How do intercalated ducts differ from striated ducts in exocrine glands histologically?

How do intercalated ducts differ from striated ducts in exocrine glands histologically?

• A. Intercalated Ducts Are Stratified Squamous; Striated Are Simple Cuboidal
• B. Intercalated Ducts Are Simple Cuboidal; Striated Are Tall Columnar Or Pseudostratified With Basal Striations And Infolded Membranes
• C. Intercalated Ducts Are Pseudostratified With Cilia; Striated Are Simple Squamous
• D. Intercalated Ducts Have Basal Infoldings; Striated Ducts Are Simple Cuboidal

Answer: (B)

The key idea is how duct height and basal architecture reflect function. Intercalated ducts are the smallest ducts right after the acini and are lined by simple cuboidal epithelium. They’re not tall, and they lack the pronounced basal membrane specializations seen in later ducts. Striated ducts, by contrast, are larger intralobular ducts lined by tall columnar (often pseudostratified) epithelium, and they show prominent basal striations due to extensive infoldings of the basolateral membrane with many mitochondria. Those basal infoldings give the cells a striped appearance and supply energy for active ion transport as the saliva is modified. So the contrast is simple cuboidal lining for intercalated ducts versus tall columnar/pseudostratified lining with basal infoldings for striated ducts.

The key idea is how duct height and basal architecture reflect function. Intercalated ducts are the smallest ducts right after the acini and are lined by simple cuboidal epithelium. They’re not tall, and they lack the pronounced basal membrane specializations seen in later ducts. Striated ducts, by contrast, are larger intralobular ducts lined by tall columnar (often pseudostratified) epithelium, and they show prominent basal striations due to extensive infoldings of the basolateral membrane with many mitochondria. Those basal infoldings give the cells a striped appearance and supply energy for active ion transport as the saliva is modified. So the contrast is simple cuboidal lining for intercalated ducts versus tall columnar/pseudostratified lining with basal infoldings for striated ducts.