Lecture 13: Hand Flashcards
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what type of joint are metacarpo-phalangeal joints and what movement does it allow?
condyloid joints
flexion/extension
Adduction/abduction
what muscles does musculocutaneous nerve innervate ?
The musculocutaneous nerve innervates the three muscles of the anterior compartment of the arm: the coracobrachialis, biceps brachii, and brachialis muscles. It is also responsible for cutaneous innervation of the lateral forearm.
what type of joint are interphalangeal joints and what movement does it allow?
hinge joints
flexion/extension only
what do deep transverse metacarpal ligaments attach to?
to the edges of the palmar ligaments of the metacarpophalangeal joints
where are palmar ligaments present in the hand?
metacarpophalangeal joints
interphalangeal joints
what forms the floor of fibro-osseous tunnels?
palmar lig
where do interossei muscles pass in relation to deep transverse metacarpal ligaments?
pass on the dorsal side
where do lumbrical muscles pass in relation to deep transverse metacarpal ligaments?
on the palmar side( ventrally or anteriorly)
what are the 3 major compartments of the palm and what muscles and tendons do they house?
central( houses the long flexor tendons, lumbricals etc)
lateral(houses thenar muscles)
medial( houses the hypothenar muscles)
what muscles contribute to spreading the digits?
dorsal interossei abduct digits 2, 3, 4
abductor digit minimi(AbDM) act on the little finger(5th digit)
extensor pollicis brevis and longus extend the thumb in the same plane as palm
(abduction of fingers but extension of the thumb)
what muscles abduct the thumb in a plane perpendicular to the palm?
abductor pollicis longus( AbPL)
abductor pollicis brevis( AbPB)
what muscles adduct the digits?
palmar interossei act on 1st, 2nd, 4th, and 5th digits to adduct the digits
dorsal interossei are responsible for moving the 3rd digit if required and adductor pollicis will act on the thumb to add strength to the movement
DIMAB and POMAD
what nerve innervates adductor pollicis?
ulnar nerve(deep branch)
what nerve innervates lumbricals?
2 bipennate( 3rd and 4th lumbricals): ulnar n
2 unipennate( 1st and 2nd lumbricals): median n
what nerve innervates thenar muscles?
median n
innervation of the thenar muscles?
Recurrent branch
median n
innervation of the thenar muscles?
median n
innervation of the hypothenar muscles?
ulnar n (deep branch)
how are metacarpophalangeal joints flexed?
there is no forearm muscle that inserts into the base of the proximal phalanges
flexion partially accomplished by FDS and FDP maximally shortening, as in making a tight fist, but fine control is brought about by the actions of the interossei and lumbricals , with their insertions into the edges of the dorsal digital expansion hood as this narrows over the proximal phalanx
what brings about the flexion of the IP joints?
insertion of the tendons of FDS and FDP into the bases of the middle and distal phalanges respectively
what muscles act to achieve opposition of the thumb?
opponens pollicis(OP)
opponens digit minimi(ODM)
act together with other intrinsic hand muscles