Cough cns reflex that causes air to be pushed through

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Cough - CNS reflex that causes air to be pushed through the bronchial tree under tremendous pressure, cleaning out any foreign irritant. Sneeze - reflex which is initiated by receptors in the nasal cavity forces foreign materials directly out of the system opening it for more efficient flow of gas. Macrophage Scavengers - throughout the airways macrophage scavengers move freely about the epithelium and destroy invaders. Mast cells - present in abundance and release histamine, serotonin, adenosine triphosphate, and other chemicals to ensure rapid and intense inflammatory reaction to any cell injury. URT Defense Mech - mucus, cilia, coughing, and sneezing. The end result is that the lower resp. tract is virtually sterile, an important protection against resp. infection that could interfere with essential gas exchange. URT responsibilities- warms and filters inspired air. Lower Resp. Tract Bronchial Tubes - composed of three layers, cartilage, muscle, and epithelial cells. Cartilage - keeps bronchial tubes open but becomes progressively less abundant as the bronchi divide and get smaller. Muscle - keeps bronchial tubes open and the muscles in the bronchi become smaller and less abundant with only few muscle fibers remaining in the terminal bronchi and alveoli.
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Alveoli - at the end of the bronchioles. Delivery of blood to the alveoli is referred to as pulmonary perfusion. Lungs are two spongy organs that fill the chest cavity and are separated by the mediastinum, which contains the heart, esophagus, thymus gland, and various BV and nerves. Left lung - two lobes Right lung - three lobes Gas Exchange - occurs in the alveoli, in this process CO2 is lost from the blood and O2 is transferred into the blood. Respiration - exchange of gases at the alveolar level, act of breathing to allow gas exchange. Controlled by CNS. Medulla controls respiration which depends on muscular system and balance between the sympathetic and parasympathetic system. Alveolar Sacs - holds gas allowing needed O2 to diffuse across the respiratory membrane into the capillary while CO2 which is more abundant in capillary blood, diffuses across the membrane and enters the alveolar sacs to be expired. Respiratory membrane - made up of capillary endothelium, the capillary basement membrane, the interstitial space, the alveolar basement membrane, the alveolar epithelium, and the surfactant layer. Surfactant - lipoprotein that decreases surface tension of cells that keep alveolar sac open. Absence of surfactant leads to alveolar collapse. Surfactant is produced by type II cells in the alveoli. Decrease surface tension to keep alveoli open for gas exchange. Type II cells - of alveoli produce surfactant, convert angio I to angio II by ACE, degeneration of serotonin.
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  • Spring '16
  • Loren Martin
  • cough, Histamine, lower respiratory tract, respiratory airways

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