SM_236b: Bladder Dysfunction

Question 1

Describe lower urinary tract function

Answer 1

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

Question 2

Bladder compliance is normally ___ due to ___

Answer 2

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

Question 3

Describe elastic / viscoelastic properties of bladder wall

Answer 3

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

Question 4

Parasympathetic innervation of bladder is ____

Answer 4

Parasympathetic innervation of bladder is peripheral nerves that exit craniosacral spinal cord (pelvic nerve)

Question 5

Sympathetic innervation of bladder is ____

Answer 5

Sympathetic innervation of bladder is peripheral nerves that exit thoracolumbar spinal cord (hypogastric nerve)

Question 6

Describe parasympathetic efferents for bladder

Answer 6

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

Question 7

Describe sympathetic efferents for bladder

Answer 7

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

Question 8

Describe somatic efferents to bladder

Answer 8

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)

Question 9

Describe afferent innervation of bladder

Answer 9

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

Question 10

Central coordination of the bladder occurs in the ____

Answer 10

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

Question 11

____ is a brake that modules that pontine micturition center

Answer 11

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

Question 12

Describe bladder storage

Answer 12

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)

Question 13

Describe role of adrenergic receptors (sympathetic) for bladder

Answer 13

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

Question 14

Describe bladder storage phase

Answer 14

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

Question 15

Describe emptying phase (voiding) for bladder

Answer 15

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)

Question 16

Describe cholinergic receptors in bladder

Answer 16

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

Question 17

___ is the first event in the emptying phase (voiding) of bladder

Answer 17

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

Question 18

___ is the nerve primarily responsible for bladder storage

Answer 18

Hypogastric is the nerve primarily responsible for bladder storage

Question 19

Overactive bladder is ____

Answer 19

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

Question 20

Overactive bladder treatment includes ____, ____, ____, and ____

Answer 20

Overactive bladder treatment includes Kegel exercises to inhibit bladder contraction, behavioral modification, anticholinergic medications, beta adrenergic medication

Question 21

Describe stress urinary incontinence

Answer 21

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

Question 22

Areflexia in urodynamic testing is ____

Answer 22

Areflexia in urodynamic testing is absence of either voluntary or involuntary detrusor contraction with bladder filled to capacity (> 500 cc)

Question 23

Detrusor overactivity is ____

Answer 23

Detrusor overactivity is involuntary detrusor contraction with bladder filling

Question 24

Describe diminished bladder compliance

Answer 24

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

Question 25

Describe detrusor sphincter dyssynergia

Answer 25

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

Question 26

Sustained bladder pressure of ___ will compromise renal function

Answer 26

Sustained bladder pressure of > 40 cm H20 will compromise renal function

Question 27

Describe the correlation between neurologic lesion and lower urinary tract function

Answer 27

Correlation between neurologic lesion and lower urinary tract function

• Brain lesion: detrusor overactivity
• Spinal cord lesion: variable
• peripheral lesion: variable

Question 28

Pons causes ____ of voiding

Answer 28

Pons causes inhibition of voiding

• Lesions in pons cause loss of inhibition -> detrusor overactivity / urge incontinence, no dyssynergia

Question 29

Spinal cord injury is characterized by ___

Answer 29

Spinal cord injury is characterized by detrusor areflexia

• Continent but have urinary retention

Question 30

Suprasacral spinal cord lesions are below the ____ and can affect ____ and ____

Answer 30

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

Question 31

___ is associated with a lesion above the pontine micturition center

Answer 31

Overactive bladder is associated with a lesion above the pontine micturition center

Question 32

Describe bladder management

Answer 32

Bladder management

• Men: intermittent catheterization, condom catheter drainage, indwelling catheter, urinary diversion
• Women: intermittent catheterization, pads, indwelling catheter, urinary diversion

Question 34

____, ____, and ____ may be used to treat bladder storage problems

Answer 34

Anticholingergic, beta adrenergic medications, and botulinum toxin may be used to treat bladder storage problems

• Surgery if medical management fails