WKU Anatomy: BIO 131 Final Exam Part 1 Questions And Answers Complete Study Solutions

adventitia - outermost layer of trachea/ Fibrous connective tissue that blends into adventitia of other organs of mediastinum Alveolar gas exchange - the swapping of O2 and CO2 across the respiratory membrane/ Air in the alveolus is in contact with a film of water covering the alveolar epithelium/ For oxygen to get into the blood it must dissolve in this water, and pass through the respiratory membrane separating the air from the bloodstream/ For carbon dioxide to leave the blood it must pass the other way, and then diffuse out of the water film into the alveolar air Alveolar macrophages (dust cells) - Most numerous of all cells in the lung/ Wander the lumens of alveoli and the connective tissue between them/ Keep alveoli free from debris by phagocytizing dust particles/ 100 million dust cells die each day as they ride up the mucociliary escalator to be swallowed and digested with their load of debris alveoli - 150 million alveoli in each lung, providing about 70 m2 of surface for gas exchange alveoli function - incoming air stops in these/ millions of thin-walled, microscopic air sacs/ Exchanges gases with the bloodstream through the alveolar wall, and then flows back out apex of lung - tip that projects just above the clavicle apnea - temporary cessation of breathing Arterial blood - carries about 20 mL of O2 per deciliter Atelectasis - collapse of part or all of a lung/ Can also result from an airway obstruction as blood absorbs gases from bloodATP - all body processes directly or indirectly require it Base of lung - broad concave portion resting on diaphragm