Serous gland

Serous gland
Vertical section of papilla foliata of the rabbit, passing across the folia. (Serous gland labeled at bottom right.)
Human submaxillary gland. At the right is a group of mucous alveoli, at the left a group of serous alveoli.
Details
PrecursorEpithelial tissue
SystemExocrine system
Identifiers
Latinglandula serosa
THH2.00.02.0.03035
FMA62889
Anatomical terms of microanatomy

Serous glands secrete serous fluid. They contain serous acini, a grouping of serous cells that secrete serous fluid, isotonic with blood plasma, that contains enzymes such as alpha-amylase.

Serous glands are most common in the parotid gland and lacrimal gland but are also present in the submandibular gland and, to a far lesser extent, the sublingual gland.

Structure

Serous acinar cells

Serous acinar cells are the primary secretory cells of serous glands. They have a characteristic pyramidal shape, with a broad base that rests on the basement membrane and a narrow apex that faces the lumen of the acinus. These cells typically form spherical or tubular structures called acini (singular: acinus), which are the basic functional units of exocrine glands.

Histologically, serous acinar cells exhibit:

These cells are organized into acini that connect to intercalated ducts, which then merge to form larger excretory ducts.

Ultrastructure

Under electron microscopy, serous acinar cells reveal:

Development

Serous acinar cells, like other exocrine secretory cells, develop through a process of branching morphogenesis and cellular differentiation.

Embryological origin

Developmental process

The development of serous acinar cells follows several key stages:

  1. Initial budding of epithelium into the underlying mesenchyme
  2. Branching morphogenesis guided by epithelial-mesenchymal interactions
  3. Formation of terminal end buds that will become acini
  4. Cell differentiation with acquisition of secretory machinery
  5. Maturation of secretory pathways and enzyme production

Molecular regulation

Several signaling pathways and transcription factors regulate the development of serous acinar cells:

The timing of differentiation varies by tissue, with full functional maturation of many serous acinar cells occurring postnatally, particularly in salivary and lacrimal glands.

Function

Serous acinar cells specialize in the synthesis, storage, and secretion of protein-rich, enzyme-containing fluids. Their primary functions include:

Secretory activity

Serous acinar cells produce watery, protein-rich secretions containing various enzymes including:

Secretory mechanism

Serous acinar cells utilize the merocrine secretion mechanism, whereby secretory products are released via exocytosis without loss of cellular material. The process involves: 1. Synthesis of proteins in the rough endoplasmic reticulum 2. Modification and packaging in the Golgi apparatus 3. Storage in zymogen granules 4. Fusion of granules with the apical plasma membrane and release of contents into the lumen

Secretion is primarily regulated by autonomic nervous system signals, particularly through muscarinic cholinergic and beta-adrenergic receptors.

Distribution

Serous acinar cells are found in various exocrine glands throughout the body:

Salivary glands

Other locations

Clinical significance

Serous acinar cells are involved in several pathological conditions:

Disorders

Neoplasms

See also

References

  1. ↑ "Medical Definition of SEROUS GLAND". www.merriam-webster.com. Retrieved 24 January 2021.
  2. ↑ Hand, Arthur R. (2004). "Salivary Glands, Anatomy and Histology". Encyclopedia of Gastroenterology. pp. 242–247. doi:10.1016/B0-12-386860-2/00667-X (inactive 14 November 2025). ISBN 9780123868602.{{cite book}}: CS1 maint: DOI inactive as of November 2025 (link)
  3. ↑ Young, Barbara; O'Dowd, Geraldine; Woodford, Phillip (2013). Wheater's Functional Histology: A Text and Colour Atlas (6th ed.). Churchill Livingstone. pp. 251–254. ISBN 9780702047473.
  4. ↑ Tandler, Bernard (1969). "Ultrastructure of the human submandibular gland. III. Myoepithelium". Journal of Ultrastructure Research. 27 (1): 33–54. doi:10.1016/S0022-5320(69)90018-X (inactive 14 November 2025).{{cite journal}}: CS1 maint: DOI inactive as of November 2025 (link)
  5. ↑ Patel, Vaishali N.; Hoffman, Matthew P. (2014). "Salivary gland development: a template for regeneration". Seminars in Cell & Developmental Biology. 25–26: 52–60. doi:10.1016/j.semcdb.2013.12.001. PMC 3943838. PMID 24333774.
  6. ↑ Knosp, Wendy M.; Knox, Sarah M.; Hoffman, Matthew P. (2012). "Salivary gland organogenesis". Wiley Interdisciplinary Reviews: Developmental Biology. 1 (1): 69–82. doi:10.1002/wdev.4. PMC 3288232. PMID 22662309.
  7. ↑ Pin, Christopher L.; Ryan, Jennifer F.; Mehmood, Rashid (2021). "Acinar cell organization in the developing pancreas: a perspective on the role of cell polarity in coordinating tissue growth and differentiation". Journal of Cell Science. 134 (16): jcs258680. doi:10.1242/jcs.258680. PMC 8353162. PMID 34351410.
  8. ↑ Nanci, Antonio (2017). Ten Cate's Oral Histology: Development, Structure, and Function (9th ed.). Elsevier. pp. 253–278. ISBN 9780323485180.
  9. ↑ Castle, J. David (1998). "Protein secretion by rat parotid acinar cells. Pathways and regulation". Annals of the New York Academy of Sciences. 842: 115–124. doi:10.1111/j.1749-6632.1998.tb09640.x. PMID 9599301.
  10. ↑ Ross, Michael H.; Pawlina, Wojciech (2015). Histology: A Text and Atlas (7th ed.). Wolters Kluwer Health. pp. 566–578. ISBN 9781451187427.
  11. ↑ Barnes, Leon (2005). Pathology and Genetics of Head and Neck Tumours. World Health Organization Classification of Tumours. IARC Press. pp. 209–281. ISBN 9789283224174.