The study of animal tissues with the microscope.

An integral sub-specialty of anatomy dealing with the microscopic structures of animals and plants: In histology the tissues and cells of an organism's structures are treated with special chemicals and studied with a light microscope.

The study of the structural alterations of cells and tissues that are caused by a disease: Alice was interested in learning more about histopathology and the changes in cells that occur when they are affected by disorders and illnesses.

The study of healthy tissues and cells: Judy learned that normal histology pertained to strong and active cells and tissues that were examined by using microscopic techniques.

The study of cell and tissue specialization according to the anatomic site in which they occur: Professor Smith held a lecture on one aspect of topographic histology relating how a tutor could be identified by examining the cells and tissues in an organism.