( ( A ( radio ( wave antenna ) ) ) ( ( is ( used ( to ( ( ( ( ( send signals ) ( to ( the body ) ) ) and ) then ) ( ( receive signals ) back ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN radio) (NN wave) (NN antenna)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VP (VB send) (NP (NNS signals)) (PP (TO to) (NP (DT the) (NN body)))) (CC and) (ADVP (RB then)) (VP (VB receive) (NP (NNS signals)) (ADVP (RB back)))))))) (. .)))
A radio wave antenna is used to send signals to the body and then receive signals back.
(ROOT (S (NP (NNS Hormones)) (VP (VBP send) (NP (NNS signals)) (PP (IN through) (NP (PRP$ your) (NN body)))) (. .)))