Science tells us that because of foreplay the hormonal photograph modifications: in the case of ladies essentially the most popular sex hormones are dopamine, noradrenaline and phenylethylamine (however the list is extensive and a number of other hormones are essential all through intercourse) which trigger: improved heart level heart, increased overall body temperature, hypersensitivity in the erogenous zones (i.e. the regions of the human body most sensitive to sexual stimulation) like the nipples, clitoris and vagina. The latter, the vagina, underneath the impact of hormones stretches and commences to lubricate.