The Hand Flashcards
palm characteristics
thick layer of skin
numerous sweat glands
hairless
papillary ridges
what are palmar creases
where skin attaches to deep fascia
3 palmar creases
- longitudinal
- mid-palmar
- distal creases
3 anterior wrist creases
- distal
- middle
- proximal
what is the palmar aponeurosis
triangular shaped band of deep fascia
clinical implications of issues with palmar aponeurosis
Dupuytrens contracture if scarring/fibrosis of palm
2 eminences on palmar surface
- thenar (lateral/prominent)
- hypothenar (medial/smaller)
what separates 2 eminences of palm
central concavity
3 thenar muscles
- abductor pollicis brevis
- flexor pollicis brevis
- opponens pollicis
thenar muscles innervation
median nerve
abductor pollicis brevis origin
- trapezium
- scaphoid
- flexor retinaculum
abductor pollicis brevis insertion
base of proximal phalanx and extensor hood of thumb
abductor pollicis brevis innervation
recurrent branch of median nerve
abductor pollicis brevis action
abduction at metacarpophalangeal joint
assists in thumb opposition
flexor pollicis brevis origin
tubercle of trapezium and flexor retinaculum
flexor pollicis brevis insertion
base of proximal phalanx of thumb
flexor pollicis brevis innervation
recurrent branch of median nerve
flexor pollicis brevis action
flexes the thumb at metacarpophalangeal joint
assists in thumb opposition
opponens pollicis origin
tubercle of trapezium and flexor retinaculum
opponens pollicis insertion
lateral border of first metacarpal
opponens pollicis innervation
recurrent branch of median nerve
opponens pollicis action
opposition of thumb
medially rotates and flexes metacarpal 1 during opposition
what is the carpal tunnel
tunnel formed as flexor retinaculum and carpal bones enclose area
what is inside the carpal tunnel
- 4 tendons of flexor digitorum profundus
- 4 tendons of the flexor digitorum superficialis
- tendon of the flexor pollicis longus
- Median Nerve
what is carpal tunnel syndrome
- entrapment of median nerve in carpal tunnel syndrome
- causes numbness, tingling, wasting of thenar muscles
hypothenar muscles
- abductor digiti minimi
- flexor digiti minimi brevis
- opponens digiti minimi
hypothenar muscles innervation
ulnar nerve
abductor digiti minimi origin
pisiform bone
tendon of flexor carpi ulnaris
abductor digiti minimi insertion
medial base of proximal phalanx of little finger
abductor digiti minimi innervation
ulnar nerve
abductor digiti minimi action
abducts little finger
flexor digiti minimi brevis origin
flexor retinaculum
hook of hamate
flexor digiti minimi brevis insertion
medial base of proximal phalanx of little finger
flexor digiti minimi brevis innervation
ulnar nerve
flexor digiti minimi brevis action
flexes proximal phalanx of little finger
opponens digiti minimi origin
flexor retinaculum
hook of hamate
opponens digiti minimi insertion
medial border of metacarpal 5
opponens digiti minimi innervation
ulnar nerve
opponens digiti minimi action
rotates metacarpal 5 in opposing little finger to thumb
Adductor pollicis origin
anterior surfaces of capitate and trapezoid metacarpals 2 and 3
Adductor pollicis insertion
medial base of proximal phalanx of thumb
Adductor pollicis innervation
ulnar nerve
Adductor pollicis action
adducts thumb
extensor expansion/hood
a triangular shaped connective tissue aponeurosis over proximal phalanges
Lumbrical muscles
- first lumbrical muscle
- second lumbrical muscle
- third Lumbrical muscle
- fourth Lumbrical muscle
unipennate Lumbrical muscles
first and second
bipennate Lumbrical muscles
third and fourth
Lumbrical muscles origin
tendons of flexor digitorum profundus
Lumbrical muscles insertion
extensor expansions of digits 2-5
- extending from flexor tendon to extensor expansion
- linking flexor tendons to extensors
first Lumbrical muscle innervation
median nerve
second Lumbrical muscle innervation
median nerve
third Lumbrical muscle innervation
ulnar nerve
fourth Lumbrical muscle innervation
ulnar nerve
lumbrical muscles action
flexes digits 2-5 at metacarpophalangeal joints
extends interphalangeal joints
number of palmar interossei muscles
3
number of dorsal interossei muscles
4
dorsal interossei origin
adjacent sides of metacarpals
(1, 2), (2, 3), (3, 4), (4, 5)
dorsal interossei insertion
extensor hood
base of proximal phalanges of index, middle and ring fingers
dorsal interossei innervation
ulnar nerve
dorsal interossei action
abduction
palmar interossei origin
sides of metacarpals 2, 4, 5
palmar interossei insertion
extensor hood of index, ring and little fingers
palmar interossei innervation
ulnar nerve
palmar interossei action
Adduction
palmaris brevis origin
palmar aponeurosis and flexor retinaculum
palmar aponeurosis insertion
skin on medial margin of hand
palmar aponeurosis innervation
ulnar nerve
palmaris brevis action
improves grip