( ( Circulating ( FSH levels ) ) ( ( ( vary ( throughout ( ( the ( menstrual cycle ) ) ( in response ) ) ) ) ( to ( ( estradiol and ) progesterone ) ) ) . ) )
(ROOT (S (NP (VBG Circulating) (NNP FSH) (NNS levels)) (VP (VBP vary) (PP (IN throughout) (NP (NP (DT the) (JJ menstrual) (NN cycle)) (PP (IN in) (NP (NN response))))) (S (VP (TO to) (VP (VB estradiol) (CC and) (VB progesterone))))) (. .)))
Circulating FSH levels vary throughout the menstrual cycle in response to estradiol and progesterone.
(ROOT (S (NP (NNP Estradiol)) (VP (VBZ causes) (NP (DT the) (NN endometrium) (S (VP (TO to) (VP (VB thicken) (PP (IN during) (NP (DT a) (JJ menstrual) (NN cycle)))))))) (. .)))