What is Duct in Biology?

In physiology and anatomy, a duct is a tube-like structure or a channel that transmits secretion from the endocrine organs to the place of its activity or requirement.

Ducts travel from the acinus sites that generate secretions. Ducts form a system that can be of three types:

• Intercalated duct: It is a part of the exocrine gland that leads directly from the acinus to a striated duct. This intercalated duct forms a part of the interlobular duct. This duct has the thinnest epithelium and is of simple cuboidal type.
• Striated duct: It is a gland that connects an intercalated duct to an interlobular duct. It has basal infoldings of the plasma membrane, characteristic of ion-pumping activity by the numerous mitochondria. This intercalated duct forms a part of the interlobular duct. This type of duct has simple cuboidal or simple columnar.
• Intralobular duct: It is present inside the exocrine gland leading directly from the acinus to an interlobular duct. It is composed of two subdivisions, the striated duct, and the intercalated duct.