pulmonary sequestration

loss of connection of lung tissue, and sometimes bronchi, with the bronchial tree and with the pulmonary veins, the tissue receiving its arterial supply from the systemic circulation. The mass may be completely separated anatomically and physiologically from normally connected lung (extralobar pulmonary s.) or be in anatomical contiguity with and partly surrounded by normal lung (intralobar pulmonary s.). Called also accessory lung and bronchopulmonary s.