Clavicle, Scapula and Humerus Anatomy PDF

Clavicle, Scapula and Humerus Instructor: Donnahue Dennie  Scapula The scapula forms the posterior of the shoulder girdle. It is a sturdy, flat, triangular bone. Provides attachment to several groups of muscles. Muscle attaching to scapula: teres major,...

Clavicle, Scapula and Humerus Instructor: Donnahue Dennie  Scapula The scapula forms the posterior of the shoulder girdle. It is a sturdy, flat, triangular bone. Provides attachment to several groups of muscles. Muscle attaching to scapula: teres major, subscapularis, teres minor, and infraspinatus, triceps, biceps, and deltoid, levator scapulae, trapezius, rhomboids, and serratus anterior.  Scapula Three borders Lateral border Medial/vertebral border Superior border Three angle Inferior angle Lateral angle Superior angle Two surfaces Costal surface Posterior surface  Scapula – Superior Border Slants downwards and laterally Contains a Scapula Notch – This is a depression that lies at the base of the coracoid process Scapula notch is enclose by Transverse Scapular ligament this lodges the suprascapular nerve The inferior belly of the Omohyoid arises from the transverse scapular ligament & the adjacent superior scapula border  Scapula –Medial border Directed towards the vertebra From medial to superior gives attachment for the following muscle Levator scapulae Rhomboid Minor Rhomboid Major  Scapula – Lateral Border Extends from the glenoid cavity to the inferior angle of the scapula Contains infra glenoid tubercle  Scapula - Lateral angle Glenoid cavity Articulates with head of humerus Fibrocartilage around the rim called glenoid labrium Glenoid labrium functions to widen and deepen the cavity Attached to the glenoid labrium and surrounding bone is the joint capsule Just above glenoid cavity there is a supra glenoid tubercle for attachment of the long head of biceps brachii Below glenoid cavity there is a infra glenoid tubercle for attachment of triceps brachii  Scapula - Lateral angle Coracoid process - hook like forward projection from the scapula Tip palpable just below the clavicle Forms attachment for the following: Conoid ligament Trapezoid ligament Coracoacromial ligament Coracohumeral ligament Pectoralis minor Short head of biceps and coracobrachialis  Scapula - Costal Surface Concave and smooth Medial 2/3 forms attachment for subscapularis muscles Lateral 1/3 - subscapularis bursa separates the overlying muscle from the bone Medial margin – receives insertions from the serratus anterior muscle Inferior angle also receives insertion from the serratus anterior muscle  Scapula - Posterior surface Contains a projection that is directed posteriorly – Spine Spine divides the posterior surface into a supraspinous fossa & an infraspinous fossa The infraspinatus muscle arises from the infraspinous fossa and the supraspinatus muscle arises from the supraspinatus muscle Teres Major arises inferior angle of the posterior surface Teres minor arises from a narrow area on the lateral border of the posterior surface  Scapula - Posterior surface Spine as a free anterior lateral projection – the acromion Acromion arches over the glenohumeral joint Articulates with the cavicle by a small oval facet The acromion is attached to the corocoid process by coracoacromial ligament The area between the lateral angle and the acromion is the great scapular notch The suprascapular nerve and vessels run across this notch to the infraspinous fossa  Scapula - Posterior surface The trapezius is attached to the superior border of the spine, medial margin of the acromion The deltoid muscle is attached to the inferior border of the spine, lateral border of acromion  Scapula Blood Supply and Lymphatics Arterial Supply mainly by the scapular anastomosis Scapular anastomosis- axillary artery, subclavian artery, dorsal scapular artery, the suprascapular artery, the deep scapular artery, the circumflex scapular branch of the subscapular artery, The venous drainage of the scapula is largely accomplished by the axillary vein, the suprascapular veins, and numerous small and highly variable anastomotic tributaries. The lymphatic drainage from the right scapula empties into the right lymphatic duct and into the thoracic duct from the left scapula.  Scapula Nerves The nerves to the scapula include: – the dorsal scapular, upper and lower subscapular, and suprascapular nerves  Clavicle Only bony attachment between the trunk and the upper limb It is a long bone with a S-shaped contour Medial part is convex facing forward Articulates medially with the sternum to form the sternoclavicular joint and the first rib to a smaller extent Laterally it articulates with the acromion to form the acromioclavicular joint  Sterno-clavicular joint Two synovial cavity Strengthen by the interclavicular ligament, anterior sternoclavicular ligament and the costclavicular ligament  Acromioclavicular joint The three main ligaments to support this joint are: the Acromioclavicular ligament, the coracoclavicular ligament, the coracoacromial ligament  Clavicle Inferior surface Lateral third contains conoid tubercle for attachment of the conoid ligament Trapezoid line for the attachment of the trapezoid ligament The subclavius muscle  Clavicle - attachments Posterior border Trapezius – lateral third Anterior border Pectoralis major- medial half Deltoid- lateral third Superior surface Sternocleidomastoid – medial third Inferior surface Subclavius – middle third Conoid ligament – conoid tubercule Trapezoid ligament – trapezoid line  Clavicle The shaft of the clavicle is divided into two parts medial two-thirds and lateral third. The medial two-thirds has an attachment site for: the sternocleidomastoid muscle –superior Subclavius- inferior Pectoralis major – anterior sternohyoid – posterior The lateral third of the clavicle deltoid -anterior – trapezius -posterior – Coracoclavicular ligament –inferior.  Humerus Consist of a shaft and two expanded ends Upper expanded end consist of a articular surface the end and two tubercules Between the head and the tubercules is the anatomical neck Between the expanded upper end and the shaft is the surgical neck  Humerus Head Articulates with the glenoid cavity of the scapula About four times the size of the glenoid cavity Coated with hayline cartilage Surgical neck - Axillary nerve and posterior circumflex humeral artery passes immediately posterior to the surgical neck Tubercules Greater and lesser tubercule  Humerus -Greater tubercule Laterally placed Marked by three facets Superior facet – attachment of Supraspinatus Middle facet – attachment of Infraspinatus Inferior facet – attachment of Teres Minor Expending downward from the anterior surface is the lateral lip of the intertubercular sulcus  Humerus - Lesser tubercule Anteriorly placed Expending downward from is the medial lip of the intertubercular sulcus Intertubercular sulcus Contains the tendon of the long head of the bicep brachii muscle Bridge by the transverse humeral ligament Floor of the sulcus receives insertion form the latissimus dorsi The lateral lip receives – pectoralis major Medial lip receive – Terres major  Humerus Shaft Crossection is triagular with anterior, lateral and medial border Contains a V-shaped deltoid tuberosity in the middle of the lateral side Deltoid tuberosity gives attachment to the deltoid muscle Opposite the deltoid tuberosity is the attachment of the coracobrachialis  Humerus - shaft Below deltoid tuberosity is the radial groove In this radial groove is the radial nerve and profunda brachii artery  Posterior margin of the radial groove becomes the lateral supracondylar ridge This lateral supracondylar ridge extends down to the lateral epicondyle A less prominent medial supracondylar ridge extends down to the medial epicondyle Supracondylar ridges gives attachment to intermuscular septum Between the supracodylar ridges the brachialis muscle attaches on the flexor surface of the humerus  Humerus –Lower End Contains two articular surfaces /condyle – Capitulum – articulates with radius Trochlea – articulates with ulna Contains medial and lateral epicondyle Contains three fossae Radial fossa – superior to capitulum Coronoid fossa – superior to trochlea Olecranon – found on the posterior surface of distal humerus  Question??? THE END!!!