In contrast, afferent fibers conveying pain from organs without serosa (i.e., subperitoneal viscera, such as the neck of the bladder, terminal ureters, prostate, cervix, and upper vagina), as well as fibers involved in reflex arcs, generally follow the pathways of parasympathetic innervation in a retrograde direction until they reach cranial and sacral sensory ganglia. Thus, the visceral afferents conducting pain impulses from subperitoneal viscera have cell bodies located in the S2-S4 spinal sensory ganglia, with sensations perceived in the corresponding dermatomes. Mechanoreceptors and chemoreceptors that play a role in renorenal reflexes also send projections along vagal afferent fibers to vagal sensory ganglia. Likewise, the reflexive emptying of a moderately distended bladder, such as occurs in infants, is transacted at sacral levels.