PHYSIOLOGICAL ANATOMY OF CARTILAGE. 



487 



quantity of a viscid liquid with one or more cells. They are analogous to the 

 lacunae of the bones. 



Cartilage- Cells. Near the surface of the articular cartilages the cavities 

 contain each a single cell ; but in the deeper portions the cavities are long 

 and contain two to twenty cells arranged longitudinally. The cells are of 

 about the size of the smallest cavities. They are ovoid, with a large, granular 

 nucleus. They often contain a few small globules of oil. In the costal carti- 

 lages the cavities are not abundant but are rounded and quite large. The 

 cells contain generally a certain quantity of fatty matter. The appearance 

 of the ordinary articular cartilage is represented in Fig. 164. 



The ordinary cartilages have neither blood-vessels, lymphatics nor nerves, 

 and are nourished by imbibition from the surrounding parts. In the develop- 

 ment of the body, the anatomy of the cartilaginous tissue possesses peculiar 

 importance, from the fact that the deposition of cartilage, with a few excep- 

 tions, precedes the formation of bone. 



Fibro- Cartilage. This variety of cartilage presents certain important 

 peculiarities in the structure of its fundamental substance. It exists in the 

 synchondroses, the cartilages of the ear and of the Eustachian tubes, the 

 interarticular disks, the intervertebral cartilages, the cartilages of Santorini 

 and of Wrisberg, and the epiglottis. 



Fibro-cartilage is composed of true fibrous tissue with a great predomi- 

 nance of elastic fibres, fusiform, nucleated fibres, a certain number of adipose 



FIG. 165. Section of the cartilage of the ear of the human subject (Rollett). 

 a, flbro-cartilage ; &, connective tissue. In this preparation, the cartilage had been boiled and dried. 



vesicles, cartilage-cells, blood-vessels and nerves (Sappey). The fibrous ele- 

 ments above mentioned take the place of the homogeneous fundamental sub- 

 stance of the true cartilage. The most important peculiarity in the structure 

 of this tissue is that it is abundantly supplied with blood-vessels and nerves. 



The reader is referred to works upon anatomy for a history of the action 

 of the muscles. In some works upon physiology, will be found descriptions 



