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General Introductory Topics
Published in Vadim Backman, Adam Wax, Hao F. Zhang, A Laboratory Manual in Biophotonics, 2018
Vadim Backman, Adam Wax, Hao F. Zhang
Microscopically, epithelia are classified based on three independent properties: the number of cell layers, the cell shape, and the free surface specializations. Based on the number of cell layers, epithelia are classified as simple (a single cell layer), stratified (multiple cell layers with cells getting progressively flatter as they approach the surface of the epithelial layer), pseudostratified (a single layer of cells that only appears to be stratified), or transitional (multiple cell layers with larger and flatter cells located close to the surface of the epithelial layer and taller, columnar-like cells on the bottom).
Scaffolds for tracheal regeneration
Published in Gilson Khang, Handbook of Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine, 2017
Doh Young Lee, Seong Keun Kwon
The epithelium consists of a pseudostratified columnar epithelium with kinocilia and goblet cells that also produce a mucous film (Fig. 32.2). The direction of the beat of the kinocilia toward the larynx results in the transport of particulates and cell detritus away from the lungs and its elimination from the body, which is vital for sterilization of the lower airway.
Reconstituted 2D Cell and Tissue Models
Published in Anthony J. Hickey, Sandro R.P. da Rocha, Pharmaceutical Inhalation Aerosol Technology, 2019
Nicole Schneider-Daum, Patrick Carius, Justus C. Horstmann, Claus-Michael Lehr
A partially ciliated pseudostratified epithelium characterizes the trachea as well as the large bronchi of the central lung, where columnar ciliated epithelial cells are adjacent to mucus secreting goblet cells both supported by basal cells (McDowell et al. 1978).
Assessing the in vitro toxicity of airborne (nano)particles to the human respiratory system: from basic to advanced models
Published in Journal of Toxicology and Environmental Health, Part B, 2023
Maria João Bessa, Fátima Brandão, Fernanda Rosário, Luciana Moreira, Ana Teresa Reis, Vanessa Valdiglesias, Blanca Laffon, Sónia Fraga, João Paulo Teixeira
The respiratory system is primarily composed of the nose, airways, and parenchyma. The upper respiratory tract allows the passage of air and protects the lower respiratory regions from external injuries (Thomas 2013), while gas exchange occurs in the lower respiratory tract such as the alveoli (Weibel, Sapoval, and Filoche 2005). Along the respiratory tract, cell types and morphology vary (Figure 1), which also may be affected in pulmonary diseases (Whitsett and Alenghat 2015). As illustrated in Figure 1, the upper airways are lined with a pseudostratified epithelium that is composed of ciliated, secretory (goblet and club cells), neuro-endocrine, and basal cells, these latter acting as progenitor cells for various cell types of the airway epithelium (Crapo et al. 1982; Hiemstra, McCray, and Bals 2015). The bronchioles are lined by ciliated cuboidal epithelium, with a small number of non-ciliated club cells that are more dominant in the distal portion (Khan and Lynch 2018). In addition, the alveolar epithelium is important for maintaining lung homeostasis and is constituted by cuboidal alveolar epithelial type 1 cells (AEC1) and type 2 cells (AEC2).
Impact of stainless-steel welding fumes on proteins and non-coding RNAs regulating DNA damage response in the respiratory tract of Sprague-Dawley rats
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Jayaraman Krishnaraj, Abdul Basit Baba, Periasamy Viswanathan, Veeran Veeravarmal, Viswalingam Balasubramanian, Siddavaram Nagini
Tissues were fixed in 10% neutral buffered formalin and embedded in paraffin blocks from which tissue sections of 5 μm thickness were made using a microtome. Tissue sections were first de-waxed by heating on a hotplate at 60°C for 10 min and immersing in xylene, then serially rehydrated with descending grades of alcohol (100%, 90%, 70%, and 50%) to water and stained in hematoxylin for 3 min followed by washing in running tap water for 10 min. The tissue sections were then treated with 1% acid alcohol and stained with eosin for a minute. Then, the sections were dehydrated through ascending grades of alcohol (50%, 70%, 90%, and 100%), cleared in xylene and mounted with DPX. Slides were then visualized under a light microscope attached with CCD camera and images were captured. Variation in size, shape, and organization of cells in the respiratory tract characterized the dysplastic lesions. Metaplasia was characterized by replacement of pseudostratified ciliated columnar epithelium with squamous epithelium. Reid index refers to the ratio of the thickness of the mucous gland layer to the thickness of the wall between the epithelium and the cartilage.