What is the study of the structures of the human body and the substances these structures are made of called?

The study of the structures of the human body and the substances these structures are made of is known as anatomy. This field involves examining the organization of various body parts, including bones, muscles, organs, and tissues, to understand how they relate to one another and function as a whole. Anatomy provides the foundational knowledge necessary for various healthcare and biological fields, enabling the understanding of physical systems in both normal and pathological states.

In contrast, physiology focuses on the functions and processes of these structures, explaining how they work to maintain life. Histology looks specifically at the microscopic structure of tissues, while cytology is concerned with the study of individual cells. Each of these disciplines contributes to our overall understanding of biology, but they address different aspects—anatomy specifically emphasizes structure, making it the correct choice for this question.