Pathophysiology NU 545-- Unit 5-- Pulmonary/ Kidney I Rated A+

Pathophysiology NU 545-- Unit 5-- Pulmonary/ Kidney I Rated A+ Alveolar Type 1 cells Alveolar Type 2 cells Surfactant Cells which provides structure for alveoli. Cells of the alveoli which secrete surfactant. A lipoprotein that coats the inner surface of the alveolus and facilitates its expansion during inspiration. Lowers alveolar surface tension at end expiration and prevents lung collapse. Contributes to control of lung inflammation and innate and adaptive immunity. Surface Tension The tendency for liquid molecules that are exposed to air to adhere to one another. This phenomenon decreases the surface area exposed to the air. Law of Laplace The pressure required to inflate a sphere is equal to two times the surface tension divided by the radius of the sphere, or P=2T/r. Alveolar ventilation Distention, is made possible by surfactant, which lowers the surface tension by coating the air-liquid interface in the alveoli. Infant Surfactant 30 weeks. Chronic Bronchitis Is produced by 20-24 weeks of gestation and is secreted into the fetal airways by Hypersecretion of mucous and chronic productive cough that continues for at least 3 months of the year (usually the winter months) for at least 2 consecutive years. Patho of Chronic Bronchitis Inspired irritants result in airway inflammation with infiltration of neutrophils, macrophages, and lymphocytes into the bronchial wall. Manifestations of Chronic Bronchitis Decreased exercise intolerance, wheezing, and SOB, productive cough, evidence of airway obstruction (decrease in FEV1) on spirometry, copious amounts of sputum, frequent pulmonary infections, FVC and FEV1 values are markedly reduced,FRC and Residual volume (RV) measurements are increased, decreased alveolar ventilation, increased PaCO2,polycythemia, cyanosis, pulmonary HTN, cor pulmonale which can lead to severe disability or death. Ventilation The mechanical movement of gas or air into and out the lungs. Respiration The exchange of O2 and CO2 during cellular metabolism. PAO2 The amount of oxygen in the alveoli. Gas Transport Pors of Kohn The delivery of oxygen to the cells of the body and the removal of CO2. Tiny pores which permit some air to pass through the septa from alveolus to alveolus, promoting collateral ventilation and even distribution of air among the alveoli. Asthma A chronic inflammatory disorder of the bronchial mucosa that causes bronchial hyperresponsiveness, constriction of the airways, and variable airflow obstruction that is reversible. Acinus Consists of respiratory bronchioles, alveolar ducts, and alveoli. Early Asthmatic Response Antigen exposure to bronchial mucosa activates dendritic cells to present the antigen to CD4+ Tcells, which differentiate into Th2 cells. These cells release numerous cytokines IL-4, IL-5, IL-8 & IL-13. IL-4 In Asthmatic response it stimulates B-cell activation, proliferation, and production of antigen specific IgE. IgE In asthmatic response it causes mast cell degranulation with the release of a large number of inflammatory mediators (histamine, prostaglandins, and leukotrienes) IL-5 In asthmatic response it stimulates the activation, migration, and proliferation of eosinophils, which cause direct tissue injury and release toxic neuropeptides that contribute to increased bronchial hyperresponsiveness, fibroblast proliferation, and airway scarring. IL-8 In asthmatic response it activates polymorphonucleocytes that contribute to a more exaggerated inflammatory response. IL-13 In asthmatic response it impairs mucociliary clearance, enhances fibroblast secretion, and contributes to bronchoconstriction. TNF, IL-1 In asthmatic response it alters muscarinic receptor function, leading to increased levels of acetylcholine, which causes bronchial smooth muscle contraction and mucus secretion -These changes, combined with epithelial cell damage (caused by eosinophil infiltration) produ