GENERAL ZOOLOGY 



Skull 



Clavicle 

 Scapula 



Humerus 



Sternum 



Tarsals x^^ 



Fig. 4.6. ITie human skeleton. This fieture, 

 as well as Fis;. 4.7, is taken from Andreas 

 Vesalius, De Hutnam Corporis Fahrica in the 

 Opera Omnia published in Leyden in 1725; 

 they appeared originally in the first edition, 

 Basel, 1543. These figures are not the earli- 

 est known anatomical illustrations, but they 

 are the first to combine accuracy with 

 arti.stic merit; they were prepared, under 

 Vesalius' direction, by pupils of Titian. 



The vertebrate skeleton is composed of two main parts, the axial and the 

 appendicular skeleton (Figs. 4.5 and 4.6). The axial skeleton includes the 

 skull, the skeleton of the head enclosing the brain, and the spinal or vertebral 

 column, which surrounds the spinal cord. Ribs articulate dorsally with the 

 vertebral column and, in birds and mammals, connect ventrally with the 

 sternum, or breastbone, in the part of the trunk known as the thorax, or chest. 

 The remainder of the trunk region, unsupported ventrally, is the abdomen. 

 The skeletal structures of the thorax are sometimes known as the thoracic cage 

 and protect the heart and lungs. Although the skeletons of different vertebrates 



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