secretory

Taken as a whole this is often called the "secretory balance" or "internal secretory balance."

Considering epithelium from the point of view of function, it may be classified as protective, absorptive or secretory.

In the secretory portion of the gland and in the smaller ducts the epithelial layer is one cell thick only.

In the second main variety of gland the secretory portion is enlarged and the lumen variously increased in size.

They have been considered as secretory organs, answering to the pancreas in vertebrate animals.