ductules

A ductule is a very small duct that serves as a conduit between secretory units and the larger duct system in many exocrine glands and some organ tissues. The term is often used in histology to describe the initial portions of ducts that receive secretions from acini or tubules before they flow into intercalated or larger ducts.

Structure and histology

Ductules are typically lined by simple cuboidal epithelium, and in some contexts by low columnar epithelium. They may lack a distinct muscular layer, with periductal connective tissue providing most of the support. Myoepithelial cells around secretory units assist in expelling secretions toward the ductal system.

Locations and examples

In the pancreas, ductules (centroacinar or intercalated ducts) drain secretions from acini and feed into intralobular ducts. In salivary glands, intercalated ducts are sometimes referred to as ductules, channeling saliva from serous and mucous acini to larger ducts. In the liver, small bile ductules connect canaliculi to larger interlobular ducts within portal tracts. Mammary and lacrimal glands also contain ductular portions that lead to the main duct systems.

Function

The primary role of ductules is to transport secretions from glandular secretory units toward larger ducts where further modification and transport occur. They may participate in initial modification of the secretion, such as ion balance, but major processing typically occurs in subsequent, larger ducts.

Clinical notes

Ductule dilation or obstruction can affect glandular flow and may be observed in various glandular diseases. Histological identification of ductules helps distinguish ductal from acinar components in tissue samples.