GENERAL ZOOLOGY 







Fig. 3.15. Sustentative tissues. A, cells of mucous connective tissue, which occurs in the 

 umbilical cords of mammals; the gelatinous intercellular material is not represented. B, 

 mesenchyme cells. C, reticular connective tissue from the spleen. Z), fibrous connective 

 tissue from the submucosa, showing both collagenous and elastic fibers. E, elastic fibers of 

 fibrous connective tissue from the nuchal ligament of the ox; no cells are shown. F, adipose 

 tissue, showing various stages of storage of fat drops in the cells. G, hyaline cartilage from 

 the end of a rib, showing cells and an empty lacuna. H, elastic cartilage from the external 

 ear, showing capsules of hyaline cartilage and elastic fibers. /, fibrous cartilage from an 

 intervertebral disk, showing capsules of hyaline cartilage and collagenous fibers. /, bone 

 cell lying in a lacuna. K, bone lacuna and canaliculi from dried bone. L, Haversian system 

 in which lacunae are arranged concentrically around a central or Haversian canal; canaliculi 

 connect the lacunae and the canal. {A, E, //, K, and L from drawings by D. F. Robertson.) 



between the vertebrae has collagenous fibers in its matrix and is called fibrous 

 cartilage (Fig. 3.15/). 



Bone, or osseous tissue, is characterized by its very hard matrix, which is 

 impregnated with calcium and phosphorus salts. There is twice as much 

 inorganic material in bone as there is organic. The long bones of the body, 

 such as the femur, have a central marrow cavity filled with yellow or fatty 

 bone marrow. In the much smaller marrow spaces at the ends of long bones 

 and in the vertebrae and sternum is found the red bone marrow, which is 

 the site of differentiation of red blood cells and of granular white blood cells. 

 Bone marrow is not osseous tissue; it is merely contained in the cavities of 

 bones. The bone cells lie in lacunae within the matrix (Fig. 3.15/ and K). 



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