PAT 20A/B Study Guide - Final Guide: Peripheral Artery Disease, Pulmonary Circulation, Metabolic Acidosis
21 Jan 2017
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Document Summary
The blood vessels in the pulmonary circulation are highly sensitive to alveolar oxygen levels. When alveolar oxygen levels are < 60 mm hg marked vasoconstriction occurs. When alveolar hypoxia no longer exists blood flow is restored. Vasoconstriction is localized to a specific region of the lung. Vasoconstriction has the effect of directing blood flow away from the hypoxic regions of the lungs. Occurs at high altitudes and in persons with chronic hypoxia due to lung disease. Prolonged hypoxia= pulmonary htn + increased workload on the right heart. Blood that moves from the right to the left side of the circulation without being oxygenated. Anatomic shunt: blood that moves from the venous to the arterial side of the circulation without moving through the lungs. Reduction in blood o2 levels to below normal. Results in a decrease in tissue oxygenation. Inadequate circulation of blood through the pulmonary capillaries. Ventilation perfusion impairment (including shunt & dead space)
