There isn't a single widely-accepted alternative term for "microscopic physiology." However, depending on the context, you could use:

* Cellular Physiology: This term focuses on the functions of individual cells, which is the primary level of study in microscopic physiology.

* Histophysiology: This term emphasizes the physiology of tissues, which are groups of similar cells working together.

* Microanatomy: This term focuses on the structure of tissues and cells, which is closely related to their function.

* Ultrastructure: This term refers to the fine details of cell structure that are revealed by electron microscopy.

Ultimately, the best alternative term depends on the specific topic you are discussing. For example, "cellular physiology" might be most appropriate for studying the mechanisms of protein synthesis, while "histophysiology" would be more relevant for understanding the function of a specific organ.