ANATOMY OF UPPER LIMB

DR. MOHAMMAD REHAN ASADMBBBS, MD (ANATOMY)ANATOMY OF UPPER LIMB

Learning objectives: At the end of session, the students should able to : Describe the bones and joints of upper limbEnlist the major muscles of upper limbEnumerate major arteries and veins of upper limbDefine special spaces like axilla and cubital fossa with its contentsDescribe brachial plexus and its main braches.

ANATOMY OF THE UPPER LIMB

1- Bones of the upper limb.2- Muscles of the upper limb.3- Vesseles of the upper limb.4- Nerves of the upper limb.5- Joints of the upper limb.

ANATOMY OF THE UPPER LIMBSurface anatomy of the upper limb.The upper limb divided to The ShoulderThe armThe forearmThe handThe axilla & the breast

ANATOMY OF THE UPPER LIMBSHOULDER: CONTAINS SCAPULA& CLAVICLE that articulate with the sternum & the humerus.

THE SCAPULA2 surfaces (ventral& dorsal).&3 angles (superior, lateral& inferior).& 3 borders (medial ,lateral & superior).spine ,acromial process &coracoid process.

THE SCAPULAThe ventral (costal) surface is concave &forms the subscapular fossa.

THE SCAPULAThe dorsal surface is convex &divided by the spine of the scapula to 2 fossae:1- a small supraspinous fossa.2-a large infraspinous fossa.

Articulation of the scapula

There are 2 synovial & 2 fibrous joints.synovial joints :glenoid cavity with the head of the humerus to form the shoulder joint .Acromio-clavicular joint

Articulation of the scapula

fibrous joints :coraco- clavicular joint (strong joint covered with strong ligament)coraco- acromial joint (strong joint covered with strong ligament)

THE CLAVICLE

It lies horizontally in the root of the neck. It covers the flat 1st rib& its medial 2/3 are curved.It has 2 important functions: To transmit forces from the upper limb to the bones of the axial skeleton (sternum) To act as strut holding the arm free from the trunk.

CLAVICLEIT HAS BODY AND 2 ends:Sternal end articulate with the manuberium of the sternum forming the sterno- clavicular joint.Acromial end articulate with the acromial process of the scapula forming the acromio- clavicular joint. Body is convex in medial 2/3 concave in lateral 1/3.

HUMERUSIt is a tubular long bone composed of upper end , body (shaft ) & lower end.upper end formed fromhead neck ( anatomical &surgical )tubercles (greater & lesser )

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HUMERUSBody (shaft)lateral & medial borders of the lower shaft are continued below to form the lateral & medial supracondylar ridges (crests) which end with lateral & medial epicondylesMiddle of the shaft there is deltoid tuberosity & the spiral groove

HUMERUSThe lower end formed from( from medial to lateral ) :anterior aspect :medial epicondyle , trochlea ,capitulum & lateral epicondyle . With 2 fossae (coronoid & radial ) .

posterior aspect: medial epicondyle , trochlea & lateral epicondyle with one fossa (olecranon) . medial epicondyle carries a shallow groove in the posterior surface for the ulner nerveHUMERUS

HUMERUSNerves related to the humerus :circumflex (axillary) N. may be injured in fracture of surgical neck .radial N. (which lies in the spiral groove ) may be injured in fracture of the middle of the shaft .ulnar N. may be injured in fracture of the lower end (the medial epicondyle)

RADIUSLong bone , consist of thin narrow upper end ,body & thick expanded lower end .The upper end consist of :head :articulate with capitulum of humerus.lateral surface with the radial notch of the ulna . neck :constricted part below the head . radial tuberosity :below the medial part of the neck .

ULNAIt is along bone with upper end , body (shaft ) & lower end.The upper end consist of :1- The olecranon process :the upper part of the trochlear fossa .2- The coronoid process : the lower part of the trochlear fossa .3- The ulnar tuberosity :below the coronoid process on the anterior surface ..

bones of the handCarpals , metacarpals & phalanges bonesCarpal bones 8 arrange in 2 rows ( proximal & distal ) From lateral to medial:proximal row : scaphoid ,lunate , triquetral & pisiformdistal row : trapezium , trapezoid , capitate & hamate

bones of the handMetacarpal bones : are 5Each metacarpal bone has : base ,shaft & head .The phalanges : all the fingers have 3 phalanges ( proximal , middle & distal ) except the thumb has only 2 (proximal & distal ). Each phalanx has base , shaft & head

articulation/joints of the carpal bonesThe scaphoid & lunate articulate with the lower end of the radius .the triquetral articulates with the lower end of the ulna The bones of the proximal row joins with the bones of the distal row in mid carpal (transverese carpal) joint.

Joints of upper limbSternoclavicular jointAcromioclavicular joint: synovial plane Glenohumeral joint: synovial Ball and socket Elbow joint: synovial Hinge Radioulnar joints:Wrist joint: ellipsoid type of synovial CarpometacarpalInterphalngeal joint

Movements on different joints

In general they divided to Muscles attached the upper limb to axial skeleton . Muscles of the upper limb proper .

THE MUSCLES OF THE UPPER LIMB

Muscles attached the upper limb to axial skeleton .Anterior MusclesPectoralis major , Pectoralis minor & subclavius Mm.Medial : serratus ant M.

THE BACK MmLatissmus dorsi , trapezius , levator scapulae , rhomboideus minor & rhomboideus major Mm.Only the pect. Major & latissmus dorsi are inserted in the humerus while all the others are inserted in the shoulder girdle( scapula & clavicle) .

Muscles attached the upper limb to axial skeleton .

MOVEMENTS OF THE SHOULDER GIRDLE1- ELEVATION: trapezius & levator scapulae Mm.2-DEPRESSION: by pect.major , pect.minor &latissmus dorssi Muscles. 3- RETRACTION: by middle Ff. of trapezius, rhomboideus major & minor Mm.4- PROTRACTION: by serratus ant. ,levator scapulae & pect. Minor.5- ROTATION UP : trapezius &serratus anterior Mm.6-ROTATION DOWN : levator scapulae ,rhomboideus major & rhom. minor Mm.

MUSCLES OF THE SHOUlDER REGIONSix muscles: deltoid , teres major , teres minor ,supraspinatus , infraspinatus& subscabularisThe last 4 called Rotator cuff musclesAll of them arise from the scapula ( all from the dorsal surface except subscapularis M. from the anterior surface ) & all inserted in the tuberosities of humerus .They rotate the arm(medially or laterally) & adduct the arm (except the deltoid &supraspinatus Mm.) all suplied by C5, C6 Nn.

MUSCLES OF THE FRONT OF THE ARMThey are :Biceps , Brachialis & coraco -brachialis all supplied by musculo-cutaneous N.Biceps stablize shoulder joint and flexor for elbowThe brachialis M. from the shaft of humerus to the tuberosity of ulna, act as flexor to the elbow.The coracobrachialis act as flexor & adductor to the arm.

MUSCLES OF THE BACK OF THE ARM.: Triceps M.: the long ,medial & lateral heads inserted in the upper post. Part of olecranon processsupplied by the radial N. act as extensor of the elbow & stabilize the elbow jt.

FOREARM MUSCLES Divided to 2 groups: flexor- pronator group extensor- supinator group

FLEXOR PRONATOR GROUP : * flex the wrist ,fingers & pronate the forearm. * divided to superficial & deep groups. *The superficial group arise from the front of medial epicondyle of humerus, pass in front of the forearm& the wrist to inserted in bones of the hand .

FLEXOR PRONATOR GROUP Superficial:Pronator teres , Fl. Carpi-radialis , Fl. Carpi-ulnaris ,Fl. Digitorum superficialis &palmaris longus Mm .

FLEXOR PRONATOR GROUP Deep muscles of flexor forearmFour muscles

EXTENSOR - SUPINATOR GROUP. *extend the wrist & the fingers & supinate the forearm * divided to superficial & deep groups:superficial group arise from the back of the lateral epicondyle of humerus to pass on the back of the forearm & inserted in the bones of the hand . 7 in number

EXTENSOR - SUPINATOR GROUP.The deep group are five muscles:

EXTENSOR - SUPINATOR GROUP.The muscles of the thumb are : Abductor pollicis longus , Ext. pollicis brevis & ext. pollicis longus.

RETINACULUM IN HANDFlexor retinalculum: thick band made of dense white fibrous tissue which stretch across the anterior surface of the carpal bones. Form a tunnel known as carpal tunnelIn the tunnel pass the median nerve & tendons of musclesExtensor retinaculum: It is a thickening of deep fascia between the lower ends of radius & ulna .

MUSCLES OF THE HANDDivided to thenar & hypothenar muscles. Thenar Mm: Abductor pollicis brevis , flexor pollicis brevis & opponens pollicis Mm.Hypothenar Mm : abductor digiti minimi ,flexor digiti minimi & opponens digiti minimi Mm. 4 lumbrical Mm & 7 Interosseous Mm. in the fingers.All these Mm responsible for fine movements of fingers.

BREAST( THE MAMMARY GLAND) :It lies in the superficial fascia . modified sweat covered by a skin contain the nipple & the areola.It extends from the 2nd rib to 6th rib & from the edge of sternum to the mid-axillary line.Each gland is formed of 16-20 lobes & each lobe divided to lobules.

AxillaPyramid shape spaceContents: axillary artery, axillary vein, cords of brachial plexus, and lymph nodes.

LYMPH NODES OF THE AXILLAdivided to :central group : in the base of the axilla .lateral group: along the axillary vein anterior ( pectoral) group .

apical group :in the apex of the axillaposterior (subscapular ) group.

ARTERIES OF THE UPPER LIMB:AXILLARY ARTERY :It begins at the outer border of the 1st rib as a continuation of the Subclavian A. & ends at the lower border of the teres major M. by becoming the Brachial A.pectoralis minor M . divided it to 3 parts:Total six branches

BRACHIAL ARTERY :It supplies all the Mm. of the arm & gives 3 branchesprofunda brachii A.superior ulnar collateral A.inferior ulnar collateral A.Profunda brachii A. is the largest branch & pass with the radial N. in the spiral groove of the humerus to end in 2 terminal branches above the elbow joint .

RADIAL ARTERY:Starts at cubital fossa & ends in the palm by becoming the deep palmer archdescend in the lateral part of the front of the forearm .At the lower end of the radius , it leaves the front of the forearm & turns backward round the lateral border of the wrist , below the styloid process of the radius& enter the anatomical snuff-box where the pulsation can be felt then pass to the palm .

ULNAR ARTERY :Starts at cubital fossa & ends in the palm by becoming theSUPERFICIAL PALMER ARCH.It runs obliquely-medially in the upper part & vertically in the lower part of the forearm.

VEINS OF THE UPPER LIMBThere are superficial & deep veins in the upper limb .deep veins are the veins which accompany the main Artery ( way & name ).superficial veins : start as superficial venous network on the back of the hand. this network drains in 2 directions ;laterally into Cephalic V & medially to the basilic V.

VEINS OF THE UPPER LIMBCEPHALIC VEIN : starts in the superficial fascia just behind the styloid process of the radius .Runs upward to the anterior surface of the forearm ; in the upper arm it lies in a groove along the lateral border of biceps M. then pierces the deep fascia in a groove between the deltoid & pectoralis major Mm. to inter the axillary vein.

VEINS OF THE UPPER LIMBBasilic veinoriginates from the dorsal venous network of the hand.ascends the medial aspect of the upper limb.At the border of theteres major, the vein moves deep into the arm. Here, it combines with thebrachial veinsto form the axillary vein

VEINS OF THE UPPER LIMBTHE MEDIAN CUBITAL VEIN :most prominent superficial vein in the body joins the cephalic & the basilic Vein just distal to the front of the elbow joint.superficial veins are more important than the deep Vv. Because they are larger in size & used for intravenous injections.

BRACHIAL PLEXUSplexus: it is a complex arrangement of the anterior primary rami of certain spinal nerves that gives branches to supply the Muscles & skin of a certain part of a body.BRACHIAL PLEXUSformed by the anterior primary rami of C5,C6,C7,C8 &T1 Nerve called ROOTS of the plexus.It lies in the lower part of the neck behind the clavicle & in the axilla & formed of 4 main parts : Roots , Trunks , Divisions & cords.

BRACHIAL PLEXUSroots: lie in the neck.trunks : passes lower part of the posterior triangle of the neck .divisions : lie behind the middle 1/3 of the clavicle. cords : lie in the axilla .

BRACHIAL PLEXUSGives 16 branches , 11 small branches & 5 big branches : radial , ulnar , median , circumflex (axillary) & musclocutaneous Nn.

BRACHIAL PLEXUS5 main Nn. Arise opposite the lower border of the pectoralis minor M. near the coracoid process .circumflex (axillary ) N. supplies deltoid & teres minor Mm. then become the lateral cutaneous N. of the arm. Musculocutaneous N. supplies the biceps , coracobrachialis & brachialis Mm. then become the lateral cutaneous N. of the forearm . Median N supplies most of the Mm. of front of the forearm with sensation of lateral 3 & fingers anteriorly .

BRACHIAL PLEXUSRadial N supplies most of the mm. of the back of the forearm. With sensation of lateral 3 & fingers posteriorly. Unar N. supplies Mm. on the medial side of the forearm with sensation of medial 1 & fingers anteriorly & posteriorly .

DERMATOMES OF THE UPPER LIMBIt is the cutaneous sensation of the upper limb.C4 supplies the skin over the tip of the shoulder .C5 supplies the lateral side of the arm & upper lateral part of the forearm . C6 supplies the lateral side of the lower part of the forearm & the lateral aspect of the handC7 supplies the middle aspect of the hand (ant.& post.) .

DERMATOMES OF THE UPPER LIMBC8 supplies the medial side of the hand & the medial lower part of the forearm.T1 supplies the medial part of the upper part of the forearm & the medial lower part of the arm. T2 supplies the medial side of the upper part of the arm & the floor of the axilla.

Reference book: Greys Anatomy for studentsThank you

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