Transcript 35-rectum_&_urinary_..

RECTUM (LOCATION)
The rectum is the
most posterior
part of the pelvic
viscera.
It begins in front
of the 3rd sacral
vertebra.
As a continuation
of the sigmoid
colon.
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RECTUM (LOCATION)
It pierces the pelvic
diaphragm and
continues with the
anal canal in front of
the tip of the coccyx.
Its lower end is 
dilated to form the
rectal ampulla.
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ANORECTALJUNCTION
It bends downwards
and backwards at its
junction with the
anal canal.
It is pulled forwards
by the puborectalis
part of the levator
ani.
The anal canal 
moves in a posterior
direction.
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DESCRIPTION
The rectum follows the
anterior concavity of
the sacrum.
It has three lateral 
curvatures.
The upper and lower to
the right.
The middle to the left. 
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PERITONEUM
Upper 1/3 : 
Covered on the
front and sides.
Middle 1/3 : 
Covered on the
front.
Lower 1/3 : 
Devoid of 
peritoneum.
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MUSCULAR COAT
The longitudinal 
muscle fibers form
a broad band on
the anterior and
posterior surfaces.
MUCOUS MEMBRANE
With the circular
muscle layer, it
forms three
transverse folds
of the rectum.
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DESCRIPTION
Unlike the colon,
the rectum lacks:
Taeniae coli. 
Appendices. 
Sacculations. 
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POSTERIOR RELATIONS
Bones : 
Sacrum and coccyx. 
Muscles : 
Piriformis. 
Coccygeus. 
Levator ani. 
Nerves : 
Sacral plexus. 
Sympathetic trunk. 
ANTERIOR RELATIONS (MALE)
The upper 2/3 (covered 
by peritoneum) related
to:
The rectovesical pouch 
and its contents (coils of
ileum & sigmoid colon).
Lower 1/3 : 
Posterior surface of the 
bladder.
Prostate. 
Termination of the vas 
deferens and seminal
vesicle.
ANTERIOR RELATIONS
(FEMALE)
Upper 2/3 : 
Rectouterine 
(Douglas pouch)
and its contents.
Lower 1/3 : 
Posterior surface of
the vagina.
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ARTERIAL SUPPLY
(1) Superior rectal 
artery :
It is the main 
arterial supply to the
mucous membrane.
It is the direct 
continuation of the
inferior mesenteric
artery.
It divides into right 
and left branches.
ARTERIAL SUPPLY
(2) Middle rectal : 
It arises from the 
internal iliac.
It supplies the 
muscular coat.
(3) Inferior rectal: 
It arises from the 
internal pudendal.
It anastomoses with
the middle rectal.
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VENOUS DRAINAGE
The veins follow their 
arteries.
They drain to the 
following veins
respectively :
Inferior mesenteric. 
Internal iliac. 
Internal pudendal 
The union of the rectal 
veins form an important
porto systemic
anastomoses.
INTERNAL HEMORRHOIDS
The superior rectal 
vein divides into
right and left
branches.
The right branch 
redivides into
anterior and
posterior branches.
Internal hemorroides
are two on the right
side and one on the
left.
LYMPH DRAINAGE
Pararectal lymph nodes. 
Upper part : 
Follows the superior 
mesenteric artery to
inferior mesenteric nodes.
Lower part : 
Follows middle rectal 
artery to the internal iliac
nodes.
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NERVE SUPPLY
The rectum is 
sensitive to
stretch only.
Its sympathetic 
and
parasympathetic
supply is from
the inferior
hypogastric
plexus.
PELVIC PART OF URETER
(MALE)
It enters the pelvis
by crossing the
bifurcation of the
common iliac
vessels in front of
sacroiliac joint.
It descends in front
of the internal iliac
artery along the
lateral pelvic wall.
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PELVIC PART OF URETER
(MALE)
At the ischial spine:
It turns forwards. 
At its termination: 
It is crossed by the
vas deferens.
It enters the lateral
angle of the
bladder.
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PELVIC PART OF URETER
(FEMALE)
It runs downwards 
and backwards in
front of the internal
iliac artery and
behind the ovary.
At the ischial spine: 
It lies beneath the 
broad ligament.
It is crossed by the 
uterine artery.
URINARY BLADDER
It is the most 
anterior pelvic
viscera (just behind
the pubic bones).
POSITION (ADULTS)
The empty 
bladder:
Is a pelvic organ.
The full bladder:
Expands
superiorly into
the abdomen.
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POSITION (CHILDREN)
The empty 
bladder projects
above the pelvic
inlet because of
the small sized
pelvic cavity.
SHAPE
It is a three sided 
pyramid that lies on
one of its margins.
It has: 
Apex. 
Base. 
Neck. 
Superior and two 
Inferolateral surfaces.
APEX
Lies behind the 
upper margin of
the symphsis
pubis.
It is directed 
anteriorly.
The median 
umbilical ligament
(remnant of
urachus) connects
it to the umbilicus.
BASE (POSTERIOR SURFACE)
It faces 
posteroinferiorly.
It is shaped like an 
inverted triangle.
The two ureters enter
the bladder at each of
the upper corners of
the base.
The urethra drains 
inferiorly from the
lower corner.
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BASE
The terminal parts
of the two vasa
differentia lie side
by side on the
posterior surface.
They separate the
seminal vesicles
from each other.
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BASE (POSTERIOR SURFACE)
The peritoneum
covers its upper
part.
It forms the 
anterior layer of
the rectovesical
pouch.
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BASE (POSTERIOR SURFACE)
The lower part is
separated from
the rectum by:
Rectovesical
fascia.
Vasa differentia.
Seminal vesicles.
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POSTERIOR SURFACE (IN
FEMALE)
Is separated 
from the rectum
by the vagina.
SUPERIOR SURFACE
It is covered by 
peritoneum.
It is related to coils of 
ileum or sigmoid colon.
Laterally, the peritoneum 
is reflected onto the
lateral pelvic walls.
It forms the paravesical 
fossae.
SUPERIOR SURFACE (IN
FEMALE)
It is covered by
peritoneum.
It is related to:
Uterovesical
pouch.
Body of uterus.
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INFEROLATERAL SURFACES
Anterior : 
Retropubic pad of
fat .
Pubic bones. 
Posterior : 
Obturator internus
(above).
Levator ani 
(below).
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NECK
It is the most inferior
part of the bladder.
It surrounds the origin
of the urethra (at the
meeting of the
inferolateral surfaces
and the base).
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NECK
It rests on the upper 
surface of the
prostate.
It is held in position 
by a pair of
fibromuscular bands
(Puboprostatic)
ligament.
It is the most fixed 
part of the bladder.
NECK (IN FEMALE)
The bladder lies at
a lower level
because of the
absence of the
prostate.
The neck rests on
the upper surface
of the urogenital
diaphragm.
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NECK (IN FEMALE)
It is held in position by:
Pubovesical ligaments. 
FULL BLADDER
The posterior 
surface and the
neck remain
unchanged in
position.
Only the superior
surface rises into
the abdomen.
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MUCOUS MEMBRANE
Mostly in the 
empty bladder, it
is thrown into
folds.
These disappear 
when the bladder
is full.
TRIGONE
Its mucous membrane 
is always smooth
because it is firmly
adherent to the
underlying muscular
coat.
It is limited above by 
the interureteric ridge
(from the opening of
one ureter to the
other).
UVULA VESICAE
It is a small 
elevation
immediately
behind the
urethral orifice.
It is produced by
the median lobe
of the prostate.
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SUPPORT OF THE BLADDER
It depends on : 
1) The Puboprostatic
& Pubovesical
ligaments.
(2) Levator ani 
muscles.
(3) Pubic bones. 
(4) Perineal 
membrane and the
associated muscles.
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ARTERIAL SUPPLY
In male : 
Superior & inferior
vesical arteries.
In female : 
Superior vesical &
vaginal arteries.
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VENOUS DRAINAGE
Vesical plexus. 
It drains into: 
prostatic plexus
(in male).
Vaginal plexus 
(in female).
Internal iliac 
vein.
NERVE SUPPLY
Sympathetic : 
Inferior hypogastric
plexus.
Parasympathetic : 
Pelvic splanchnic 
nerves.
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