Pelvis lectures.pdf

Pelvis
Prof. Dr. Mona Mohamed
Attia
Professor of Anatomy and
Embryology
Tanta Faculty of Medicine

Bones of the pelvis

Is divided into two parts by
The pelvic brim
-
-
Pelvic cavity
is formed of :
the pelvic brim
Posterior.
The sacral promontory
Laterally,
the ileo-pectineal
lines
- Anterior,
symphysis pubis
The greater (false) pelvis is located above
the pelvic brime.
The lesser (true) pelvis is located below
it.
The pelvic brim
Pelvic inlet

Greater pelvis (flase pelvis)
Posterior,
sacrum
On each side
muscle
the lumbar vertebrae and the base of the
,
the iliac fossa and ilacus
Anterior , the anterior abdominal wall
It is considered as a part of the
abdominal cavity

Lesser pelvis (true pelvis)
Pelvic inlet:
Anterior: -
Posterior: -
On each side:
-

Pelvic outlet:
Anterior:
On each side
Posterior:

Ligaments of the pelvis
Sacrotuberous ligament:
Superior
Inferior

Sacrospinous ligament:
From the ischial spine
to the lateral margins of
sacrum and coccyx.
It is the degenerated
dorsal part of coccygeus
muscle
It lies ventral to the
sacrotuberous

Pelvic cavity (True pelvis)
It lies between the inlet and outlet of the
pelvis
It is posterior wall is longer than its
anterior wall

Pelvic cavity
It lies between the inlet and outlet of the
pelvis
It is posterior
anterior wall
wall is longer than its
Walls of the pelvic cavity:
Anterior:
symphysis pubis,
pubic rami
Posterior:
anterior surface of sacrum
and coccyx, piriformis muscle& parietal
pelvic fascia
On each side; ilium & ischium,sacrotuberous&
sacrospinous ligaments, obturator membrane
&obturator internus and its covering fascia
Inferior: the floor of the pelvis (pelvic
diaphragm), the levator ani and
coccygeus muscles and their covering
fascia

The muscles of the pelvic walls
1- Piriformis
N S1,2
2- Obturator internus
L5&S1,2

3- Levator ani muscle

3-Levator ani muscle
•Origin: along a line
from the back of the
body of the pubis (a),
obturator fascia (b)
(white line) and the
ischial spine (c).
The Levator ani of both sides meet
together forming the greater part of the
floor of the pelvis.
the fibers of levator ani can be
differentiated into three parts ..
anterior (1),
intermediate (2) &
posterior (3)
Insertion: by fleshy fibers into
1 Perineal body
3Anococcygeal body
4Tip of coccyx
a
b
c
1) Levator prostatae
●
●
●
●
1
Rectum
2
3) Ilio-coccygeus
2) Pubo-rectalis
3

INSERTION OF LEVATOR ANI
Anterior fibers:
which are called
levator prostatae in male or
sphincter vaginalis in female.
In male,
they pass across the -
sides of the prostate gland to
reach their insertion into the
perineal body and tip of the
. coccyx
In female,
they pass across the -
side of the vagina to reach their
Insertion into the perineal body.
The fibers of both sides thus
. form a sphincter for the vagina
Middle fibers or
pubo-rectalis
Post. fibers or iliococcygeus
Ischial
spine
Coccygus m.
Ilio
coccygeu
s
Pubic bone
Coccyx
Urethra
Vagina
Ano
coccygeal
body
Prostate
Sphincter
vaginalis
Ant. fibers or
levator prostatae
Perineal
body
Pubo
rectalis
Anal canal
Ano coccygeal
body
Perineal
body
Ana
l
can
al

Middle fibers (Pubo-rectalis)
:
arise from the body of the
. pubis
They meet the fibers of the -
opposite side forming
together a U-shaped sling
around the recto-anal
. junction
Posterior fibers (Ilio-
:They sweep coccygeus)
downwards and medially to be
inserted into the side of the
anal canal, ano-coccygeal
body and the last two pieces
. of coccyx
RELATIONS OF LEVATOR ANI
Obturator
Internus
Origin of
levator ani
Middle fibers or
Pubo-rectalis
Rectum
Anal canal

Relations of levator ani:
Pelvic (upper) surface:
●In
male,
it is related to the
urinary bladder, prostate, seminal
vesicles and rectum from before
backwards.
In female,
it is related to the
urinary bladder (1). Vagina(2),
broad ligament and rectum (3)
from before backwards.
Perineal (lower) surface: forms
the medial wall of the ischio-
rectal fossa.
Ant. border
Pevic surfac of
levator ani
1
2
Pelvic
diaphragm
Pelvis
3
Obturator
Internus
Perineal
surface of
Post. border levator ani
3
Relations of
female levator
ani
Pelvic wall
Perineum

PELVIC DIAPHRAGM
It is formed of the levator ani
and coccygeus muscles of both
sides.
This diaphragm forms a
partition between the pelvis and
perineum.
Pelvic
diaphragm
Pelvis
Obturator
Internus
Pelvic wall
Perineum

Pelvic Fascia
1-Parietal pelvic fascia
1-Parietal pelvic fascia
On the lateral pelvic wall: The obturator fascia.
On the posterior pelvic wall: Piriformis fascia.
On the pelvic floor:
fascia of the pelvic diaphragm
a- Superior fascia of the pelvic diaphragm.
b- Inferior fascia of the pelvic diaphragm
2- Visceral pelvic fascia

2- Visceral pelvic fascia
Puboprostatic ligaments. In female pubovesical ligament -
Lateral ligament of the uterus and bladder-
-
Fascial septa : in male rectovesical septum. In female
rectovaginal septum

PERITONEAL COVERING OF THE PELVIC VISCERA IN MALE
Rectum:
upper third:
front and
sides, middle third:
front only,
lower third: no peritoneal
covering.
Anal canal: no peritoneal
covering.
Urinary bladder: only its upper
surface and uppermost part of
its posterior surface.
Seminal vesicle: only its upper
end. Prostate gland: no
peritoneal covering.

PERITONEAL COVERING OF THE PELVIC VISCERA IN FEMALE
Rectum:
-Upper third: front and sides.
-Middle third: front only.
-Lower third: no peritoneal covering.
Anal Canal: no peritoneal covering.
Vagina: Upper most part of its posterior
wall.
Uterus
-Fundus:anterior, upper and posterior
aspects.
-Body: anterior and posterior surfaces.
-Cervix: posterior surface only.
Urinary bladder: upper surface only.
Ovary: is attached to the upper surface
of the broad ligament by mesovarium.

ARTERIES OF THE PELVIS
External iliac artery
Internal iliac artery
Median sacral artery.
Superior rectal artery
Gonadal arteries

External iliac artery
It’s the larger of the two
terminal branches of the
common iliac artery. It
begins opposite the disc
between the 5 th L and 1 st S
vertebra
It extends to the midinguinal
point, behind the
inguinal ligament where
it enters the thigh as the
femoral artery.

External iliac artery
At its origin:
the ureter.
in both sexes its crossed by
In female its crossed by the ovarian
vessels.
Along its course:
peritoneum
its coverd by the parietal
Near its end,
the artery is crossed by
genital branch of genito-femoral nerve.
In male,
vas deferen & testicular
artery
In female , round ligament of
uterus
Postero-laterally, its related to the psoas
major muscle.

External iliac artery
Branches,
it gives off 2 branches
just above the inguinal ligament:
1- Inferior epigastric artery.
2- Deep circumflex iliac artery.

INTERNAL ILIAC ARTERY
Origin: Its one of the two terminal
branches of the common iliac artery.
Its begins opposite the disc between the 5 th
lumbar and 1 st sacral vertebra.
Course: It descends in front of sacroiliac
joint into the pelvis. It passes downwards
and backwards and ends at the upper
margin of greater sciatic foramen by
dividing into anterior and posterior
divisions.

Relation:
Anterior-inferior:
Ureter –
Ovary
Posterior-
superior:
Internal iliac vein – lumbosacral trunck –
sacroiliac joint.
Laterally: Exteranal iliac vein – obturator nerve.
Medially: Parietal peritoneum- Ileum on the right side-
Sigmoid colon on the left side

Branches of posterior division:
1.Ilio-lumbar artery (I).
2.Lateral sacral arteries (II).
3.Superior gluteal artery (III).
All branches of the posterior
division are parietal.
INTERNAL ILIAC ARTERY
Branches of anterior division:
Parietal:
1-obturator artery (1).
2-internal pudendal artery (2).
3-inferior gluteal artery (3).
Visceral:
1.Umbilical artery (A) and its
superior vesical (a) branches.
2.Middle rectal artery (B).
3.Interior vesical artery (C) in male
(vaginal artery in female).
4.Uterine artery in female (C).
Umblicus
Median
umblical lig.
a
Urinary
bladder
Ant. division
A
B
Int. iliac a.
1
C
Rectum
III
I
Post.
division
3
2
I
II
II
Piriforms
Sacrum

Branches of posterior division:

Branches of anterior division:

Median sacral artery.
Its arises from the back of the lower end of
Abdominal aorta just above its bifurcation
Its descends in the median plane over
the 4th and 5th lumbar vertebrae.
It ends in a fibro-cellular mass in front
of the coccyx known as glomus coccygeum.
Branches:
The 5 -
th pair of lumbar arteries1
Twigs to the sacrum. -
Twigs to the rectum and anal canal-

This plexus is formed
by:
the lumbosacral
trunk and
the ventral rami of
the upper three and
upper part of the
fourth sacral nerves .
SACRAL PLEXUS

A. From the
roots
BRANCHES OF SACRAL PLEXUS
of the Plexus:
1.Muscular
branches:
to the piriformis (S1,S2),
levator
ani , and coccygeus and to the sphincter ani externus
(S4).
2.Pelvic
splanchnic nerves (S2,S3):
These constitute
the sacral part of the parasymphatetic system.
-They unite with the sympathetic pelvic plexus to be
distributed to the pelvic viscera and lower part of the
colon along the blood vessels.

B. From the ventral surface of the plexus:
1.Nerve to quadratus femoris (L. 4.5, 5.1).
2.Nerve to obturator internus (L. 5.5, 1.2).
C. From the dorsal surface of the plexus:
1.Superior gluteal nerve (L. 4.5, 5.1).
2.Inferior gluteai nerve (L. 5.5, 1.2).
D. From both ventral and dorsal surfaces of
the plexus:
-Posterior cutaneous nerve of the thigh (S.
1, 2, 3)..
E. Terminal branches:
1.Sciatic nerve (L. 4,5 S. 1, 2, 3)
2.Pudendal nerve (S. 2, 3, 4,).
BRANCHES OF SACRAL PLEXUS

URINARY BLADDER

PARTS OF URINARY BLADDER

PERITONEAL COVERING OF BLADDER IN MALE AND FEMALE

APEX AND NECK OF URINARY BLADDER IN MALE AND FEMALE

RELATIONS OF URINARY BLADDER

INFERO-LATERAL SURFACE & RETRO PUPIC SPACE

RELATIONS OF THE BASE OF URINARY BLADDER

INTERIOR OF URINARY BLADDER

Thanks

ARTERIAL SUPPLY OF URINARY BLADDER
1.Superior vesical artery
(1):-Branch from the
umbilical artery.
2.Inferior vesical artery
(2):-Branch of the anterior
division of the internal
iliac artery, in male. In
female, it is replaced by
branches from the vaginal
and uterine arteries.
3.Twigs from obturator &
inferior gluteal arteries.
1
2
Umbilical a.
3
Int. iliac

The ureter is 10 inches
(25cm) long , with
its upper ½situated
in the abdomen
proper and its lower
½ in the pelvis.
Parts of the ureter:
Abdominal
Pelvic
Intramural
URETER

PELVIC PART OF THE URETER
The ureter enters the pelvis by
crossing the end of the common iliac
artery on each side (1).
-Then, it passes backwards and
downwards along the lower border of
the internal iliac artery (2).
-At the level of the ischial spine (3) it
curves forwards and medially to reach
the posterosuperior angle of the
bladder (4).
Ureter
4
1
2
3
Pelvic floor
Ureter
Ureter

RELATIONS OF THE PELVIC PART OF URETER
•It is covered medially by
peritoneum. As it descends, it
crosses the external iliac artery (1),
external iliac vein (2), obturator
nerve (3) obturator artery (4) and
obturator vein from above
downwards.
Ischial spine
4
Urinary
bladder
3
Ureter
2
1

In male,
it is crossed by the vas
deferens near the wall of the
bladder.
It crosses the upper end of the
seminal vesicle.
In female, it passes closely lateral
to the upper end of the vagina
below the root of the broad
ligament. In this part of its course
the ureter is crossed above by the
uterine vessels.
PELVIC PART OF THE URETER
Ureter crossed by
uterine vs.
Ureter lat. to vagina
Female
Ureter
Vagina
Uterine artery

INTRAMURAL PART OF URETER
•The ureter runs a very oblique
course through the bladder wall for
about 2cm before it opens into the
bladder. This arrangement forms a
valve-like mechanism which
prevents reflux of urine into the
ureter when the bladder is
distended.
Ureteric orifice
Intramural part of
ureter
Bladder wall

NORMAL CONSTRICTIONS OF THE URETER

Arteries of the ureter :
The ureter gets its
arterial branches
from:
Renal artery (supplies
the renal pelvis).
Abdominal aorta.
Gonadal artery.
Common iliac artery.
Internal iliac artery.
Uterine artery (in the
female).
Inferior vesical artery
BLOOD SUPPLY OF URETER

PROSTATE GLAND
Shape: the prostate glands is conical inshape,
having a base (1), an apex (2), anterior
(3), posterior (4) and two infero-lateral
surfaces.

RELATIONS:
Base:
directed upwards It is
continuous with the neck of
bladder, and is pierced by urethra.
●Apex:
Lies on the pelvic fascia
●Anterior
surface:
behind the
symphysis pubis gives
attachments to puboprostatic
ligaments.
●Posterior
surface: flattened, and
is related to the rectum.
-the ejaculatory ducts pass
throught its upper part.
●Inferolateral
surfaces: related to
levator ani on each side
Median lobe of
prostate
Post.
Ejaculatory
duct
Prostatic
sheath
Apex of prostate
Deep Perineal
pouch
Urinary bladder
Deep perineal pouch
Membranous
urethra
Ant.
Prostatic plexus of
veins
Pubo prostatic lig.
Pubic
bone
Deep dorsal
of penis
Perineal
membrane

Lobes of the gland:
1. The median lobe:
-It is the part of the gland which
intervenes between the
ejaculatory ducts on either
sides and behind the prostatic
urethra. 2.The right and left
lobes
-They occupy the right and left
sides of the gland respectively
.
Blood supply of the prostate:
LOBES OF PROSTATE GLAND
Urinary
bladder
-Arteries: The arterial supply of the prostate is
derived from branches of the following arteries: 1.
Inferior vesical, 2. Middle rectal, 3. Internal
pudendal.
-Veins:The veins drain the prostate form a plexus
embedded in its fascial sheath.
The plexus then drains into internal iliac veins.
●
Ejaculatory
duct
Prostate
Prostatic
urethra
Median
lobe
Symphysis
pubis
Lt. lobe
Prostate
Post. surface
of urinary
bladder
Rt. lobe

MALE URETHRA
This is a long canal, about 20 cm.
(8 inches), which conveys urine and
semen to the outside of the body.
Divisions:
1. prostatic part,
2.membranous part,
3. spongy part.

PROSTATIC URETHRA
This part is about one inch long.
-It is the widest and most dilatable division of
the urethra.
-The mucosa on the posterior wall presents a
median ridge known as the urethral crest. The
grooves along the sides of the crest are
known as the prostatic sinuses.
About the middle of the gland, the urethral
crest forms a rounded elevat-ion known as
the seminal colliculus.
-The prostatic utricle.
-It is about half an inch long and opens on the
seminal colliculus.
-The ejaculatory ducts open on the seminal
colliculus
-The prostatic ducts open on each side of
the urethral crest into the prostatic sinuses.

MEMBRANOUS & SPONGY URETHRA
Membranous urethra:
-This part is about half an inch long. It is the
narrowest and least dilat-able division of the
urethra.
-It begins at the lower part of the prostate
gland and traverses the deep perineal pouch.
-It is sur-rounded by the sphincter urethrae.
●Spongy
(penile) urethra:
This is longest division of the urethra.
-It enters into the bulb of the penis, and
transverses the bulb and corpus
spongiosum lengthwise.
-In the bulb, the urethra expands to form a
dilatation called the intrabul bar fossa.
-At its termination in the glans penis, the
urethra expands also to form a dilatation
known as the fossa terminalis (fossa
navicularis). The fossa navicularis narrows
to form the external urethral orifice, which is
the narrowest point of the whole urethra.

FEMALE URETHRA
the female urethra is very short, being about
4 cm. long.
-It is wider and more dilatable than the male
urethra.
-It begins at the neck of the bladder and
descends down-wards and forwards.
-It traverses the deep and superficial perineal
pouches, and opens into the vestibule (by
external urethral orifice) infront of the vaginal
orifice.
-Its upper part (in the deep pouch) is
surrounded by the sphincter urethrae.
-Anteriorly, the female urethra is separated by
fat from the symphysis pubis.
-Posteriorly, the female urethra is closely
applied to the anterior wall of vagina.
Ant.
Retropubic
spaces
Pubo vesical
lig.
Urethral
glands
External urethral
orifice
Post.
Sphincter
urethrae
Vagina

UTERUS
Diminsions:
Length:3 inches
Breath:2 inches at the fundus and 1
inch at the cervix
Thickness (Anteroposterior
diameter):1 inch
Divisions:
Fundus
2.Body.
3.Cervix (neck)
Peritoneal Covering Of UTERUS

RELATIONS OF UTERUS
It is covered by peritoneum on both
surfaces.
It has two surfaces:
A.Anterior (vesical) surface: related
to the upper surface of the urinary
bladder.
Its peritoneal covering is reflected at
the junction of the body with the
cervix on to the upper surface of the
bladder to form the utero-vesical
pouch.
B.Posterior (intestinal) surface:
related to the pelvic colon and coils
of the ileum.
Its peritoneal covering extends on
the back of the cervix and upper part
of vagina where it is reflected to
cover the rectum, forming the rectovaginal
pouch.

CERVIX OF THE UTERUS
Cervix: about one inch long and one
inch in diameter.
A.Supravaginal portion of the cervix:
-Anteriorly, it has no peritoneal
covering and is related to the base of
the bladder.
-Posteriorly, it is covered by
peritoneum and is related to ileum
which separate it from rectum
-Laterally, it is related to the uterine
vessels.
B.Vaginal portion of the cervix:
surrounded by the vaginal fornices.
-It opens into the vagina by an, opening
which is known as the external os.
●Cervical canal: (1). fusiform in shape,
It communicates with the body through
an opening known as the internal os
(2), and opens into the vagina by the
external os (3).

NORMAL POSITIONS OF THE UTERUS
The normal position of the uterus is
anteflexion and antevertion position.
-The longs axis of the uterus forms a
right angel with the long axis of the
vagina (antevertion angel),
and
-The long axis of the body forms an
angel open forward with the long
axis of the cervix (anteflexion angel).

NORMAL POSITIONS OF THE UTERUS

Parts of the broad ligament:
1.Mesosalpinx
2.Mesometrium
3.Suspensory ligament of the
ovary (infudibulo-pelvic
ligament)
4.The mesovarium
BROAD LIGAMENT OF UTERUS
3
4
Broad ligament
1
2

The uterus is connected
to the pelvic walls by
several ligaments.
These ligaments are:
A. Peritoneal folds:
1.Uterovesical fold
2.Rectovaginal fold
B. Non peritoneal
ligament:
1.Transverse ligament of
the cervix (Mackenrodt’s
ligament)
2.Uterosacral ligament
3. Ovarian Ligament
4. Round ligament of the
uterus
SUPPORTS OF UTERUS
Uterovesical
fold
Rectovaginal
fold

Arteries:
-Mainly, from the uterine
artery, branch of anterior of
internal iliac artery.
-Ovarian artery, branch of the
aorta.
Veins:
Through two venous
plexuses which is drained by
a pair of two uterine veins
which open into internal iliac
vein.
BLOOD SUPPLY OF THE UTERUS

LYMPHATIC DRAINAGE OF THE UTERUS
●Lymphatic drainage:
1. Fundus and upper part of the body of
the uterus: are drained into the lateral
aortic and preaortic lymph nodes, few
pass to the external iliac nodes.
2. Lateral angel of the uterus: is drained
by vessels which end in the superficial
inguinal lymph nodes.
3. Lower part of the body of the uterus:
is drained mainly into the external iliac
nodes.

UTERINE TUBE

OVARIES

OVARIES
-Each ovary is almond-shaped,
about 3 cm length and 1.5 cm in
width.
●Site:Each ovary occupies an
area in the lateral wall of the
lesser pelvis known as the
ovarian fossa.
The fossa is bonded anteriorly
by the umbilical artery (1) and
posteriorly by the ureter (2) and
internal iliac artery (3).
Ant.
Obturator n & vs.
1
2
Ext. iliac a.
3
Post.
Ovary

BLOOD SUPPLY OF OVARIES
Arterial supply: by branches of the ovarian artery from
abdominal aorta.
●Venous drainage: the veins of the ovary form a small
pampiniform plexus in the mesovarium which collect into
the ovarian vein.
The right ovarian vein drains into the inferior vena cava;
while the left ovarian vein drains into the left renal vein.
●Lymph drainage: The ovary drain into the preaortic and
lateral aortic lymph nodes.

Each ovary has:
Two surface: medial and lateral.
Two ends: upper (tubal) and lower (uterine).
Two borders: free and mesovarian (attached)
border.
●Medial
surface:
Covered by the fimbriated end of the uterine tube.
●Lateral
surface:
Related to the ovarian fossa, obturator nerve and
vessels.
●Tubal
end:
Gives attachment to the ovarian fimbria of the tube
and the suspensory ligament of the ovary.
●Uterine
end:
Attached to the lateral angle of the uterus by the
ligament of the ovary.
●Free
border: is convex and separated from the
ureter by peritoneum.
●Attached
(mesovarian) border:
is attached to the
superior layer of broad ligament by a short fold of
peritoneum called mesovarium.
The vessels and nerves of the ovary pass between
the two layers of mesovarium to reach the ovary.
RELATIONS OF OVARIES
Ant.
Umbilical a.
Broad lig.
(posterior layer)
Blood
vessels &
nerves
Attached
border
Mesovaria
n
Suspensory lig.
of ovary carrying
ovarian vs.
Medial
surface
Obt.
n.
Obt. vs.
Int.
iliac a.
Ureter
Tubal
end
Uterine
end
Free
border
Uterin
e tube
Fundus of uterus
Post.
Lig. of ovary

Base of the urinary
bladder
Ant.
1
Urethra
Vagina
Ant. wall of vagina
3
2
Post.
VAGINA
Lat. fornix
Ant.
Middle 2/4 of post. wall
of vagina
Lower 1/4 of post. wall
of vagina
2
1
Vagina
Rectovaginal pouch
Rectum
Anal canal
Perineal body
Post.
Sup. fascia of pelvic
diaphragm
Levator ani
Inf. fascia of
pelvic
diaphragm

ARTERIAL SUPPLY OF THE VAGINA

Male pelvis
Median umbilical lig.
Ant.
Urinary
bladder
Urethra
Recto
vesical pouch
Prostate
Sacrum
RECTUM
Rectum
Post.
Female pelvis
Arrangement of the viscera
in pelvis
Urinary bladder
Ant.
Recto vaginal pouch
(Douglas pouch)
Vagina
Uterus
Sacrum
post.
Rectum

RECTUM
Position: The rectum begins at the third
(middle) piece of sacrum as a continuation
of the pelvic (sigmoid) colon, and ends at
the recto-anal angle where it becomes
continuous with the anal canal.
*The recto-anal junction is situated about
one inch in front and below the tip of the
coccyx.
Flexures of the rectum:
The rectum is not straight,
known forming three curves
as the lateral flexures.
The upper and lower flexures are
concave to the left.
The middle flexure is concave to
the right. The lower part of the
rectum is dilated to form the rectal
ampulla.
Peritoneum its upper
2/3
Recto-vesical
pouch
Middle flexure
(concave to rt.)
Ampulla
Rectum
begins at
s3
It ends one inch in front &
below tip of coccyx
Upper flexure
Lower flexure
(concave to lt.)
(concave to lt.)

Peritoneal coverings:
-Upper third : front and sides.
- Middle third: front only.
- Lower third : no peritoneal covering
RELATIONS OF THE RECTUM
Anteriorly:
A.In male:
-above: recto-vesical
pouch (1).
-below: base of the
bladder (2), seminal
vesicles (3), 2ampulla
of vasa deferens,
terminal parts of the
ureters and prostate
gland (4).
Ureter
Ampull
a of vas
Semina
l
vesicle
RECTUM
Peritoneum of
Recto-vesicle
Pouch
Prostate
Base of
bladde
r
Para-rectal fossa
Upper 1/3 of rectum
Middle 1/3 of rectum
Lower 1/3 of rectum
1
4
Sacrum
2
3
Rectum

RELATIONS OF THE RECTUM
Anteriorly:
B.In female:
recto-vaginal pouch (1). -above:
posterior wall of vagina (2). -below:
On each side (Lat. relations):
Pararectal fossa (A). -above:
-below: Branches of the superior rectal artery
(B), coccygeus & levator ani (C).
Ant. relations of
rectum in female
Rectum
Anal canal
Lat. Relations of rectum
Recto-vaginal
pouch
Rectum
Vagina
(Post. wall)
Sup. rectum a.
B
C
A

POSTERIOR RELATIONS OF RECTUM
Posteriorly:
-Lower part of sacrum
and coccyx.
-Median sacral vessels.
-Branches of superior
rectal vessels.
-Glomus coccygeum and
ganglion impar.
-Sympathetic trunks,
lower sacral and
coccygeal nerves
-Piriformis coccygeus
and levator ani

ARTERIAL SUPPLY OF RECTUM
Arterial supply of the rectum and anal
canal:
1.Superior rectal artery: continuation of
the inferior mesenteric artery.
2.Middle rectal artery: One on each
side, branch of the anterior division of
the internal iliac artery.
3.Inferior rectal artery: One on each
side, branch of the internal pudendal
artery.
-It divides into two branches which
reach the anal canal.
-The corresponding veins begin from
the rectal venous plexus.
-These -veins form an important site for
anastomosis between the portal and
systemic circulations.
Internal iliac a.
Sup. rectal. a.
Middle rectal a.
Internal pudendal a.
Inf. rectal. A.
Rectal Folds
Anal valves
Anal column
Anal sinuses

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