236 bladder dysfunction

Question 1

What is bladder compliance?

Answer 1

change in bladder volume divided by change in bladder pressure at bladder capacity

Question 2

How does bladder compliance affect renal function?

Answer 2

long-term high bladder pressures can cause hydronephrosis and loss of renal function

Question 3

What bladder controls are under parasympathetic innervation?

Answer 3

micturition
pontine micturition center (coordination of detrusor, sphincter)
pelvic splanchnics

Question 4

What bladder controls are under sympathetic innervation?

Answer 4

suprapontine = inhibits PMC
pontine storage center = increased striated sphincter activity
hypogastric nerve = increases accommodation to filling; increased tone of IUS
Pudendal (somatic)= increased striated muscle activity, increases striated sphincter activity in EUS

Question 5

Where is the origin of the pontine micturition center? What does it do?

Answer 5

rostral pons
central coordination of detrusor and sphincter (allowing micturition to occur)
parasympathetic

Question 6

What pelvic splanchnics are associated with bladder control?

Answer 6

S2-S4

Question 7

Where is the origin of the suprapontine control of micturition? What does it do?

Answer 7

cortex

inhibits PMC to block micturition

Question 8

What is the origin of the hypogastric nerve to the bladder? What does it do?

Answer 8

T10-L2

increases accommodation to filling, increases tone of internal urethral sphincter

Question 9

What is the origin of the pudendal nerve? What does it do for bladder control?

Answer 9

S2-S4

increases striated muscle activity, increases striated sphincter activity in external urethral sphincter (via ACh)

Question 10

What role does the PMC play in voluntary control of the bladder?

Answer 10

it sends excitatory signals (makes the bladder want to pee)

inhibited by the suprapontine center, which is in the cortex and allows for conscious control of voiding

Question 11

What is the impact of neurologic diseases above the PMC on bladder function?

Answer 11

detrusor overactivity in absence of coordination and pressure problems
aka “overactive bladder”
no source of inhibition from the cortex

Question 12

What is the impact of neurologic diseases in the cervical spinal cord on bladder function?

Answer 12

detrusor sphincter dysnergia
loss of coordinating influence of PMC, leading to possible hydronephrosis due to sustained high bladder pressures
aka bladder and sphincter are squeezing at the same time, leading to high pressures

Question 13

What is the impact of neurologic diseases in the thoracic spinal cord on bladder function?

Answer 13

detrusor sphincter dysnergia
high bladder pressures because bladder and sphincter are squeezing at the same time
can lead to hydronephrosis

Question 14

What is the impact of neurologic diseases in the sacral spinal cord on bladder function?

Answer 14

detrusor sphincter dysnergia

variable loss of bladder compliance

Question 15

What are the three “zones” of the lower urinary tract?

Answer 15

zone 1: smooth muscle detrusor (endoderm)
zone 2: trigone, bladder neck, and prostate –> internal urethral sphincter (mesoderm)
zone 3: external urethral sphincter (skeletal muscle)

Question 16

What is the innervation of zone 1 of the lower urinary tract?

Answer 16

parasympathetic innervation from PSN (muscarinic receptors) –> detrusor contraction
sympathetic innervation from hypogastric nerve (T10-L2; B3 receptors) –> detrusor relaxation

Question 17

What is the innervation to zone 2 of the lower urinary tract?

Answer 17

sympathetic innervation via HGN (T10-L2; alpha 1a receptors) –> contraction of IUS

Question 18

What is the innervation to zone 3 of the lower urinary tract?

Answer 18

pudendal nerve (somatic; S2-4) –> contracts EUS

Question 19

What are the causes of OAB?

Answer 19

idiopathic

can also be due to bladder cancer or neurogenic dysfunction

Question 20

What are the causes of stress urinary incontinence?

Answer 20

weakened support of bladder neck/urethra

also incompetent sphincter, neurogenic disease, or surgery

Question 21

What are treatments for neurogenic failure to store urine in the bladder?

Answer 21

medications (anti-cholinergics; beta blockers), botulinum injections, surgical enlargement with ileal bladder augmentation

Question 22

What are treatments for conditions causing failure to empty the bladder (atony)?

Answer 22

catheterization, indwelling catheter

Question 23

Describe the expected urinalysis and urine culture findings in patients with chronic indwelling catheters or on intermittent catheterization.

Answer 23

chronically colonized with bacteria (so urinalysis would look like infection)
treatment only initiated if symptomatic