Week 12 Content Flashcards
which part of the hand is supplied mainly by the radial artery and which part is supplied mainly by the ulnar artery?
radial artery supplies the thumb and half of the 2nd finger
ulnar artery supplies the other half of the 2nd finger and fingers 3-5
what are the functions of the dorsal interosssei, palmar interossei, lumbricals, adductor pollicis, and palmaris brevis?
along with the flexors of the forearm, they work to improve the grip of the hand
name the thenar muscles, what is the function of them?
flexor pollicis brevis
abductor pollicis brevis
opponens pollicis
these muscles control the movement of the thumb towards the middle of the palm
why are the intrinsic muscles of the palm and thenar muscles so important for normal hand function?
apes and humans are the only mammals that can oppose their thumbs, which allows us to pick up small objects, pin buttons, etc.
name the hypothenar muscles. what is their function?
opponens digiti minimi
flexor digiti minimi brevis
abductor digiti minimi
they control the little finger
what does the extensor indicis allow you to do? what layer is it in?
point with your index finger; deep layer
to return form pronation to supination, what must happen?
the supinator and biceps brachii must contract to rotate the radius back to the anatomical position
name the forearm extensors from medial to lateral.
extensor carpi ulnaris extensor digiti minimi extensor digitorum extensor carpi radialis brevis extensor carpi radialis longus
the tendons of ECRB and ECRL pass under the tendons of which muscles?
abductor pollicis longus and extensor pollicis brevis
what is the name given to inflammation that occurs at the intersection of the muscle bellies of APL and EPB crossing over the ECRL and ECRB?
intersection syndrome
what is the purpose of the extensor retinaculum?
prevents bowing of the long extensor tendons
what is the purpose of the flexor retinaculum? what are its attachments?
converts the carpals into a concave surface forming the carpal tunnel. it attaches medially to the pisiform and hook of hamate and laterally to the trapezium and scaphoid
what is the purpose of the carpal tunnel?
allows passage of the flexor tendons and median nerve into the palm of the hand
describe the palmar aponeurosis.
thickening of the fascia in the palm of the hand that serves to protect the soft tissues of the palm and maintain the position of the flexor tendons
it extends from the flexor retinaculum to the heads of the metacarpals where it divides into 4 longitudinal heads adhering the fibrous tissue of the proximal phalanges
describe the synovial sheaths of all the digits and how they differ.
digits 1 and 5 have synovial sheaths that are continuous with the synovial sheaths of the palm; digits 2-4 terminate about the middle of the palm and are not continuous with the synovial sheaths of the palm
describe OINA for abductor pollicis brevis
O: scaphoid and trapezium
I: lateral side of base of proximal phalanx
N: recurrent branch of median n.
A: abducts thumb at CMC joint
describe OINA for flexor pollicis brevis.
O: flexor retinaculum and trapezium
I: lateral side of base of proximal phalanx
N: recurrent branch of median n.
A: flex thumb
describe OINA for opponens pollicis.
O: flexor retinaculum and trapezium
I: lateral side of the first metacarpal
N: recurrent branch the median n.
A: oppose thumb
describe OINA for abductor digiti minimi.
O: pisiform
I: base of proximal phalanx of 5th digit
N: ulnar n.
A: abduction of 5th digit
describe OINA for flexor digiti minimi brevis.
O: hamate
I: base of proximal phalanx of 5th digit
N: ulnar n.
A: flexes 5th digit
describe OINA for opponens digiti minimi.
O: hamate
I: medial border of 5th metacarpal
N: ulnar n.
A: oppose the 5th digit
describe OINA for adductor pollicis.
O: carpal bones and bases of metacarpals 2 and 3 (oblique head) and shaft of 4rd metacarpal (transverse head)
I: base of proximal phalanx of thumb
N: ulnar n.
A: adduct thumb
describe OINA for lumbricals.
O: tendons of FDP
I: lateral side of the extensor expansions
N: median n. (lumbricals 1 and 2) and ulnar n. (lumbricals 3 and 4)
A: flexes MP joints and extends PIP joints
describe OINA for palmar interossei.
PAD3
O: sides of metacarpal bones
I: base of proximal phalanges and extensor expansion
N: ulnar n.
A: adduct fingers
describe OINA for dorsal interossei.
DAB4
O: 2 heads from adjacent sides of the metacarpals between which they lie
I: proximal phalanges and extensor expansion
N: ulnar n.
A: abduct fingers at MP joints
describe the median nerve in the hand.
it enters through the carpal tunnel and supplies motor input to the 3 thenar muscles and lumbricals 1 and 2
it supplies sensory information to the anterior surface of digits 1-3 and the lateral half of digit 4 as well as the lateral surface of the palm
describe the ulnar nerve in the hand.
it enters the palm on the medial side of the wrist through the canal of guyon
it supplies motor input to the hypothenar muscles, adductor pollicis, lumbricals 3 and 4, and the PADs and DABs
it supplies sensory input to the medial aspect of the palm, medial aspect of the dorsum of the hand, digit 5, and the medial half of digit 4
describe the radial nerve in the hand.
supplies NO motor control of hand muscles
supplies sensory to lateral 2/3 of the dorsum of the hand via the superficial radial branch
describe the radial artery in the hand.
it runs posterior to the 1st digit through the anatomical snuffbox and enters the palm between the heads of the first DAB
gives rise to the princeps pollicis artery that supplies blood to the 1st digit, the radialis indicis artery which supplies the 2nd digit, and then forms the deep palmar arch
superficial radial branch arises from the radial artery before it enters the anatomical snuffbox. it runs superficial and joins with the superficial palmar arch
describe the ulnar artery in the hand.
it enters the palm through the canal of guyon and divides into a deep palmar branch (which forms the deep palmar arch) and a superficial palmar branch (which forms the superficial palmar arch)
describe the digital arteries in the hand.
there are 3 digital arteries that arise from the superficial palmar arch and the deep palmar arch
describe OINA for extensor carpi ulnaris.
O: lateral epicondyle
I: base of 5th metacarpal
N: posterior interosseus n.
A: extends and ulnar deviates the wrist
describe OINA for extensor carpi radialis brevis.
O: lateral epicondyle
I: base of 3rd metacarpal
N: deep radial n.
A: extends and radial deviates hand
describe OINA for extensor carpi radialis longus.
O: lateral supracondylar ridge
I: base of 2nd metacarpal
N: radial n.
A: extends and radial deviates hand
describe OINA for extensor digitorum.
O: lateral epicondyle
I: extensor expansions
N: posterior interosseus n.
A: extends digits 2-5
describe OINA for extensor digiti minimi.
O: ulnar side of extensor digitorum
I: extensor expansion of digit 5
N: posterior interosseus n.
A: extends digit 5
name the superficial muscles in the extensor compartment of the forearm.
ECU ECRB ECRL EDC EDM
name the deep muscles in extensor compartment of the forearm.
APL
EPB
EPL
EI
anatomical snuffbox also in this layer
describe the boundaries and contents of the anatomical snuffbox.
anterior boundary: tendons of APL and EPB
posterior boundary: tendon of EPL
contents: radial a.
describe OINA for abductor pollicis longus.
O: posterior surface of middle ulna, radius, and interosseus membrane
I: base of 1st metacarpal
N: posterior interosseus n.
A: abducts thumb
describe OINA for extensor pollicis brevis.
O: middle 1/3 of posterior radius and interosseus membrane
I: base of proximal phalanx of thumb
N: posterior interosseus n.
A: extends thumb
describe OINA for extensor indicis.
O: posterior surface of ulna and interosseus membrane
I: extensor digitorum tendon to index finger
N: posterior interosseus n.
A: extends index finger
describe the innervation of the posterior (extensor) compartment of the forearm.
The radial nerve enters the forearm by crossing anteriorly to the lateral epicondyle between the brachialis and the brachioradialis muscles. at this point the nerve divides into the superficial and
deep branches.
the deep branch of the radial n. pierces the supinator (thru Arcade of Frohse) and extends into the posterior forearm. gives rise to the posterior interosseous nerve
the superficial branch of the radial n. continues underneath the brachioradialis muscle and then emerges superficial near the distal end of the
forearm, where it provides cutaneous and articular innervation to the dorsum of the hand
describe the arterial supply to the posterior (extensor) compartment of the forearm.
the posterior interosseus artery supplies the posterior aspect of the forearm and is a branch of the common interosseus
describe the SC joint, including classification, location, ligaments, and supply.
saddle type synovial joint
articular disc connecting medial clavicle to the 1st costal cartilage and sternum
thickenings of fibrous capsule form anterior and posterior sternoclavicular ligaments
blood supply: internal thoracic a., suprascapular a.
nerve supply: branches of suprascapular n. and n. to subclavius
describe the AC joint, including classification, location, ligaments, and supply.
plane synovial joint
junction of the lateral clavicle to acromion process
capsule is strengthened superiorly by the acromioclavicular ligament
coracoclavicular ligament strengthens the lateral end of the clavicle and has 2 parts – trapezoid and conoid
blood supply: suprascapular a. and thoracoacromial a.
nerve supply: lateral pectoral n. and axillary n.
describe the GH joint, including classification and capsule characteristics.
synovial ball and socket, both surfaces covered with hyaline cartilage; glenoid labrum deepens shallow glenoid fossa. superior labrum blends with LH of biceps tendon
fibrous capsule lined w/ synovial membrane
extensions of the capsule form bursa about the shoulder joint
describe the intrinsic ligaments of the GH joint.
glenohumeral ligaments: 3 fibrous bands that radiate laterally from the supraglenoid tubercle into superior, middle, and inferior bands; strengthen capsule anteriorly
transverse humeral ligament: greater to lesser tubercle, converts groove into a canal; maintains LH of biceps tendon in bicipital groove and synovial sheath
coracohumeral ligament: base of the coracoid to the anatomical neck of the humerus; strengthens the capsule superiorly
describe the extrinsic ligament of the GH joint.
coracoacromial ligament: coracoid process to acromion
forms the coracoacromial arch with the acromion and coracoid, which protects the humerus from superior displacement
describe the bursae of the GH joint.
subscapular bursa: between subscapularis tendon and the neck of the scapula; an extension of the synovial capsule
subtendinous bursa: extension of synovial capsule under the transverse humeral ligament for protection of the LH of biceps tendon
subacromial bursa: between acromion and supraspinatus tendon; extends between the deltoid and proximal humerus to form the subdeltoid bursa
describe blood and nerve supply to the GH joint.
blood: anterior and posterior humeral circumflex arteries and branches from the suprascapular a.
nerve: suprascapular, lateral pectoral, and axillary nerves
what makes up the elbow joint?
complex joint involving 3 articulations (humeroulnar, humeroradial, proximal radioulnar) collectively known as the cubital articulation
first 2 are hinger joints, proximal radioulnar is a pivot joint
describe the intrinsic ligaments of the elbow joint.
ulnar collateral: divided into anterior, posterior, and intermediate/oblique bands that extend from the medial epicondyle to the coronoid and olecranon processes. anterior is strongest, posterior is weakest, and oblique deepens the socket for the trochlea of the humerus
radial collateral: lateral epicondyle to annular ligament
annular ligament: thickening of the capsule of the proximal radioulnar joint which encircles the head of the radius and holds it in the radial notch of the ulna
describe the bursa of the elbow joint.
subcutaneous olecranon: between skin and olecranon
subtendinous olecranon: between triceps tendon and olecranon
intratendinous tendon: sometimes present in the tendon of the triceps
radioulnar: between extensor digitorum, radiohumeral joint, and the supinator muscle
bicipitoradial: between biceps tendon and anterior part of radial tuberosity
describe the blood and nerve supply of the elbow joint.
blood: anastomosis around the joint
nerve: musculocutaneous, radial, and ulnar nerves
describe the proximal and distal radioulnar joints, including classification, location, and supply.
proximal: articulation of head of radius with radial notch of ulna, held in place by the annular ligament. radius rotates in annular ring, allowing for pronation and supination. supplies by anterior and posterior interosseus nerves and arteries
distal: pivot joint with radius moving around relatively fixed distal ulna. fibrocartilaginous articular disc binds radius to ulna, referred to as triangular ligament. supplied by anterior and posterior interosseus nerves and arteries.
describe the radiocarpal joint, including classification, location, and supply.
condyloid synovial joint with a fibrous capsule surrounding the joint and attaching to the distal end of the radius and ulna and the proximal row of carpal bones; lined with synovial membrane
articular disc of distal radioulnar joint also intervenes between the head of the ulna and the carpals
supplied by dosral and palmar arches
innervated by anterior and posterior interosseus nerves, and the ulnar n.
describe the intrinsic ligaments of the RC joint.
palmar radiocarpal ligaments: radius to the 2 rows of carpal bones; directs the hand to follow the radius during supination
dorsal radiocarpal ligaments: found on dorsal surface and provide similar function as palmar ligaments
ulnar collateral ligament: attached at the ulnar styloid process and extends to the triquetrum, strengthening the medial capsule
radial collateral ligament: radial styloid process to scaphoid, strengthens lateral capsule
