Which process is an enlargement in tissue mass due to increased work by the tissue?

• A. Hyperplasia
• B. Hypertrophy
• C. Atrophy
• D. Metaplasia

Answer: (B)

When tissue mass grows because it has to do more work, the cells themselves enlarge rather than multiplying. This is hypertrophy. It’s an adaptive change where, in response to higher functional demand, cells increase in size to handle the workload—like skeletal muscle fibers getting bigger with resistance training or heart muscle thickening under chronic pressure overload. This differs from hyperplasia, where tissue mass increases due to more cells being produced rather than bigger cells. Atrophy is the opposite: a loss of tissue mass from reduced use or aging. Metaplasia is a change where one mature cell type is replaced by another in response to chronic irritation, not a simple increase in cell size. The essence is that hypertrophy reflects enlargement of existing cells to meet greater demand.