Hand Flashcards
Dermatomes for Hand
C6= thumb; C7= digits 2 and 3; C8= digits 4 and 5
Palmar aponeurosis
Strong, heavy, dense, well-defined triangular layer of the deep fascia in the middle of the palm
dupuytren’s contracture
Progressive fibrosus, which typically produces abnormal bands of fibrous tissue that extend from the aponeurosis to the bases of the phalanges., pulling one or more digits into flexion (unabled to be straightened)
What forms the boundary of the carpal tunnel and what passes through it (the carpal tunnel)?
Posterior boundary= carpal bones. Anterior boundary= flexor retinaculum
10 structures which pass through it: 4 flexor digitorum superficialis tendons, 4 flexor digitorum profundus tendons, flexor pollicis longus and the Median nerve
Carpal Tunnel Syndrome
Results from any lesion that will decrease the size of the carpal tunnel (fluid retention, infection, excessive exercise). The median nerve is depressed, since it is the sofest structure in the tunnel.
Wasting of thenar muscles often seen in this disease
Mnemonic for what the median nerve controls in the hand
1/2 LOAF= 1st and 2nd lumbricals, Opponens Pollicis, Abductor Pollicis BREVIS, Flexor Pollicis BREVIS
Flexors vs Lumbricals
Flexors allow you to make the “OK” sign, whereas Flexors + Lumbricals are needed together in order to pinch. In other words the lumbricals will help extend a flexed finger, due to their insertion on the Extensor expansion.
Dorsal Digital Extensor Expansion
Common “hood” which aids in extension of fingers.
Receives extensor digitorum, interossei, and lumbrical tendons
PAD and DABS
PAD—> Palmar Interossei, extension of proximal and distal interphalangeal joints and ADduction of digits 2,4, and 5. There are 3 of these muscles (3 letters in PAD)
DABS—> Dorsal Interossei, extension and ABduction of proximal and distal interphalangeal joint of digits 2-4. There are 4 of these muscles (4 letters in DABS)
Adductor Pollicis Muscle
Fan shaped muscle with 2 heads., at web of had (between thumb and index finger). Functions to ADduct thumb. Wider muscle= Tranverse head. Skinnier Muscle= Oblique head.
Ulnar nerve controlled. Radial Artery runs between them (after moving through the snuff box)
Arterial Supply to the Hand
USRD. Ulnar Superficial; Radial Deep—-> Deep and Superficial Palmer Arches of the Radial and Ulnar Arteries
Digital branches of Ulnar artery (superficial branch) which go to fingers
Common palmar digital arteries—-> pass between metacarpals
Proper palmar digital arteries—-> run on either side of digits 2-5
Important branches off of the radial artery in hand
Gives off princeps pollicis artery to supply medial side of thumb.
Gives off radialis indicis artery to supply lateral side of 2nd digit.
Continues through palm as the deep palmar arch
What eventually happens to the deep and superficial radial an ulnar arches/branches?
They anastomose (blend) with their counterpart of the other artery (deep with deep, superficial with superficial)
Names of median nerve descendants in the skin of the central palm
Common and proper palmar digital nerves (also provide same function in the area of the nail bed).
