Quiz 2 Flashcards
Palm of Hand
- skin adheres directly to palmar aponeurosis
- very taut, not a lot of space between skin and aponeurosis, doesn’t really swell
- thick dense irregular CT (type 1 irregular collagen)
- palmaris longus tendon and palmaris brevis inserts into
- does not cover thenar or hypothenar eminences
- extends into palmar side of fingers
- fan shaped but also has transverse fibers
Vascular Supply to Hand
- radial and ulnar arteries
- radial: one branch anterior under palmar ligament (not under flexor retinaculum and goes to thenar side), one branch posterior through anatomical snuff box-splits before wrist
- ulnar: through tunnel of guyon, then splits to superficial and deep branch-splits after wrist
Vascular Arches of Hand
- superficial from anterior branch of radial and anterior branch of ulnar anastomosis (anterior to flexor tendons)
- deep from posterior branch of radial and posterior branch of ulnar (posterior to flexor tendons)
- interosseous branches come off each arch, anastomose with each other, split at web spaces then travel down sides of each digit
- be able to draw this
If you cut your hand what would you cut from superficial to deep?
-skin, aponeurosis, superficial vascular arch, flexor digitorum superficialis, flexor digitorum profundus and lumbricals running parallel, deep arch, then bone (past bone would be interossei)
Finger Pulleys
- aka finger retinaculums
- alternate annular and cruciate
- go around bones into palmar surface of phalanx or volar plates (much like annular ligament of elbow) meant to hold tendons in place
- inside sheaths are superficialis and profundus-named by shape
- prevent bowstringing of long flexor tendons
- annular: 5 that surround
- cruciate: 4 that cross
- most proximal one is A1 pulley
Intrinsic Muscles of Hand
- thenar muscles: abductor pollicis brevis, flexor pollicis brevis, opponens pollicis, adductor pollicis
- hypothenar muscles: flexor digiti minimi, abductor digiti minimi, opponens digiti minimi
- interossei: 4 dorsal 3 palmar
- 4 lumbricals
Fromont Sign
- pad to pad: ulnar nerve weakness of intrinsic muscles
- tip to tip: median nerve weakness of extrinsic muscles
Dorsal Interossei
: 4 dorsal interossei #1 goes to second finger; 2nd goes between metacarpals 2 and 3 of middle finger on radial side; 3rd also goes to middle finger on ulnar side; 4th lives between 4th and 5th metacarpal and goes into proximal phalanx of 4th finger on dorsal side; all go to proximal phalanx and extensor mechanism
-draw this too as well as palmar interossei
Interossei and Lumbrical Muscles
- palmer interossei: PADS
- dorsal interossei: DABS
- lumbricals-4: cross on radial side of MCPs
- all flex MCPs and extend IPs
Extensor Mechanism of Fingers
- extensor digitorum longus tendons into
- hood: fibers at 90 degrees, anchors to volar plate
- lateral bands: off hood, cross posterior and lateral to PIP, joint together proximal to DIP, cross DIP and insert into base of distal phalanx
- central slips: cross PIP and insert into base of middle phalanx
- palmar interossei, dorsal interossei and lumbricals all insert into it
- cross MCP on flexor side then into extensor mechanism
- extensor digitorum comes down, hood fibers come off and attach to volar plate, central slip comes off hood and goes down to base of middle phalanx, lateral bands come off sides and attach at the base of distal phalanx
- volar plates=palmar side ligaments covered in articular cartilage so flexor tendons can slide, located at MCs, PIPs, and DIPs and they restrict hypertension
Vincula
- CT that goes from bone down to flexor tendon that contain tiny arteries and give additional blood supply to superficialis and/or profundus
- weakest spot of any tendon is in the middle where there is a little bit less of a blood supply (one end of supply comes from muscle and other comes from bone on the other-long tendons have lousy blood supply)
Innervation to Hand
- median nerve: motor and sensory
- ulnar nerve: motor and sensory
- radial nerve: sensory only (no intrinsic hand muscles)
- all muscles of hand are ulnar nerve except abductor pollicis brevis, flexor pollicis brevis, opponens pollicis and first 2 lumbricals which are median
PICTURES
- study pictures at end of slideshow
- color and know regions
TFCC
- articulates with triquetrum
- ligament that holds distal radius and ulna together (others include interosseous membrane, and posterior and anterior radioulnar collateral ligaments)
Recurrent Branches of Median and Ulnar Nerves
- medial doesn’t go under carpal tunnel and does sensory innervation of small part of hand
- ulnar has a branch that doesn’t go under tunnel of Guyon and innervates small portion of hand
