Refractory period (sex) autonomic feedback mechanism, rather than through central chemicals like oxytocin, serotonin, and prolactin. Autonomic feedback is already known to regulate other physiologic systems, such as breathing, blood pressure, and gut motility. This theory suggests that after male ejaculation, decreased wall tension in structures such as the seminal vesicles leads to a change in the fine autonomic signals sent from these organs, effectively creating a negative feedback loop. Such a mechanism is similar to decreased gastric and bowel motility once gastric contents have passed through. Once the feedback loop has been created, the refractory period remains until the loop is broken
Birthing chair has been seen around the globe, not isolated to a particular region. The birthing chair can be traced to Egypt in the year 1450 B.C.E. Pictured on the walls of The Birth House at Luxor, Egypt, is an Egyptian queen giving birth on a stool. It can also be traced to Greece in 200 B.C as it is featured on an ancient Grecian sculpted votive. Celtic items from 100 B.C.E in Britain also depict women sitting in the same upright position as if in a birthing chair. Birthing chairs fell out of use after physicians began using the flat bed