Sentence:  The pulmonary artery , in addition to supplying the distal portion of the respiratory bronchiole , the alveolar <WSD>duct</WSD> , and the alveoli , continues on and directly supplies the thin pleura ( fig. 8 ) . 
Meaning of the word marked with <WSD> tags:  a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance