Goblet cell
Exocrinocytus caliciformis
Also known as: mucous cell, mucin, mucinogen granules, unicellular gland
A goblet-shaped, mucus-secreting unicellular exocrine gland scattered among the columnar cells of intestinal and respiratory epithelia.
Overview
The goblet cell's narrow base (stem) contains the nucleus, RER and mitochondria, while its expanded apical theca is packed with large mucinogen granules, giving the shape of a wine goblet. The Golgi apparatus, lying between nucleus and theca, heavily O-glycosylates the mucin core proteins (gel-forming mucins: MUC2 in the intestine, MUC5AC in the airways). Granules are released by merocrine exocytosis, both continuously and in bursts after irritation, and the mucin hydrates to form a protective mucus gel that lubricates, traps particles and microbes and, with secreted IgA and antimicrobial peptides, forms the mucosal barrier.
Goblet cells are scattered among enterocytes from the duodenum to the rectum, becoming most numerous in the colon, and among ciliated cells in the airways (to the bronchi). They also occur in the conjunctiva. In routine H&E their mucin is pale or unstained ("empty" apical cup), but it stains strongly magenta with PAS and blue with Alcian blue. Like other gut epithelial cells, intestinal goblet cells are renewed from crypt stem cells every few days.
- Location
Small and large intestine (increasing distally), conducting airways (trachea, bronchi), conjunctiva.
Anatomy
- Histology
Pale, foamy, cup-shaped apical cytoplasm with a compressed basal nucleus; PAS-positive.
Function
- Secretion of mucus to lubricate and protect epithelial surfaces.
- Trapping of particles and microbes (mucociliary clearance in airways).
- Delivery of luminal antigens to immune cells (goblet-cell-associated antigen passages).
Clinical significance
Goblet-cell hyperplasia and metaplasia
Chronic bronchitis and asthma increase airway goblet cells (excess mucus, mucus plugging). Goblet cells in oesophageal biopsies define the intestinal metaplasia of Barrett oesophagus.
Mucinous tumours
Signet-ring and mucinous adenocarcinomas produce abundant mucin; appendiceal mucinous neoplasms can cause pseudomyxoma peritonei.
Test yourself
The trachea is lined by:
- Simple columnar epithelium with microvilli
- Stratified squamous non-keratinised epithelium
- Pseudostratified ciliated columnar epithelium with goblet cells
- Simple cuboidal epithelium
Answer: Pseudostratified ciliated columnar epithelium with goblet cells
"Respiratory epithelium": all cells touch the basement membrane but not all reach the lumen, so nuclei lie at different levels. Cilia and goblet-cell mucus form the mucociliary escalator.
Compiled from standard anatomy and physiology references — see the Cells & Tissues sources. For education only; not medical advice.