Feb
5
The pee shivers
The [phenomenon of pee shivers] is an example of the human body’s autonomic nervous system (ANS) at work. We are not conscious of the ANS. It runs on automatic, hence its name, “autonomic”, which literally means “self controlling, working independently”. The urination reflex is relayed through the ANS. The reflex is directly related in strength to the amount of stretch of the bladder. Thus, the degree of shivering is generally related to how full the bladder is at the time of urination.(…)
In any case, at the moment of urination, there is a slight blood pressure rise and a momentary flushing or euphoria shortly after relaxing the urethral sphincter. Some find this feeling pleasurable. At such moments, some people say “ah”. This same response in its most extreme forms causes fainting. All of this is the ANS doing its job.[via]