Patho asthma

Environmental factors interact with inherited factors to caused asthmatic reactions withassociated bronchospasms in asthma bronchial lining over react to various stimuli,causing episodic smooth muscle spasm that severely constrict the airways. Onsubsequent exposure to antigen, mast cells degranulate and release mediators. Mastcells in the lungs interstitium are stimulated to release histamine and Leukotrienes.Histamine attaches to receptor sites in larger bronchi, where causes swelling of smoothmuscles. Mucus membranebecome inflamed, irritated and swollen. The patient mayexperience dyspnea, prolonged expiration and an increased respiratory rate.Leukotrienes attached to the receptor site in the smaller bronchi and can cause localswelling of the smooth muscle. Leukotrienes also caused prostaglandin to travel throughthe blood stream to the lungs, where they enhance the histamine’s effect. A wheezemaybe audible during coughing – the higher the pitch, the narrower the bronchial lumen.Histamines stimulates the mucos membranes to secrete excessive mucusto furthernarrow the bronchial lumen. Goblet cells secrete viscous mucus that is difficult to coughout resulting in coughing, rhonchi, increase pitch wheezing and increases respiratorydistress. Mucosal edema and thicken secretions further block the airways. On inhalation,the narrow bronchi lumen can still expand slightly, allowing air to reach the alveoli. Onexhalation, increase intrathoraxic pressure closes the bronchial lumen .