part of smooth muscle cell bronchial smooth muscle cell 2011-03-06T05:46:39Z Any smooth muscle cell that is part of some bronchus. BTO:0004402 Bronchial smooth muscle cells are specialized types of cells found in the bronchi of the respiratory system in mammals. These bronchi are tubular structures that function to carry air from the trachea into the lungs. As part of the smooth muscle tissue, bronchial smooth muscle cells are involuntary cells, meaning they function with minimal direct voluntary control. They are characterized by their elongated spindle-shaped structure, with each cell containing a single central nucleus. The primary function of bronchial smooth muscle cells is to control airway diameter, which directly influences the flow of air into and out of the lungs. Muscular contractions and relaxations mediated by these cells enable the bronchi to constrict or expand, facilitating the regulation of respiratory airflow. Additionally, these cells play a pivotal role in immune responses as they produce and release various substances that can instigate or lessen inflammation of airway tissue. Furthermore, bronchial smooth muscle cells can proliferate and lay down collagen and other extracellular matrix proteins, contributing to the structural integrity of the bronchial tubes. In pathological conditions, such as asthma and chronic obstructive pulmonary disease, the function and biology of bronchial smooth muscle cells change. Asthma, for example, is associated with an abnormal increase in the mass of the bronchial smooth muscles, leading to narrowing of the airways and resultant breathing difficulties. These cells also exhibit altered contractile behavior and an augmented immune response during inflammatory lung diseases. (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.) https://cellxgene.cziscience.com/cellguide/CL_0002598 tracheobronchial smooth muscle cell Homo sapiens bronchus