PHYSL212 Lecture 2: Lecture 2
23 Feb 2015
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Document Summary
External respiration is the exchange of oxygen and carbon dioxide between the atmosphere and the mitochondria, also called pulmonary physiology. Internal respiration is mitochondria-oxygen being the last electron acceptor. Utilization if ixygen in the metabolism of organic molecules by cells. Gas gets into the alveoli by ventilation, and gets across the blood gas barrier and into the blood by diffusion. The blood flow or pulmonary circulation removes gas from the lung. Ventilation-perfusion relationships are how matching of gas and blood determines gas exchange. Gases are moved to the peripheral tissues by the blood. Usually, gas moves from areas of high concentration to areas of low concentration, and gas exchange is regulated by control of ventilation. The conducting zone extends from the top of the trachea to the beginning of the respiratory bronchioles. This zone contains no alveoli and has no gas exchange with the blood.
