Anatomy would be classified under biology, specifically under the sub-branch of morphology.

Here's why:

* Biology is the study of life and living organisms. Anatomy deals with the structure of living organisms, making it a part of biology.

* Morphology is the study of the form and structure of organisms. Anatomy focuses specifically on the internal structures of organisms.

While anatomy is closely related to other fields like physiology (function of the body) and medicine, it's fundamentally a branch of biology and morphology.