The hand Flashcards
How are the thumb and digits named?
Thumb Index Finger Middle Finger Ring Finger Little Finger
Name the carpal bones.
SLTP + TTCH
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
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
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 carpi ulnaris (FCU)
Middle compartment:
Flexor digitorum superficialis (FDS)
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 11 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),
Opponens digiti minimi (ODM)
Flexor digiti minimi (FDM),
Adductor: Adductor pollicis (AP)
numonic = All For One And One For All
Interossei and Lumbricals: Palmar interossei (PAD) Dorsal interossei (DAB) 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: 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 on the lateral side relative to the axial midline (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 wrap cause abduction of the index and little fingers
Describe the attachments of the palmar interossei.
Palmar interossei are attached to the extensor expansion on the medial side relative to the axial midline (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 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 carpal tunnel then they enter a common synovial sheath
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.
The little finder digital synovial sheaths is continuous with the common synovial sheath
The thumb synovial sheath is separate from the other sheaths
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 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
What are the two types of pulley that hold the tendons down to the bone?
Annular and Cruciform
Describe the posterior tendinous anatomy of the hand.
You get the extensor retinaculum followed by synovial tendon sheaths and intertendinous bands
At the end of the long extensors there are extensor expansions
Which muscles attach to the extensor expansions?
Lumbricals and some interossei
What are the two fibrous capsules found at the wrist joint?
Radio-carpal joint
Distal radio-ulnar joint
Which two ligaments are found on the radial and ulnar sides of the wrist?
Radial Collateral Ligament
Ulnar Collateral Ligament
Which muscles are important for the following wrist movements:
Flexion:
Flexor carpi radialis
Flexor carpi ulnaris
(and the long flexors of the thumb and fingers + palmaris longus and abductor pollicis longus)
Extension: Extensor carpi radialis longus Extensor carpi radialis brevis Extensor carpi ulnaris (and long extensors of the thumb and fingers)
Radial Deviation: Flexor carpi radialis Extensor carpi radialis longus Extensor carpi radialis brevis Abductor pollicis longus
Ulnar Deviation:
Flexor carpi ulnaris
Extensor carpi ulnaris
What is the name given to the joint between the two rows of carpal bones?
Midcarpal joint
Which carpal bone does the thumb metacarpal articulate with?
Trapezium
What movements are the metacarpophalangeal joints capable of?
Flexion and extension
Abduction and adduction
What ligament prevents hyperextension of the interphalangeal joints?
Palmar plates (AKA volar plates)
Which ligaments prevent abduction and adduction of the interphalangeal joints?
Collateral ligaments
What are the two main arteries of the hand and what do they divide into?
Ulnar Artery: found beside the flexor carpi ulnaris
Interosseous arteries of the forearm
Superficial palmar arch – palmar digital arteries
Deep palmar branch
Radial Artery: under brachioradialis and beside flexor carpi radialis in the wrist
Found in the anatomical snuff box
Deep palmar arch
Palmar metacarpal arteries
What are the anterior and posterior interosseous arteries a branch of?
Ulnar Artery
What is the arch on the dorsal side of the hand called?
Dorsal carpal arch
What are the two divisions of palmar digital arteries that come off these arches?
Common palmar digital arteries
Proper palmar digital arteries
Where do you find anastomoses in the hand?
Between the dorsal and palmar digital arteries
The arches and plexuses are also places of anastomoses between the radial and ulnar arteries
What are the two main superficial veins of the arm?
Cephalic and Basilic
What happens to the basilic and cephalic veins as they pass into the upper arm?
The basilic vein dives deep just above the elbow to form the axillary artery
The cephalic artery joins the axillary artery higher up
At what point does the axillary vein become the subclavian vein?
As it passes over the first rib
What pattern do the deep veins from the hand follow?
They pass in the opposite direction to the arteries
What vein links the cephalic and basilic vein in the cubital fossa?
Median cubital vein
Which spinal nerves contribute to the:
Ulnar Nerve : C8-T1
Median Nerve: C6-T1
Radial Nerve: C5-T1
What is the main motor nerve of the hand?
Ulnar nerve
What is the radial nerve responsible for in the hand?
Sensory innervation of the lateral half of the dorsum of the hand
What type of nerve are the digital nerves?
They are purely sensory because the motor innervation to the muscles controlling the fingers happens more proximally
What are the contents of the carpal tunnel?
4 tendons of flexor digitorum superficialis
4 tendons of flexor digitorum profundus
Flexor pollicis longus tendon
Median nerve
Where does the median nerve lie relative to the forearm muscles at the wrist?
In between FDP and FDS
Deep to PL
What intrinsic hand muscles does the median nerve provide motor supply to?
LOAF Lumbricals (1 and 2) Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis
What does the median nerve provide sensory supply to?
Palmar surface of thumb Index finger Middle finger Half of the ring finger Some of the dorsal surface of those digits
Describe the position of the ulnar nerve at the wrist.
It lies by flexor carpi ulnaris
It runs over the flexor retinaculum, lateral to the pisiform
What are the two branches of the ulnar nerve in the hand and what are their roles?
Superficial branch sensory to:
Little finger and medial half of right finger
Deep branch motor to: Hypothenar muscles Abductor pollicis Lumbricals 3 and 4 All the interossei (In other words: all the muscles except LOAF)
The radial nerve divides into two branches just above the elbow. What are the two branches of the radial nerve?
Superficial radial nerve (sensory)
Posterior interosseous nerve (motor)
Which part of the hand does the radial nerve supply sensory innervation to?
Dorsum of the hand (mainly thumb, index finger and middle finger)
What sensory branches does the median nerve give off before passing under the flexor retinaculum?
Palmar cutaneous branch
Dorsal branch
What branches do the superficial radial nerve and dorsal branch of the ulnar nerve split into?
Dorsal digital nerves/branches
What are the bony attachments of the carpal tunnel that forms a gutter?
Scaphoid
Trapezium
Pisiform
Hamate
What is the roof of the carpal tunnel?
Flexor retinaculum
Through which canal do the ulnar nerve and artery pass through?
Guyon’s Canal
What are the three different types of grip and which muscles are involved in each type?
Power Grip:
Long flexors of the fingers and thumb
Intrinsic muscles of the palm
Extensors of the wrist joint
Precision Grip:
The wrist and fingers are held rigidly by the long flexors and extensors
The intrinsic muscles of the hand carry out the fine movements needed
Hook Grip:
Consumes little energy
Mainly involves long flexors of the digits (e.g. carrying shopping bag or briefcase)
What wrist movement do you need to achieve full flexion of the fingers and why?
The flexors have to be slightly longer than need be to allow the wrist and fingers to fully extend
This means that to get full flexion you need to extend the wrist to shorten the flexors so that they can fully flex
This is why you can more easily take something from someone’s grip if you flex the wrist to loosen the grip
