Download Appendicular Skeleton Pectoral Girdle General:

Pompilii-­‐ Anatomy and Physiology Chapter Six – The Skeletal System THE PECTOTRAL GIRDLE Appendicular Skeleton Pectoral Girdle General: P a g e | 1 Name: ________________________________ ¨ 126 bones ¨ Includes ¤ bones of the limbs (appendages) ¤ Supporting bones of the pectoral and pelvic girdles (connect limbs to axial skeleton) ¤ forms the shoulder ¤ Consists of two bones ¤ clavicle (collarbone)-­‐ long bone n Latin word “clavicula” = little key ¤ scapula (shoulder blade) ¤ Allows free movement of upper limb ¤ Sternoclavicular joint – where the clavicle meets the sternum ¤ Acromioclavicular joint – where the clavicle meets the scapula ¤ Loose attachment allows scapula to move freely ¤ Shoulder joint is poorly reinforced by ligaments n Easily dislocated Pectoral Girdle Consists of 1.The Clavicle: P a g e | 2 ¤
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Aka Collarbone Slender, doubly curved bone Acts as a brace to hold the arm away from the thoracic cage Helps prevent shoulder dislocation Structures to know: ¤ Acromioclavicular joint and sternoclavicular joint 2. The Scapula P a g e | 3 ¤ Aka Shoulder blade (little shovel) ¤ Anatomy: ¤ Flattened body ¤ Spine (posterior) n Supraspinous fossa – Superior to (above) the spine ¤ Origin of the supraspinatus muscle (rotator cuff) (posterior) n Infraspinous fossa – Inferior to (below) the spine ¤ Origin of the supraspinatus muscle (rotator cuff) (posterior) ¤ Additional Fossae: n Subscapular fossa-­‐ anterior ¤ Origin of the subscapularis muscle (rotator cuff) (anterior) ¤ Acromion process = enlarged end of the spine of the scapula n Articulates with the clavicle to form the acromioclavicular joint n Comes from the Greek word “Akron”(peak) and “Omos”(shoulder) ¤ Coracoid process = “beak”-­‐like process n Points over the top of the shoulder and anchors arm muscles ¤ Suprascapular notch = nerve passageway n Forms a foramen (ossification of transverse ligament) that provides passage way for the suprascapular nerve. ¤ Glenoid fossa(cavity) = shallow socket that receives the head of the arm n Comes from the greek work “glene” (socket) ¤ Borders: ¤ Lateral (axillary) border ¤ Medial (vertebral) border ¤ Superior border The Upper Limb: The Arm: Proximal features: Features of the Diaphysis: P a g e | 4 ¨ 30 separate bones in each upper limb ¨ Arm, foreharm, hand ¨ The humerus – single typical long bone of the upper arm ¨ Articulates proximally with scapula and clavicle and distally with radius and ulna ¨ Proximal features: ¤ Head – fits into glenoid cavity of scapula ¤ Greater and lesser tubercles – two bony projections lateral to the head n Separated by the intertubercular sulcus n Attachment of tendons ¤ Anatomical neck – slight constriction just inferior to the head ¤ Surgical neck – most frequently fractured part of the humerus ¨ Features of the diaphysis (shaft): ¤ Deltoid tuberosity: attachment for the deltoid(shoulder) muscle Radial groove-­‐ marks the course of the radial nerve Distal Features: The Forearm: P a g e | 5 ¨ Distal features: ¤ Lateral and medial epicondyles: ¤ External and internal condyles: ¤ Olecranon fossa: groove that receives the olecranon process of the ulna upon extension of the arm. ¤ Coronoid fossa: groove that receives the coronoid process of the ulna upon flexion of the arm. ¤ Trochlea (medial) articulates with trochlear notch of the ulna. ¤ Capitulum (lateral) articulates with head of the radius ¨ Consists of two bones 1. Radius = lateral bone when in anatomical position 2. Ulna = medial bone when in anatomical position 3. Radioulnar joints = sight of articulation of radius and ulna ¨ Two bones are connected along their entire length by interosseous membrane ¨ Structures to know: radial tuberosity, styloid process, coronoid process, olecranon process, trochlear notch The Hand: P a g e | 6 ¨ Wrist (carpals) = 8 short bones ¨ Palm (metacarpals) = 5 long bones ¨ Fingers (phalanges)= long bones ¤ Thumb has 2 phalanges ¤ Each finger has 3 phalanges n Proximal phalange n Medial phalange n Distal phalange Figure 1: Articulated right shoulder (pectoral) girdle showing the relationship to bones of the thorax and sternum. P a g e | 7 Figure 2: Superior and Inferior views of the right clavicle. Figure 3: Anterior and Posterior right scapula P a g e | 8 General Anatomical Terms to know: Use page 153 to complete the table Term Description Definition Process Ramus Trochanter Tuberosity Tubercle Crest Line Spine Head P a g e | 9 Term Description Definition Neck Condyle Trochlea Facet Fossa Sulcus Foramen Canal or Meatus Fissure Sinus P a g e | 10 P a g e | 11