The hand Flashcards
How are the thumb and digits named?
Thumb Index Finger Middle Finger Ring Finger Little Finger
Name the carpal bones.
Scaphoid, Lunate Triquetrum, Pisiform
Trapezium, Trapezoid, Capitate, Hamate
What other bones make up the hand?
Metacarpals
Proximal, Middle + Distal Phalanges
How many radio-ulnar joints are there?
2: proximal + distal
Describe the distal articulation of the radius and ulna with the carpal bones.
Radius: articulates with scaphoid + lunate
Ulna: 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 flexor carpi ulnaris tendon
What are the four parts of the metacarpals?
Head (distal), tubercle, shaft + 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? (If present)
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 + 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 + splits in 2 about midway up the proximal phalanx
FDP then runs between the 2 divisions of FDS
The 2 branches of FDS attach to the middle phalanx + 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 4 compartments of the hand.
Thenar
Hypothenar
Adductor
Central
What separates the compartments of the hand?
Fibrous septa
From palmar aponeurosis to little finger metacarpal medially
From palmar aponeurosis to middle finger metacarpal laterally
What are the two main spaces found within the hand?
Midpalmar
Thenar
What structures do the septa form within the hand?
Channels that contain structures e.g. long flexors passing from the wrist into the digits
What does ‘carpi’ mean?
Acting on the wrist
What does ‘digitorum’ mean?
Acting on >1 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 the superficial muscles of the forearm?
Common flexor origin (at 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 the muscles in the deep anterior compartment of the forearm attach?
Flexor digitorum profundus (FDP)
Posterior + medial borders of ulna + interosseous membrane
To the distal phalanges of the 4 fingers
Flexor pollicis longus (FPL)
Interosseous membrane + 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 + pronator teres
State the 12 muscles of the posterior compartment of the forearm.
Extensor carpi radialis longus (ECRL) Extensor carpi radialis brevis (ECRB) Extensor carpi ulnaris (ECU) Extensor indicis (EI) Extensor digitorum (ED) Extensor digiti minimi (EDM) Abductor pollicis longus (APL) Extensor pollicis longus (EPL) Extensor pollicis brevis (EPB) Brachioradialis Supinator Extensor retinaculum (not a muscle)
What is the common proximal attachment of most of the posterior forearm 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 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 + 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 fingers
Dorsal = ABduction of fingers