Salivary glands Serous salivary gland Notes Serous salivary

Salivary glands • Serous salivary gland Notes • Serous salivary gland- magnified • Mucous salivary gland Notes • Mucous salivary gland- magnified • Mixed salivary gland Notes • Mixed salivary gland- magnified Index

Notes Serous salivary gland Intralobular duct Blood vessel Serous acini Interlobular duct Interlobular septum

Notes Serous salivary gland- magnified Rounded nucleus Serous acinus Intralobular duct

Notes Mucous salivary gland Blood vessel Mucous acinus Interlobular septum Intralobular duct

Notes Mucous salivary gland- magnified Mucous acinus Connective tissue Flattened nucleus

Notes Mixed salivary gland Interlobular septum Serous acinus Group of mucous acini Intralobular duct

Notes Mixed salivary gland- magnified Serous demilunes Group of serous acini Group of mucous acini

Serous salivary gland: Externally gland is covered with capsule made up of collagen fibers. From the capsule numerous septa arise and divide the gland into lobules. Within the septa are the interlobular ducts lined by simple columnar or cuboidal epithelium and blood vessels. Each lobule contains numerous serous acini and many intralobular ducts. Each acinus is rounded in shape and lined by single layer of columnar cells with basal nuclei resting on basement membrane. Apical part of the cells contains secretory vesicles called zymogen granules. Intralobular ducts are lined by simple cuboidal epithelium. Eg. - Parotid gland

Mucous salivary gland: A capsule made up of collagen fibers covers it. Numerous septa pass into the gland from the capsule to divide the gland into lobules. Running within the septa are the interlobular ducts lined by simple columnar or cuboidal epithelium and blood vessels. Lobules contain mucous acini and few intralobular ducts. Mucous acini are irregular in shape. Simple cuboidal or low columnar cells with flatted basal nuclei line acini. Apical part of the cells contains mucinogen granules. In H and E stained sections this part looks vacuolated which gives honeycomb appearance to the acini. Mucous acini and their lumen are usually larger than those of serous acini. Intralobular ducts are lined by simple cuboidal epithelium. Eg. - Sublingual gland

Mixed salivary gland: A capsule made up of collagen fibers covers the gland. Trabeculae travel into the gland from the capsule and divide the gland into lobules. Blood vessels and inter lobular ducts lined by simple columnar or cuboidal epithelium travel within the septa. Lobules contain more serous acini and few groups of mucous acini. Some secretory units contain both serous and mucous cells in single acinus. Here serous cells are arranged in a crescentric shaped aggregation on top of a mucous acinus. Such serous secretory units are called serous demilunes of Gianuzi. Eg. - Submandibular

Differences between the serous and mucous acini Serous Acini have granular appearance Mucous Acini have honey comb appearance Eosin stained Haematoxylin stained Lumen is smaller Lumen is larger Lined by columnar cells Lined by low columnar or cuboidal cells Rounded nucleus Flattened nucleus