Upper limb anatomy Flashcards
Where are the two articular facets on the clavicle?
What sits on the inferior lateral third of the clavicle, and what attaches here?
One facet medially for sternum
One facet laterally for acromium
On inferior surface = Conoid tubercle where conoid ligament attaches, and trapezoid line were trapezoid ligament attaches
- Both from coracoid process
- Both together make up the coracoclavicular ligament
Describe the structure of the scapula?
Lateral part marked by glenoid cavity
Above this is supraglenoid tubercle = long head of biceps brachii
Below this is infraglenoid tubercle = long head of triceps brachii
From glenoid cavity a prominent spine passes inferomedially on posterior scapula = supraspinous fossa and infraspinous fossa
Acromium is anterolateral projection of the spine
What three joints make up the shoulder joint?
And what ligaments strengthen each part?
Sternoclavicular joint:
Anterior sternoclavicular ligament, interclavicular ligament and costoclavicular ligament
ACJ:
Reinforced by acromioclavicular ligament
Trapezoid ligament and conoid ligament = coracoclavicular ligament
Glenohumeral joint
What is glenoid labrum, and what is it continuous with superiorly?
What are the three areas it is thickened?
Fibrocartilagenous ring, attached to free edge of glenoid cavity
Superiorly it is continuous with tendons of long head of biceps
- Anterosuperior to form superior, middle and inferior glenohumeral ligaments - attach to lesser tubercle
- Superiorly between coracoid process and greater tubercle = coracohumeral ligament
- Between greater and lesser tubercle = transverse humeral ligament = holds long head of biceps in place in the intertubercular groove
Trapezius?
Elevates scapula and rotates it in humeral abduction
- middle fibres retract scapula
- lower fibres depress scapula
Origin = superior nuchal line, spinous processes of C7-T12
Insertion = Superior edge of scapula spine, acromium and lateral third of clavicle
Accessory nerve
Deltoid?
Major abductor of shoulder once past 15-degrees
Origin = Inferior crest of scapular spine, lateral acromium and lateral third of clavicle
Insertion = deltoid tuberosity of humerus
Axillary nerve
Levator scapulae?
Action = elevates scapula
Origin = transverse process of C1/2 + posterior tubercle of C3/4
Insertion = Medial border of scapula to root of spine
Dorsal scapular nerve
Rhomboid minor and major?
Both elevate and retract scapula
Both Dorsal scapular nerve
Both insert into medial scapular to the root of spine
Minor origin = lower end of ligamentum nuchae + spinous process of C7 to T1
Major origin = spinous process of T2-T5
Supraspinatus muscle?
First 15-degrees abduction
Origin = medial 2/3rds supraspinous fossa of scapula
Insertion = upper facet of greater tubercle of humerus
Suprascapular nerve
Infraspinatus muscle?
Lateral rotation of arm at glenohumeral joint
Origin = medial 2/3rds of infraspinous fossa
Insertion = middle facet of greater tubercle of humerus
Suprascapular nerve
Teres minor muscle?
Lateral rotation of arm at GHJ
Origin = upper 2/3rds of flattened strip of bone on posterior scapula
Insertion = Inferior facet on greater tubercle of humerus
Axillary nerve
Teres major muscle?
Medial rotation of arm and extension
Origin = Inferior angle of posterior scapula
Insertion = medial lip of intertubercular sulcus on anterior humerus
Inferior subscapular nerve
Long head of triceps?
Extends forearm at elbow
Origin = infraglenoid tubercle on scapula
Insertion = Common tendon with medial and lateral head attach to olecranon process of ulna
Radial nerve
4 gateways in posterior scapular region?
Quadrangular space
Triangular space
Triangular interval
Suprascapular foramen
Borders and contents of the 4 gateways in the posterior scapular region?
- Suprascapular foramen = superior transverse scapular ligament passing over suprascapular notch
- Suprascapular nerve passes through it
- Suprascapular artery and vein pass immediately superior to the ligament - Triangular space = medial margin of long head of triceps, inferior teres minor and superior teres major
- Circumflex scapular artery and vein - Triangular interval = Medial humerus, lateral long head of triceps and inferior teres major
- Radial nerve, profunda brachii artery + veins - Quadrangular space = Humerus, long head of triceps, subscapularis superiorly and teres major inferiorly
- axillary nerve
- posterior circumflex artery
Borders of the axilla?
Lateral = Humeral head Medial = chest wall and serratus anterior Anterior = lateral border of pec major Posterior = subscapularis, teres major and lats
Fascia = clavipectoral fascia
What axillary fascia do you divide in an axillary node clearance?
Clavipectoral fascia
What makes up the axillary inlet and what passes through?
Medially = lateral border of rib 1 Anterior = posterior clavicle Posterior = superior scapula
Contents = when subclavian artery turns into axillary artery
Vice versa for axillary vein
Pec Major?
Flexes, adducts and medially rotates arm
Origin = medial 2/3rds of the clavicle, manubriosternal joint and first 7 costal cartilages
Insertion = Lateral lip of intertubercular sulcus
Lateral + medial pectoral nerve
Pec minor?
Pulls tip of shoulder down and protracts scapula
Origin = ribs 3-5 Insertion = coracoid process
Medial pectoral
Subclavius?
Pulls clavicle medial to stabilise SCJ + pulls tip fo shoulder down
Origin = first rib Insertion = groove in inferior surface of middle third of clavicle
Nerve to subclavius
Serratus anterior?
Protracts and rotates scapula
Origin = lateral surface of upper 8/9 ribs Insertion = medial border of scapula
Innervation = long thoracic nerve
Subscapularis?
Medially rotates humerus
Origin = Medial 2/3rds of sub scapular fossa Insertion = lesser tubercle of humerus
Upper and lower scapular nerves
Latissimus dorsi?
Adducts, medially rotates and extends the arm
Origin = spinous process of T1-T6, lower 3/4 ribs ad iliac crest Insertion = Floor of inter tubercular sulcus
thoracodorsal nerve
Contents of the axilla?
3 nerves = long thoracic, thoracodorsal + intercostobrachial
Artery = axillary Vein = axillary
LN’s
Axilla: Course of long thoracic nerve + pathology
C5-C7
Passes anterior to scalenus posterior, posterior to clavicle but anterior to rib 1.
Lies medial on chest and supplies serrates anterior
Passes BEHIND brachial plexus
Risk in axillary surgery = winging of scapula
Axilla: What does thoracodorsal nerve innervate, course and pathology?
Lattisimus dorsi
Arises from posterior cord of brachial plexus. Runs down posterior axillary wall.
At origin it is posterior to sub scapular artery, distally moves anterior to it.
Can be damaged in axillary node clearance as it runs through the axillary nodes
= Fatigue of arm after repetitive use + problematic if going for a lat dorsi flap reconstruction
Axillary vein - boundaries, what forms it, and where does cephalic come from and join?
From lower margin of teres major up to lateral border of first rib - continuation of the basilic vein
Passes through axilla anterior and medial to the artery
Cephalic drains lateral and posterior hand.
In shoulder it passes deep to clavicular head of pec major and pierces clavipectoral fascia to join axillary vein
Axilla: Intercostobrachial nerve - what it is a branch of, what it supplies and how is it injured?
Branch of second intercostal nerve.
Leaves 2nd intercostal space at MAL, then pierces serratus anterior.
Axillary sensation
Axillary node clearance
Axillary LN’s - what are the three levels and what is divided in Pateys mastectomy ?
Level 1 = inferior to pec minor
Level 2 = posterior to pec minor
Level 3 = above pec minor
Level 1+2 in normal LN dissection, occasionally level 3 taken out but rarely.
Axillary artery - boundaries of it and its three parts, course and branches?
Lateral border of first rib to inferior margin of teres major
1st part = above pec minor
- together with axillary vein is enclosed in cords of brachial plexus
2nd part = behind pec minor
- Posterior = posteiror brachial plexus cord + subscapularis, medial is medial cord of brachial plexus (separating artery and vein), anterior = pec major and minor, and lateral is lateral cord of brachial plexus
3rd part = below pec minor
- Posterior = subscapularis, teres major and lats
- between the subscapularis and artery is radial and axillary nerve
Branches:
1st part = 1 = superior thoracic
2nd part = 2 = thoracic-acromial and lateral thoracic
3rd part. = 3 = sub scapular, anterior circumflex and posterior circumflex
Where do you insert chest drains ?
5th ICS MAL
Borders:
Anterior edge lat dorsi
Pec major lateral border
Above and below nipple
insertion of each rotator cuff?
Supraspinatus = superior facet on G tubercle
Infraspinatus = middle facet
teres minor = inferior facet
Subscapularis = lesser tubercle of humerus
Where does lateral head of triceps attach?
Liner roughing from surgical neck to deltoid tuberosity on posterior humerus
What runs through the inter tubercular groove, and what holds it there?
Biceps brachii long head tendon
Transverse humeral ligament
Which arteries supply humeral head?
where = risk of….
Anterior and posterior circumflex artery
surgical neck = avascular necrosis, as well as damage to axillary nerve and posteiror circumflex artery
Surgical neck vs anatomical neck of humerus
Surgical neck = below tubercles and head
Anatomical = narrowing just below head
On posterior shaft of humerus what is there a spiral groove for?
Radial nerve
What is the structure of distal humerus?
What articulates / attaches to each bit?
1 condyle = made up of capitulum and trochlea
CAPITAL RADIO
2 epicondyles:
Medial = anterior forearm compartment muscles
Lateral = posterior compartment
3 fossa:
Anterior = Radial fossa superior to capitulum
Anterior = Ulnar fossa superior to trochlea
POSTERIORLY = olecranon fossa, superior to trochlea
Muscles of anterior compartment of arm?
MUSCULOCUTANEOUS NERVE for all
corachobrachialis = flex arm at GHJ origin = Coracoid process of scapula Insertion = Medial humerus midshaft, linear roughening
Biceps brachii = flexor of forearm + supinator
Origin: Long head = supraglenoid tubercle, short head = coracoid process
Insertion = radial tuberosity (medial aspect of radius)
Brachioradialis = flexor of forearm origin = Anterior humerus Insertion = Tuberosity of ulna
Muscle of posterior arm?
RADIAL NERVE
Triceps brachii = extends forearm
Origin: Long head = infraglenoid tubercle. Medial and lateral head = posterior humerus
Insertion = olecranon
Which ligament wraps around head of radius?
Annular ligament of radius
Which ligaments laterally strengthen the fibrous capsule of elbow?
Which muscle inserts posteriorly into fibrous capsule?
Radial collateral = Attaches to lateral epicondyle of humerus > blends with annular ligament of radius > attaches to radial notch of ulnar
Ulnar collateral = three parts
Anterior band - medial epicondyle humerus > medial edge of coronoid process ulna
Posterior band - medial epicondyle humerus > medial olecranon
Transverse = joins the two together
Triceps tendon inserts posteriorly
What forms your cubital fossa?
Brachioradilais laterally
Pronator teres medially
Line between two epicondyles
Major contents of cubital fossa?
Median and radial nerve, brachial artery and vein and tendon of biceps brachii
Where does brachial artery bifurcate?
Apex of cubital fossa
Into radial and ulnar artery
In cubital fossa - where is median nerve vs brachial artery, and how does it leave?
It sits median to brachial artery
Leaves between two heads of pronator teres
What protects the nerve and artery in the cubital fossa?
Bicipital aponeurosis
How does radial nerve leave elbow?
Lies just underneath lip of brachioradialis
Here it splits into superficial and deep
Superficial = forearm Deep = passes between two heads of supinator to posterior compartment of forearm
How does ulnar nerve traverse elbow?
Passes posterior to medial epicondyle
What makes up roof of cubital fossa and what lies here?
what does this structure connect?
What separates this structure from the brachial artery and median nerve.
Superficial skin and fascia
Median cubital vein connect basilic vein medially to the cephalic vein laterally
Bicipital aponeurosis separates them
What muscles attach to the radius?
Upper third = supinator, FDS, FPL
Middle third = pronator teres (oval roughening)
Lower third = pronator quadratus and tendon of supinator longus
What are the three grooves on posterior distal radius for?
- Tendons of extensor carpi L+B
- Tendons of extensor pollicis longus
- Tendons of extensor indicis
What is medial and lateral on distal radius?
what does it have two facets for?
Lateral = styloid process Medial = ulnar notch
Scaphoid and lunate
Where is the radial notch on the ulnar?
Proximal to elbow
How many layers of muscles are there in the anterior forearm, and what is the innervation?
three = superficial, intermediate and deep
ALL muscles in anterior forearm = Median nerve…. Except FCU and medial FDP > ulnar nerve
- In the deep layer the median parts are via the anterior interosseous
Muscle of anterior forearm superficial compartment, medial to lateral?
FCU = flexes and adducts Origin = Humeral head to medial epicondyle, ulna head to olecranon Insertion = Pisiform bone
Palmaris longus = Flexes wrist
Origin = Medial epicondyle of humerus
Insertion = Palmar aponeurosis of hand
Flexor carpi radialis = Flexes and abducts wrist
Origin = medial epicondyle
Insertion = Base of metacarpal 2/3
Pronator teres = pronates
Origin = humeral head to medial epicondyle, ulnar head to coronoid process
Insertion = Midshaft radius laterally
Muscles of anterior forearm intermediate layer?
FDS = flexes PIPs Origin = Humero-ulnar head = medial epicondyle. Radial head = oblique line of radius Insertion = palmar surface of middle phalanges
Muscles of anterior forearm deep layer?
Via anterior interosseous branch of median
FDP = flexes DIPs
Origin = Anterior and medial ulna
Insertion = Inferior to the FDS tendons and actually pierces them
Lateral half median nerve, medial half ulna nerve
F pollicis longus = Flexes IP joint of thumb
Origin = Anterior surface of radius + interosseous
Insertion = Palmar base of distal phalanx of thumb
Pronator quadratus = pronates
Origin = distal ulnar anteriorly on linear ridge
Insertion = Distal anterior radius
Compartments and supply of posterior forearm?
Deep and superficial
All supplied by radial nerve
Superficial compartment of posterior forearm muscles, medial to lateral?
Brachioradialis = flexes forearm In pronation
Origin = Lateral supracondylar ridge
Insertion = lateral distal radius
Radial nerve prior to division into deep and superficial
Extensor carpi radialis longus = extends and abducts wrist
Origin = lateral supracondylar ridge
Insertion = dorsal surface of base of metacarpal 2
Radial nerve prior to division into deep and superficial
Extensor carpi radialis brevis = extends and abducts
Origin = lateral epicondyle
Insertion = dorsal base of metacarpal 2/3
Deep branch of radial, prior to penetrating supinator
Extensor digitorum = extends fingers
Origin = Lateral epicondyle
Insertion = Via extensor hoods into dorsal aspect of base of fingers
Posterior interosseous
Extensor digiti minimi = extends little finger
Origin = Lateral epicondyle
Insertion = Extensor hood of little finger
Posterior interosseous
Extensor carpi ulnas = extends and adduct
Origin = lateral epicondyle
Insertion = Tubercle on base of metacarpal 5
Posterior interosseous
Anconeus = Abducts ulnar in pronation, accessory extensor of forearm
Origin = Lateral epicondyle
Insertion = Olecranon and posterior ulna
Radial nerve via branch to medial head of triceps
Muscles of deep compartment of posterior forearm?
All via posterior interosseous = continuation of deep branch of radial nerve
Supinator
Origin: superficial part = lateral epicondyle, deep part = supinator of crest of ulna
Insertion = lateral radius
Abductor pollicis longus = abducts thumb at CMC
Origin = Posterior ulna and radius
Insertion = lateral base of metacarpal 1
Extensor pollicis brevis = extends MCP joint of thumb
Origin = posterior radius
Insertion = dorsal base of proximal phalanx
Extensor pollicis longus = extends IP joint of thumb
Origin = posterior ulnar
Insertion = dorsal base of distal phalanx of thumb
Extensor indices = extends index finger
Origin = posterior surface of ulnar
Insertion = Extensor hood of index finger
Order of carpal bones?
Proximal row, Lateral to medial:
Scaphoid
Lunate
Triquetrum + pisiform
Distal row, lateral to medial: Trapezium Trapezoid Capitate Hamate
What articulates with the scaphoid?
Proximally = radius Medially = lunate / capitate Distally = trapezium and trapezoid
Boundaries of the anatomical snuff box?
Contents?
Posteriorly = tendons of flexor pollicis longus Anteriorly= tendo of flexor pollicis brevis Proximally = radial styloid process Distally = Apex Floor = scaphoid and trapezium
Radial artery
Why is the thumb joint so mobile?
Joint between trapezium and metacarpal bone = saddle joint.
The thumb also does not have a transverse metacarpal ligament holding it in place like there is between fingers 2-5
Boundaries of the carpal tunnel
formed by carpal bones and flexor retinaculum
Flexor retinaculum attaches :
medially > pisiform and hamate
laterally > scaphoid and trapezium
Contents of carpal tunnel, anterior to posterior?
Median nerve
4 FDS tendons
tendon of flexor pollicis longus
4 FDP tendons
FDS and FDP surrounded by single synovial sheath
FPL has own sheath
How does flexor carpi ulnaris pass through wrist?
Passes via single synovial sheath WITHIN flexor retinaculum
Via a groove formed by attachment of lateral retinaculum to a groove on trapezium
Which three structures pass anterior to flexor retinaculum?
Ulnar artery and nerve
Tendon of palmaris longus
How are extensor tendons of the wrist held in place?
Extensor retinaculum
Attaches to:
Medially > pisiform and triquetrum
Laterally > end of radius
How is the extensor compartment divided up passing through extensor retinaculum?
6 COMPARTMENTS
Extensor digitorum and indices share a compartment and synovial sheath
ECU and extensor digiti minimi each have their own sheath on medial wrist
Laterally there are three more compartments:
Abductor pollicis longus + Ext pollicis brevis
Ext carpi radialis longus and brevis
Extensor pollicis longus
What is the apex of the palmar aponeurosis continuous with?
What does it form distally?
Flexor retinaculum + palmaris longus tendon
distally blends with fibrous digital sheaths
Where do fibrous digital sheaths begin and end?
Whats in them?
Begin proximally anterior to MCP joints, extend to distal phalanges
Hold tendons to bony plane
Within each sheath is muscular tendons, surrounded by synovial sheath
What forms extensor hoods? What are their attachments?
Tendons of extensor digitorum and extensor PL pass onto dorsal aspect of digits, and expand over proximal phalanges to form extensor hoods
Apex attaches to distal phalanx
Central region attaches to middle
Each corners attaches to deep transverse ligament and wraps around side
What applies force to extensor hoods, and what does this cause?
Intrinsic muscles = interossei and lumbricals
Cause flexion of MCP with IP extension
How do we break up the muscles of the hand?
Intrinsic muscles of hand - interossei, lumbricals and palmaris brevis + adductor pollicis
Thenar muscles = Opponens pollicis, abductor pollicis brevis, flexor pollicis brevis
Hypothenar = Opponens digiti minimi, abductor digiti minimi and flexor digiti minimi
Innervation of muscles of the hand?
Thenar = recurrent branch of median nerve
Hypothenar = Deep branch of ulnar
Intrinsic ones = Deep branch of ulnar, except palmaris brevis = superficial branch. Lateral 2 lumbricals are MEDIAN nerve
Intrinsic hand muscles?
Palmaris brevis = grip
Origin = flexor retinaculum + palmar aponeurosis
Insertion = Dermis of skin on medial hand
Superficial branch of ulnar nerve
Dorsal interossei. = abduct middle, index and ring finger
DAB
Origin = Adjacent metacarpals
Insertion = Extensor hood and proximal phalanx
MIDDLE CAN ABDUCT BILATERALLY
Palmar interossei = Adduct thumb, index, ring and little
PAD
Origin = Side of metacarpals
Insertion = proximal phalanx of thumb
Adductor pollicis = adducts thumb
Origin = transverse head - metacarpal 3, oblique head - capitate and base of 2/3 metacarpals
Lumbricals = flex MCP whilst extending IP's Origin = Tendons of FDP Insertion = Extensor hoods of 2-5 Medial 2 = ulnar Lateral 2 = median
Thenar muscles?
RECURRENT BRANCH OF MEDIAN
Opponens pollicis = medially rotates thumb
Origin = tubercle of trapezium
Insertion = Lateral margin of metacarpal 1
Abductor pollicis brevis = Abducts thumb at MCP joint
Origin = tubercle of scaphoid + trapezium
Insertion = Proximal phalanx and extensor hood
Flexor pollicis brevis = flexes thumb at MCPJ
Origin = tubercle of trapezium
Proximal phalanx of thumb
Hypothenar muscles?
DEEP BRANCH OF ULNAR
Opponens digiti minimi = laterally rotates
Origin = hook of hamate
Insertion = Medial aspect of metacarpal 5
Abductor digit minimi = abducts at MCPJ
Origin = pisiform and pisohamate ligament
Insertion = proximal phalanx of little finger
Flexor digiti minimi brevis = flexes at MCPJ
Origin = hook of hamate
Insertion = Proximal phalanx
Which artery supplies the supra and infraspinatus muscles?
How does this artery enter the posterior scapular region?
Suprascapular = branch of thyrocervical trunk = branch of subclavian
Enters via suprascapular notch - immediately above the foramen which the nerve passes through
What are the branches of the thoracoacromial artery, where does this itself branch from?
from 2nd part of axillary artery
Passes over upper border of pec minor, before piercing clavipectoral fascia and giving off its branches
4 branches:
1. Pectoral - descends between two pectoral muscles
- Acromial - runs laterally over coracoid process and under deltoid. Then pierces the deltoid and ends up on acromion.
- Clavicular = runs upwards and medial to SCJ. Supplies this articulation and subclavius
- Deltoid = crosses pec minor and passes in same groove as cephalic vein, between pec major and deltoid
Which artery leaves the axilla via the triangular space?
Circumflex scapular artery, branch of subscapular artery which comes from 3rd part of subclavian
Which artery leaves the axilla via the quadrangular space?
With which other structure?
Posterior circumflex humeral
Axillary nerve
Which is the biggest. branch of the brachial artery?
What does it supply?
How does it enter this area?
Profunda brachii
Continues in the radial groove and supplies posterior compartment of arm
Enters posterior compartment via triangular interval = Inferior border of teres major, humeral shaft and long head of triceps lateral margin
Is radial artery deep or superficial to brachioradialis?
Deep
What two tendons does radial artery lie in-between?
Laterally = tendon of brachioradialis medial = large tendon of FCR
How does radial artery penetrate posterior hand?
Pierces between base of metacarpals 1 and 2
Branches of the radial artery?
Radial recurrent = anastomotic network around elbow
Palmar carpal branch = network to carpal bones
Superficial palmar branch = enters hand passing over thenar muscles and anastomoses with same branch from ulnar
Ulnar artery in relation to median nerve and ulnar nerve?
ulnar nerve is always more medial.
Median nerve is medial for 2-3cm proximally, the median nerve passes anteriorly over the ulnar artery and moves laterally to it.
What does the ulnar artery enter the hand lateral to?
The pisiform bone and superficial flexor retinaculum
Branches of the ulnar artery?
Ulnar recurrent = network to elbow
Common interosseous:
Divides into anterior and posterior
- Anterior passes distally along anterior interosseous membrane = deep anterior compartment of forearm
- posterior passes posteriorly over interosseous membrane to supply posterior compartment
2 small branches = dorsal and palmar
How does the ulnar artery enter the hand?
Enters on medial aspect of wrist. Superficial to palmaris brevis and flexor retinaculum, enters with ulnar nerve
It is medial to the hook of hamate then swings laterally to form superficial palmar arch = superficial to the flexor tendons
What muscles does the deep palmar arch of the ulnar artery penetrate?
Penetrates origin of hypothenar muscles
Then curves medially around hook of hamate to then move laterally and anastomose with the radial equivalent
How does radial artery enter hand?
what muscles does it pass through?
Passes laterally around wrist, along floor of anatomical snuff box
Passes between two heads of first dorsal interossei and then between two heads of adductor pollicis > deep palmar arch
Which veins make up the superficial system vs the deep system?
Superficial = cephalic and basilic
Deep = radial, ulnar and brachial
Course of the superficial veins of the arm?
Basilic = medial from the dorsal aspect of hand.
- near region of cubital fossa is joined by median cubital vein
- at border of teres major moves into deep arm where it joins with brachial > axillary vein
- at Teres major, anterior and posterior humeral circumflex also feed in
Cephalic runs laterally up the arm
- at the shoulder it runs in the deltopectoral groove > with the deltoid branch of thoracoacromial artery
- empties into the axillary vein in the axilla
Outline the course of the deep veins of the arm?
Formed as pairs either side of each artery
Termed vena comitans due to the pulsating artery assisting return
Multiple perforating veins between deep and superficial system
Draw the brachial plexus and all its branches and what they supply….
Good luck!
Does the brachial plexus form from dorsal or ventral rami?
Ventral rami of C5 - T1
In the neck what does the brachial plexus pass deep to?
Platysma
Inferior belly of omohyoid
Suprascapular nerve
Transverse cervical artery
Then passes deep to clavicle and suprascapular vessels to enter axilla
How do ventral rami of brachial plexus enter neck?
Via posterior triangle
Which trunk of the brachial plexus groove rib 1, and what is its relation to subclavian artery?
Lower trunk
Posterior to artery
What is Erbs palsy?
Damage to C5/C6, commonly shoulder dystocia at birth
loss of sensation in arm
Paralysis of deltoid, bicep and brachioradilais
Waiters tip = arm hangs by side, forearm extended and pronated
What is Klumpkes palsy
C8/T1 - infant being pulled, or falling and catching a branch
Loss of sensation over medial forearm, loss of wrist flexors
Claw hand
Horners syndrome
How is the proximal brachial plexus related to subclavian / axillary artery vs distal plexus?
Proximal = posterior Distal = wraps around it
Brachial plexus - branches of the roots?
Dorsal scapular = rhomboids and levator scapulae
Long thoracic = serratus anterior
Brachial plexus - branches of trunks?
Both SUPERIOR TRUNK
Suprascapular = infraspinatus and supraspinatus
- Passes via scapular notch, deep to trapezius
Subclavius = subclavius
- Passes over subclavian artery and vein
Brachial plexus - Medial cord branches?
Medial pectoral = pec major and minor
- Passes anteriorly between axillary artery and vein
two cutaneous branches
Brachial plexus - posterior cord braches?
Inferior sub scapular = subscapularis and teres minor
Superior sub scapular = subscapularis
Thoracodrosal = Lats
Brachial plexus - lateral cord branches?
Lateral pectoral = pec major
Passes anteriorly with thoracoacromial artery to pierce clavipectoral fascia
What three muscles does the musculocutanerous nerve innervate?
Brachialis
Biceps brachii
Corachobrachialis
Path of the musculocutaneous nerve?
Penetrates corachobrachialis, passing obliquely between biceps brachii and brachialis to the lateral side of the arm
Above elbow = pierces deep fascia lateral to tendon of biceps
Continues in forearm as lateral cutaneous nerve
Motor and sensory innervation of axillary nerve?
Motor = deltoid, teres minor and lateral head of triceps
Sensory = regimental patch
Route of axillary nerve?
Passes posterior to the axillary artery at lower border of subscapularis
Then exits axilla via quadrangular space with posterior circumflex arteries
Passes posteriorly around surgical neck
Then divides into anterior and posterior branches
Radial nerve supply?
BEST + anconeus + abductor pollicis longus
Main nerve = triceps, brachioradialis anconeus and extensor carpi radialis
Posterior interosseous branch = All other extensors, supinator, abductor pollicis longus
Sensory innervation of radial nerve?
Lateral posterior 3.5 fingers, not the tips
Route of the radial nerve?
In axilla it lies posterior to the axillary artery
Enters arm via triangular interval, passing with profunda brachii artery
- Enters arm medial to humerus, between brachial artery and long head of triceps (POSTERIOR to brachial artery)
- Spirals around humerus in radial groove
- In the distal and lateral part of humerus, it pierces inter muscular septum + descends in front of lateral epicondyle
At lateral epicondyle passes between brachioradialis and brachialis = divides into deep and superficial branches
Deep branch crosses supinator to become posterior interosseous
Where does the posterior interosseous nerve come from and its path?
How can it get trapped?
Comes from radial nerve
Formed when deep branch crosses supinator
Emerges from supinator between superficial extensor muscles and lowest fibres of supinator
Can get trapped in arcade of Frosche = thickened edge of supinator heads
What does the median nerve supply?
Which ones does the anterior interosseous supply?
All the flexors apart from FCU and medial 2 FDP
Pronator teres and quadratus
Palmaris longus
LOAF
Ant. interosseus = classically 2.5 muscles: pronator quadratus, lateral 2 FDP’s and FPL
What is the route of the anterior interosseous nerve?
What is it a branch of?
Branch of median nerve
Branches off as it passes between 2 heads of pronator teres
Then accompanies interosseous artery along the anterior interosseous membrane
Between the tendons of FPL and FDP (ergoooo what it supplies!!)
Path of median nerve?
Exits axilla at inferior margin of teres major
Descends anterior and lateral to brachial artery, crossing medially as it passes down.
When brachial becomes ulnar artery it initially lies medial to brachial artery then crosses anteriorly back over to lateral side of it.
Passes deep to bicipital aponeurosis and median cubital vein in elbow
Then passes between two heads of pronator teres and runs on deep surface of FDS (within its synovial sheath)
Near wrist becomes superficial passing beneath flexor retinaculum, but superficial to long flexor tendons
Sensory innervation of median nerve?
Lateral palmar aspect of 2.5 fingers, + tips only dorsally
What does LOAF stand for and what supplies it?
Lateral two lumbricals
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
All from median
The thenar muscles are specifically from the recurrent branch of median
What does the ulnar nerve supply?
Muscular branch = FCU and FDP (medial two) + FD minimi
Deep branch:
- hypothenar muscles = abductor and opponens digiti minimi
- Interossei and medial lumbricals
- Adductor pollicis
- Palmaris brevis
Cutaneous branches to medial 1.5 fingers
What does deep branch of ulnar nerve supply?
Hypothenar muscles, interossei, medial two lumbricals, adductor pollicis and palmaris brevis
Injury to ulnar nerve at wrist vs elbow?
Wrist = clawing as lose the lumbricals to medial two fingers = no extension of IP’s and no flexion of MCPJ’s
Lateral two lumbricals spared as these are median
At elbow = minimal clawing as also lose FDP’s = flexion of dIP’s is now lost
FDS still intact so can still flex PIPs
Path of ulnar nerve?
In axilla medial to axillary artery
Enters posterior compartment anterior to triceps brachii
Then passes behind medial epicondyle.
Passes beneath FDS and FCU, but above FDP
In distal forearm ulnar artery is lateral. Both then pass superficial to flexor retinaculum
At wrist get superficial and deep branches
Deep branch arises lateral to pisiform bone
Path of the deep ulnar nerve?
Arises lateral to pisiform bone
Passing between abductor and short flexor of little finger = penetrates hypothenar muscles
Then pierces opponens digiti minimi near its origin and then turns laterally over distal surface of hook of hamate
Eventually passes between two heads of adductor pollicis ending in first dorsal interosseous muscle
What is guyots canal and what passes through here?
Between hook of hamate and flexor tendons
Deep ulnar nerve
what relation does the median, radial and ulnar nerve have to axillary/brachial artery?
Median = anterior and lateral to brachial, but crosses medially distally. Crosses back laterally one brachial artery becomes ulnar artery
Ulnar = medial to axillary
Radial = posterior to axillary
Branches of axillary artery and routes?
- Superior thoracic
- Thoraco-acromial:
- Wraps around the upper part of pec minor, then gives off four branches
- 4 branches = pectoral, deltoid, clavicular, acromial. - Lateral thoracic:
- Follows inferior margin of pec minor to thoracic wall. - Subscapular
- Posterior and anterior circumflex humeral
Lymphatics of the axilla?
Humeral, pectoral, subscapular and central nodes = go to apical nodes
Apical nodes have efferent vessels which form subclavian trunk.
On right this joins venous system at junction between R IJV and R subclavian vein, alongside jugular and bronchomediastinal trunk
On left this drains directly into thoracic duct, alongside jugular and bronchomediastinal trunk
Draw anterior cubital fossa and contents please.
Page 99 in book
Draw extensor tendons of wrist please.
Page 109 of book.
Which scalene muscles does the brachial plexus pass between?
Anterior and medius scalene muscles
