AND TIIYSIOLOGY. 



57 



they enlarge the cavity of the chest. The true ribs are the 

 seven uppermost ones, and the false the five lower ones, and 

 are so arranged that they form a cone with the apex at the 

 neck. The two lowest ribs are sometimes called 

 because they are only attached to the vertebrse. 



[ 1 floating, 



Fig. 12. 



129. Clavicle. — 

 The Collar Bone is the 



commencement of 

 the upper extremity. 

 It is one of the class 

 of long bones ex- 

 tending from the An Anterior View of the Clavicle of the Right 

 highest point of the Side. 1> The Anterior Face of the Body of the Bone. 



, , 2, Origin of the Clavicular portion of the Sterno- 



SCapUla tO the Upper Cleido-Mastoid Muscle. 3, The Sternal Extremity of 

 "Dart of the Sternum tiie -^ one - 4 ' ^ Qe Acromial Extremity of the Bone. 

 * ' 5, Articular Face for the Acromion Process of the Scapu- 



and bears a partial la. 6, Point of Attachment of the Conoid Ligament, 

 resemblance tO the 7, Point of Attachment of the Rhomboid Ligament. 



Italic letter F. The name is from the Latin Clavis } u & 

 key," since it remotely resembles an antique key. 



180. Scapula. — A large, flat, and triangular bone upon 

 the upper part of the back, and forming the shoulder, is 

 called the Scapula, or Shoulder Blade. It has a high and 

 narrow ridge running through its longest diameter, which is 

 the bone so distinctly felt upon the shoulder and upper part 

 of the back. Its only articulations are with the clavicle and 

 humerus, the posterior part being kept in its place by mus- 

 cles and ligaments. (Fig. 73 3 p. 58). 



131. Humerus,— The Humerus is the bone of the upper 

 arm or shoulder. (Fig. 74, p. 53.) It is a long bone with 

 a cylindrical shaft, and has a rounded head for its upper ex- 

 tremity. The lower extremity is flattened from before back- 



What two classes are they divided into? What do they all unite with behind? 

 129. What two bones does the Clavicle unite with ? 130. What is the general outline of 

 the Scapula ? Where is it located? What are its only articulations ? 131. What is the 

 bone of the upper arm ? 



