Hand Flashcards
What can you find under skin on dorsal side of hand?
Superficial radial nerve, dorsal branch ulnar nerve, dorsal interossei
Wrist Bones
So Long to Pinky,
Here comes the thumb
Palmar View
Proximal: Scaphoid, Lunate, Triquetrum, Pisiform
Distal: Hamate, Capitate, Trapezium, Trapezoid
Most common hand fracture?
Scaphoid: falls on base of palm forcing capitate into scaphoid.
Only two wrist bones to articulate with radius?
Scaphoid and lunate
Metacarpals
5 bones numbered from lateral - medial
Common characteristics: base articulates with the carpal bones; linear shaft; rounded head
Phalanges
14 bones
2 in thumb (proximal and distal)
3 in digits 2 to 5 (proximal, middle, and distal)
Each bone has a base (proximal), shaft and head (distal)
What cutaneous regions does the median nerve inervate in hand?
Palmar: Thumb, first 2.5 fingers
Dorsal: tips of same fingers
What cutaneous regions does the ulnar nerve inervate in hand?
Palmar: last 1.5 fingers
Dorsal: Same area plus first half of middle finger
What cutaneous regions does the radian nerve inervate in hand?
Dorsal: Thumb to middle finger but only halfway up fingers
Dermatomes in hand
C6 - Thumb
C7 - 2 -3
C8 - 4-5
Palmar Aponeurosis
Thick layer of fascia in palm of hand attached to palmaris longus
Dupuytren’s Contracture
Progressive fibrosus producing abnormal bands of fibrous tissue from aponeurosis to bases of phalanges, pulling digits into marked flexion. Cannot open hand completely.
Synovial Sheaths
Go around tendons to help slide through hand. Flexor digitorum sheath: escases profundus and superficialis
Borders of Carpal Tunnel
Posterior: carpal bones.
Anterior: flexor retinaculum.
Contents of Carpal tunnel
Flexor digitorum superficialis (4 tendons)
Flexor digitorum profundus (4 tendons)
Flexor pollicis longus
Median Nerve
Causes of carpal tunnel syndrome
Fluid retention
Infection
Excessive exercise
Effects of Carpal Tunnel syndrome
Thenar wasting, sensory loss
What are the Thenar muscles?
“OAF”
Oponens policis
Abductor policis brevis
Flexor Policis Brevis
Innervated by recurrent median nerve in thumb side
Innervated by recurrent Ulna nerve in pinky side
Lumbricals
Flex the hand while extending proximal and distal interphalangeal joints
What inervates lumbricals?
1-2 median, 3-4 ulnar
Where do lumbricals originate?
Profundus tendon
Extensor Expansion
Common “hood” which aids in extension of fingers
Receives extensor digitorum, interossei, and lumbrical tendons.
Dorsal Interossei
Go between bones on dorsal and Palmar Group
Dorsal: DABS - Dorsal ABdcut (4 of them, 4 letters) move fingers away from midline
Palmar: PAD (3) ADDuct (3 letters) move fingers back to midline
Ulnar or radial artery deep in hand?
USRD
Radial deep
What fingers does only radial a. supply
Thumb and lateral side of index
Which artery is in canal of Guyon?
Ulnar
What does median nerve inervate in hand?
1/2 LOAF 1-2Lumbercals Oponens policis Abductor policis brevis Flexor Policis Brevis ALL OTHER MUSCLES IN HAND DONE BY ULNAR NERVE
Most dommonely dislocated bond in wrist?
Lunate
Why is adduction spared in carpal tunnel?
Adductor policis is inervated by the ulnar nerve
OAF Iintrinsic or extrinsic?
Intrinsic
What side of digits to lumbricals insert on?
Lateral
Ulnar artery branches in hand
Superficial Palmar Arch - Anastamose swith superficial branch of radial artery.
Deep branch - Passes between abductor digiti minimi and flexor digiti minimi
Anastomoses with deep palmar arch
Radial artery branches in hand
Superficial Palmar – branches off radial before wraps around the lateral carpals, passes through thenar muscles to anastamose with superficial palmar arch.
Deep Palmar Arch - Continues through palm as the deep palmar arch, anastamosing with deep branch of ulnar a.
Venous return from fingers
Follows superficial palmar arch to ulnar vein.
- Deep venous arcades
Follow deep palmer arch to radial vein.
Does Entire median nerve go through carpal tunnel?
Palmar cutaneous branch does not! Provides feeling to skin
Lumbricals below or on top of interosseous?
On top - palmar side
