( ( Surrounding ( the heart ) ) ( ( is ( ( a sac ) ( known ( as ( ( ( the pericardium ) , ) ( which ( consists ( of ( ( ( two membranes ) , ) ( ( the ( outer layer ) ) ( being ( ( ( the fibrous ) ( ( ( parietal pericardium ) and ) ( the ( inner layer ) ) ) ) ( being ( the ( serous ( visceral pericardium ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (S (VP (VBG Surrounding) (NP (DT the) (NN heart)))) (VP (VBZ is) (NP (NP (DT a) (NN sac)) (VP (VBN known) (PP (IN as) (NP (NP (DT the) (NN pericardium)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ consists) (PP (IN of) (NP (NP (CD two) (NNS membranes)) (, ,) (NP (NP (DT the) (JJ outer) (NN layer)) (VP (VBG being) (VP (NP (DT the) (NNS fibrous)) (NP (NP (JJ parietal) (NN pericardium)) (CC and) (NP (DT the) (JJ inner) (NN layer))) (S (VP (VBG being) (NP (DT the) (JJ serous) (JJ visceral) (NN pericardium))))))))))))))))) (. .)))
Surrounding the heart is a sac known as the pericardium, which consists of two membranes, the outer layer being the fibrous parietal pericardium and the inner layer being the serous visceral pericardium.
(ROOT (S (NP (NP (DT The) (NN pleura)) (SBAR (WHNP (WDT that)) (S (VP (VBZ surrounds) (NP (DT the) (NNS lungs)))))) (VP (VBZ consists) (PP (IN of) (NP (CD two) (NNS layers)))) (. .)))