Physiology of Micturition

1. Physiology of Micturition Hann-Chorng Kuo Department of Urology Buddhist Tzu Chi General Hospital, Hualien

2. Neuroanatomy of Micturition • Storage– Stability and good compliance of Bladder • Empty – Contraction of detrusor and opening of Urethra • Parasympathetic - Pelvic nerve • Sympathetic - Hypogastric nerve • Somatic nerves- Pudendal nerve

3. Neuroanatomy of Lower Urinary Tract

4. Neuroanatomy of Micturition • Micturition reflex center – sacral cords 2-4 • Micturition control center – pons • Sensory motor center – frontal lobe • Limbic system • Cerebellum, Basal ganglia

5. Neuroanatomy of Micturition

6. Sensory Afferents • A-delta fibers – Micturition reflex, stretch and fullness sensation • C-fibers – Noxious sensation, capsaicin sensitive primary afferents (CSPA) • Dual sensory afferents in mammalian urinary bladder

7. Dual Sensory Innervation of Urinary Bladder

8. Storage of Urine • Stable bladder • Good compliance • Competent urethra- mucosa, submucosa, smooth muscles, striated skeletal muscles (external sphincter) • Good pressure transmission and hammock effect during stress

9. Stable Bladder in Filling Phase

10. Positive Pressure Transmission during Coughs in UPP Tracing

11. Poor Pressure Transmission during Coughs in Stress UPP

12. High Leak Point Pressure in SUI with good Hammock Effect

13. Empty of Urine • Sustained detrusor contraction- cholinergic parasympathetic fibers • Relaxation of bladder neck – alpha-adrenergic sympathetic nerves • Relaxation of external sphincter- cholinergic pudendal nerves • Patent non-obstructive urethra

14. Detrusor Contraction during Voiding Phase

15. Bladder Outlet Obstruction during Voiding Phase in Man

16. Bladder Outlet Obstruction during Voiding Phase in Woman

17. Neurophysiology of Micturition Reflexes 排尿中樞PONS 胸腰髓 T10-L2 交感神經節 薦髓 S2,3,4 膀胱 膀胱頸 括約肌

18. Modulation of Sympathetic nerves in Parasympathetic Ganglion 往橋腦排尿中樞 T10-L2髓 薦髓S2,3,4逼尿肌核 SIN 副交感神經節 尿道外括約肌

19. Innervation of Lower Urinary Tract • Bladder- cholinergic parasympathetic- contraction; beta-adrenergic & NO– relaxation • Bladder neck – alpha-adrenergic- contration • Urethral muscles- cholinergic parasympathetic, NO, cholinergic somatic nerves

20. 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

21. Urodynmic Tracing in Micturition

22. Initiation of Micturition- Relaxation of External Sphincter

23. Sustained Detrusor Contraction- Urethrovesical Reflex • Stretch receptors in urethral wall • Detrusor overactivity in urgency- frequency syndrome and SUI • Role of incompetent bladder neck • Low detrusor contractility in incompetent urethral sphincter after prostatectomy

24. 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

25. Detrusor instability and Inadequate contractility (DHIC)

26. Low Detrusor Pressure in Woman with SUI

27. Low Detrusor Pressure and BOO

28. Detrusor overactivity and BPO

29. 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

30. Urethral Stricture and BOO

31. Anterior Urethral Valve and BOO

32. Cystocele and BOO

33. Autonomic Dysreflexia

34. Detrusor External Sphincter Dyssynergia

35. Dysfunctional Voiding in Woman

36. Pseudodyssynergia in Girl with Incontinence and UTI

37. 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

38. Detrusor Overactivity after Resiniferatoxin Treatment

39. Initial Excitatory Responses after Capsaicin Treatment

40. Pharmacology of Micturition- Increase empty efficiency • Parasympathomimetic agent- Urecholine • Adrenergic blockers- inhibition of detrusor relaxation (?)

41. Pharmacology of Micturition- Increase outlet resistance • Increase smooth muscle tone Imipramine, methylephedrine • Increase striated muscle tone Nitric oxide synthase inhibitor Pelvic floor muscle training

42. 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

43. Reduction of MUCP after Nitric Oxide Donors (NTG)

44. Improved Voiding Efficiency after Botulinum Toxin Injection

45. Decreased MUCP after Botulinum Toxin Injection

46. Combination of Medication- Improve Voiding Efficiency • Increased bladder sensation- intravesical capsaicin, RTX • Detrusor overactivity- anticholinergic, intravesical RTX, botulinum toxin • Detrusor underactivity – parasympathomimetics, alpha-blocker, NO donors, striated muscle relaxant, periurethral botulinum toxin injection

47. Combined Medication – Improved Voiding Efficiency Urethral sphincter hypertonicity- alpha-blocker, NO donors, striated skeletal muscle relaxant • Urethral sphincter overactivity- alpha-blocker, striated muscle relaxant, NO donors, botulinum toxin • Bladder neck dysfunction- alpha-adrenergic blocker

48. Combined Medication- Improved Storage Efficiency • Detrusor Overactivity- anticholinergics, sympathomimetics, imipramine • Intrinsic sphincter deficiency- imipramine, sympathomimetics • DHIC- depends on voiding efficiency and grades of incontinence