Dissection of the hand Flashcards
What inserts into the hand?
Long tendons
Which long tendon inserts into the 5th metacarpal?
Flexor carpi ulnaris
What does flexor digitorum superficialis form?
4 muscle bellies that give off 4 tendons
What does flexor digitorum profundus give off?
4 muscle bellies that give off 4 tendons
Where does flexor digitorum profundus lay?
Deep to flexor digitorum superficialis
Where do the superficialis tendons of 3 and 4 sit?
Above 2 and 5
What happens to the tendons as they pass towards d2-5 through the carpal tunnel?
Enter fibrous digital sheaths
Name the ligaments that form the fibrous digital sheaths
Annular
Cruciate
What are the annular ligaments known as?
Pulleys
What happens to the superficialis tendons in the digits?
Split to allow flexor digitorum profundus tendons to pass through
Where do the flexor digitorum superficialis tendons insert?
Middle phalanx
Where do flexor digitorum profundus tendons insert?
Distal phalanx
Where does extensor carpi radialis longus sit?
Above extensor carpi radialis brevis
Where does extensor carpi radialis longus insert?
second metacarpal
Where does extensor carpi radialis brevis insert?
Third metacarpal
What is the function of the flexor carpi radialis muscles?
Extend and adduct the wrist
Where does extensor carpi ulnaris insert?
Base of fifth metacarpal
What is the function of extensor carpi radialis?
Extend and adduct the wrist
What does extensor digitorum give off?
4 tendons
What does extensor digitorum do?
Extends wrist and metacarpophalangeal joints in proximal and distal d2-5
What do the accessory extensor muscles join?
Extensor digitorum
What forms the anatomical snuffbox?
(from lateral to medial) the tendons of abductor pollicis longus, extensor pollicis brevis and extensor pollicis longus
What are the dorsal digital expansions, or extensor hoods? What are they formed from?
They are flattened aponeurotic ‘hoods’ of connective tissue over the dorsum of each finger that are formed from the tendons of extensor digitorum
What 3 areas can the palmar surface be divided into?
Central palmar area
Thenar eminence
Hypothenar eminence
What extends over the central palmar area?
Palmar aponeurosis
Describe the structure of the palmar aponeurosis
It extends distally from the flexor retinaculum and divides into slips, one to each of the digits 2 to 5. Each slip is attached to the fibrous flexor sheath of each digit
What constitutes the thenar eminence?
abductor pollicis brevis, flexor pollicis brevis and opponens pollicis
Where do the thenar eminence muscles originate?
flexor retinaculum and the most lateral carpal bones.
Where do the abductor pollicis brevis and flexor pollicis brevis muscles insert?
Proximal phalanx of the thumb
What is the function of the abductor pollicis brevis and flexor pollicis brevis muscles?
Abduct and flex the thumb
Where does the opponens pollicis muscle lay?
deep to abductor and flexor pollicis brevis
Where does opponens pollicis muscle insert?
First metacarpal
What is the function of opponens pollicis?
brings the thumb into contact with the little finger, thereby performing the movement of opposition.
Name the muscles that constitute the hypothenar eminence
abductor digiti minimi
flexor digiti minimi
opponens digiti minimi.
Where do the hypothenar eminence muscles originate?
flexor retinaculum and the most medial carpal bones.
Where do the abductor digiti minimi and flexor digiti minimi muscles insert?
proximal phalanx of digit 5 and abduct and flex the little finger respectively.
Where does opponens digiti minimi lay?
deep to the abductor and flexor digiti minimi
Where does opponens digiti minimi insert?
5th metacarpal
What is the function of opponens digiti minimi?
bring the little finger towards the thumb during opposition.
How many lumbrical muscles are there?
4
Where do the lumbrical muscles sit?
on the radial side of the tendons of flexor digitorum profundus.
Give the origin of the lumbrical muscles
tendons of flexor digitorum profundus
Where do the lumbrical muscles insert?
dorsal digital expansion
Name the two groups of interossei muscles
dorsal interossei and the palmar interossei
Where do the dorsal interossei muscles originate?
sides of the metacarpal bones
Where do the dorsal interossei muscles insert?
dorsal digital expansion
Give the origin of the 3 palmar interossei muscles
2nd, 4th and 5th metacarpals
Give the insertion of the 3 palmar interossei muscles
dorsal digital expansions
Where does the adductor pollicis muscle lay?
Deep to the thenar muscles
Name the two heads of adductor pollicis
Transverse
Oblique
Give the origin of the transverse head
third metacarpal
Give the origin of the oblique head
second and third metacarpals and adjacent carpal bones.
Where do the heads of adductor pollicis insert?
base of the proximal phalanx of the thumb
What is the function of adductor pollicis?
bring the abducted thumb back into contact with the index finger
Describe the blood supply in the hand
ulnar artery is relatively superficial and passes into the palm of the hand lateral to the pisiform bone.
The ulnar artery proceeds into the palm of the hand to form the main part of the superficial palmar arch, which is superficial relative to the long flexor tendons. From the convexity of this arch, three digital arteries arise that divide to supply blood to adjacent sides of the digits.
Which artery does the superficial palmar arch join?
Radial artery
What does the radial artery form in the palm?
Deep palmar arch
Name the nerves which supply d1-half of d3
Digital nerves
What are digital nerves a branch of?
Median nerve
What supplies the thenar muscles?
Recurrent branch
What does the ulnar nerve divide into at the wrist?
Deep and cutaneous nerves
