CONNECTIVE TISSUES 



the abdomen, around the kidneys^ between the furrows on 

 the surface of the heart and in bone marrow. It has a rich 

 blood supply. 



(5) Cartilage. Those tissues in which the intercellular 

 substance has undergone condensation until it appears homo- 

 gqneous are classified as cartilage. 

 Consequent upon the differences 

 exhibited by the intercellular ma- 

 trix it is divided into the follow- 

 ing varieties: (a) Hyaline, (b) 

 elastic, and (c) fibrous. 



(a) Hyaline cartilage is of firm 

 consistence, considerable elasticity 

 and is pearly blue in color. It is 

 enveloped in a fibrous membrane, 

 the perichondrium, from the vessels 

 of which it derives its nutrition. It 

 is composed of cells, irregular in 

 outline and arranged in patches of 

 various shapes, which are embedded 

 in a homogeneous matrix. The 

 articular surfaces of bones, the 

 costal cartilages, and the larger 

 cartilages of the larynx, trachea and 

 bronchi, and also, those of the 

 nose and Eustachian tube are 

 formed of this variety. In the em- 

 bryo this cartilage forms nearly 

 the whole of the future bony 

 skeleton. 



(b) Elastic cartilage is characterized by the presence of an 

 abundance of elastic fibers in the matrix. These resemble 

 those found in the yellow variety of elastic tissue. This va- 

 riety or cartilage is found in the external ear, epiglottis, 

 cornicula laryngis and Eustachian tube. 



(c) Fibrous cartilage is characterized by the presence of a 



FIG. 12. Sections of 

 Hyaline cartilage. 



a, Fibrous layer^ of peri- 

 chondrium ; b, genetic layer of 

 perichondrium; c, youngest 

 chondroblasts ; d, older chon- 

 droblasts; e, capsule; f, cells; 

 g, lacuna. (Radasch.) 



