Definition of Pathology

The word “Pathology” comes from two Greek roots “Pathos” that means disease or sufferings and “Logos” that means science or systematic study.

Thus, Pathology is the systematic study of diseases.

Pathology is the study of derangement of molecules, cells, tissues and functions that occur in living organisms in response to injurious agents or deprivation.

Injurious agents

The agents that cause changes to molecules or cells or tissues or functions of an organism are known as injurious agents.

There are three types of injurious agents-

        i.            Physical: Trauma, pressure, heat, cold, radiation etc.

    ii.            Chemical:

                               a.            Organic: Insecticide, fungicide, rodenticide

                              b.            Inorganic: Acid, alkali, metals and their salts.

                           iii.            Biological: Bacterium, virus, fungus, parasite, rickettsia, arthropod etc.

Deprivations

Lack of supply of something is known as deprivations, such as,

v Lack of blood supply

v Lack of nerve supply

v Lack of oxygen

v Lack of nutrition