These cellular structures increases the superficial surface area of a

Micro villi

Explanation:

The cellular structures that increases the superficial surface area of the cell is known as micro villi. It is an extension of cell membrane.

This structure helps in the increasing the surface area for the maximizing the absorption of food materials.

It also helps in providing a large area in a very compacted space. It is found at many places in the human body such as in small intestine.