Forearm and wrist Flashcards
what is the medial epicondyle?
- on humerus
- point of attachment for flexors
- where ulnar nerve passes
what is the lateral epicondyle?
- on humerus
- point of attachment for extensors and aconeus
what is the radial tuberosity?
point of attachment for biceps tendon
what can be found on the radius distally?
styloid process and articular surface for carpal bones
how is the radius connected to the ulna?
by a interosseus membrane
what is special about the pisiform?
sesamoid bone
bone embedded within a tendon or muscle
what processes can be found on the head of the ulna?
- olecranon posteriorly
- coronoid anteriorly
what does the olecranon articulate with?
- olecranon fossa of humerus
- has a trochlear notch for the trochlea of the humerus
what is the distal styloid process of the ulna?
articular surface for the attachment of the radius and carpal bones
what are the forearm muscles categorised into?
flexors and pronators - anteriorly
extensors and supinators - posterioly
what is the common origin of the muscles in the superficial anterior compartment of the forearm?
common flexor tendon
on medial epicondyle of humerus
what are the muscles in the superficial anterior compartment of forearm?
- pronator teres
- flexor carpi radialis
- flexor carpi ulnaris
- palmaris longus
- flexor digitorum superficialis
what are the proximal and distal attachment sites of the pronator teres?
proximal: common flexor tendon, ulnar head
distal: midpoint of radius
what are the proximal and distal attachment of the FCR?
Proximal: common flexor tendon
Distal: proximal head of metacarpal of index finger
what are the proximal and distal attachment of FCU?
proximal: common flexor tendon, ulnar head, middle third of radius
distal: metacarpals of middle 3 fingers
what are the proximal and distal attachments of the palmaris longus?
proximal: common flexor tendon
distal: metacarpals of middle 3 fingers
what are the proximal and distal attachments of the flexor digitorum superficialis?
proximal: common flexor tendon, ulnar head, middle third of radius
distal: 2nd phalanges of 4 fingers
what are the muscles in the deep anterior compartment of the forearm?
flexor digitorium profundus
flexor pollicis longus
pronator quadratus
what are the proximal and distal attachments of the FDP?
proximal: proximal 2/3rds of ulna
distal: most distal phalanges of 4 fingers
what are the proximal and distal attachments of the FPL?
proximal: middle third of radius
distal: distal phalanx of thumb
what are the proximal and distal attachments of the PQ?
proximal: distal part of ulna
distal: distal part of radius
what is a retinaculum?
thickened ligament that holds down tendons so they don’t bow
what is the flexor retinaculum also known as?
transverse carpal ligament
how is the extensor retinaculum different to the flexor retinaculum?
lot thinner
has to cover fewer tendons
what are the extensor muscles that move the wrist?
- extensor carpi ulnaris
- extensor carpi radialis longus
- extensor carpi radialis brevis
what are the extensor muscles that move the digits?
- extensor digitorium
- extensor indicis
- extensor digiti minimi
what are the extensor muscles that move the thumb?
- abductor pollicis longus
- extensor pollicis brevis
- extensor pollicis longus
what is the boundaries of the snuffbox?
demarcated by tendons of EPL in ulnar direction
EPB and APL in radial direction
describe the elbow joint
- articulation of radius with the capitulum of the humerus
- ulnar olecranon process with its fossa
- coronoid process with fossa around the trochlea of humerus
what is the elbow joint stabilised by?
radial and ulnar collateral ligaments
annular ligaments of radius - also allow pronation/supination
what stabilised the proximal radio-ulnar joint?
annular ligament of radius
what is the effect of the pronator teres on the proximal radio-ulnar joint?
acts across this joint to turn head of radius about ulna
what is the effect of the pronator quadratus on the distal radio-ulnar joint?
acts across it to bring the head of the radius up and over the ulna to pronate the hand
why does the ulna not articulate with the triquetrium?
articular disc of distal radio-ulnar joint interferes
what stabilised the wrist joint?
radial and ulnar collateral ligaments
what nerves innervate elbow flexion?
C5, C6
which muscles are involved in elbow flexion?
biceps brachii
brachialis
brachioradialis
pronator teres
what nerves innervate elbow extension?
C6, C7
which muscles are involved in elbow extension?
triceps
anconeus
which muscles are involved in wrist pronation?
pronator teres pronator quadratus Flexion carpi radialis Pollicis longus brachioradialis
which muscles are involved in wrist supination?
supinator
biceps
Extensor Pollicis Longus
Extensor Carpi Radialis Longus
which muscles are involved in wrist flexion?
flexor carpi ulnaris flexor carpi radialis pollicis longus abduction pollicis longus long flexors of thumb and fingers
which muscles are involved in wrist extension?
extensor carpi radialis longus
extensor carpi radialis brevis
extensor carpi ulnaris
long extensors of thumb and fingers
which muscles are involved in wrist abduction?
extensor carpi radialis longus
extensor carpi radialis brevis
flexor carpi radialis
abduction pollicis longus
which muscles are involved in wrist adduction?
extensor carpi ulnaris
flexor carpi ulnaris
when the subclavian artery passes over the first rib, what does it become?
Axillary artery
what does the axillary artery become below the teres major? what does it also give up?
brachial artery
also gives off profunda brachii
what does the brachial artery split into at the elbow?
ulnar and radial arteries
what can the brachial artery also give rise to?
superior and inferior collateral ulnar arteries
these join the recurrent ulnar arteries around the elbow
what does the profunda brachii give rise to?
medial collateral artery
what does the medial collateral artery anastomose with?
anastomoses with interosseus recurrent artery which is a branch of the posterior interosseous artery behind elbow joint
what does the ulnar artery give off?
common interosseous branch
this immediately splits into anterior and posterior interosseous arteries
what are the arches of the hand formed by?
they are anastomoses of the radial and ulnar arteries
what helps to form the dorsal carpal arch?
anterior and posterior interoseous arteries join on the dorsal side of the hand
what is the cubital fossa?
triangle anterior to elbow joint
what are the borders of the cubital fossa?
medial border: lateral border of pronator teres
lateral border: medial border of brachioradialis
line b/ epicondyles
what does the cubital fossa contain?
radial nerve,
biceps tendon,
brachial artery,
median nerve
where does the cephalic (superficial) vein run?
runs up lateral border of arm
where does the basilic (deep) vein run?
medial border of arm
how is the axillary vein formed?
basilic vein joins venae commitantes to form the axillary vein
how does the cephalic join the basilic?
via medial cubital vein (not always present)
or joins at axillary vein in axilla
what does the superficial venous palmar arch give rise to?
perforating veins of the forearm
some of these join cephalic vein
some form the median vein of the forearm
describe the deep drainage of the arm
follows the arteries
what does the deep palmar arch give rise to?
ulnar and radial veins
anterior interosseous vein
these are the venae comitantes
what does the dorsal venous network give rise to?
some of the radial veins
posterior interosseous veins
where do superficial and deep lymphatics run?
with veins
which lymph nodes drain most of the forearm and hand?
cubital lymph nodes
which nodes drain the distal parts of the upper limb?
axillary nodes
what spinal segments make up the musculocutaneous nerve?
C5,6,7
what does the musculocutaneous nerve give motor supply to?
anterior compartment of arm
what does the musculocutaneous give sensory supply to?
lateral part of forearm
what spinal segments make up the radial nerve?
C5,6,7,8 T1
what does the radial nerve supply?
main supply to posterior compartment of arm and forearm
supplies triceps
what does the radial nerve divide into just above the elbow?
deep posterior interosseous nerve (motor)
superficial radial nerve (sensory)
what spinal segments make up the median nerve?
C6,7,8 T1
what does the median nerve supply?
main motor supply to muscles of forearm
in what places is the median nerve easily damaged?
- distal part of humerus as it passes the medial supracondylar ridges
- passes near head of scaphoid which is very weak
what spinal segments make up the ulnar nerve?
C8, T1
what does the ulnar nerve supply?
main supply to muscles of the hand
supplies only FCU, ulnar half of FDP
At what point is the ulnar nerve vulnerable to damage?
as it courses around the posterior part of medial epicondyle