The hand (A) Flashcards
How are the thumb and digits named?
Thumb Index Finger Middle Finger Ring Finger Little Finger
Name the carpal bones.
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Scaphoid, Lunate Triquetrum, Pisiform
Trapezium, Trapezoid, Capitate, Hamate
What other bones make up the hand?
Metacarpals
Proximal, Middle and Distal Phalanges
How many radio-ulnar joints are there?
2 – proximal and distal
Describe the distal articulation of the radius and ulna with the carpal bones.
Radius – articulates with scaphoid and lunate
Ulna – doesn’t directly articulate with the carpal bones, it articulates with an articular disc
What separates the anterior and posterior compartments of the forearm?
Interosseous membrane
What type of bone is the pisiform bone?
Sesamoid – it is encased within a tendon (flexor carpi ulnaris)
What are the four parts of the metacarpals?
Head (distal), tubercle, shaft and base
Which two carpal bones have bone protrusions?
Hook of Hamate
Tubercle of Trapezium
What type of skin do you get on the palms of your hands?
Palmar-plantar skin
Which muscle forms the palmar aponeurosis?
It is the distal end of palmaris longus
What is the palmar aponeurosis distally and proximally continuous with?
Distal – fibrous digital sheaths
Proximal – flexor retinaculum
What is contained within the fibrous digital sheaths?
Flexor tendons and their synovial sheaths
Which muscle tendons are found within the fibrous digital sheaths? Describe their attachments.
Flexor digitorum superficialis
Flexor digitorum profundus
FDS lies superficial to FDP and splits in two about midway up the proximal phalanx
FDP then runs between the two divisions of FDS
The two branches of FDS attach to the middle phalanx and FDP attaches to the distal phalanx
Which small quadrate muscle is found proximal to the hypothenar compartment?
Palmaris brevis
What is another name for the flexor retinaculum?
Transverse carpal ligament
Name the compartments of the hand.
Thenar Hypothenar Adductor Central interosseous
What separates the compartments of the hand?
Fibrous septa
What are the two main spaces found within the hand?
Midpalmar
Thenar
What structures do the septa form within the hand?
Channels that contain various structures e.g. long flexors passing from the wrist into the digits (slide 13 pic)
What does ‘carpi’ mean?
Acting on the wrist
What does ‘digitorum’ mean?
Acting on more than one finger
State the muscles in the superficial anterior compartment of the forearm.
Pronator teres (PT) Flexor carpi radialis (FCR) Palmaris longus (PL) Flexor digitorum superficialis (FDS) Flexor carpi ulnaris (FCU)
What is the name given to the proximal attachment of all of these muscles?
Common flexor origin (at the medial epicondyle of the humerus)
What muscles are in the deep anterior compartment of the forearm?
Flexor digitorum profundus (FDP) Flexor pollicis longus (FPL) Pronator quadratus (FQ)
Where do these muscles attach?
Flexor digitorum profundus (FDP)
Posterior and medial borders of ulna and interosseous membrane
To the distal phalanges of the four fingers
Flexor pollicis longus (FPL)
Interosseous membrane and anterior surface of radius
To palmar side of the distal phalanx of the thumb
Pronator quadratus (PQ)
Anterior surface of distal ulna
To anterior surface of distal radius
Which muscles of the anterior compartment do not cross the wrist?
Pronator quadratus and pronator teres
State the 12 muscles of the posterior compartment of the forearm.
Supinator Brachioradialis Abductor pollicis longus (APL) Extensor pollicis longus (EPL) Extensor pollicis brevis (EPB) Extensor indicis (EI) Extensor digitorum (ED) Extensor digiti minimi (EDM) Extensor carpi radialis longus (ECRL) Extensor carpi radialis brevis (ECRB) Extensor carpi ulnaris (ECU) Extensor retinaculum (not a muscle)
What is the common proximal attachment of most of these muscles?
Common extensor origin (just distal to the lateral epicondyle)
Which muscles have a proximal attachment along the ulna rather than the common extensor tendon?
Abductor pollicis longus (APL) Extensor pollicis longus (EPL) Extensor pollicis brevis (EPB) Extensor indicis (EI)
Describe the attachment of brachioradialis.
Distal lateral side of the humerus
To the lateral part of the styloid process of the radius
Name all the intrinsic muscles of the hand.
Thenar: Abductor pollicis brevis (APB), Flexor pollicis brevis (FPB), Opponens pollicis (OP)
Hypothenar:Abductor digiti minimi (ADM), Flexor digiti minimi (FDM), Opponens digiti minimi (ODM)
Adductor: Adductor pollicis (AP)
-Interossei and Lumbricals: Palmar interossei+Dorsal interossei
-Lumbricals
What movements are the lumbricals responsible for?
Flexion of metacarpophalangeal joint (MCP)
Extension of the interphalangeal joints (IPJs)
What movements are the palmar and dorsal interossei responsible for?
PAD & DAB
Palmar = ADduction of the fingers
Dorsal = ABduction of the fingers
Which muscles are responsible for the following thumb movements: - abduction -adduction extension flexion opposition
Abduction: Abductor pollicis longus (APL), Abductor pollicis brevis (APB)
Adduction: Adductor pollicis (AP), First dorsal interosseus
Extension: Extensor pollicis longus (EPL), Extensor pollicis brevis (EPB), Abductor pollicis longus (APL)
Flexion: Flexor pollicis longus (FPL), Flexor pollicis brevis (FPB)
Opposition: Opponens pollicis
Why is adductor pollicis in a different compartment to the other pollicis muscles?
It is innervated by the ulnar nerve whereas the thenar muscles are all innervated by the median nerve
How many lumbricals, dorsal interossei and palmar interossei are there?
Lumbricals – 4
Dorsal interossei – 4
Palmar interossei - 3
Describe the attachments of the dorsal interossei and explain why they cause abduction of the fingers.
Dorsal interossei are attached proximally to adjacent metacarpals
They attach distally to the base of the proximal phalanx and extensor expansion towards the axial line (through the middle finger) of the hand
Dorsal interossei 2 and 3 are attached to opposite sides of the middle finger so it fixes the middle finger in the midline while dorsal interossei 1 and 4 cause abduction of the index and little fingers
Describe the attachments of the palmar interossei.
Palmar interossei are attached to the extensor expansion away from the axial line (there is no palmar interossei attached to the middle finger)
The cause adduction of the fingers whilst the middle finger remains still
Describe the attachments of the lumbricals.
They are attached proximally to the tendons of flexor digitorum profundus
They come around the lateral side of the digits and inserts onto a hood of connective tissue called the extensor expansion over the proximal interphalangeal joint
Describe the sheaths that that the tendons of flexor digitorum superficialis and flexor digitorum profundus travel in after passing under the flexor retinaculum.
They travel under the flexor retinaculum in the common synovial sheath in the carpal tunnel
Then the tendons going to the middle three fingers enter digital synovial sheaths
Describe how the little finger and thumb sheaths are different to the other three fingers.
Their digital synovial sheaths are continuous with the common synovial sheath
Describe the arrangement and attachment of flexor digitorum superficialis and flexor digitorum profundus as it runs along the fingers.
Flexor digitorum superficialis splits around flexor digitorum profundus around the middle of the proximal phalanx
Flexor digitorum superficialis then attaches to the middle phalanx
Flexor digitorum profundus attaches to the distal phalanx
Describe how the arrangement of the digital fibrous sheaths, synovial sheaths and osseo-fibrous sheaths.
The entire thing is an osseo-fibrous sheath
This contains digital fibrous sheaths, which, in turn, contain synovial sheaths
