bladder neurophysiology
TRANSCRIPT
Bladder Neurophysiology
DR. ALI M AHMADMBBCH, MS, MD, MRCS-ED, EBPS
ASSOCIATE CONSULTANT PEDIATRIC SURGERY; KAAUH_ PNU
Anatomy of Urinary Bladder
Detrusor Fundus Neck
• internal sphincter Functional ,due to circular arrangement
• External sphincter Striated muscle under voluntary control
Trigone Located at base of bladder Extends from urethral orifices to bladder neck
Anatomy of Urinary Bladder
Storing the urine till convenient time to empty Function depends upon interaction among:
o Peripheral parasympathetico Sympathetico Somatic innervations
Modulation from central nervous system
Neuroanatomy of the micturition
Storing the urine till convenient time to empty
Function depends upon interaction among:
o Peripheral parasympathetico Sympathetico Somatic innervations
Modulation from central nervous system
Neuroanatomy of the micturition
Originates from T10 – L2
Travel to lumbar sympathetic ganglion and from there to fundus and neck through hypogastric nerves
Provide excitatory input to bladder neck and inhibitory to fundus of bladder {relaxation of detrusor and contraction of internal sphincter hence enhancing storage of urine}
Action through alpha & beta adrenergic receptors
Sympathetic Efferent
Originates from detrusor nucleus in S2-4 Travel through pelvic nerves to ganglion in
fundus of detrusor
Provide excitatory input to fundus of bladder & contraction of detrusor
Action through Action through cholinergic receptors
Para Sympathetic Efferent
Originates from pudendal nucleus in S 2-4
Travel through pudendal nerve
Provide excitatory /inhibitory output to pelvic floor & external sphincter
Somatic Efferent
Sensation carried through hypogastric, pelvic & pudendal nerves to dorsal columns of Lumbosacral spinal cord
In the spinal cord sensation carried through lateral spinothalamic and dorsal columns
Afferents
PONTINE MICTURITION CENTER Receives input from cerebral cortex ,
cerebellum , basal ganglion & hypothalamus
Most of the input is inhibitory but few are facilitatory.
Cerebellum important in o Maintenance of tone in pelvic flooro Co-ordination between bladder
contraction and external sphincter relaxation
Central control
MICTURITION HAS TWO PHASES
Filling PhaseVoiding phase
Occurs when person not trying to void Sensations of fullness carried through the afferents
and then through dorsal and spinothalamic tracts to pontine micturition center which is under the inhibitory influence of higher centers
Little rise in bladder pressure Maintained by progressive increase in sympathetic stimulation causing relaxation of body of bladder and stimulation of sphinctersS2-4 in
cauda equina
pelvic & pudendal ns
PMCFilling Phase
At convenient time and place Withdrawal of inhibitory influence from PMC & + Excitatory
input from other centers
Increase in parasympathetic derive Decrease in sympathetic derive Contraction of bladder and relaxation of sphinctersS2-4 in
cauda equina
pelvic & pudendal ns
PMCVoiding Phase