Pulmonary sequestration is defined as a nonfunctioning mass composed of dysplastic lung parenchyma. embryologically detached from the tracheobronchial tree and receiving its own blood supply from a systemic artery. usually the thoracic or abdominal aorta. It may be intralobar or extralobar depending on the presence of an independent pleural envelope. https://www.fitnessgravesyardes.shop/product-category/flywheel-w-bracket-bearing/