Why is anatomy the basis of physiology?
Anatomy is the study of structure, while physiology is the study of function. Function in most cases is directly related to the structure.
The study of Anatomy is the study of the physical make up of the structures of the organism.
The study of Physiology is the study of the life functions that make the organism alive.
In most cases the ability to function is directly related to the structural design.
For instance, you would not build a restaurant and then use it as a gas station. The structural components necessary for a functioning gas station would not be included in the design mechanism of the restaurant.
Therefore, we study the anatomical components and their structure in order to understand why those anatomical components can physiologically function.
The anatomical structure of red blood cells, erythrocytes, are flat biconcave discs containing hemoglobin and iron. These characteristics allow for greater surface area for the oxygen to attach to the iron on the hemoglobin. This allows red blood cells to line up single file through the capillaries for the diffusion of oxygen and carbon dioxide between the blood and the body tissues.