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
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 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
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: 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 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.
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
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 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 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
Arch supplied by radial artery
Deep palmar supplying palmar metacarpal arteries
Where is radial artery found
Under brachioradialis by flexor carpi radialis
Arch from ulnar artery
Superficial palmar arch supplying palmar digital arteries
3 types of grip
Power Precision Hook
Muscles involved in power grip
Flexors of thumbs and fingers Intrinsic muscles of palm Wrist extensors
Muscles of precision grip
Wrist and fingers by long extensors and flexors Intrinsic muscles of hand carrying out fine movements
Muscles of hook grip
Long flexors of digits
What is a main proximal branch of ulnar artery
Interossesous arteries
Where does medial septa attach
Metacarpal of little finger
Where does lateral septa attach
Middle finger metacarpal
Muscles of thenar region
Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis
Muscles of adductor region
Adductor pollicis
Muscles of interosseous region
Interossei- palmar and dorsal Lumbricals
Hypothenar region muscles
Opponens digiti minimi Flexor digitor minimi Abductor digiti minimi
What is the thenar region
Prominent part medial to thumb due to heavy muscular supply to thumb
