In veterinary pathology:
Atrophy: Reduction in size and/or cell number of a previously normal, fully developed organ or tissue due to nutrient starvation, disuse, or disease.
Hypertrophy: Increase in the size of cells resulting in enlarged organ size.
Aplasia: Failure of an organ to develop completely during embryogenesis.
विकसित हो चुके अंग या ऊतक की कोशिकाओं के आकार या संख्या में कमी आने से अंग के सिकुड़ने को एट्रॉफी (Atrophy) कहा जाता है।