: Cells within the duct (e.g., in salivary glands) can actively modify the ion concentration or pH of the fluid they transport.
An is a tubular structure lined by epithelial cells that serves as a conduit for the transport of secretions (like sweat, saliva, or milk) or fluids (like urine) from glands or organs to their destination. 1. Structure and Tissue Type epithelial duct
: Delivering enzymes (pancreas), hormones, or waste (kidneys). : Cells within the duct (e
: To maintain a strict barrier—such as in renal collecting ducts —epithelial cells are joined by tight junctions to prevent the leakage of fluids into surrounding tissues. 2. Key Biological Functions Structure and Tissue Type : Delivering enzymes (pancreas),
: Larger ducts, such as those in the breast or sweat glands, often feature stratified cuboidal or columnar epithelium to provide structural durability.
: Most small and medium-sized ducts are lined by simple cuboidal epithelium , which is optimized for secretion and absorption.