Blood pressure and respiratory patterns during human coitus.

There are few experimental investigations of the natural coital process in human subjects; the relatively small literature on this topic deals mainly with extracoital orgasm. Boas & Goldschmidt (1932) made simultaneous recordings of the heart rate of a man and woman in coitus. There was a peak in the heart rate of the woman with each of her four orgasms, and of the man with ejaculation. Mendelsohn (1896) published pulse tracings recorded by Kolb during coitus. These tracings were used to illustrate the degree of exertion involved in coitus and its effect on the heart. Bartlett (1956) repeated Boas & Goldschmidt's experiment with three couples, with comparable results, and made observations on the respiratory system in addition to the heart rate. He reported also that there was frequently