Chap. 7 



TISSUES 



115 



Fig. 7.7. Development of adipose (fatty) tissue in the larynx of a newborn kitten; 

 c, blood capillaries; /, nucleus of developing fibers (cells); s, signet fat cell. A, in 

 a region in which fat droplets (white spots) have appeared in only one cell; B, 

 another region in which fat droplets almost fill the cells crowding the cytoplasm 

 and nucleus against the cell membrane so that the shape is like a signet ring. Cells 

 containing large amounts of fat are found in connective tissue almost everywhere 

 throughout the body. (Courtesy, Nonidez and Windle: Textbook of Histology, 

 ed. 2. New York, McGraw-Hill Book Co., Inc., 1953.) 



Cartilage. The intercellular substance of cartilage is firm and gumlike. 

 Normally it contains no lime but with age may gather deposits of it. Hyaline, 

 glassy cartilage or gristle, occurs in the higher vertebrates in many regions, 

 such as the ventral ends of the ribs, the joints, end of the nose, the rings of 

 the trachea (Fig. 7.8). The cells are surrounded by their semitransparent 

 secretion in which there are no blood vessels. Yellow elastic cartilage contains 

 a network of elastic fibers and is more flexible and elastic than the hyaline 

 type (Fig. 7.9). It constitutes much of the external ear of mammals, such 

 as man, bats, donkeys. White fibrous cartilage composes the intervertebral 

 discs which act as cushions between the vertebrae (Fig. 7.10). Those of the 

 human body are subject to various disarrangements especially in the lumbar 

 region where there is most pressure upon them. 



Bone. This is a supporting tissue composed of bone cells surrounded by 

 organic material, collagenous (protein) fibers, and inorganic salts (Fig. 7.11). 



