What are the functions of spongy tissue?

There is a spongy tissue located in the leaf of the plant. Its peculiarity is that it is soft and has large intercellular spaces, in which fluid accumulates. The epidermis is located under it. The main function is the implementation and regulation of transpiration processes through the stomata located in the epidermis from the intercellular spaces. And there is spongy bone tissue, which is located in the epiphyses of the tubular bones of mammals. Performs a hematopoietic function, since the process of formation of cells of the red bone marrow is carried out in it.