Neural control of the lower urinary tract: Peripheral and spinal mechanisms

Abstract

This review deals with individual components regulating the neural control of the urinary bladder. This article will focus on factors and processes involved in the two modes of operation of the bladder: storage and elimination. Topics included in this review include: (1) The urothelium and its roles in sensor and transducer functions including interactions with other cell types within the bladder wall (''sensory web''), (2) The location and properties of bladder afferents including factors involved in regulating afferent sensitization, (3) The neural control of the pelvic floor muscle and pharmacology of urethral and anal sphincters (focusing on monoamine pathways), (4) Efferent pathways to the urinary bladder, and (5) Abnormalities in bladder function including mechanisms underlying comorbid disorders associated with bladder pain syndrome and incontinence.

Afferent Pathways Arising from the Lower Urinary Tract after Complete Spinal Cord Injury or Cauda Equina Lesion: Clinical Observations with Neurophysiological Implications

“…It seems that myelinated axons are the most sensitive axons to sense distension; they not only sense bladder fullness but also reinforcing reflex control of the bladder by monitoring the contractile state of the detrusor [13]. These Aδ bladder afferents are activated at pressure thresholds in the range of 5–15 mm Hg, which are similar to pressures at which humans report the first sensation of bladder filling [14,15,16].…”

Immunohistochemical characteristics and distribution of neurons in the intramural ganglia supplying the urinary bladder in the male pig

“…These mentioned functions require a complex neural control system that coordinates the activities of a variety of effector structures including the smooth muscle of the urinary bladder and the smooth and striated muscle of the urethral sphincters Arner 2004, Fowler et al 2008). It has been well recognized so far that the innervation of the urinary bladder is supplied by three sets of peripheral nerves: sacral parasympathetic (pelvic nerves consisting of mainly preganglionic fibres supplying the intramural ganglia as well as of postganglionic fibres (Crowe and Burnstock 1989, Gabella 1990, Birder et al 2009), thoracolumbar sympathetic (hypogastric nerves -their fibres are mainly postganglionic and a few preganglionic supply so called short adrenergic neurons' found within ganglia located very close to pelvic organs (Downie 1981, Feher andVajda 1981) and sacral sensory (pudendal nerves (De Groat and Booth 1993). These pathways are a structural basis for constitution of reflexes, which either keep the bladder in a relaxed state, enabling urine storage at low intravesical pressure, or which initiate bladder emptying by relaxing the outflow region and contracting detrusor muscle.…”

Prostaglandin D2 effects and DP1/DP2 receptor distribution in guinea pig urinary bladder out‐flow region

“…The majority of vessels and nerves of the bladder enter and concentrate in the trigone making it very sensitive to expansion 1, 4. Continence is maintained by three major urethral sphincter mechanisms, and which differ between male and female, namely the internal urethral sphincter (IUS), the external urethral sphincter (EUS) and the periurethral levator ani muscles.…”