THE PHYSIOLOGY AND ECOPHYSIOLOGY OF EJACULATION

Abstract

Different studies dealing with ejaculation view this process as a part of the male copulatory behavior. Some of them explain ejaculation as the consequence of a neuroendocrine feedback loops or from a purely anatomical perspective. The goal of the present review is to discuss the traditional and novel themes related to the biology of ejaculation. The text begins with the description of the behavioral motor patterns that lead to ejaculation. The anatomo-physiological mechanisms are explained under the notion that ejaculation is more than genitals and an excurrent duct system; thus it is also included the participation of the striated perineal musculature. Although ejaculation is a sexual spinal reflex, it is inhibited tonically by supraspinal structures. Such supraspinal modulation may explain the prudent sperm allocation, by which males adjust the number of sperm per ejaculate while copulating under distinct competitive scenarios. In some mammals, ejaculate components facilitate seminal coagulation, an adaptation that may increase the male reproductive fitness. Finally, there is a reflection of the so-called human ejaculatory disturbances, which from an ecophysiolgical perspective could represent advantages instead of sexual malfunction as are recognize under the medical view.