OSTEOLOGY AND SYNDESMOLOGY. 11 



fluids necessary to life, as the blood, the lymph, and the chyle, are kept in 

 constant movement. They include arteries, veins, and lymphatics. 



5. The Nerves {Neurology). Under this head we treat of the nervous 

 system, a series of tubular sheaths filled with a whitish matter, and united 

 in larger or smaller bundles, which traverse the entire body, proceeding 

 from a central organ of great development, the brain and spinal marrow. 

 Of nerves we distinguish two kinds : the one conveying impressions from 

 the outer world to the central organs {nerves of sensation) ; the other serving 

 as the medium for the transmission of volitions {nerves of inotion). 



6. The Viscera {Splanchnolofßj). This subject embraces various com- 

 plicated organs, adapted to special purposes. Thus, in the head and neck 

 there are the organs of sight, of hearing, of smell, of taste, and of voice ; in 

 the thorax, we have the respiratory organs {the lungs), with the thymus 

 and thyroid glands ; in the abdominal cavity, the apparatus of digestion 

 {chylopoietic viscera), the urinary apparatus {uropoietic viscera), and the organs 

 of generation. 



I. ANATOMY OF THE BONES AND LIGAMENTS. 



(OSTEOLOGY AND SYNDESMOLOGY.) 



1. Articulations of the Human Skeleton. 



The bones are those hard, compact, and inflexible portions of the body 

 which are inclosed by the muscles, and are united together by ligaments 

 and other modes of attachment into the skeleton. This union may be of 

 such a nature as to permit of little or no relative motion of the two con- 

 tiguous bones; or, on the other hand, such motion may readily take place 

 by means of synovial joints. 



We therefore distinguish two kinds of union among bones, each having 

 various subdivisions, which we shall now proceed briefly to enumerate. 



A. Synarthrosis. The essential characters of this kind of articulation 

 are : 1. That they are very limited in their motions, so as by some to be 

 considered as immovable; 2. That their surfaces are continuous, or with- 

 out the intervention of a synovial cavity, but with that of some structure 

 different from bone. The principal varieties are as follows : 



a. Sutura. This may be either true {vera), as when the margins of two 

 contiguous bones are mutually interlocked in each other, or false {notha), 

 where the bones are in juxtaposition by plane but rough surfaces. Sutura 

 vera may be either dentata, when the processes are long and dentiform, as 

 in the inter-parietal suture of the human cranium ; serrata, when the 

 indentations or processes are small and fine like the teeth of a saw, as in 

 the suture between the two portions of the frontnl bone ; limhosa, when, 

 together with the dentated margins, there is a bevelment, so that one edge 

 rests on the other, as in the occipito-parietal suture. Of sutura notha there 



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