£4 . BOXES OF THE UPPER LIMB. 



usually pierces the iuferic^r .surface of tiie spine, and others are to be 

 found on the anterior surface of the bone, near the neck. 



THE CLAVICLE. 



The clavicle or collar-bone extends transversely outwards, with an 

 inclination backwards, from the summit of the sternum to the acro- 

 mion process of the scapula, and connects the upper limb with the 

 trunk. 



It is curved somewhat like an italic /: the convexity of the internal 

 curve is directed forwards, and extends over two-thirds of the length 

 of the bone ; that of the outer curve looks backwards, and is most 

 marked near the outer fourth of the bone. 



The clavicle, towards its scapular end, is compressed and broad from 

 above downwards, but in the extent of its inner curve it is more or 

 less prismatic or cylindrical. In its description, four surfaces of the 

 shaft may be distinguished, together with the two extremities. 



Fis. 70. 



Fig. 70. -The Bight Cla- 

 vicle. (A. T.) i 



B, from 



A, from above : 

 below. 



1, sternal end ; 2, acromial 

 end ; 2', small facet for arti- 

 culation with the acromion ; 

 3, gi'oove on the lower 

 surface for the subclavius 

 muscle ; 4, rough elevation 

 at the place of attachment 

 of the coraco-clavicular liga- 

 ments ; 5, rough depression 

 at the place of attachment 



of the costo-clavicular or rhomboid ligament ; 6, in front, the mark of the attachment of 



the pectoralis major ; 7, that of the deltoid muscle. 



The superior surface is broadest in its outer part ; it is principally 

 subcutaneous, but near the inner extremity presents a slight roughness, 

 marking the clavicular attachment of the sterno-cleido-mastoid muscle. 

 The anterior surface opposite the outer curve is a mere rough border, 

 from which the deltoid muscle takes origin, but in the inner half of its 

 extent is broadened out into an uneven space more or less distinctly 

 separated from the inferior surface, and giving attachment to the 

 pectoralis major muscle. The jiosferior surface is i)roadcst at the inner 

 extremity, and smooth in the whole extent of the internal curvature ; 

 but towards its outer extremity it forms a narrow rough border which 

 separates it from the superior surface, and gives attachment- to the 

 _trapezius muscle. On the inferior surface an elongated roughness near 

 • the scapular extremity marks the attachment of _thc coraco-clayiciilar 



"^"^^r Ijganients; extending inwards from this, over the middle third of the 



bone, is a groove in which the subclavius muscle is inserted ; and near 

 A ( " \ ^^^ sternal end is a smaller rough depression, to which the cqsto- 

 '-' ■ "■" clavicular ligament is attached. On this surface also is found the open- 

 ing of a small nutritious foramen. 



The sternal end is the thickest part of the clavicle. It presents a 

 somewhat triangular concavo-convex surface, with its most prominent 



