Skeleton (Bones) of Upper Limb (PDF)

Skeleton (Bones) of Upper Limb (extremity) Prof. Dr. Selda Önderoğlu Anatomy Department  Appendicular skeleton: 1- upper limb (extremity) 2- Lower limb (extremity)  Begins: Anteriorly: from Sternoclavicular Joint Posteriorly: from muscles and ligaments that...

Skeleton (Bones) of Upper Limb (extremity) Prof. Dr. Selda Önderoğlu Anatomy Department  Appendicular skeleton: 1- upper limb (extremity) 2- Lower limb (extremity)  Begins: Anteriorly: from Sternoclavicular Joint Posteriorly: from muscles and ligaments that bind the scapula to the thorax ( chest). Ends at: Tips of the fingers of the hand  Regions of upper limb -4 regions 1- SHOULDER: attachment to to the trunk (through scapula+clavicle) 2- ARM: Between shoulder joint - elbow joint 3- FOREARM: bw. Elbow J. – wrist J. 4- HAND: bw. Wrist J.-tips of the fingers of the hand SHOULDER REGION formed by two bones: 1- Clavicle 2- Scapula Scapula+ clavicle: form the pectoral girdle  Clavicle Extends laterally & almost horizontally across the neck from sternum to scapula Clavicle Shape:S Shaped (When looked from above) Borders:anterior&posterior Surfaces: superior & Inferior Ends: Medial ( sternal) & lateral (acromial)  Clavicle Inferior Surface: -groove for subclavius muscle -at the lat part: trapezoid line & conoid tubercle Clavicle-superior surface:mm. Attach here Scapula Large, flat, triangular bone Located at the back and lateral part of thorax(chest) Extends between 2-7 ribs  SCAPULA 2 surfaces: post.(dorsal) & Ant. (costal) ventral 3 angles: superior+ inferior+lateral 3 borders: medial+ lateral+ superior 3 processes: Spine +Acromial +Coracoid dorsal Ventral surface Dorsal surface Processes Spine Acromion Coracoid Ventral surface  Dorsal surface Spine of scapula - divides this surf. into 1-supraspinous fossa 2- infraspinous fossa Spine of scapula Projects backwards from upper part of dorsal surface Triangular in shape Acromion On the dorsal surface Projects from lat. end of spine, forwards, almost at right angle, Just under the skin, can be felt Coracoid process On the superior border Projects laterally & forwards  Medial border: Presents Trigone of the spine of scapula: where the spine of scapula meets the medial border Lateral border: Covered by muscles,Can’t be palpated At its sup.end: infraglenoid tubercle  Superior (scapular) border Structures at this border: 1- Coracoid process ( extends forwards and laterally) 2- scapular notch ( at the base of coracoid Process) Angles Inferior angle: Overlies 7th rib Superior angle: At the junction of sup. & med. borders, at the level of 2nd rib Lat eral angle: broad, forms shoulder joint with humerus Lateral angle has glenoid cavity, for articulation with humerus Supraglenoid tubercle& infraglenoid tubercle: Small elevations just above and below the lateral angle  ARM REGION one bone: HUMERUS -Longest & largest bone of upper limb Parts : proximal end+Body (shaft)+Distal end Anterior view At the Proximal end: Head Neck Greater tubercle Lesser tubercle HEAD of HUMERUS Directed backwards and medially & upwards Articulates with the glenoid fossa ( of scapula) Anatomical Neck: Anterior Where the head is view constricted  Greater & lesser tubercles Greater tubercle: lateral to the head Lesser tubercle: anterior to the head Intertubercular sulcus / bicipital groove: the anterior groove between those tubercles. Tendon of biceps brachii m. passes here  Surgical neck At the lower part of Proximal end Medial to it; axillary n! & post humeral circumflex a. anterior Prox. End fracture:anat&surg neck When Proximal end is fractured: axillary n. May be damaged! ( not must!) Impressions on greater tubercle (where mm. attached) Supraspinatus muscle Infraspinatus m. anterior Teres minor m. Post.view  Shaft ( body) 3 Borders: -Anterior - medial - lateral 3 Surfaces: -Anterolateral(ventrolat.): - deltoid tuberosity anterior -anteromedial (ventromed.) -posterior -radial groove Posterior surface: RADIAL GROOVE ( radial nerve courses here) Post.view at distal end: Olecranon fossa  Distal end-Wider important features: Capitulum ( on lateral side, convex) Trochlea (medial side, pulley- anterior shaped) Medial epicondyle lateral epicondyle Coronoid fossa(ant.,superior to trochlea) radial fossa (ant.,superior to capitulum) Sulcus for the ulnar nerve (post., inferior to medial condyle) Olecranon fossa (posterior)  Distal end Capitulum: articulates with radial head Trochlea:articulates with trochlear notch (of ulna) med.epicondyle:subcutaneous, visible in passive flexion, post surface is crossed by ulnar n. Med. Supracondylar ridge: distal part of medial border Lat. Epicondyle: lat border ends Lat. supracondylar ridge: distal part of lateral border  THE FOREARM REGION two bones: radius Radius (lateral) Ulna (medial) ulna  Radius Lateral bone HAS: Proximal end Shaft Distal end  Proximal end Head Disc shaped Prox surface; shallow cup for capitulum of humerus Medially contacts radial notch (of ulna) Neck Constriction distal to head radial tuberosity Distal to medial part of neck  Shaft 3 borders : Interosseous border: sharp and located medially Anterior border Posterior border 3 surfaces: Anterior: Between ant & interosseous borders Posterior: Between post & interosseous borders Lateral:Convex  Distal end Widest part Laterally: projection called the styloid process inferior surface: articular surface which articulates with carpal bones Medial side: Ulnar notch  Ulna Has : proximal end Shaft ( body) Distal end Proximal end Trochlear notch Articulates with trochlea of humerus Olecranon: above troch.notch Coronoid process Below troch. notch Radial notch On the Lat. surface Articulates with radial head Tuberosity of ulna On distal part of coronoid process  Shaft 3 borders & 3 surfaces Borders:Anterior+posterior + interosseous Surfaces:Anterior+ posterior+ medial laterally has the :supinator crest  Distal end Head of ulna Laterally fits ulnar notch ( of radius) Has Styloid process Projection on the medial side Hand region Carpal bones (Carpus) (at wrist) Metacarpal bones Phalanges ( at fingers)  Carpal bones (carpus) 8 bones; 4 proximal+ 4 distal Proximal: from lat.to medial: Scaphoid, lunate, triquetral, pisiform Distal; from lat. To medial: Trapezium, trapezoid, capitate, hamate Pisiform articulates with triquetral Palmar carpal surface forms carpal groove (deeply concave)  Some remarks Carpal groove turns into an osseo-fibrous carpal tunnel by the flexor retinaculum attached to its margins -Scaphoid; most frequently fractured carpal bone  Metacarpal bones 5 in number From lat to medial:1-5 Each Has: -base ( proximal ) -shaft (body) -head ( distal ) heads articulate with proximal phalanges Metacarpal bases articulate with distal carpal row  Phalanges 14 in number 3 in each finger 2 in thumb Each phalanx: Proximal end / base Shaft Distal end / Head