CHAPTER I. 



DEFINITIONS. 



Pathology is the science of disease. It is the science which 

 treats of the nature, causes, progress, symptoms and termina- 

 tion or result of disease. It includes etiology, i. e., the study 

 of the causes of disease, and pathogenesis, that is, the study of 

 the course, abnormal functions and lesions produced in disease. 



General Pathology is confined to the explanation of the sum- 

 mary of the facts obtained in the study of special pathology. It 

 is concerned essentiallj' in the solution of general principles of 

 those morbid conditions that are common to the entire organism, 

 as malformation, degeneration, regeneration, inflammation, neo- 

 formation and fever. 



Special Pathology deals with all the abnormalities or diseased 

 conditions of one part or organ as the diseases of the ear, skin, 

 etc., and consequently special pathology is further sul)divided 

 into otologic pathology, dermatologic pathology, etc. 



Pathologic Physiology, is that part of pathology which has to 

 do with the investigation and description of abnormal functions 

 of a diseased organ or animal. The pathologic physiology' is, 

 in many cases, the principle symptom of a disease, e. g., paraly- 

 sis of the radial nerve. Abnormal function is frequently the 

 onlv evidence discernible in a disease, e. g., epilepsy. 



Pathologic Anatomy, or morbid anatomy, is concerned in the 

 structural changes in a diseased tissue or organ. Pathologic 

 changes in the structure of a tissue or organ are collectively 

 termed lesions. Lesions may be sufficiently gross that they are 

 readily observed with the unaided eye or they may be so min- 

 ute that the miscroscope is necessary for their detection. The 

 investigation and the recording of facts observed in the study 

 of gross and minute lesions are included in gross, or macroscopic 

 pathologic anatomy land minute, or microscopic pathologic an- 

 atomy respectively. 



Human Pathology has to do with the facts observed in the 

 study of the diseases of the human. 



Comparative Pathology, is the name applied to the study of 

 the diseases of all animals in which the diseases of one genus, 

 (group of animals) is taken as a standard and the diseases of all 

 other animals are discussed in comparison with the type selected. 



Veterinary Pathology, is a discourse on the diseases of domestic 

 animals. 



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