urinary Bladder anatomy 2

urinary Bladder anatomy 2

1. Dept of Urology
GovtRoyapettahHospital and KilpaukMedical College
Chennai
1

2. Moderators:
Professors:
Prof. Dr. G. Sivasankar, M.S., M.Ch.,
Prof. Dr. A. Senthilvel, M.S., M.Ch.,
Asst Professors:
Dr. J. Sivabalan, M.S., M.Ch.,
Dr. R. Bhargavi, M.S., M.Ch.,
Dr. S. Raju, M.S., M.Ch.,
Dr. K. Muthurathinam, M.S., M.Ch.,
Dr. D. Tamilselvan, M.S., M.Ch.,
Dr. K. Senthilkumar, M.S., M.Ch.
Dept of Urology, GRH and KMC, Chennai. 2

3. ➢Hollow, retroperitoneal organ
➢Pyramidal in shape
➢Capacity about 400-500ml
➢When empty bladder, tetrahedral in shape
➢Apex, base, superior, two inferolateralsurface, &
neck
3Dept of Urology, GRH and KMC, Chennai.

4. RELATIONS
➢Apex -pointed anterior
-lies behind upper
margin of pubic
symphysis
-connected to
umbilicus by umbilical
ligament
4Dept of Urology, GRH and KMC, Chennai.

5. ➢Base (posterior) -triangular
-superolaterallyjoins by the ureter
-inferior angle rise to urethra
-two vas lie side by side on posterior
-upper part-covered by peritoneum, forms
ant wall of rectovesicalpouch
-lower part –seperatesfrom rectum by
seminal vesicles & recto vesicalfascia
5Dept of Urology, GRH and KMC, Chennai.

6. 6Dept of Urology, GRH and KMC, Chennai.

7. ➢Superior ;
covered with peritoneum
when bladder fills , bladder becomes
contact with anterior abdominal wall
➢Inferolateral-
related to front of retro pubic, perivesicalpad of
fat & loose connective tissue-SPACE OF RETZIUS
7Dept of Urology, GRH and KMC, Chennai.

8. 8Dept of Urology, GRH and KMC, Chennai.

9. ➢Neck-
lies inferiorly
rests on prostate
held in positions –puboprostaticligament
➢Interior-
mucous membrane are thrown into folds-
empty bladder,
disappears on full bladder
9Dept of Urology, GRH and KMC, Chennai.

10. LIGAMENTS OF BLADDER
➢TRUE LIGAMENTS
1. Median umbilical ligament( Urachus) -
dome of bladder to umbilicus
2. Lateral umbilical ligament-lateral wall of
bladder to tendinousarch of pelvic fascia
3. Medial umbilical ligament –inguinal ligament
( OBLITERATED UMBILICAL ARTERY)
4. Medial & lateral Puboprostatic ligament -
pelvic wall to prostate gland
10Dept of Urology, GRH and KMC, Chennai.

11. 11Dept of Urology, GRH and KMC, Chennai.

12. ➢False ligaments
Superior false ligament –course the urachus
Lateral false ligament -bladder to wall of
pelvis
Lateral superior ligament –covers the medial
umbilical ligaments
Posterior ligament -around rectum to ant
aspect of sacrum
12Dept of Urology, GRH and KMC, Chennai.

13. PERITEONAL RELATIONS
➢Covers superior &
posterior surface of
bladder
➢Continues along surface
of bladder as
rectovesicalpouch of
douglas
13Dept of Urology, GRH and KMC, Chennai.

14. TRIGONE
➢Triangle of smooth urotheliumbetween two
uretericorifice and internal urethral meatus
➢Firmly adherent to muscular coat
➢superior angle-corresponds to uretericorifice
➢inferior angle –internal urethral orifice
➢muscular thickened between uretericorifice –
INTERURETERIC CREST or MERCIER BAR
➢between uretersand internal urethral meatus
BELL MUSCLE
14Dept of Urology, GRH and KMC, Chennai.

15. ➢Three distinct layers
➢SUPERFICIAL-
derived from longitudinal
layers of uretericsmooth
muscle and inserts to
verumontenum.
➢DEEP –
Continues from waldeyer’s
sheath(fibroelastictissue)
which inserts into bladder
neck.
15Dept of Urology, GRH and KMC, Chennai.

16. ➢Detrussorlayers –
from outer longitudinal
& middle circular and inner longitudinal.
These fibers form a network that enables coor-dinated
emptying of the bladder.
Longitudinal fibers are continuous with the prostatic
urethra.
The circular fibers form the internal urethral sphincter.
16Dept of Urology, GRH and KMC, Chennai.

17. URETEROVESICAL JUNCTION
➢Spiral fibresof ureterbecomes longitudinally
& enchased in waldeyer’ssheath
➢enters the bladder posteroinferiorly course about
2 cm as intramural ureter& terminates at ureteric
orifice
➢unique anatomy of intramural ureter& trigone
contributes intrisiniccontinence, prevents UV reflex
17Dept of Urology, GRH and KMC, Chennai.

18. BLOOD SUPPLY
ARTERIAL
-Superior & inferior vesicalartery
through 1. Lateral
2. Posterior pedicle
-branch of internal iliac artery
multiple other branches arising from the hypogastric
artery also contribute to the vascular pedicles of the
bladder,
18Dept of Urology, GRH and KMC, Chennai.

19. 19Dept of Urology, GRH and KMC, Chennai.

20. 1.Superior vesicalartery :
-supplies the superior part of bladder
2.Inferior vesicle artery:
-supplies the lower ureter,bladder base , prostate
and the seminal vesicalin male
-in female supply the ureter,bladder base and
vagina
3.Trigone is mainly supplied by
-vesiculo-deferential artery in male
-uterine artery in female
20Dept of Urology, GRH and KMC, Chennai.

21. VENOUS
-The veins form a plexus within these pedicles and drain
to the internal iliac vein
LYMPHATIC
-lymphaticsfrom the bladder start in the lamina propria
layer and then drain largely to the external iliac lymph
nodes, with some drainage to the internal iliac and
obturatorlymph nodes as well.
significant cross-drainage of lymphaticsfrom the
bladder, with drainage to both sides of the pelvis .
21Dept of Urology, GRH and KMC, Chennai.

22. Peripheral Nerve Supply
Somatic (S2-S4)
Pudendalnerves
Excitatory to external
sphincter
Parasympathetic (S2-S4)
Pelvic nerves
Excitatory to bladder,
relaxes sphincter
Sympathetic (T10-L2)
Hypogastricnerves to
pelvic ganglia
Inhibitory to bladder body,
excitatory to bladder
base/urethra
Dept of Urology, GRH and KMC, Chennai.

23. Efferent fibers come from the anterior portion of the pelvic plexus.
The bladder has a high density of parasympathetic cholinergic nerve
endings, with relatively little sympathetic innervation.
There are also nonadrenergic, noncholinergic(NANC) fibers that
innervate the bladder and are thought to use purinesas
neurotransmitters (Yoshida et al., 2001).
The bladder neck has dense alpha 1-receptors in males, enabling
closure of the bladder neck for antegradeejaculation and aiding
continence.
Nitric oxide synthasecontaining neurons can also be found in the
bladder neck and trigone, which may promote relaxation during
micturition.
The afferent nerves from the bladder travel with the hypogastric
plexus to reach the dorsal root ganglia in the spine.
23Dept of Urology, GRH and KMC, Chennai.

24. HISTOLOGICAL STRUCTURE
➢Urothelium
-lined by transitional epithelium
-characterized by outer layer of umbrella
cells sealed closely together communicate
via tight junctions
➢Lamina propria
-connective tissue
24Dept of Urology, GRH and KMC, Chennai.

25. 25Dept of Urology, GRH and KMC, Chennai.

26. ➢Muscularispropria
detrusorsmooth muscle course in
outer-longitudinal, middle –circular
inner –longitudinal
-prominent at bladder neck
-middle layer continues as preprostaticsphincter
➢adventitia
26Dept of Urology, GRH and KMC, Chennai.

27. 27Dept of Urology, GRH and KMC, Chennai.

28. Normal LUT function
Two-Phase Concept:
Filling/Storage
Emptying/Voiding
28Dept of Urology, GRH and KMC, Chennai.

29. 29Dept of Urology, GRH and KMC, Chennai.

30. Bladder compliance (C) is defined as the change in
volume (V) relative to the corresponding change in
intravesicalpressure (P).
C = ΔV/ΔP
When there is decreased compliance of the bladder
(steep filling curve), it may be the result of multiple
factors including (1) fast filling rate; (2) change in
composition of the bladder wall (e.g., more
collagen, less elastin); (3) hyperactivity of the
smooth muscle; and (4) a combinationof any of
these factors.
30Dept of Urology, GRH and KMC, Chennai.

31. Neural pathway
Pelvic parasympathetic nerves arise at the sacral level
of the spinal cord, excite the bladder, and relax the
urethra.
Lumbar sympathetic nerves inhibit the bladder body
and excite the bladder base and urethra.
Pudendalnerves excite the EUS.
Afferent fibers innervate the LUT via pelvic,
hypogastric(lumber splanchnic), and pudendalnerves
31Dept of Urology, GRH and KMC, Chennai.

32. 32Dept of Urology, GRH and KMC, Chennai.

33. 33Dept of Urology, GRH and KMC, Chennai.

34. STORAGE PHASE VOIDING PHASE
34Dept of Urology, GRH and KMC, Chennai.

35. 35Dept of Urology, GRH and KMC, Chennai.

36. 36Dept of Urology, GRH and KMC, Chennai.

37. Bladder in Filling Phase
Bladder accommodation –
passive
dependent on visco-elastic property
Increase in collagen leads to decreased compliance
37Dept of Urology, GRH and KMC, Chennai.

38. Outlet in Filling phase
“Guarding reflex”
Urethral wall tension is not only a product of Smooth
and striated muscle but also of the elastic, collagenous,
and vascular components of the urethral wall
soft or plastic inner layer capable of being compressed
to a closed configuration
“Mucosal seal mechanism”
38Dept of Urology, GRH and KMC, Chennai.

39. Bladder in Voiding phase
inhibition of the spinal somatic and sympathetic
reflexes
activation of the vesicalparasympathetic pathways
the organizational center is in the rostral brainstem
shaping or funneling of the relaxed outlet-smooth
muscle continuity between the bladder base and the
proximal urethra
39Dept of Urology, GRH and KMC, Chennai.

40. Bladder Compartments
Urothelium
Lamina propriaand vasculature
Stroma–Collagen
Elastin and Matrix
Smooth muscle
40Dept of Urology, GRH and KMC, Chennai.

41. Smooth muscle -Detrusor
Detrusor cells contraction-“crossbridgecycling”
between the thick and thin filaments
Thick filaments (15nm diameter) –myosin. Thin
filaments (6to 8nm diameter) -actin.
41Dept of Urology, GRH and KMC, Chennai.

42. Action potential
Rise in intracellular Calcium
Calcium binds to CaM
Activation of MLCK
MLCK phosphorylates MLC20
Phosphorylated MLC20 forms crossbridges
42Dept of Urology, GRH and KMC, Chennai.

43. 43Dept of Urology, GRH and KMC, Chennai.

44. •Phase 1 fast upstroke of the
AP is composed of a Ca2+
inward current
•Phases 2 repolarization and
3 hyperpolarization of AP
are the result of a K+
outward current
•Blockage or inhibition of any
of these K+ channels would
promote myocyte
contractility and increase the
propensity of spontaneous
myocyeactivity. 44Dept of Urology, GRH and KMC, Chennai.

45. Propagation of Electrical Responses
Specialized proteins called connexin43 (gap-junction
proteins) are expressed between the membranes of
connected smooth muscle cells.
Detrusor is less well coupled electrically than other
smooth muscles.
Poor coupling could be a feature of a normal detrusor
that prevents synchronous activation of the smooth
muscle cells during bladder filling.
45Dept of Urology, GRH and KMC, Chennai.

46. 46Dept of Urology, GRH and KMC, Chennai.

47. Key Points
Muscarinic receptors induce detrusor contraction, in
response to AChreleased from parasympathetic nerve
terminals, by calcium entry through Ca2+ channels
The contractile response is slower and longer lasting
than that of skeletal and cardiac muscle
Interstitial cells or myofibroblasts-pacemakingrole in
spontaneous activity of the bladder.
47Dept of Urology, GRH and KMC, Chennai.

48. In addition to smooth muscle, the human bladder is
composed of roughly 50% collagen and 2% elastin.
With injury, obstruction, or denervation, collagen content
increases
When collagen levels increase, compliance falls.
Bladder wall thinning during filling is the result of a
rearrangement of the muscle bundles and also alteration of
collagen coil structure
During filling, the detrusor reorganizes and muscle
bundles shift position from a top-to-bottom to a side-to-
side configuration
48Dept of Urology, GRH and KMC, Chennai.

49. External urethral sphincter
Twitch type –slow twitch and fast twitch
Slow-twitch fibers -maintaining sphincter tone for
prolonged periods
Fast-twitch-add to sphincter tone rapidly to maintain
continence when intra-abdominal pressure is abruptly
increased.
49Dept of Urology, GRH and KMC, Chennai.

50. Male -35% fast-twitch and 65% slow-twitch fibers.
Female -87% slow-twitch and 13% fast-twitch fibers.
50Dept of Urology, GRH and KMC, Chennai.

51. `
THANK YOU.
51Dept of Urology, GRH and KMC, Chennai.