Anatomy of Lower Urinary Tract

1. Anatomy of Lower Urinary Tract Hann-Chorng Kuo Department of Urology Buddhist Tzu Chi General Hospital

2. Embryology of Lower Urinary Tract • Cloaca • Procodeum- ectodermal depression in hindgut • Cloacal membrane • Cloaca separates to urogenital sinus and rectum • Bladder proper – hallow muscular organ • Detrusor and urethral muscles have the same origin

3. Embryology of Lower Urinary Tract

4. Development of Urogenital Ductsin an 8-week old fetus

5. Development of Prostate and Female Genital Organs (12 weeks)

6. Embryology of Genital Tract • Mesonephric duct – ejaculatory duct • Fused Mullerian duct – prostate and membranous urethra (M), whole urethra (F) • Fused Mullerian duct – upper 2/3 of vagina, uterus, fallopian tubes (F)

7. The Urinary Bladder • A hallow muscular organ • Anterior wall – behind pubic symphysis • Apex – median umblical ligament – umbilicus • Dome – peritoneal covering • Posterior wall – trigone and ureteral orifices • Bladder neck - urethra

8. Sonography of Urinary Bladder

9. Cystography of Urinary Bladder

10. Structure of the Bladder • Epithelial lining – transitional cell • Loose submucosal connective tissue • Muscular wall • Serosal layer

11. Cystoscopy of Urinary Bladder

12. The Detrusor • Widely separated coarse muscle bundles • No definite orientation • Tree definite layers at the bladder neck • Longitudinal muscles fused to deep trigone and penetrate base of prostate gland • Muscle fibers wrap around the urethra and return to the bladder

13. Bladder Musculature in Cystoscopy

14. Anatomy of Bladder in Image Study • Smooth wall, well distended, smooth base • Trabeculation in bladder outlet obstruction • Bladder neck incompetence in stress incontinence • Cystocele in pelvic floor weakness • Bladder base elevation in prostatic enlargement • No vesico-ureteral reflux

15. Bladder Trabeculation in Cystogram

16. Stress Urinary Incontinence

17. Cystocele

18. Prostate Enlargement and Bladder Base Indentation

19. Blood Supply of the Bladder • Arterial supply – superior, middle,inferior vesical arteries branched from hypogastric artery • Also from inferior gluteal, obturator, uterine and vaginal ateries • Venous drainage – hypogastric veins • Communicating with retropubic venous plexus or Santorini plexus

20. Neuroanatomy of Bladder • Sympathetic nerves – T11-T12, L1- L2 • Sympathetic trunk- lumbar splanchic nerves – hypogastric plexus- pelvic plexus- trigone, lower end of ureter, bladder neck • Parasympathetic nerves – S2-S4 • Pelvic parasympathetic plexus- hypogastric plexus – vesical branches – detrusor • Sensory pathways – sympathetic (pain,touch, temperature) and parasympathetic nerves (stretch, fullness)

21. Neuroanatomy of Urinary Bladder

22. The Ureterovesical junction • Comprise (1) lower ureter, (2) trigone, (3) adjacent bladder wall • Waldeyer’s sheath- juxtavesical ureter • Intravesical ureter – intramural segment and submucosal segment • Ureteral muscle fiber continue to the trigone and extend to the bladder neck

23. Anatomy of Vesicoureteral Junction

24. The Trigone • Superficial trigone Continuous extension of longitudinal ureteral fibers to bladder base and proceed to urethra • Deep trigone Fibers of Waldeyer’s sheath continue downward to bladder base • Two trigone layers continue with the lower ureter

25. Function of Vesicoureteral Junction • Free efflux of urine from ureter to bladder • Prevent reflux of urine from bladder to ureter • As bladder is filled,the trigone is stretched • Increased resistance of the intravesical ureter • During detrusor contraction, trigone contracts concomitantly, completely sealing ureter against efflux and reflux

26. Vesicoureteral reflux during Voiding Phase

27. Vesicoureteral Reflux and Pseudodyssynergia in Child

28. Grades of Vesicoureteral Reflux

29. Appearance of Uretreral Orifice

30. The Bladder Neck • The trigonal musculature- superficial layer continue with ureteral muscle, deep layer continue with Waldeyer’s sheath • Detrusor distributes into three layers – inner longitudinal, middle circular, outer longitudinal m. • Bladder neck opens during voiding and closed during ejaculation

31. Cystoscopy of Bladder Neck

32. Postoperative Symphysis pubis Symphysis pubis Bladder Neck Incompetent urethra Incompetent Bladder Neck Urethra * * * * Sling Sling B A Sonography of Bladder Neck

33. Bladder Neck Incompetence in Urgency- Frequency and SUI

34. The Female Urethra • A 4-cm muscular tube in females • Inner longitudinal and outer circular musculature • Both muscles are connecting with the detrusor • Surrounded by striated skeletal muscle – external sphincter, in an omega shape • Pelvic floor muscles

35. Cystoscopy of Female Urethra

36. Sonography of Female Urethra

37. Relationship of Urethra and Pelvic Floor Muscles & Endopelvic Fascia Bladder Smooth muscle Striated Symphysis pubis Striated muscle Smooth muscle Urethropelvic ligament Smooth muscle

38. Relationship of Urethra and External Urethral Sphincter 逼尿肌 膀胱頸 黏膜下靜脈 直行平滑肌 尿道黏膜 環狀平滑肌 尿道橫紋肌 陰道黏膜 骨盆底肌肉

39. The Male Urethra • Striated external sphincter bulk around membranous urethra and extend over apex of prostate, especially anteriorly • Contains slow twitch (35%)-sustained tonus, fast twitch fatigable fibers (50%), and fast twitch fatigue resistant (15%)- for emergency • External sphincter is about 1 inch long and 6 mm deep

40. Cystoscopy of Male Urethra

41. Benign Prostate Enlargement

42. Transrectal Sonography of Male Urethra and Prostate 逼尿肌 恥骨聯合 尿 道 前列腺移行區 前列腺周圍腺體 儲精囊

43. Anatomy of Male Urethra and Adjacent Organs

44. Sonography of Prostate Enlargement

45. Transrectal Sonography of ProstateProstatic Transition Zone

46. The Male Urethra • Prostate urethra, Membranous urethra, Bulbous urethra, Penile urethra, Urethral meatus 膀胱 膀胱頸 前列腺尿道 尿道外括約肌 球莖狀尿道 陰莖尿道

47. Urethral Pressure Profile in Male

48. The Female Urethra • Mucosa is transitional epithelium, becoming stratified squamous toward meatus • Submucosa is very vascular • Innervated by parasympathetic cholinergic fibers and sympathetic alpha-adrenergic fibers • Abundant nitric oxide synthase in smooth muscle and striated muscles

49. Urethral Pressure Profile in Women

50. urethra Incompetent urethra * Sling * Cross Section of Female Urethra