The hand Flashcards
what kind of joint is the CMC joint at the base of the thumb
synovial saddle joint
the synovial saddle joint at the base of the thumb permits
opposition of the thumb
the MCP joints of all the digits are
synovial condyloid joints
what movements are allowed at the MCP joints
flexion extension abduction adduction small degree of circumduction
what type of joints are the IP joints
synovial hinge
what movements are allowed at IP joints
flexion and extension of the fingers
what type of joints are between carpal bones
synovial plane - small gliding movements allowed
what are the bones of the hand
carpals
metacarpals
phalanges - proximal, middle, distal
(thumb doesnt have a middle phalanx)
what is the first structure seen immediately beneath the skin of the palm
palmar aponeurosis
what does the palmar aponeurosis do
tough connective tissue layer that adheres to the skin of the palm - it helps to hold the skin of the palm in place during movement to prevent skin from slipping and loss of grip
also protects the delicate nerves and vessels of the palm
what tightens the palmar aponeurosis
palmaris longus from the forearm
where is palmaris brevis
thin intrinsic muscle that lies superficial to the muscles of the hypothenar eminence
what is the origin and insertion of palmaris brevis
palmar aponeurosis and flexor retinaculum to dermis
what is the function of palmaris brevis
grip
what is the innervation of palmaris brevis
ulnar nerve (superficial C8,T1)
what nerve innervates most of the muscles of the hand
ulnar nerve
what is the difference between intrinsic and extrinsic muscles of the hand
intrinsic are entirely within the hand
extrinsic muscles enter the hand from the forearm
what are the deepest muscles of the hand called
interossei because they lie between the metacarpal bones of the hand
the thumb (lateral) side of the hand is dominated by what nerve
median - some but not all muscles are supplied by it
the little finger (medial) side of the hand is dominated by
ulnar nerve
the deepest intrinsic muscles of the hand are supplied by
ulnar nerve
how many muscles make up the thenar eminence
3 - two superficial and one deep
the muscles of the thenar eminence all act on what
CMC joint of the thumb
what muscle lies on the lateral side of the eminence
abductor pollicis brevis
what does abductor pollicis brevis do
acts to pull the thumb away from the plane of the palm
what muscle is medial in the thenar eminence
flexor pollicis brevis
what does flexor pollicis brevis do
acts to bend the joint of the thumb in the same plane as the palm
the long abductor and flexor muscles originate where
forearm
flexion of the thumb is dominated by what nerve
median nerve
abduction of the thumb is what nerve
both radial and median
what is the deepest muscle in the thenar eminence
opponens pollicis
what does opponens pollicis do
acts to oppose the thumb by pulling the base of the thumb across the palm allowing the pulp of the thumb to touch the pulp of other digits
opposition of the thumb is controlled by what nerve
median nerve
the muscles of the thenar eminence are supplied by
median nerve - although sometimes the ulnar nerve may send innervation to flexor pollicis brevis
what branch of the median nerve supplies the thenar eminence
recurrent branch of the median nerve - the median nerve sends a branch that passes backwards towards the thenar eminence
what are the attachments of abductor pollicis brevis
scaphoid and trapezium to base of proximal phalanx of thumb
abductor pollicis brevis does what
CMC joint abduction
what nerve supplies abductor pollicis brevis
median nerve (recurrent C8, T1)
what are the attachments of the flexor pollicis brevs
flexor retinaculum, capitate, trapezium to base proximal phalanx of thumb
what is the function of flexor pollicis brevis
CMC joint flexion
what is the innervation of flexor pollicis brevis
median (recurrent) and some texts also say ulnar nerve (C8,T1)
what are the attachments of opponens pollicis
trapezium to first metacarpal
what is the function of opponens pollicis
CMC joint opposition
what is the innervation of opponens pollicis
median nevre (recurrent C8, T1)
what is the other intrinsic muscle of the thumb
adductor pollicis
is adductor pollicis part of the thenar eminence
no
what are the attachments of adductor pollicis
transverse head from 3rd metacarpal; oblique head from capitate and 2nd/3rd metacarpals to base of proximal phalanx of thumb
what are the functions of adductor pollicis
adduction of CMC joint of thumb
flexion of MCP joint of thumb
what is the innervation of adductor pollicis
ulnar nerve (deep C8, T1)
adductor pollicis is one of the deep/superficial intrinsic muscles
one of the deeper layer
the muscles of the hypothenar eminence do what
move the MCP joint of the little finger
the muscles of the hypothenar eminence are all supplied by the
ulnar nerve