Caption

Bronchial epithelium. Coloured scanning electron micrograph (SEM) of a cultured bronchial epithelial cell. The respiratory epithelium is composed of a mixed population of ciliated, nonciliated, and mucous-secreting cells from proximal to distal airways. In vitro models ( cell culture) using primary cells and cell lines are essential for understanding the function and pathophysiology of these cells in diseases such as asthma. Magnification: x 2000 when printed 10 centimetres wide.