Etiology (or cause) Carl Posner Rudolf Virchow Two major classes of etiologic factors--- Acquired Infection,Nutritional, Chemical,and physical Genetic Genetic mutation All forms of organ injury start with molecular or 1821-1902 structural alteration in cells, "All disease is disease of a concept first put forth cells";"All cells come from during the 19th century by pre-existing cells". Dr.Rudolf Virchow. ----Cell Pathology Etiology (or cause) Two major classes of etiologic factors--- Acquired Infection, Nutritional, Chemical, and physical ＆ Genetic Genetic mutation All forms of organ injury start with molecular or structural alteration in cells, a concept first put forth during the 19th century by Dr. Rudolf Virchow. 1821-1902 “All disease is disease of cells”; “All cells come from pre-existing cells”. ----Cell Pathology