The intercalated duct, also called intercalary duct, is the portion of an exocrine gland

Exocrine gland

Exocrine glands are a type of ductal glands that secrete their products into ducts that lead directly into the external environment...

 leading directly from the acinus

Acinus

An acinus refers to any cluster of cells that resembles a many-lobed "berry," such as a raspberry...

 to a striated duct

Striated duct

A striated duct is a gland duct which connects an intercalated duct to an interlobular duct. It is characterized by the basal infoldings of its plasma membrane, characteristic of ion-pumping activity by the numerous mitochondria...

. The intercalated duct forms part of the intralobular duct

Intralobular duct

An intralobular duct is the portion of an exocrine gland inside a lobule, leading directly from acinus to interlobular duct. It is composed of two subdivisions, the intercalated duct and the striated duct....

. This duct has the thinnest epithelium of any part of the duct system, and the epithelium is usually classified as "low" simple cuboidal.

They are found in both the pancreas

Pancreas

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...

 and in salivary gland

Salivary gland

The salivary glands in mammals are exocrine glands, glands with ducts, that produce saliva. They also secrete amylase, an enzyme that breaks down starch into maltose...

s.