( ( CAPILLARY ( a ( small ( blood vessel ) ) ) ) . )
(ROOT (NP (NP (NNP CAPILLARY)) (NP (DT a) (JJ small) (NN blood) (NN vessel)) (. .)))
CAPILLARY a small blood vessel.
(ROOT (S (NP (NNP Oxygen)) (VP (VBZ is) (VP (VBN transferred) (PP (IN through) (NP (NNS capillaries))))) (. .)))