<prompt> Which of the following statement are true regarding pathogenesis of bronchitis?Initiating factor is exposure to noxious stimuli or tobaccoHypersecretion of mucus in large airwaysInflammatory infiltrateAll of the above  <response>: Chronic Bronchitis The primary or initiating factor is exposure to noxious or irritating inhaled substances such as tobacco smoke 90 of patients are smokers and dust from grain, cotton, and silica. Earliest feature is hypersecretion of mucus in the large airways, associated with hyperophy of the submucosal glands in the trachea and bronchi. Inhalants that induce chronic bronchitis cause cellular damage, eliciting both acute and chronic inflammatory responses 