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The cell and tissues
Published in Peate Ian, Dutton Helen, Acute Nursing Care, 2020
This particular epithelium looks like stratified epithelium but is, in fact, composed of cells of different sizes. These cells are typically found in the respiratory tract and some are known as goblet cells, that produce mucus.
Secreted effectors of the innate mucosal barrier
Published in Phillip D. Smith, Richard S. Blumberg, Thomas T. MacDonald, Principles of Mucosal Immunology, 2020
Michael A. McGuckin, Andre J. Ouellette, Gary D. Wu
A fundamentally important role for goblet cells has emerged that is functionally distinct from their role in producing the secreted mucus barrier but is linked mechanistically to secretory events. Goblet cells in the small intestine sample soluble antigens from the luminal environment via exocytosis following granule release, and this antigen is then delivered by transcytosis to underlying dendritic cells closely opposed to the basal membrane of the goblet cell. This mechanism regulates antigen-specific controlled immune responses against the microbiota. In early neonatal life, this sampling function also occurs in goblet cells in the colon but is suppressed in adult life by exposure to microbial TLR ligands. The neonatal colonic goblet cell antigen transfer drives the establishment of regulatory T cells, and ablation of this function predisposes to subsequent inappropriate mucosal immune responses. Interestingly, colonic goblet cell antigen transfer is turned on in adults by suppression of the microbiota with antibiotics.
The respiratory system
Published in Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella, Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella
All the conducting airways, the trachea up to the terminal bronchioles, are lined with pseudostratified ciliated columnar epithelium. There are approximately 300 cilia per epithelial cell. Interspersed among these epithelial cells are mucus-secreting goblet cells. Furthermore, mucus glands are found in the larger airways. Consequently, the surface of the conducting airways consists of a mucus-covered ciliated epithelium. The cilia beat upward at frequencies between 600 and 900 beats/min and continuously move the mucus away from the respiratory zone and up toward the pharynx at a rate of 1–2 cm/min. This mucociliary escalator provides an important protective mechanism that removes inhaled particles from the lungs and particles larger than about 6 μm are typically stopped from reaching the respiratory zone. Mucus that reaches the pharynx is usually swallowed or expectorated. An additional mechanism by which airway mucus protects the lungs involves the presence of immunoglobulins. These substances, also referred to as antibodies, destroy or neutralize inhaled pathogens. The activity of the immunoglobulins was discussed in detail in Chapter 3, The Immune System. Interestingly, the nicotine found in cigarette smoke paralyzes the cilia and impairs their ability to remove the many toxic substances found in smoke.
The possible effect of lycopene in ameliorating experimentally induced ulcerative colitis in adult male albino rats (A histological, immunohistochemical, and ultrastructural study)
Published in Ultrastructural Pathology, 2023
Shaimaa Mostafa Kashef, Rania Ibrahim Yassien, Dalia El-Sayed El-Ghazouly
As regard the goblet cells, they have a significant protective role in the intestine by producing various mediators, such as the mucin. Under stress conditions, goblet cells liberate the mucin in the lumen making the mucus gel layer over the epithelial cells. The mucus in colon plays a main protective role against ulceration caused by chemicals, and may help the repair of the damaged epithelial cells. In addition, this layer greases the intestinal surface and hinders entrance of substances from the lumen to the inside of mucosa. 46 In the present study, the statistical results of alcian blue-stained sections revealed highly significant decrease in goblet cell number of UC group (III) compared to control group. Such finding was supported by our electron microscopic results in which goblet cells appeared with few abnormal mucus granules. The decrease in goblet cell number was reported in other studies on UC. Goblet cells depletion can be explained by being part of tissue damage which happens during the inflammatory process.47
Eye Make-up Products and Dry Eye Disease: A Mini Review
Published in Current Eye Research, 2022
Mazyar Yazdani, Katja Benedikte Prestø Elgstøen, Tor Paaske Utheim
Tear fluid and particles attached to the ocular surface are drained by the nasolacrimal duct into the inferior meatus of the nose. Anatomically, the lacrimal passages are divided into bony and membranous lacrimal sections. The latter include the lacrimal canaliculi, lacrimal sac, and the nasolacrimal duct. The last two parts are lined by a double-layered epithelium containing superficial columnar cells and basal flattened cells. Goblet cells may also be present in the epithelial layer. During blinking, tears are wiped and pushed into the lacrimal puncta, small openings located in the nasal upper and lower eyelids. The punctum ends in the canaliculus, where the fluid drains into the lacrimal sac followed by the nasolacrimal duct canal before reaching the nasal cavity.31
Diagnostic and therapeutic challenge of unclassifiable enteropathies with increased intraepithelial CD103+ CD8+ T lymphocytes: a single center case series
Published in Scandinavian Journal of Gastroenterology, 2021
Christina Hartl, Jürgen Finke, Peter Hasselblatt, Wolfgang Kreisel, Annette Schmitt-Graeff
The histological evaluation of duodenal biopsies revealed heterogeneous patterns of altered mucosal architecture. The majority of patients exhibited mild or marked villous blunting with increased IEL, thus corresponding to Marsh type 3a or 3b lesions, respectively (Figures 1 and 2, Table 2). Inflammatory changes involved the epithelium and the lamina propria including prominent CD3+ CD8+ CD103+ IEL (≥25 lymphocytes/100 enterocytes). Interestingly, the topographical distribution of IEL not only involved the surface epithelium or the tips of residual villi, but also the deeper parts including the base of crypts. The mucosa generally showed a mild to moderate depletion of goblet cells. Scattered intraepithelial apoptotic cells were present in all samples. However, markedly increased apoptotic epithelial cells at the base of the crypts reminiscent of graft-versus-host disease (GvHD) I–II° were seen in 2 patients (#8, #9). In addition, intraepithelial clusters of ≥3 T-cells with epithelial distortion were consistent with lymphoepithelial lesions (Figure 3(A–D)). Intraepithelial lymphocytes had a mature T-cell phenotype, positive for CD3, CD5, CD7 and CD8 but negative for CD56 and frequently expressed CD103 (Figures 1–3). Marked granulocytic infiltrations including crypt abscesses were only present in one patient (#8). Inflammatory infiltrates were observed in the lamina propria of all patients including a high content of CD3+ CD4+ T-cells, polyclonal plasma cells and occasional neutrophils, eosinophils and mast cells.