpals
Phalanges
Name the carpal bones
Lunate Scaphoid Triquteal/triquteum Pisiform Trapezium Trapezoid Capitate Hamate
What is the clinical significance of a fracture to the scaphoid column?
slow recovery - poor blood supply to proximal part: avascular necrosis
Name the joints of the hand
Wrist (radiocarpal) Midcarpal/intercarpal Carpometacarpal Metacarpophalangeal Interphalangeal
Where is the wrist (radiocarpal) joint located?
Between radius/disc and first carpal row
What reinforces the radiocarpal joint?
Ligaments
What is the function of the radial and ulnar ligaments?
Limits abduction/adduction
What is the function of the ligaments on the palmar and dorsal surfaces?
Limits extension and flexion
What is the function of the radial styloid process?
Limits range of abduction
What movements does the wrist perform?
Flexion/extension
Circumduction
Abduction/adduction
What type of joints are the carpometacarpal?
Planar - limited movement
Where is the saddle joint located?
Carpometacarpal of the thumb - opposable thumb
Name the movements of the thumb
extension, flexion, abduction, adduction, opposition, reposition
What type of joints are the metacarpophalangeal joints?
Condylar joints
What movements do the metacarpophalangeal joints perform?
Flexion/extension
Abduction/adduction
Describe the deep transverse metacarpal ligament
- Unifies metacarpals
- Not between digit 1 and 2
What type of joints are the interphalangeal joints?
Hinge joints
What movement do the interphalangeal joints perform?
Flexion/extension
Name the two interphalangeal joints
Proximal
Distal
Describe the palmar aponeurosis
Thickened deep fascia
Triangular
What is the palmar aponeurosis continuous with?
Palmaris longus
What is the clinical significance of the palmar aponeurosis?
Dupuytren’s contracture
Describe the travel of the long flexor tendons to the digits
From muscles in anterior forearm
Pass through carpal tunnel
What digits do Flexor digitorum superficialis and Flexor digitorum profundus extend to?
d2-5
Which digit does Flexor pollicis longus extend to?
d1
What is the function of Flexor retinaculum
(transverse carpal ligament)?
Prevents bowing of tendons
Which long extensor tendons innervate d2-d5
Extensor digitorum
Extensor indicis
Extensor digit minimi
Which long extensor tendons innervate d1?
Extensor pollicis longus
Extensor pollicis brevis
Abductor pollicis longus
Give the borders of the anatomical snuffbox
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Where does abductor pollicis longus insert?
To base of 1st metacarpal
Where does extensor pollicis brevis insert?
To base of proximal phalanx
Where does extensor pollicis longus insert?
To base of distal phalanx
What inserts into the extensor hoods?
Lumbricals and interossei
Describe lumbricals
Link flexor to extensor tendons
- Extend interphalangeal joints and flex MCP joints - Precision grip (hold pen / pinch)
Describe the palmar interossei
Interossei sit between the metacarpals Palmar adduct (PAD) MCP joints
How many palmar interossei are there?
3
Where are there no palmar interossei?
No palmar interossei for D1 (performed by adductor pollicis muscle) or D3
How many dorsal interossei are there?
4
Describe the function of dorsal interossei
Dorsal abduct (DAB) MCP joints
Where are there no dorsal interossei?
No dorsal interossei for D1 or D5 (performed by thenar and hypothenar muscles
What is the function of the thenar muscles?
Fine movements of the thumb (d1)
What is the function of the hypothenar muscles?
Fine movements of the little finger (d5)
Where do the thenar and hypothenar muscles originate?
flexor retinaculum and adjacent carpal bones
Name the 3 thenar muscles
Opponens pollicis (deepest)
Abductor pollicis brevis
Flexor pollicis brevis
Where does opponens pollicis insert?
Into first metacarpal
Where do abductor pollicis brevis and flexor pollicis brevis insert?
Into proximal phalanx
Name the 3 hypothenar muscles
Opponens digiti minimi (deepest)
Abductor digiti minimi
Flexor digiti minimi
Where does opponens digiti minimi insert?
Into fifth metacarpal
Where do abductor pollicis brevis and flexor pollicis brevis insert?
Into proximal phalanx
Which muscles are involved in adduction of the thumb
Adductor pollicis:
Name the heads of the adductor pollicis muscle
Oblique and transverse
Where does the oblique head of adductor pollicis originate?
Base 2nd and 3rd metacarpal + carpal bones
Where does the oblique head of adductor pollicis insert?
Proximal phalanx
Where does the transverse head of adductor pollicis originate?
3rd metacarpal
Where does the transverse head of adductor pollicis insert?
Proximal phalanx
Where is adductor pollicis found?
Deep to the thenar muscles
Which arteries anastomose at the hand
Radial and ulnar artery
Where is the deep palmar arch located?
Below long flexor tendons
Which artery is the main supply to D1 and D2?
Radial artery
Where is the superficial palmar arch located?
Above long flexor tendons
Which artery is the main supply to half D2to D5?
Ulnar artery
Where does the median nerve pass?
Passes through the carpal tunnel
What is the function of the digital nerves?
Lateral 2 lumbricals
Sensory d1 to ½ d4
What is the clinical significance of the median nerve?
Carpal tunnel
What is the clinical significance of the ulnar nerve?
Clawed hand
What is the function of the deep branch of the ulnar nerve?
Hypothenar muscles
Interossei
Medial 2 lumbricals
Adductor pollicis
What is the function of the superficial branch of the ulnar nerve?
Sensory ½ d4 and d5
