Neurogenic bladder Flashcards
Describe anatomy of the bladder:
- Detrusor : smooth muscle bundles, fibers crisscross & interlace.Intervation ratio 1:1.
2 Bladder wall: 50% collagen
3 Trigone: Located inferior base of the bladderExtends from ureteral orifices to bladder neck
4 Bladder neck
- Urethra: Male 3 parts: prostate, membranous, anteriorFemale 4 cm in length
6 Internal urethral sphincter: smooth muscle/mixed twitch T11-L2: hypogastric n. (sympathetic) Contracts for storage Involuntary
7 External urethral sphincter: skeletal/striated muscle/slow twitchS2-4: pudendal n. Prevents emptyingVoluntary
Name the different receptors in neurogenic bladder: and locations (
1 Cholinergic muscarinic
(M2 and M3) widely distributed
- Body of the bladder, trigone, bladder neck, and urethra
- Contraction of detrusor
2 Cholinergic nicotinic receptors
- Located in the striated sphincter
- Adrenergic receptors (α1 )
- Trigone, bladder neck, & urethra
Contraction of internal sphincter and bladder neck
- Norepinephrine binds to these receptors to cause contraction - β2- and β3-adrenergic receptors
- Body of the bladder
- Relaxation at the bladder neck on initiation of voiding
- Relax the bladder body to enhance storage.
- alpha receptors mostly in:
- beta receptors mostly in:
- cholinergic receptors mostly in:
- trigone, bladder neck, urethra
- body of bladder
- diffuse
Receptors with function: (bladderO) 1. Norepinephrine 2. Purine receptors 3. Vasointestine Polypeptide 4. Neuropolypeptide Y 5 Tachykinins (in afferent nerves) 6 Prostaglandins 7 PTHrp
- Main effector for urethra contraction via A1 receptors
- P1 – adenosine driven; P2 – ATP driven
Inhibitory on pelvic ganglia and facilatory on neuroeffector junction in detrusor - Enhances Ach in pelvic ganglia; inhibits Ach in detrusor
4 Excitatory on detrusor
5 Augment micturition reflex, transmits pain sensationAugment contraction & vascular response in inflammatory states.
6 Slow onset contraction of detrusor
7 Relaxation of detrusor
central pathways for bladder: name function
- frontal lobe:
- Pons:
- Spinal cord:
1 Frontal lobe - Micturition center
Sends inhibitory signals to PONS until a socially acceptable time and place to urinate is available “Higher voluntary control” over pelvic floor
2 Pons (Pontine Micturition Center) – “reflex center” Major relay/excitatory center Coordinates the urethral sphincter relaxation & detrusor contraction to facilitate urination Affected by emotions (ex: incontinence when excited or scared)
3 Spinal cord
Intermediary between upper and lower control
Describe parasympathetic and sympathetic patheways of the bladder
Parasympathetic – efferent (S2-S4)
- Pelvic nerves
- Excitatory to bladder, contraction of the body
Sympathetic - efferent (T10-L2)
- Hypogastric nerves to pelvic ganglia
- Inhibitory to bladder body, relaxation of the body
- Excitatory to bladder base/urethra, contracts
Sympathetics “Store”. Parasympathetics “Pee”
Bladder:
Efferent:
Afferent:
Efferent - somatic
- pudendal nerves (onuf nucleus)
- contraction of the EUS and the pelvic floor muscles
Afferent fibers
- stretch receptors on detrusor muscle
- A-delta fibers respond to bladder distension
- capsaicin or vanilloid receptors subtype 1 (VR1) receptors - pathology (C-fibers)
Role of nerves in bladder function:
- hypogastric n:
- Pelvic n
- pudendal n:
- T10-L2: To pelvic ganglia.
Inhibits body – relaxation (B2,3)
Excitatory to base/urethra (A1) - Pelvic N: S2-4 Efferent
Excitatory on detrusor. (Cm) - Pudendal N (Onufs Nucleus) S2-4: somatic
Contracts ex. Sphincter & pelvic floor
SNS primarily controls ___ and ____
Somatics (pudendal N) regulates __- and ____
bladder and IUS
- Bladder increases capacity but not pressure
- Internal urinary sphincter to remain tightly closed
- Parasympathetic stimulation inhibited
EUS and pelvic diaphragm
1 Bladder distension sensed by the
2 Send signal to sacral cord via
3 Message goes to ___ then ___
- stretch receptors
2 afferents (A-delta) - Pons to frontal lobe
normal voiding: emptying phase:
Socially acceptible situation results in: 3
PNS stimulation, SNS is suppressed
Stimulates detrusor to contract
Pudendal nerve is inhibited external sphincter opens facilitation of voluntary urination
Infants/Children - “reflex bladders”
1 Empty at ___ volumes
Initially no awareness or voluntary control
2 Detrusor reflex develops by ___ (90%)
3 ____% have immature or “infantile pattern” between voids
1 50-100cc
2 5yoa
3 10
corrects by puberty
Adults
1. ______: minimal increase in intravesicle pressure despite filling
2 _____ occurs: voluntary relaxation of floor, followed by release of inhibition of detrusor reflex at pontine level.
- accomodation
2. normal voiding
Common in elderly (bladder dysfunction) 4
Common: frequency, urgency, incontinence, incomplete emptying
Name the five different classifications of neurogenic bladder
1 Anatomical Classification 2 Neurourologic Classification (Hald & Bradley, Bors and Comarr) 3 Functional Classification (International Continence Society, Wein) 4 Neurologic Classification (Bradley) 5 Urodynamic Classification (Lapides, Krane, Siroky)
describe anatomical classification of neurogenic bladder
Supraspinal (suprapontine) lesions Suprasacral spinal lesions Infrasacral lesions Peripheral autonomic nerve lesions Muscular lesions
describe neuro-urologic classification of neurogenic bladder
- uninhibited bladder
- upper motor neuron bladder
- mixed type A bladder
- mixed type B bladder
- lower motor neuron bladder
Uninhibited bladder has lesions where?
____ is lost
_____ is presevered
Lesions above pontine micturition center
ex: stroke, tumor
Inhibition from cortex is lost
Detrusor/sphincter tone preserved
in UMN bladder includes lesions:
Can have _____
Results in ____ bladder
_____ occurs
Lesions between pontine micturition center and sacral spinal cord (traumatic SCI, MS involving cervicothoracic cord)
Detrusor Sphincter Dyssynergia
Results in high-pressure bladder (up to 80-90cm H2O)
Bladders and sphincters considered “spastic”
Vesicoureteral reflux occurs
What is considered “high-pressure” in high pressure bladders?
up to 80-90cm H2o
Describe differences between mixed type A and B bladders. Where is lesion?
Mixed type A bladder: sacral cord lesion
Damaged detrusor nucleus. “detrusor areflexia”
Pudendal nucleus spared – hypertonic/spastic EUS
Low pressure; results in retention
More common
Mixed type B bladder: sacral cord lesion
Spared detrusor nucleus – spastic bladder
Pudendal nucleus damaged – flaccid EUS
Capacity/pressures low, results in incontinence
LMN bladder lesions are located:
____ is lost
can have detrusor _____
____ remains intact
Results in ___ and ____
Lower motor neuron bladder
Sacral cord lesion or sacral nerve roots
Thoracic SNS outflow to lower urinary tract intact.
Detrusor areflexia – high capacity; low pressure
IUS innervation intact
Results in overflow incontinence and UTI
Describe functional classification of neurogenic bladder:
- failure to store
- bladder: hyperactivity, decreased compliance
- Outlet: denervated pelvic floor, bladder neck descent, intrinsic bladder neck sphincter failure
Failure to empty
- Bladder: areflexia, hypocontractility
- outlet: DSD, nonrelaxing voluntary sphincter, mechanical obstruction
Suprapontine/supraspinal lesions
1. examples: 7
2 Characteristics: 4
- TBI, stroke, brain tumor, hydrocephalus, CP, MS, parkinsons disease
- Detrusor Hyperreflexia without Detrusor sphincter dyssynergia (DSD)
Urge incontinence
Usually small/absent residual volumes
Failure to store
Suprasacral spinal cord lesion:
- examples 5
- characteristics 4
- Myelomeningocele, MS, spinal cord tumor, transverse myelitis, traumatic SCI
- Detrusor hyperreflexia
Detrusor sphincter dyssynergia
Urge incontinence
High PVRs
INfrasacral lesions
- examples: 5
- characteristics 3
- Spinal tumor, sacral SCI, herniated disc, lumbar laminectomy, pelvic trauma
2 Areflexic bladder, DSD may be seen
Urinary retention, overflow incontinence
High PVRs