In my opinion it’s Anatomy
Anatomy deals with the structure of the heart like how many chmbers,where its located,what is the relation of the heart to other body organs which enables it to do its function efficiently
Physiology deals with the mechanism by which the heart do the function and the factors that affect this function
Anatomy and physiology are closely related concepts that are often studied together. In a few words, anatomy is a study of the physical structure of an organism, while physiology involves the study of the functions of individual structures and systems within an organism, as well as the function of an organism as a whole. An understanding of anatomy is critical to the study of physiology, and learning about physiology is important to people who want to understand how anatomical structures work.