has plasma membrane part surfactant secreting cell club cell Club cells, originally termed Clara cells, are specialized nonciliated epithelial cells primarily located in the bronchioles, or small airways, of the lungs. Compared to other cells in the lung epithelium, they are distinguished by their characteristic dome shape often marked by short, microvilli-like projections (but no cilia). Underneath their dome-like apex, they possess a large amount of cytoplasm containing numerous granules, and they have a round, centrally located nucleus. Their name 'club' was adopted to signify their appearance, which resembles a club or goblet. Club cells perform various crucial roles in maintaining the homeostasis of the respiratory tract. Among their functions is the production and secretion of a variety of proteins, including the club cell secretory protein (CCSP), which plays a role in the immune response of the lungs, particularly, in mitigating inflammation. The secretion of surfactant proteins by these cells also contributes to reducing surface tension in the alveoli, thus facilitating the process of gas exchange. Besides helping to defend against oxidative stress and inflammatory response, surfactants also aid in preventing the air sacs in the lungs from collapsing. Another vital role of club cells is their capacity to self-proliferate and differentiate into ciliated cells or basal cells, highlighting their regenerative capacity. This quality is especially critical for maintaining the integrity of the epithelial layer in the lung following any injury or inflammation, aiding the lung tissue to recover and restore its function. Furthermore, it is speculated that club cells might minimize the adverse impact of harmful substances in the air we inhale, thanks to a range of cytochrome P450 enzymes present in them. These enzymes assist in detoxifying harmful substances, a protective mechanism that helps preserve the overall health of the lungs. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) A non-mucous, epithelial secretory cell that is part of the tracheobronchial tree. A club cell has short microvilli but no cilia. A club cell is able to multiply and differentiate into ciliated cells to regenerate the bronchiolar epithelium and it also protects the tracheobronchial epithelium. FMA:14119 BTO:0004811 Clara cell https://cellxgene.cziscience.com/cellguide/CL_0000158 epithelial cell of tracheobronchial tree respiratory tract secretory epithelial cell progenitor cell microvillus Homo sapiens