( Lead ( ( is ( ( excreted mainly ) ( ( ( ( in ( the urine ) ) ( -LRB- ( ( in ( ( a process ) ( that ( depends ( on ( ( ( glomerular filtration ) and ) ( tubular secretion ) ) ) ) ) ) ) -RRB- ) ) ) and ) ( in ( the feces ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Lead)) (VP (VBZ is) (VP (VBN excreted) (ADVP (RB mainly)) (PP (PP (IN in) (NP (DT the) (NN urine))) (PRN (-LRB- -LRB-) (PP (IN in) (NP (NP (DT a) (NN process)) (SBAR (WHNP (WDT that)) (S (VP (VBZ depends) (PP (IN on) (NP (NP (NN glomerular) (NN filtration)) (CC and) (NP (JJ tubular) (NN secretion))))))))) (-RRB- -RRB-)) (CC and) (PP (IN in) (NP (DT the) (NNS feces)))))) (. .)))
Lead is excreted mainly in the urine (in a process that depends on glomerular filtration and tubular secretion) and in the feces.
(ROOT (S (NP (NP (DT The) (JJ main) (NNS functions)) (PP (IN of) (NP (NN epithelia)))) (VP (VBP are) (NP (NP (NN protection)) (PP (IN from) (NP (NP (DT the) (NN environment) (, ,) (NN coverage) (, ,) (NN secretion) (CC and) (NN excretion)) (, ,) (NP (NN absorption)) (, ,) (CC and) (NP (NN filtration)))))) (. .)))