The vessel walls at a P aO2 less than 7.3 kPa (55 mmHg). The mechanism is triggered directly by smooth muscle contraction in As the altitude increases, theīarometric pressure decreases and the partial pressure of oxygen in the alveolarĬompensatory mechanism in alveoli with low ventilation and low oxygen partial Starts to increase by carotid body stimulation. This is the threshold, below which the ventilation Hypoxia may be present both with low P aO2 and with normal P aO2.Ĭharacterised by a P aO2 less than 7.3 kPa (55 mmHg). Tissues due to insufficient delivery of oxygen or inability to utilize Hypocapnia is a hyperventilation disorder with abnormally reduced P aCO2 at rest (below 33 mmHg or 4.4 kPa).Hypercapnia refers to a resting condition with hypoventilation, where P aCO2 is higher.When the distanceīetween the capillary blood and the cells is large, diffusion becomes a limiting Tension in the pulmonary capillaries and the alveolar lumen. Per unit of pressure gradient (D L = V ° O2 / D P ).Įxchange is a condition where equilibration does not occur between the gas Diffusion is a transport of atoms or molecules caused by their random thermalĬapacity for the lung (D L ) is defined as the volume of gas diffusing through the lung barrier per min and.Leaving the left (or the right) ventricle each min. Uptake of oxygen molecules into the passing pulmonary blood - into the cardiac Regional ventilation-perfusion ratio in health and disease, and peripheral gas To explain the alveolar dead space, veno-arterial shunts, uneven Oxygen uptake and carbon dioxide output, pulmonary vascular resistance and Perfusion, use the alveolar gas equation, the alveolar ventilation equation, theįinal V ° A / Q ° - equation, and the law of mass balance in calculations. Pulmonary perfusion, and its measurements, describe the P O2- P CO2-diagram, hypo-and hyperventilation, pulmonary waterīalance, and mixed venous blood composition. ĭalton’s laws, factors of importance for the lung diffusion capacity and , and the ventilation-perfusion ratio ( V ° A / Q ° -ratio). Hypocapnia, hypoxia, respiratory quotient (RQ), ventilatory exchange ratio( R) Pathophysiology Equations Self-Assessment Answersĭiffusion, diffusion- and perfusion-limited gas exchange, hypercapnia, Study_ Objectives Principles Definitions Essentials

New Human Physiology | Paulev-Zubieta 2nd Edition Chapter 14: Gas Exchange and Disorders

What is the total dead space in lungs