1) Capillary 2) Cousin of a capillary 3) Piece of macaroni 4) Small cylindrical structure 5) Small pipe 6) Tiny hollow cylinder 7) Tube 8) Tube-shaped structure Found on https://www.crosswordclues.com/clue/tubule
• (n.) A small pipe or fistular body; a little tube. • (n.) A minute tube lined with glandular epithelium; as, the uriniferous tubules of the kidney. Found on http://thinkexist.com/dictionary/meaning/tubule/
(too´būl) a small tube; especially, a minute canal found in various structures or organs of the body. adj., tu´bular., adj. Found on http://www.encyclo.co.uk/local/21001