Week 9 - forearm and wrist Flashcards
Flexor pollicis longus
Flexion of the thumb
Extensor digiti minimi
Extension of little finger
Flexor carpi radialis
Flexion and radial deviation of wrist (movement of wrist towards radius - wrist abduction)
Extensor carpi ulnaris
Extension and ulnar deviation (movement of wrist towards ulna - wrist adduction)
Where do the flexors of the wrist and digits lie
On the anterior aspect of the forearm
3 layers of muscle of the flexors of the wrist and digits
2-1-3 formation
2 on the deep layer
1 on the intermediate
3 on the superficial layer
What does each member of this football team do (2-1-3 formation)
Goalkeeper keeps sucking his thumb
Defender has very long fingers, meaning he can hold a book and make profound statements
Midfielder has quite long fingers
Central striker likes scoring with palm of hand
Two wingers - one keeps shouting FCR and the other FC-U
2 muscles in the deep layer
Flexor pollicis longus (goalkeeper)
Flexor Digitorum profundus (long fingered defender)
Origin and insertion of the flexor pollicis longus
Anterior radius –> distal phalanx of thumb
Origin and insertion of flexor digitorum profundus
Ulna –> distal phalanges of fingers
1 muscle in the intermediate layer
Flexor digitorum superficialis (long fingered midfielder)
Origin and insertion
Medial epicondyle of elbow –> middle phalanges of fingers
Difference between the flexor digitorum superficialis and the flexor digitorum profundus
The flexor digitorum superficialis inserts into the middle phalanges of fingers and the flexor digitorum profundus inserts into the distal phalanges meaning the profundus can flex the ends of the fingers (distal interphalangeal joint)
3 muscles in the superficial layer
Flexor carpi radialis (FCR)
Flexor carpi ulnaris (FCU)
Palmaris Longus
Flexor carpi radialis
What does it do + origin/insertion
Flexes wrist
Radial devotion
Medial epicondyle of elbow –> base metacarpal II
Flexor carpi ulnaris
What does it do + origin/insertion
Wrist flexion
Ulnar deviation
Medial epicondyle of elbow –> metacarpal V
Palmaris Longus
What does it do + origin/insertion
Weak wrist flexor
Anchors skin and fascia of hand
Medial epicondyle of elbow –> palmar fascia
Where do the extensors of the wrist and digits lie
On the posterior aspect of the forearm
Wrist flexion and extension
Wrist flexion is moving fingers towards palm of hand
5 muscles in the posterior superficial layer
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris
All the superficial extensors originate from the
Lateral epicondyle of elbow
Extensor carpi radialis longus
Wrist extension
Radial deviation
Lateral epicondyle –> base metacarpal II
Extensor carpi radialis brevis
Wrist extension
Radial deviation
Lateral epicondyle –> base metacarpal III
Extensor digitorum
Extends fingers
Lateral epicondyle –> dorsal digital expansion
What is the dorsal digital expansion
Fibrous extension of extensor digitorum tendons on back of fingers
Extensor digiti minimi
Extends little finger
Lateral epicondyle –> dorsal digital expansion
Extensor capri ulnaris
Wrist extension
Ulnar deviation
Lateral epicondyle –> base metacarpal V
4 muscles in the posterior deep layer
Extensor indicis
Extensor pollicis longus
Extensor pollicis brevis
Abductor pollicis longus
Extensor indicis
Extends index finger
Inserts into dorsal digital expansion
Extensor pollicis longus
Extends thumb
Inserts into distal phalanx (therefore extends every digit in thumb)
Extends pollicis brevis
Extends joint
Inserts into proximal phalanx (dosent extend IP joint)
Abductor pollicis longus
Abducts and extends thumb
Inserts into base metacarpal I
Thenar and hypothenar eminence
Thenar - fleshy compartment at base of thumb - moves the thumb
Hypothenar - fleshy compartment at base of little finger - moves the digiti minimi
2 muscles that create opposition of the thumb and little finger
Opponens policis muscle
Opponens digiti minimi
2 muscles that flex the thumb and little finger
Flexor pollicis brevis
Flexor digiti minimi
2 muscles that abduct the thumb and little finger
Abductor pollicis brevis and abductor digiti minimi
How does abduction and adduction work in the hand
We take a new centre line - the middle finger
Movement away from middle finger = abduction
Muscles that adduct the fingers
First palmar interosseous - on the side of the first finger towards the middle finger
Second palmar interosseous (on third finger)
Third palmar interosseous (on fourth finger)
Muscles that abduct the fingers
First dorsal interosseous - first finger
Second dorsal interosseous - middle finger - has 2 attatchment points to allow it to abduct from midline both ways
Third dorsal interosseous - third finger
Fourth dorsal interosseous - forth finger
Role of the lumbricals
Link the flexor and extensor tendons of hand
Flex at metacarpal joint whilst extending at interphalangeal joint
