GENERAL DISEASES. 



By Rush Shippen Huidekoper, M. D., Yet. 



[Re\'ised in li)03 by Leonard Pearson, B. S., V. M. D.] 



ANI.ALVL TISSUES. 



The nonprofessional reader may regard the animal tissues, which are 

 suhjcct to inflammation, as excessively simple structures, as similar, 

 simple, and fixed in their org-anization as the joists and boards which 

 frame a house, the bricks and iron coils of pipe which build a furnace, 

 or the stones and mortar which make the support of a great railroad 

 bridge. Yet while the principles of structure arc thus simple, for the 

 general understanding In' the student who begins their study, the com- 

 plete appreciation of the shades of variation, which differentiate one 

 tissue from another, which define a sound tendon or a ligament from a 

 fibrous band — the result of disease filling in an old lesion and tying one 

 organ with another — is as complicated as the nicest jointing of Chinese 

 woodwork, the building of a furnace for the most difficult chemical 

 analysis, or the construction of a bridge which will stand for ages and 

 resist any force or weight. 



All tissues are composed of certain fundamental and similar elements 

 which are governed bj" the same rules of life, though they maj' appear 

 at first glance to be widely different. These are {a) amorphous sub- 

 stances, (b) fibers, and (c) cells. 



{a) Amorphous substances ma}' be in liquid form, as in the iluid of 

 the blood, which holds a vast amount of salts and nutritive matt<n' in 

 solution; or the}' may be in a scmiliquid condition, as the plasma which 

 infiltrates the loose meshes of connective tissue and lubricates the sur- 

 face of some membranes; or they may be in the form of a glue or 

 cement, fastening one structure to another, as a tendon or muscle end 

 to a bone; or again they hold similar elements firmly together as in 

 bone, where they form a stiff matrix which becomes impregnated with 

 lime salts. Amorphous substances, again, form the protoplasm or 

 nutritive element of cells or the elements of life. 



(h) Fibers are formed of elements of organic matter which have only 

 a passive function. They can be assimilated to little strings, or cords, 

 tangled one with another like a mass of waste yarn, woven regularly 

 like a cloth or bound together like a rope. They are of two kinds — 

 white connective tissue fibers, only slightly extensible, pliable, and 

 very strong, and yellow elastic fibers, elastic, curly, ramified, and very 

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