Micturition

The filling state of the bladder is registered by stretch receptors in the bladder wall and reported to the brain via afferent vegetative nerves. From a filling level of approx. 350ml the pulse frequency increases and causes the feeling of urge to urinate. Information about efferent vegetative (parasympathetic) nerves is transmitted to the bladder via the micturition centre in the brainstem via the sacrum. There it comes to the contraction of the Detrusor vesicae. At the same time the inner sphincter muscle slackens via the pubic nerve.