Upper Limb Anatomy Notes Booklet PDF

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Summary

UPPER LIMB OSTEOLOGYCLAVICLE: convex medially concave laterallySCAPULA: 3 angles, 3 depressions, 3 processes Humerus anatomical neck= where head meets tubercles Humerus surgical neck= where head meets body Axillary nerve & circumflex humeral arteries (branches of 3rdpartaxillary artery) i...

Description

UPPER LIMB ANATOMY UPPER LIMB OSTEOLOGY

CLAVICLE: convex medially concave laterally

SCAPULA: 3 angles, 3 depressions, 3 processes

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Humerus anatomical neck= where head meets tubercles Humerus surgical neck= where head meets body Axillary nerve & circumflex humeral arteries (branches of 3rd part axillary artery) in close relation to surgical neck  surgical neck fracture leads to bleeding & nerve damage (pain & numbness over regimental badge area)

CARPALS Proximal carpals involved in wrist joint o Lateral  medial: She Likes To Play Distal carpals involved in CMC joints o Lateral  medial: Try To Catch Her N.B. pisiform is a sesamoid bone = small protruding bone that embeds into bone or tendon

UPPER LIMB ANATOMY SHOULDER SHOULDER JOINT (GLENOHUMERAL JOINT)   

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Synovial ball-and-socket multiaxial joint between glenoid cavity of scapula and humeral head Common features of synovial joint High mobility o Flexion- biceps, coracobrachialis, deltoid, pec major o Extension & hyperextension- triceps, deltoid, latissimus dorsi, teres major o Abduction- supraspinatus (15*) o Adduction- triceps, latissimus dorsi, teres major, coracobrachialis, subscapularis, pec major o Lateral rotation- teres minor, infraspinatus, deltoid o Medial rotation- subscapularis, teres major, deltoid, latissimus dorsi, pec major Low stability o synovial o shallow glenoid cavity which cannot fully envelop humeral head (1;4 disproportion)  deepened by glenoid labrum (fibrocartilaginous rim) o very lax fibrous joint capsule  strengthened by the rotator cuff muscles  reinforced by fibrous articular capsule and further by many ligaments: o Glenohumeral ligaments – superior, middle, inferior – 3 bands run over fibrous joint capsule from neck of glenoid cavity to anatomical neck of humerus – reinforce anterior aspect of GH joint capsule o Coracohumeral ligament – runs from coracoid process of scapula to greater tubercle of humerus – strengthens joint capsule superiorly o Transverse humeral ligament – runs between greater & lesser tubercles of humerus, strengthens capsule, holds tendon of long head of biceps in intertubercular groove o Coracoacromial ligament – does not reinforce/thicken fibrous joint capsule – overlies GH joint, prevents superior displacement of humeral head o Explains why humeral head more commonly dislocates inferiorly & posteriorly due to weaker ligament reinforcement in this direction Synovial bursae- reduce friction in GH joint – fluid filled sacs acts as cushion between tendons & other joint structures o Subacromial bursae- inferior to deltoid & acromion, superior to supraspinatus tendon & joint capsule. Supports deltoid & supraspinatus muscles. Inflammation of subacromial bursae is a cause of many shoulder problems o Subscapular bursae- between subscapularis tendon & scapula. Reduces wear & tear of tendon during shoulder movements Joint Blood supply- anastomoses formed by suprascapular artery (branch of subclavian), anterior & posterior circumflex humeral arteries (branches of axillary artery) Joint innervation- suprascapular nerve (C5&C6), axillary nerve articular branch, lateral pectoral nerve (branch off lateral cord of BP)

UPPER LIMB ANATOMY MUSCLES OF THE SHOULDER/chest/upper back area MUSCLE ORIGIN INSERTION INNERVATION BLOOD SUPPLY ACTION Rotator cuff muscles SITS **stabilise ball-and-socket synovial shoulder joint -help hold humeral head in glenoid cavity (shallow to provide extensive mobility but therefore needs extensive support), fuse with fibrous articular capsule of GH joint ** N.B. musculotendinous ROTATOR CUFF strengthens the shoulder joint on its superior, anterior and posterior – 95% shoulder dislocations in anteroinferior direction due to a weakness in this aspect of shoulder joint. Suprascapular nerve (C5&C6)- passes through the suprascapular notch of scapula. Suprascapular nerve (C5&C6)

Subscapular fossa of (anterior aspect of) scapula

Superior facet of Greater tubercle of humerus (inserts posteriorly) Middle facet of Greater tubercle of humerus (inserts posteriorly) Inferior facet of Greater tubercle of humerus (inserts posteriorly) Lesser tubercle of humerus (inserts anteriorly)

Posterior aspect of scapula near inferior angle

Medial lip of intertubercular groove of humerus

Inferior subscapular nerve (C5&C6)

3 ORIGINS 1. inferior edge of spine of scapula 2. lateral acromion 3. inferior edge of lateral 1/3 clavicle

Deltoid tuberosity of the lateral aspect of the midshaft of the humerus

Axillary nerve- anterior branch

Supraspinatus

Supraspinous fossa of posterior scapula

infraspinatus

Infraspinous fossa of posterior scapula

Teres minor

Upper posterior surface of scapula near lateral border

Subscapularis

Teres major *posterior shoulder Deltoid *superficial shoulder

Axillary nerve- posterior branch (C5&C6) Inferior and superior subscapular nerve (C5&C6)

Suprascapular artery (branch of thyrocervical trunk)

Initial 15’ abduction of arm at GH joint Stabilises GH joint

Suprascapular and circumflex scapular arteries Subscapular and circumflex scapular (branch of subscapular) arteries Subscapular artery (branch of 3rd part axillary artery)

Lateral rotation of arm at GH joint Stabilises GH joint Lateral rotation of arm at GH joint Stabilises GH joint

Circumflex scapular artery and the posterior circumflex humeral artery (branch of 3rd part axillary artery) Thoracoacromial artery (branch of 2nd part axillary)

Medial rotation, extension & adduction of arm at GH joint

Creates continuous Ushaped line of attachment

Medial rotation & adduction of arm at GH joint Stabilises GH joint

3 PARTS= 3 FUNCTIONS Major function by the middle/lateral deltoid fibres –Abduction of arm at GH joint beyond initial 15’ achieved by supraspinatus Spinal/posterior deltoid fibres –Extension and lateral rotation of arm at GH joint

Mirrors the adjacent insertion sites of the trapezius

Clavicular/anterior deltoid fibres –Flexion & medial rotation of arm at GH joint Muscles of the axilla region/anterior shoulder – connecting the upper limb to the thoracic wall, arise from anterior or lateral thoracic wall Pectoralis major 2 HEADS= 2 ORIGINS Lateral lip of Thoracoacromial artery TOGETHER-Adduction and Medial and lateral (branch of 2nd part Clavicular head: intertubercular medial rotation of arm at GH pectoral nerves of BP anterior surface of groove/sulcus of joint. (branches of medial and axillary) medial half of clavicle humerus lateral cords) CLAVICULAR FIBRES- flex Sternocostal head: arm at GH joint Upper 6 costal cartilages, aponeurosis STERNOCOSTAL FIBRESextend flexed arm at GH joint of sternum Thoracoacromial artery Depression of point of Ribs 3 4 5 Coracoid process of Medial pectoral nerve of Pectoralis minor nd (branch of 2 part shoulder by depressing scapula BP scapula axillary) *deep to pec Protraction of scapula Nerve then penetrates major If scapula fixed – it elevates pec. Minor to reach and the ribs of origin (ribs 345). innervate pec. major Aids with flexion of arm Serratus anterior

Lateral surface of upper 8 ribs and associated fascia

** deep to pectoralis major & minor

Subclavius

Extends around thoracic wall

Long thoracic nerve (roots C5-C7)

Medial border and inferior angle of scapula at anterior costal surface Junction of first rib and costal cartilage

Inferior surface of clavicle

Nerve to subclavius (roots C5&C6)

Superior and lateral thoracic arteries (branches of axillary artery)

Draws scapula anteriorly/forward around thoracic wall- protracts scapula.

Thoracodorsal artery (branch of subscapular artery) Clavicular branch of Thoracoacromial artery (branch of 2nd part axillary artery) Suprascapular artery

Rotates scapula

Depress clavicle

UPPER LIMB ANATOMY

OTHER JOINTS OF THE UPPER LIMB/pectoral girdle Scapulothoracic    

Between anterior surface of scapula and posterior aspect of ribcage Not true joint – only muscles between e.g. serratus anterior & subscapularis Also held in place by rhomboids, Levator scapulae, trapezius etc Movements: o Abduction & adduction (of upper limb) o Protraction, retraction, elevation & depression (of scapula)

Sternoclavicular        

Synovial saddle (double plane/double hinge) multiaxial joint Between medial/sternal end of clavicle, clavicular notch of manubrium of sternum & 1 st costal cartilage of rib 1 Only attachment of upper limb to axial (core) skeleton Movements – elevation (shrugging shoulders), depression (drooping shoulders), protraction, retraction, rotation Common features of synovial joint except articular surfaces coved in fibrocartilage rather than hyaline Interclavicular ligament – superior reinforcement + thickening of joint capsule Sternoclavicular ligaments – anterior & posterior reinforcement + thickening of joint capsule Costoclavicular -main stabilising force of joint, resists elevation of pectoral girdle

Acromioclavicular      

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Synovial plane joint (for gliding movements only) Between lateral end of clavicle + acromion of scapula Common features of synovial joint except articular surfaces covered in fibrocartilage not hyaline No muscles act directly on joint – all movement passive & initiated by movement of other joints e.g. sternoclavicular & scapulothoracic Strengthened by trapezius muscle Reinforced by o Acromioclavicular ligament – horizontally over acromion & lateral clavicle, reinforcing superior aspect of fibrous joint capsule o Coracoacromial ligaments – diagonally from coracoid process of scapula to acromion, over GH joint capsule o Coracoclavicular ligament  Very strong  Conoid ligament medially – vertically from conoid process of scapula to conoid tubercle of inferior clavicle  Trapezoid ligament more laterally -vertically from coracoid process of scapula to trapezoid tubercle of inferior clavicle Blood supply – suprascapular artery (branch off thyrocervical trunk off subclavian artery) & thoracoacromial artery (branch off axillary artery) Joint innervation – suprascapular nerve (C5&C6 of BP, runs through suprascapular notch of scapula) & lateral pectoral nerve (lateral cord of BP)

Elbow 

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Joint complex  Elbow joint = synovial hinge joint (flexion and extension but cannot hyperextend)  3 articulations: 1. Trochlea of humerus (acts like a pulley) + trochlear notch of ulna (MEDIAL) 2. Olecranon on posterior ulna + olecranon fossa of posterior humerus (POSTERIOR) 3. Capitulum of humerus + head of radius (LATERAL) o Supported by annular ligament (encircles proximal radial head from the radial notch of ulna), ulnar collateral ligament (medial epicondyle to ulna) & radial collateral ligament (lateral epicondyle to radius)  Proximal Radioulnar joint o between Head of radius + radial notch of ulna o Synovial Pivot joint used in pronation & supination o supported by proximal radioulnar ligament blood supply- articular branches from anastomoses around elbow = branches of brachial, radial & ulnar arteries joint innervation- branches from musculocutaneous, median, radial & ulnar nerves

wrist

UPPER LIMB ANATOMY  

condyloid/ellipsoid synovial (type of synovial joint where the articular surface of one bone has an ovoid convexity sitting within an ellipsoidal cavity of the other bone) radio-carpal joint  articulating surfaces:

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articular disc of distal radioulnar joint (synovial pivot joint involving head of ulna, ulnar notch of radius & interosseous membrane) carpals- scaphoid, lunate, triquetrum

reinforced by ligaments:

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distal end of radius

ulnar collateral ligament- ulnar styloid process to triquetrum & pisiform carpals radial collateral ligament- radial styloid process to scaphoid & trapezium carpals

bi-axial joint 2 main movements: flexion & extension limited adduction/ulnar deviation (muscle: FCU) & abduction/radial deviation (muscle: FCR) due to ulnar & radial styloid processes respectively CLINICAL: scaphoid has a notoriously poor blood supply & recovers poorly when fractured following wrist injury

MIDCARPAL JOINT  

Between the 2 rows of carpal bones Synovial plane joints  allow gliding motion & assist with wrist motions

CARPOMETACARPAL JOINTS   

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Between distal row of carpals & proximal end of metacarpals Palmar & dorsal CMC ligaments CMC joints 2-5 = Synovial plane joints  o limited range, mostly passive o Provide stability > mobility CMC joint 1 of thumb (between trapezium + MC 1) = freely moving synovial saddle joint o Very mobile o This is the joint involved in Benette’s fracture= dislocation of the base of 1st MC

METACARPALPHALANGEAL JOINT     

Synovial condyloid/ellipsoid joint Between convex head of metacarpal & concave base of proximal phalanx ** flexion of the fingers from the knuckles is flexion of MCP joints MCP joints 2-5 are held together by deep transverse ligament related to lumbrical & interossei tendons Fibrous joint capsule is reinforced by collateral ligaments on either side of the joint which fuse on the anterior aspect of MCP joints to form the palmar ligaments (palmar plates)

INTERPHALANGEAL  

Synovial hinge joints  flex & extend but cannot hyperextend Similar ligaments to MCP joints

MUSCLES OF THE UPPER LIMB

MUSCLES OF THE ARM MUSCLE

ORIGIN

INSERTION

INNERVATION

BLOOD SUPPLY

ACTION

UPPER LIMB ANATOMY FLEXORS/ANTERIOR COMPARTMENT BI=2 HEADS= 2 ORIGINS Biceps Brachii ** crosses elbow joint & GH joint ** although majority of muscle (belly) located anteriorly to humerus, it has no attachment to the humerus bone itself. ** tendon of long head of biceps has highest rate of spontaneous rupture in body (associated with rotator cuff injuries or repetitive lifting)

Longhead: Supraglenoid tubercle of glenoid cavity of scapula. Travels superficially along intertubercular/bicipital groove of humerus

Brachialis

Distal half of anterior, medial and lateral aspects of humerus

** crosses elbow joint ** deep to biceps brachii ** more distal than other anterior arm muscles ** forms floor of cubital fossa Coracobrachialis

Short head: Tip of Coracoid process of scapula  2 heads form a single muscle belly

Muscle splits into 2 Main tendon- inserts distally into Radial Tuberosity of proximal radius

Musculocutaneous nerve (C5-C7) (continues as lateral cutaneous nerve of forearm when reached elbow)

Bicipital aponeurosis  flattened tendon/sheet of CT  blends with the deep fascia of the medial anterior forearm (ulna)  protects brachial artery and median nerve. (contents of cubital fossa)  forms the roof of cubital fossa Ulnar tuberosity (proximal end of ulna) & coronoid process

Musculocutaneous nerve (C5-C7)

Deep brachial artery

Major Flexor of forearm at elbow joint Weak flexor of arm at GH joint *only flexes when forearm supine/ stronger when forearm supinated Powerful supinator of FLEXED forearm at elbow joint e.g. Biceps working when unscrewing a cork from a bottle(supination) and pulling the cork out (flexion). Flexion of forearm at elbow joint

(contributions of radial nerve)

Tip of Coracoid process of scapula

** crosses GH joint but does not cross elbow joint ** deep to the biceps brachii EXTENSORS/POSTERIOR COMPARTMENT Triceps brachii TRI=3 HEADS= 3 origins

Midshaft of medial humerus (at level of deltoid tuberosity)

Olecranon process (top of ulna)

Lateral head (more lateral that long head): Posterior humerus superior to radial (/spiral) groove of humerus Medial head: Posterior humerus inferior to radial groove of humerus. (deep to long and lateral heads) 

Musculocutaneous nerve (C5-C7)

Deep brachial artery

Flexion & weak adduction of arm at GH joint. **cannot flex forearm

Long head (medial to lateral head): Infraglenoid (inferior glenoid) tubercle of glenoid cavity of scapula

Radial nerve directly 

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Long head may also receive innervation from axillary nerve Lateral head penetrated by the inferior lateral cutaneous nerve of arm & medial head penetrated by the posterior cutaneous nerve of forearm (sensory branches of radial nerve)

Separating lateral & medial heads= radial groove containing radial nerve and deep brachial artery

MUSCLES OF THE FOREARM FLEXORS/ANTERIOR COMPARTMENT OF FOREARM  

Deep brachial artery

Primarily FLEX WRIST & FINGERS ALL MUSCLES INNERVATED BY MEDIAN NERVE EXCEPT 1.5 MUSCLES=FCU & medial ½ FDP

Deep brachial artery

Major extensor of forearm at elbow joint Long head also Adducts arm at GH joint & steadies head of abducted humerus

UPPER LIMB ANATOMY MUSCLE ORIGIN INSERTION INNERVATION Superficial layer ** originate from MEDIAL EPICONDYLE of humerus BY CFT (common flexor tendon) Midshaft of radius Median nerve 2 HEADS= 2 ORIGINS Pronator teres Humeral head - Medial epicondyle of humerus by ** Lateral CFT border of Ulnar head- coronoid pronator teres process of ulna forms medial border of cubital fossa Base of metacarpals 2 Median nerve Flexor carpi Medial epicondyle by CFT &3 radialis Travels distally toward RADIAL side of carpus Medial epicondyle by CFT Palmar aponeurosis Median nerve Palmaris and flexor retinaculum longus ** Absent in 15% of population Flexor carpi ulnaris

2 HEADS: Humeral head- Medial epicondyle by CFT Ulnar head- olecranon process and posterior border of ulna

 Travels distally toward ULNAR side of carpus Intermediate layer Flexor 2 HEADS=2 ORIGINS digitorum superficialis Humeroulnar headMedial epicondyle by CFT, Coronoid process of ulna, (Digitorum = into fingers or ulnar collateral ligament toes) Radial head- proximal half of anterior Radius Deep layer Flexor digitorum profundus

Anterior Ulna & associated interosseous membrane

Anterior surface of radius & surrounding interosseous membrane

Lies laterally to FDP

(on THUMB side/lateral side of anterior forearm)

Pronator quadratus

Distal anterior end of ulna

Square shaped Found deep to tendons of FDP & FPL therefore it is the DEEPEST muscle of the anterior forearm

ACTION

Branches of brachial, ulnar and radial arteries

Pronation of forearm at proximal radioulnar joint (when it contracts it pulls radius over ulna) (distal pronation by pronator quadratus) Flexion of elbow

Radial artery

Flexion and abduction of hand at wrist

Branches of ulnar artery Median artery

Flexion of hand at wrist Tightens palmar aponeurosis

Pisiform and hook of hamate carpal bones (wrist) & 5th metacarpal bone.

Ulnar nerve

Branches of ulnar artery

Flexion and adduction of hand at wrist

4 tendons travel distally through carpal tunnel of wrist

Median nerve

Branches of ulnar artery

Flexion of MCP joints and proximal IP joints of medial 4 fingers (25, not thumb)

Palmar surface of middle phalanges of medial 4 fingers (fingers 2-5 not thumb) 4 tendons travel distally through carpal tunnel...