what can potentially happen when there is a traumatic finger injury? what is the presentation
rupture of extensor digitorum tendon (extensor tendon rupture)
cannot extend DIP joint of affected area
stays flexed at rest
mallet finger> distal phalanx remains flexed (unopposed action of flexor digitorum profundus)
what is/are pathological issues that can arise from aponeurosis? what is the clinical presentation?
dupuytren contracture
disease of palmar fascia, shortening and thickening of plamar aponeurosis
partial flexion of digits 4 and 5 at MCP and IP joints (fixed)
nodules and raised ridges on palmar surface (extend and form ridges)
no impact on sensory innervation
what allows for contnious spread of infection from the hand up to the forearm
the midpalmar space in the hand is continuous with the carpal tunnel in the forearm, allowing for the spread of infection from the hand to the forearm
how does infection/blood/fluid get trapped in the hand?
via the midpalmar and thenar spaces in the hand
why is the median nerve susceptible to compression in the hand
it sits superficially in the carpal tunnel space
how does carpal tunnel syndrome happen? what is the clinical presentation?
swelling of contents in carpal tunnel
infiltration of fluid from infection/overuse
protrusion of a dislocated carpal bone
-median nerve is most sensitive to increased pressure and
critical signs reflect the nerve’s distribution > tingling, weakness on palmar surface of lateral 3 1/2 digits
weakness/atrophy in thenar compartment
what is the most commonly dislocated carpal bone
lunate
what is the most commonly broken carpal bone
scaphoid
what happens when there is compression of the ulnar nerve at the wrist? what is the clinical presentation?
guyon’s canal syndrome/ulnar tunnel syndrome/ulnar claw hand
hyperextension at MCP joints (digits 4 & 5 most often affected)> due to loss of lumbrical and interosseous function= inability to flex MCP joints
hyperflexsion at ICP> due to loss of interosseous action on extensor digitorum> flexor digitorum and superficialis and profundus have unopposed action
possible hypothenar atrophy and sensory deficits consistent with the ulnar nerve distribution
passive sign
where are the metarpophlangeal joints (MCP) located? what movement does it contribute to?
between heads of metacarpals and bases of proximal phalanges
digits 2-5: flexion, extension, ab/adduction
thumb: flexion, extension
true or false
the MCP joint does not allow the thumb to oppose/add/abduct. that is the work of the carpo-metacarpal joint
true
what does the carpo-metacarpal (CMC) joint connect? what does it allow the thumb to do?
the distal carpal bones and the base of the metacarpal bones in the hand
allows the thumb to oppose, add/abduct
where are the proximal/distal interphalangeal joints located? what movements do they allow?
what about the thumb
proximal: between proximal phalanx and middle phalanx (digits 2-5)
distal: between middle phalanx and distal phalanx
both allow for flexion/extension of digits 2-5
thumb only has one IP joint, flexion and extension as well
tendons in the hand are covered by ____ in the hand
synovial tendon sheath
what do extensor tendons do? where are they located
responsible for straightening the fingers and wrist
flatten to form dorsal digital expansions> wrap around teh sides of the MCP joint
found from the dorsum of the forearm and fan out from the wrist
what supports the insertion of the digital expansion
1 median band
2 lateral bands
muscles of the palm (lumbricals and interosseous)
true or false
the radian nerve supplies hand muscles
false. its superficial branch supplies skin over the lateral aspect of the dorsum of the hand/ approx 3 1/2 (1,2,3) digits
true or false
the median nerve enters the hand via the carpal tunnel
true
what parts of the hand do the common and proper branches of the hand innervate sensory information
common palmar digital nerves> middle of palm near thumb side not including finger tips of digits 2 and 3 on palmar side
proper palmar digital nerves> dorsum side the fingertips of digits 1,2 and 3
true or false
the skin of the palmar side of the hand with digits 4 and 5 (medial) are supplied by the common and proper palmer nerves that come off the ulnar nerve via the superficial branch
true
what does the dorsal cutaneous branch of the ulnar nerve supply on the hand
the dorsal skin of the hand and medial 1 1/2 digits (pinky and part of ring finger)
what arteries supply blood to the hand
ulnar and radial arteries
how does the ulnar artery enter the hand
Guyon’s canal
runs with the ulnar nerve
the ulnar artery gives rise to the ____ and tehn continues as the superficial palmar arch
deep palmar branch
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CNS47
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PNS48
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Back and Upper Arm81
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Axilla and Arm77
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Gametogenesis, Teratogens, Lead, Weeks 1-4, placenta178
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Twinning43
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axial muscoskeletal development embryo36
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Upper limb Development Embryo47
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Forearm53
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hand42
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Joints of the the upper limb27
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innervations + myotomes/dermatomes11
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100 concepts0
