SM_236b: Bladder Dysfunction Flashcards
Describe lower urinary tract function
Lower urinary tract function
- Low pressure urine storage without leakage
- Complete, periodic, voluntary expulsion of urine
- Involves coordination of peripheral autonomic, somatic, and central nervous system
Bladder compliance is normally ___ due to ___
Bladder compliance is normally high due to passive bladder wall properties and elastic / viscoelastic properties of bladder wall
- Compliance = ∆ volume / ∆ pressure
- Innervation is required to maintain high compliance
Describe elastic / viscoelastic properties of bladder wall
Elastic / viscoelastic properties of bladder wall
- Reorientation of smooth muscle and connective tissue: parallel to lumen
- Lamina propria thins
- Urothelium flattens to increase surface area
- ECM collagen is important: increase in type III collagen found in bladders with poor (low) compliance
Parasympathetic innervation of bladder is ____
Parasympathetic innervation of bladder is peripheral nerves that exit craniosacral spinal cord (pelvic nerve)
Sympathetic innervation of bladder is ____
Sympathetic innervation of bladder is peripheral nerves that exit thoracolumbar spinal cord (hypogastric nerve)
Describe parasympathetic efferents for bladder
Parasympathetic efferents for bladder
- Preganglionic nerves exit S2-4
- Nerves travel long distances to ganglia within or next to target organ
- Pelvic nerve
- Modulate bladder contractions
Describe sympathetic efferents for bladder
Sympathetic efferents for bladder
- Preganglionic nerves exit T10-L2
- Variable ganglia locations: next to vertebrae (paraganglia), between vertebra and organ (preganglia), with end organ (peripheral ganglia)
- Hypogastric nerve
- Modulate contraction of bladder neck smooth muscle and relaxation of bladder via alpha and beta adrenergic receptors respectively
- Inhibit parasympathetics so indirectly inhibit bladder contraction
Describe somatic efferents to bladder
Somatic efferents to bladder
- Preganglionic nerves exit S2-4
- Nerve bodies located in Onuf’s nucleus
- Pudendal nerve
- Modulates striated (voluntary) urethral sphincter contraction via nicotinic receptors (ACh)
Describe afferent innervation of bladder
Afferent innervation of bladder
- Contained in pelvic, hypogastric, pudendal nerves
- Enter via dorsal root ganglia: pelvic and pudendal are sacral, hypogastric is lumbar
- Numerous neurotransmitters
Central coordination of the bladder occurs in the ____
Central coordination of the bladder occurs in the pontine micturition center
- Barrington’s nucleus
- Mediates normal micturition reflex
- Coordinates detrusor, sphincter (autonomic, somatic nervous systems) - electrical stimulation causes detrusor contraction and urethral relaxation
- Receives input from cerebellum, basal ganglia, thalamus, hypothalamus, cerebral cortex
____ is a brake that modules that pontine micturition center
Cerebral cortex is a brake that modules that pontine micturition center
- Inhibits PMC
- Coordination with conscious activities allows patient to defer voiding until a socially appropriate time
Describe bladder storage
Bladder storage
- Bladder fills and activates aferent fibers
- Sympathetics are stimulated: internal sphincter contraction (alpha) and bladder relaxation (beta)
- Increased somatic activity via pudendal nerve: increased EUS tone
- Parasympathetics inactive: sympathetic inhibition of parasympathetic transmission at ganglia level (alpha)
Describe role of adrenergic receptors (sympathetic) for bladder
Adrenergic receptors (sympathetic) for bladder
- Bind catecholamines released for postganglionic sympathetic neurons
- Alpha receptors: vasoconstriction, smooth muscle contraction
- Beta receptors: increased myocardial contractility, smooth muscle relaxation
Describe bladder storage phase
Bladder storage phase
- Sympathetic stimulation of alpha receptors: bladder neck contraction
- Sympathetic stimulation of beta receptors: bladder body relaxation
- Somatic stimulation of nicotinic (cholingergic) receptors at the external sphincter: increased external sphincter tone
Describe emptying phase (voiding) for bladder
Emptying phase (voiding) for bladder
- Increased bladder afferent activity triggers switch from storage to voiding
- Relaxation of external urethral sphincter (initial event): inhibition of somatic activity
- Inhibition of sympathetic outflow
- Activation of parasympathetic outflow to bladder: bladder contraction (muscarinic receptors), urethral relaxation (NO)
Describe cholinergic receptors in bladder
Cholinergic receptors in bladder
- Bind ACh released from postanglionic parasympathetic neurons, preganglionic autonomic neurons, and somatic neurons
- Muscarinic (M1-M5): M3 is responsible for contraction, M2 may enhance response to M3 by inhibiting sympathetics
- Nicotinic
___ is the first event in the emptying phase (voiding) of bladder
Inhibition of somatic outflow to external sphincter is the first event in the emptying phase (voiding) of bladder
- Parasympathetic stimulation of M3 and M2: results in detrusor muscle contraction
- Sympathetic outflow inhibited
___ is the nerve primarily responsible for bladder storage
Hypogastric is the nerve primarily responsible for bladder storage
Overactive bladder is ____
Overactive bladder is urgency in the absence of pathologic or metabolic conditions that might explain these symptoms
- Loss of cortical inhibition: no warning
- Similar symptoms often seen with neurologic disease
- No testing needed for diagnosis, rule out bad causes
Overactive bladder treatment includes ____, ____, ____, and ____
Overactive bladder treatment includes Kegel exercises to inhibit bladder contraction, behavioral modification, anticholinergic medications, beta adrenergic medication
Describe stress urinary incontinence
Stress urinary incontinence
- Leakage with physical activity
- Due to loss of support of bladder neck: urethral muscle tone, fascia support, and muscle floor muscle contractions
- Treat primarily with surgery or with Kegel exercises or incontinence pessary
Areflexia in urodynamic testing is ____
Areflexia in urodynamic testing is absence of either voluntary or involuntary detrusor contraction with bladder filled to capacity (> 500 cc)
Detrusor overactivity is ____
Detrusor overactivity is involuntary detrusor contraction with bladder filling
Describe diminished bladder compliance
Diminished bladder compliance
- Abnormal increase in detrusor pressure with filling (> 15 cm water / mL over 300 mL filling)
- Sustained bladder pressure > 40 cm H2O will inhibit delivery of urine to the bladder and produce hydronephrosis
- Normal compliance is key to maintaining renal function and preventing urinary leakage
Describe detrusor sphincter dyssynergia
Detrusor sphincter dyssynergia
- Sphincter either fails to relax or contracts paradoxically with detrusor contraction
- Detrusor external sphincter dyssynergia: loss of coordinating influence with the PMC
- Cervical or thoracic level spinal cord injury
- Sustained bladder pressure > 40 cm H20 will inhibit delivery of urine to the bladder and produce hydronephrosis
Sustained bladder pressure of ___ will compromise renal function
Sustained bladder pressure of > 40 cm H20 will compromise renal function
Describe the correlation between neurologic lesion and lower urinary tract function
Correlation between neurologic lesion and lower urinary tract function
- Brain lesion: detrusor overactivity
- Spinal cord lesion: variable
- peripheral lesion: variable
Pons causes ____ of voiding
Pons causes inhibition of voiding
- Lesions in pons cause loss of inhibition -> detrusor overactivity / urge incontinence, no dyssynergia
Spinal cord injury is characterized by ___
Spinal cord injury is characterized by detrusor areflexia
- Continent but have urinary retention
Suprasacral spinal cord lesions are below the ____ and can affect ____ and ____
Suprasacral spinal cord lesions are below the PMC and can affect bladder compliance and coordination of the detrusor and sphincter
- Type of lower urinary tract dysfunction is variable and cannot be reliably predicted based on symptoms, other neurologic manifestations, or the nature of neurologic injury
___ is associated with a lesion above the pontine micturition center
Overactive bladder is associated with a lesion above the pontine micturition center
Describe bladder management
Bladder management
- Men: intermittent catheterization, condom catheter drainage, indwelling catheter, urinary diversion
- Women: intermittent catheterization, pads, indwelling catheter, urinary diversion
____, ____, and ____ may be used to treat bladder storage problems
Anticholingergic, beta adrenergic medications, and botulinum toxin may be used to treat bladder storage problems
- Surgery if medical management fails
