‘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. Tue 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 motion). 
6. THE Viscera (Splanchnology). 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 
(chyloporetic viscera), the urinary apparatus (uropovetic viscera), and the organs 
of generation. 
IL 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 frontal bone ; lmbosa, 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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