( ( ( The ( spinal cord ) ) ( is ( surrounded ( by ( three ( protective membranes ) ) ) ) ) ) ( , ( ( called ( ( meninges , ) ( which ( ( extend ( around ( the brain ) ) ) ( as well ) ) ) ) ) . ) ) )
(ROOT (SINV (S (NP (DT The) (JJ spinal) (NN cord)) (VP (VBZ is) (VP (VBN surrounded) (PP (IN by) (NP (CD three) (JJ protective) (NNS membranes)))))) (, ,) (VP (VBD called)) (NP (NP (NNS meninges)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP extend) (PP (IN around) (NP (DT the) (NN brain))) (ADVP (RB as) (RB well)))))) (. .)))
The spinal cord is surrounded by three protective membranes, called meninges, which extend around the brain as well.
(ROOT (S (NP (NP (DT The) (CD three) (NNS layers)) (PP (IN of) (NP (NP (JJ protective) (NNS coverings)) (PP (IN of) (NP (DT the) (JJ spinal) (NN cord)))))) (VP (VBZ is) (VP (VBN called) (NP (DT the) (NNS meninges)))) (. .)))