The hand (B) Flashcards
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
Extension
radial deviation
ulnar deviation
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 (ulnar gives off common interosseous artery in forearm)
- main contributor of Superficial palmar arch (and a small contribution to deep palmar arch via its deep palmar branch)
- palmar digital arteries (from superficial palmar arch)
Radial Artery:
- under brachioradialis and beside flexor carpi radialis in the wrist
- Found in the anatomical snuff box
- main contributor of Deep palmar arch and small contribution to superficial palmar arch via its superficial palmar branch
- Palmar metacarpal arteries (from the deep palmar arch)
NB palmar metacarpal arteries and palmar digital arteries anastomose
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 - source is from both radial and ulnar arteries: anastomosis
What arteries come off the palmar arches?
What arteries come off the dorsal carpal arch?
Superficial palmar arches gives off Common palmar digital arteries which then give off the Proper palmar digital arteries. The deep palmar arch gives off the palmar metacarpal arteries which join/anastomose with the common palmar digital arteries before it gives off the proper palmar digital arteries
Dorsal carpal arch itself arises from both radial and ulnar artery anastomosis. It first gives off dorsal metacarpal arteries which then becomes the dorsal 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 ARM?
The basilic vein dives deep to form the axillary artery (by joining with the brachial vein venae comitantes of brachial 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 Adductor 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
