( ( At ( ( the beginning ) ( of ( each ( menstrual cycle ) ) ) ) ) ( , ( ( the ( pituitary gland ) ) ( ( secretes ( ( ( a hormone ) , ) ( ( ( FSH ( -LRB- ( ( follicle ( stimulating hormone ) ) -RRB- ) ) ) , ) ( that ( ( acts ( upon ( the ovaries ) ) ) ( to ( prepare ( for ovulation ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN At) (NP (NP (DT the) (NN beginning)) (PP (IN of) (NP (DT each) (JJ menstrual) (NN cycle))))) (, ,) (NP (DT the) (JJ pituitary) (NN gland)) (VP (VBZ secretes) (NP (NP (DT a) (NN hormone)) (, ,) (NP (NP (NNP FSH)) (PRN (-LRB- -LRB-) (NP (JJ follicle) (JJ stimulating) (NN hormone)) (-RRB- -RRB-)) (, ,) (SBAR (WHNP (WDT that)) (S (VP (VBZ acts) (PP (IN upon) (NP (DT the) (NNS ovaries))) (S (VP (TO to) (VP (VB prepare) (PP (IN for) (NP (NN ovulation)))))))))))) (. .)))
At the beginning of each menstrual cycle, the pituitary gland secretes a hormone, FSH (follicle stimulating hormone), that acts upon the ovaries to prepare for ovulation.
(ROOT (S (NP (NNP Ovulation)) (VP (VP (VBZ takes) (NP (NN place)) (PP (IN in) (NP (DT the) (NN ovary)))) (CC and) (VP (VBZ is) (NP (NP (NN part)) (PP (IN of) (NP (DT the) (JJ menstrual) (NN cycle)))))) (. .)))