What does atrophy describe in a medical context?

Atrophy refers to the decrease in size, mass, or function of a tissue or organ, often resulting from lack of use, disease, or aging. This process is characterized by the weakening or wearing away of body tissues, which can occur in muscles, organs, or other areas of the body. For instance, prolonged immobility can lead to muscle atrophy where the muscle fibers decrease in size due to disuse.

The other options signify different processes: growth of tissue pertains to hypertrophy or hyperplasia, which involve an increase in tissue size, while the development of new tissues relates to regeneration or healing processes. Inflammation of tissue refers to a response to injury or infection, which can cause swelling and redness, but does not specifically describe tissue shrinkage or weakening. Therefore, the choice that accurately defines atrophy is the one that mentions the weakness or wearing away of body tissues.