SCAPULA, CLAVICULA 



55 



The margins are called the superior, the vertebral, and the axillary; the 

 angles, lateral, medial, and inferior. The inferior angle and vertebral border 

 or margin usually project a little backward, sometimes very notably, making 

 the so-called "winged scapula." 



The anterior surface (costal surface) is called the subscapular 

 fossa, and is filled with the subscapular muscle. The posterior or 



dorsal surface is crossed by a rough 

 ridge called the spine of the scapula 

 which terminates in an important 

 process, the acromion, overhanging 

 the shoulder-joint. 



Below and in front of the acromion is 

 the coracoid process. 



FIG. 49. SCAPULA, POSTERO- FIG. 50. CLAVICLE, INFERIOR ASPECT. 



EXTERNAL ASPECT. ^ Lon g itudinal depression for insertion 



i, Supraspinous fossa; 2, infra- of subclavius muscle; 2, rough impression 



spinous fossa; 3, superior or coracoid for attachment of costoclavicular ligament; 



border; 4, coracoid or suprascapular 3, 3, for attachment of coraco-clavicular 



notch; 5, axillary or lateral border; ligaments; 4, 4, posterior border; 5, 5, an- 



6, anterior angle and glenoid cavity; terior border; 6, facet for articulation with 



7, inferior angle; 8, rough impression sternum; 7, facet for articulation with 

 for long head of triceps; 9, medial or acromion. (Sappey.} 



spinal or vertebral border; 10, spine; 

 n, smooth surface over which tra- 

 pezius muscle glides; 12, acromion; 13, 

 base of spine; 14, coracoid process. 

 (Sappey.} 



The lateral angle presents a shallow depression called the 

 glenoid cavity. This cavity forms the socket of the shoulder-joint. 



Clavicula (or collar-bone, Fig. 50). Long in shape, but having 

 no medullary canal. It is curved like an italic letter / and placed 

 horizontally across the front of the upper ribs. The medial ex- 

 tremity articulates with the sternum and is therefore called the 

 sternal extremity. The lateral extremity articulates with the 

 acromion process of the scapula, and is called the acromial 

 extremity. 



Clinical note. The weight and curves are increased by exercise, 

 and both bones are usually more developed in men than in women. 



