This document provides an overview of the anatomy of the urinary bladder. It describes the urinary bladder as a muscular reservoir located in the pelvis that stores urine. It details the bladder's location, size, shape, capacity, external features and internal structure. It also discusses the arterial supply, venous drainage and nerve supply of the urinary bladder. The document is intended to provide clinicians with important anatomical information about the urinary bladder and its clinical relevance.

1. THE URINARY BLADDER
Presented by: Dr Diksha Ojha
Assisstant Professor
Department of Anatomy
University of Patanjali

3. INTRODUCTION
 The urinary bladder is a muscular
reservoir of urine
 lying in the anterior part of the pelvis.
 It is commonly involved in clinical
conditions such as retention of urine,
cystitis (inflammation of the urinary
bladder), calculus, disorder of
micturition, and cancer.
 Hence, its anatomy is of immense
importance to clinicians

4. Location
 The urinary bladder is situated in the
anterior part of the lesser pelvis
immediately behind the pubic symphysis
and in front of rectum in male and uterus
in the female.
 When the bladder is empty it lies entirely
within the lesser pelvis but when it
becomes distended with urine, it
expands upward and forward into the
abdominal cavity.

7. Size and shape
 It is tetrahedral in shape when empty
and ovoid in shape when distended.

8. Capacity
 Normally in adult male the capacity varies
from 120 to 320 ml.
 The mean capacity is about 220 ml.
 1. An amount of urine beyond 220 ml
causes a desire to micturate but the
bladder is usually emptied at about 250–
300 ml.
 2. The filling of urine up to 500 ml may be
tolerated but beyond this, it causes pain
due to tension of its wall. On collection of
urine about 800 ml, the micturition is
beyond one’s voluntary control.

9. External features
 The urinary bladder has
1. Apex
2. Base
3. Neck
It has 3 surfaces and 4 borders
Surfaces :
 superior surface
 2 inferolateral surface
Borders:
 Anterior border
 Posterior border
 2 lateral borders

11. Apex
 It provides attachment to the median
umbilical ligament and lies posterior to
the upper margin of the pubic
symphysis.

12. Base
In males:
 1. Upper part is separated from rectum by the
rectovesical pouch containing coils of the
small intestine.
 2. Lower part is separated from rectum by the
terminal parts of vasa deferentia and seminal
vesicles.
 3. The triangular area between the vasa
deferentia is separated from the rectum by
rectovesical fascia (of Denonvilliers).
In the females :
 It is separated from the cervix of uterus and by
the vesicouterine pouch

13. Male Female

14. Neck
 It is the lowest and most fixed part of the
bladder. It is situated where the
inferolateral and the posterior surfaces of
the bladder meet. It is pierced by the
urethra. Its relations are:
 In the male, it rests on the upper surface
of the prostate where the smooth muscle
fibres of the bladder wall are continuous
with those of the prostate.
 In the female, it is related to the urogenital
diaphragm.

17. Superior surface
 In the male, it is completely covered by
the peritoneum which separates it from:
 coils of the ileum,
 sigmoid colon.
 In the female, it is covered by the
peritoneum except for a small area near
the posterior border, which is related to the
supravaginal part of the uterine cervix.
Here the peritoneum is reflected on to the
uterine isthmus forming vesicouterine
pouch

19. Inferolateral surface
 The inferolateral surfaces are devoid of
peritoneum and in both male and female
are related:
 In front to
– retropubic space,
– pubic symphysis, and
– puboprostatic ligaments.
 Behind to
– obturator internus muscle above, and
– levator ani muscle below.

20. Internal structure of Urinary
Bladder

21.  There is a triangular area, called the trigone,
formed by three openings in the floor of the
urinary bladder.
 Two of the openings are from the ureters and
form the base of the trigone.
 Small flaps of mucosa cover these openings
and act as valves that allow urine to enter the
bladder but prevent it from backing up from
the bladder into the ureters.
 The third opening, at the apex of the trigone,
is the opening into the urethra.
 A band of the detrusor muscle encircles this
opening to form the internal urethral
sphincter.

22. Arterial supply of urinary
bladder
 superior and inferior vesical arteries
which are the branches of anterior
division of internal iliac arteries.
 Obturator and inferior gluteal arteries.
 Uterine and vaginal arteries in the
female.

23. VENOUS DRAINAGE
 The veins of the bladder do not follow the arteries.
 They form a complicated plexus on the inferolateral
surfaces near the prostate called vesical venous
plexus.
 1. This plexus passes backward in the posterior
ligaments of the urinary bladder to drain into the
internal iliac veins.
 2. It communicates:
 (a) In the male with the prostatic venous plexus.
 (b) In the female with the veins at the base of broad
ligament

25. Nerve supply to urinary bladder
 Vesical plexus of nerves containing both
sympathetic & parasympathetic
components.
 PARA SYMPATHETIC: S2-S4
 SYMPETHETIC: T10- L2