Physiology 1020 Lecture 10: Physiology Lecture 10 Respiratory System
29 Sep 2017
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Document Summary
Transport of oxygen from the air into the blood. Removal of carbon dioxide from the blood into the air. Forming a line of defence to airborne particles. Airway: nasal cavity and mouth, pharynx, larynx, trachea, r and l main bronchi, smaller bronchiole, alveoli. The pulmonary artery (delivers deoxygenated blood to the lungs) branches into a network of capillaries around each alveolus. The capillaries and blood flow maximizes gas exchange. Characteristics: endothelial walls, large total cross-sectional area, very low blood velocity. In the capillaries, oxygen diffuses into the blood while carbon dioxide diffuses out. Oxygen rich blood flows back to the left side of the heart through the pulmonary vein. 300 million alveoli in a healthy human lung. Walls of alveoli are one cell thick of epithelial cells (type 1) Type 2 cells secrete a fluid called surfactant that lines the alveoli. Respiratory membrane: region between the alveolar space and capillary lumen.
