Which field of study focuses on the structures of the human body?

The field of study that focuses on the structures of the human body is anatomy. Anatomy encompasses the examination of the physical components of the body, including organs, tissues, and systems, and it can be divided into various sub-disciplines such as gross anatomy (the study of structures visible to the naked eye) and microscopic anatomy (the study of structures at the cellular level).

While physiology, histology, and biochemistry are related disciplines, they address different aspects of biology. Physiology studies how the body's systems function and interact, while histology focuses specifically on the microscopic structure of tissues. Biochemistry, on the other hand, explores the chemical processes and substances within living organisms. Therefore, anatomy is the most appropriate answer, as it is specifically centered on structural aspects of the human body.