Anatomy is the study of the structure of plants and animals. This study can be divided into two fields, gross anatomy (or macroscopic anatomy) and microscopic anatomy. Gross anatomy focuses on the study of structures which can be seen by the naked eye. Microscopic anatomy can be further subdivided into histology, which is the study of tissues, and cytology, which is the study of cells.

Study of gross anatomy began much earlier than that of microscopic anatomy, which could not develop until the invention of the microscope. A primitive study of anatomy began with the teachings of Aristotle, who argued that each organ had its own function, which could be determined by observing its structure. The first school of anatomy was found later in the third century B.C. by Herophilius of Chalcedon, who encouraged his students to dissect human bodies. Herophilus is credited both with determining that...