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How does atrophy change the size and number of cells in an organ?
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atrophy
One example of atrophy is the progressive loss of bone that occurs in osteoporosis (normal bone shown on left; osteoporotic bone shown on right).
In the context of pathology, atrophy is defined as a decrease in the size of a cell, tissue, or organ that was previously of a normal size for the individual.1
When an organ undergoes atrophy, the reduction in its overall size is typically driven by one or both of the following cellular changes:
- Reduction in cell size: Individual component cells shrink, leading to a decrease in the total mass of the tissue or organ.21
- Reduction in cell number: There is a decrease in the total number of cells present within the organ.21
These processes often occur simultaneously, as seen in the aging process or in response to chronic conditions, where organs may exhibit both the shrinkage of individual fibers or neurons and a concurrent loss in their total count. In some instances, such as the atrophy of muscle or brain tissue, these changes result in a measurable reduction in the organ's weight and functional capacity.32