Fisiologi dan Patofisiologi Proses
Berkemih
dr. Bobby Hery Yudhanto, SpU
Anatomi traktus
urinarius laki-laki
Anatomy and relations of the bladder, urethra, uterus and ovary,
vagina, and rectum
Sistem Persarafan Traktus
Urinarius dan Traktus Digestivus
Physiology
• Main function of bladder :
– 1. Urine storage
– 2. Urine voiding
• Ada 2 faktor yang berpengaruh dalam proses miksi :
– 1. Buli – buli (kandung kemih) sebagai “pompa”
– 2. Saluran kemih bagian bawah, meliputi bladder neck,
prostat, sphincter urethra externa dan urethra sebagai “
jalan keluar urine”
Neuroanatomy and Neurophysiology of
micturition :
A. Peripheral :
1. Sympathetic : Filling /storage
2. Parasympathetic : voiding / emptying
3. Somatic : external sphincter
B. Central : four loops in Brain, Brainstem, Spinal cord
Peripheral innervation :
1.
1.
Afferents :
from detrusor stretch receptors, sphincter, perineum, genitalia
Efferents :
a. Parasympathetic S2 – S4
Receptors : Cholinergic – muscarinic ( at body of the bladder )
b. Sympathetic : T11 – L2
Receptors : Alpha adrenergic ( at sphincter)
Beta adrenergic ( at body of the bladder)
Central Innervation :
1.
1.
Loop I : Corticopontine-mesencephalic nuclei
From frontal lobe
Exerts inhibitory influence on parasympathetic
Sacral Micturition Center (SMS)
bladder storage
Lesions here
detrusor hyperreflexia
Loop II : Pontine-mesencephalic-sacral nuclei
Pontine Micturition Center (PMC)
To coordinate efficient detrusor and sphincter interaction
Lesions here and down
DSD
Central innervartion……..
3. Loop III : Pelvic-Pudendal nuclei :
“Sacral Micturition Center (SMC)
Lesions here
areflexic / atonic bladder
4. Loop IV : Motor Cortex to pudendal nuclei
Responsible for the voluntary control of the external
sphincter
Innervation of Lower Urinary Tract
• Bladder- cholinergic parasympatheticcontraction; beta-adrenergic & NO– relaxation
• Bladder neck – alpha-adrenergic- contration
• Urethral muscles- cholinergic parasympathetic,
NO, cholinergic somatic nerves
Innervation of the bladder
Sympathetic nerve
supply
Parasympathetic nerve supply
S2
L1
S3
L2
Pelvic nerve
L3
S4
Sympathetic
chain
Somatic
nerve supply
Hypogastric
ganglion
S2
S3
S4
Hypogastric
nerve
Urethra
External sphincter
Pudendal nerve
BLADDER FILLING
Physiology of Urine Storage
•
•
•
•
First sensation of filling
Fullness sensation
Urge sensation
Premicturition urge sensation- phasic detrusor
contraction
• Increased activity of urethral sphincter during
filling
Fase Pengisian Buli
• Terjadi relaksasi dari buli-buli dan kontraksi dari bladder neck
(dipengaruhi oleh saraf simpatis)
• Volume buli pada usia dewasa muda sekitar 500cc. Pada volume
sekitar 150cc sudah ada rangsangan untuk berkemih
• Pada volume 300cc rangsangan untuk berkemih semakin kuat
yang disertai pembukaan bladder neck secara spontan.
• Proses miksi masih bisa ditahan melalui sphincter urethra
externa (bisa diatur secara sadar/voluntary)
BLADDER EMPTYING
Fase Pengosongan Buli (berkemih)
• Dipengaruhi oleh sistem saraf parasimpatis
• Terjadi relaksasi dari otot sphincter urethra externa dan bladder
neck. Kemudian diikuti oleh kontraksi otot-otot detrusor Buli.
• Terjadi pengosongan buli sehingga volume urine di dalam bulibuli tidak tersisa atau residu urine kurang dari 50cc
Bladder filling and urine storage require:
• 1. Accommodation of increasing volumes of urine at a low intravesical
• 2. A bladder outlet that is closed at rest and remains so during increases
pressure and with appropriate sensation in intra-abdominal pressure
• 3. Absence of involuntary bladder contractions.
Bladder emptying requires:
• 1. A coordinated contraction of the bladder smooth musculature of
adequate magnitude
• 2. A concomitant lowering of resistance at the level of the smooth and
striated sphincter.
• 3. Absence of anatomic (as opposed to functional) obstruction.
Micturition detrusor pressure- depends
on urethral resistance
• High voiding pressure indicates a greater urethral resistance
• Low voiding pressure indicates a lower urethral resistance or a
low detrusor contractility
• Efficient bladder empty depends on a sustained detrusor
contraction
Efficient Bladder Empty
• Hypersensitive bladder- low detrusor contractility
• Inadequate contractility in elderly
• Bladder outlet obstruction- Bladder neck dysfunction,
Prostatic enlargement, Urethral stricture, Cystocele, External
sphincter dyssynergia
Abnormalities of micturition
1. Atonic bladder
This is due to destruction of sensory nerve fibers from urinary
from the bladder. When the dorsal sacral roots are interrupted by
diseases of the dorsal roots such as tabes dorsalis or when there is
crush injury to sacral segments of spinal cord, person looses
bladder control (abolition of reflex contractions of the bladder).
Bladder muscle looses the tone (hypotonic) and becomes flaccid).
Bladder fills to the capacity and overflows few drops at a time
through the urethra (overflow incontinence or overflow dribbling).
2. Automatic bladder (Spastic neurogenic
bladder)
During spinal shock after complete transection of spinal cord
above sacral centres of micturition, the urinary bladder looses
its tone and becomes flaccid and unresponsive. So, the bladder
is completely filled, and later urine overflows by dribbling. After
the spinal shock has passed, the voiding reflex returns although
there is no voluntary and higher centre control.
Whenever, the bladder is filled with some amount of urine,
there is automatic evacuation of the bladder.
Spinal Cord injury
• Abnormality in micturition cycle depend spinal cord injury’s
level :
– Above brain stem
detrusor hyperreflexia
– Above S2 segment
detrusor hyperreflexia with
detrusor external sphincter dyssynergia (DESD)
– Below S2 segment
detrusor areflexia with fixed
sphincter urethral external tone
3. Uninhibited neurogenic bladder
Due to a lesion in some parts of brain stem (interrupting mst
of the inhibitory signals), there is continuous excitation of
spinal micturition centres by the higher centres. There is
uncontrollable micturition. Even a small quantity of urine
collected in bladder will elicit the micturition reflex increasing
the frequency of micturition.
4. Nocturnal micturition (Bed wetting)
This is normal in infants and children below 3 years. It occurs due
to incomplete myelination of motor nerve fibers of the bladder
resulting loss of voluntary control of micturition .
Traktus Urinarius Bawah
• Gejala Iritatif
– Frekuensi
•
•
Frekuensi normal miksi orang dewasa sebanyak 5-6x/hari dengan setiap miksi
sebanyak 300cc
Penyebab :
1. penurunan kapasitas buli-buli termasuk bladder outlet obstruction dengan
penurunan daya regang buli, peningkatan residu urine, dan/atau penurunan
kapasitas fungsional buli karena iritasi
2. neurogenic bladder dengan peningkatan sensitivitas dan penurunan daya
regang buli
3. penekanan dari luar
4. anxietas.
– Disuria : nyeri pada saat kencing yang disebabkan oleh proses
inflamasi
– Nokturia : merupakan frekuensi yang terjadi malam hari
•
•
•
Normal : orang dewasa tidak terbangun lebih dari 2x semalam untuk miksi
Produksi urine pada penderita geriatri meningkat pada malam hari
Merupakan efek sekunder dari bladder outlet obstruction dan panurunan
daya regang buli
Gejala Obstruksi
1.
Penurunan pancaran kencing
•
Merupakan akibat dari bladder outlet obstruction (biasanya oleh BPH
atau striktur urethra).
•
Karena prosesnya berjalan perlahan-lahan maka seringkali tidak
dikeluhkan oleh penderita.
2.
Hesitansi : memerlukan waktu yang lama untuk memulai miksi
3.
Intermittensi : proses miksi terputus-putus
4.
Post void dribbling : keluarnya urine setelah akhir proses miksi
5.
Straining : harus mengejan untuk memulai proses miksi
• Penyakit-penyakit lain yang dapat menimbulkan keluhan iritatif :
– Penyakit neurologis (contoh : cerebrovascular accidents, diabetes mellitus dan
Parkinson's)
– Karsinoma buli-buli in situ
Inkontinensia Urine
Definisi : Keluarnya urine tanpa disadari (involunter)
a. Continuous Incontinence
– Penyebab : fistula traktus urinarius, ektopik ureter
b. Stress Incontinence
– Stress incontinence merujuk pada keluarnya urine secara
tiba-tiba pada saat batuk, bersin olahraga atau aktivitas
lain yang meningkatkan tekanan intra-abdominal.
c. Urgency Incontinence
– Merupakan keluarnya urine yang disebab dorongan kuat
yang mendadak untuk berkemih.
– Biasanya terjadi pada penderita sistitis, neurogenic bladder
atau obstruksi bladder outlet berat dengan hilangnya daya
regang buli.
d. Overflow Urinary Incontinence /Inkontinensia paradoksal
– Merupakan efek sekunder dari retensio urine dan volume residual urine yang
tinggi. (terjadi distensi buli secara kronis dan tidak dapat mengosongkan
kandung kemih secara tuntas)
e. Enuresis
– Merupakan inkontinensia urine yang terjadi pada waktu tidur.
– Secara normal terjadi pada anak-anak hingga usia 3 tahun, tetapi tetap ada
pada 15% anak usia 5 tahun dan 1 % pada usia hingga 15 tahun ( Forsythe and
Redmond, 1974 ).
– Setiap anak berusia diatas 6 tahun dengan enuresis harus dilakukan
pemeriksaan urologis
Pharmacology of Micturition- Increase
storage efficiency
• Reduce detrusor overactivity
• Anticholinergic agents- oxybutynine, flavoxate, imipramine
• Ganglion blocker- bentyl
• Beta-adrenergic agents
• Botulinum toxin
• Vanilloid receptor blockers- capsaicin, resiniferatoxin
Pharmacology of Micturition- Increase empty
efficiency
• Parasympathomimetic agent- Urecholine
• Adrenergic blockers- inhibition of detrusor relaxation (?)
Pharmacology of Micturition- Increase outlet
resistance
• Increase smooth muscle tone
Imipramine, methylephedrine
• Increase striated muscle tone
Nitric oxide synthase inhibitor
Pelvic floor muscle training
Pharmacology of Micturition- Decrease
outlet resistance
• Decrease bladder neck & urethral resistance
• Alpha-adrenergic blockers- dibenyline, terazosin, tamsulosin,
doxazosin
• Nitric oxide donors
• Botulinum toxin
• Polysynaptic blocker – baclofen, diazepam