2. 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.
3. 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.
5. SIZE AND SHAPE
• It is tetrahedral in shape when empty and ovoid in shape when
distended.
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.
6. EXTERNAL FEATURES AND RELATIONS
1. Apex.
2. Base.
3. Neck.
4. Three surfaces
(superior and two
inferolateral surfaces).
5. Four borders (anterior,
posterior and two
lateral).
7. APEX
• It provides attachment to the median umbilical ligament and lies
posterior to the upper margin of the pubic symphysis.
8. BASE
• In the male:
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 female, it is separated from the cervix of
uterus and by the vesicouterine pouch.
9. 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.
10. 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.
11. INFEROLATERAL
SURFACES
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.
13. LIGAMENTS
The ligaments of the bladder are of
two types—true and false.
1. Lateral ligaments (two in
number, right and left)
2. Puboprostatic ligaments (four in
number, two on each side—lateral
and medial)
3. Median umbilical ligament
4. Posterior ligament (two in
number, right and left)
False Ligaments
1. Anteriorly there are three folds
2. Laterally a pair of false lateral
ligaments
3. Posteriorly a pair of false
posterior ligaments
15. ARTERIAL SUPPLY
• 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.
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.