( ( ( Figure 4 ) ( -LRB- ( ( 1 kb ) -RRB- ) ) ) ( ( At ( first glance ) ) ( ( ( the cells ) ( of ( the heart ) ) ) ( ( ( ( ( have ( many similarities ) ) ( to ( skeletal ( muscle cells ) ) ) ) , ) ( with ( ( contractile filaments ) ( organized ( into ( ( sarcomeres , ) ( lots ( of ( ( ( ( mitochondria , ) ( sarcoplasmic reticulum ) ) and ) t-tubules ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (NP (NP (NNP Figure) (CD 4)) (PRN (-LRB- -LRB-) (NP (QP (CD 1) (CD kb))) (-RRB- -RRB-))) (PP (IN At) (NP (JJ first) (NN glance))) (NP (NP (DT the) (NNS cells)) (PP (IN of) (NP (DT the) (NN heart)))) (VP (VBP have) (NP (JJ many) (NNS similarities)) (PP (TO to) (NP (JJ skeletal) (NN muscle) (NNS cells))) (, ,) (PP (IN with) (NP (NP (JJ contractile) (NNS filaments)) (VP (VBN organized) (PP (IN into) (NP (NP (NNS sarcomeres)) (, ,) (NP (NP (NNS lots)) (PP (IN of) (NP (NP (NN mitochondria)) (, ,) (NP (JJ sarcoplasmic) (NN reticulum)) (CC and) (NP (NNS t-tubules))))))))))) (. .)))
Figure 4 (1 kb) At first glance the cells of the heart have many similarities to skeletal muscle cells, with contractile filaments organized into sarcomeres, lots of mitochondria, sarcoplasmic reticulum and t-tubules.
(ROOT (S (NP (DT A) (NN sarcomere)) (VP (VBZ is) (NP (NP (DT the) (JJS smallest) (NN contractile) (NN portion)) (PP (IN of) (NP (DT a) (NN muscle))))) (. .)))