A nurse is preparing to teach the staff about asthma. Which information should the nurse include? Airway hyper-responsiveness in extrinsic asthma is related to:

Choice A reason: Hereditary decrease in IgE responsiveness is not related to airway hyper-responsiveness in extrinsic asthma. IgE is an antibody that binds to allergens and triggers the release of histamine and other inflammatory mediators from mast cells. A decrease in IgE responsiveness would reduce the allergic reaction, not increase it. Choice B reason: Increased sympathetic nervous system response is not related to airway hyper-responsiveness in extrinsic asthma. The sympathetic nervous system is the part of the autonomic nervous system that prepares the body for fight or flight. It stimulates the bronchodilation, or the widening of the airways, by activating the beta2 receptors on the smooth muscle cells. This would improve the airflow, not obstruct it. Choice C reason: The release of stress hormones is not related to airway hyper-responsiveness in extrinsic asthma. Stress hormones, such as cortisol and adrenaline, are secreted by the adrenal glands in response to stress. They have anti-inflammatory and bronchodilator effects, which would reduce the symptoms of asthma, not worsen them. Choice D reason: Exposure to an allergen causing mast cell degranulation is related to airway hyper-responsiveness in extrinsic asthma. Mast cell degranulation is the process of releasing histamine and other inflammatory mediators from the granules inside the mast cells. These substances cause bronchoconstriction, or the narrowing of the airways, by stimulating the smooth muscle contraction and mucus secretion. This leads to the symptoms of asthma, such as wheezing, coughing, and dyspnea.