Transcript ABDOMINAL CAVITY

ABDOMINAL
CAVITY
•
The abdominal cavity is a large cavity so it is
subdivided descriptively into 9 regions.
• This division is made by 2 horizontal planes and
two vertical planes.
• The vertical planes are:
• They are one on each side.
• Each extends from the mid-clavicular point down
to the mid-inguinal point.
• The horizontal planes are:
1. Subcostal plane.
2. Inter-tubercular plane.
• Subcostal plane:
• It lies at the lowest limit of the costal
margin.
• Inter-tubercular plane:
• It passes between the tubercles of the two
iliac crests.
The divisions of the abdominal
cavity are:
Right hypo- Epigastrium
chondrium
Left hypochondrium
Right
lumbar
Umbilical
Left lumbar
Right iliac
fossa
Hypogastric
(suprapubic)
region
Left iliac
fossa
Transpyloric plane:
•
•
•
1.
2.
3.
4.
It cuts the body of the first lumbar vertebra.
It lies midway between the xiphoid process of
sternum and umbilicus.
Structures at this level:
Pylorus of stomach.
Hilum of left kidney.
Fundus of gall bladder.
Body of L1
Peritoneum
Peritoneum:
• It is a closed serous sac
present inside the abdominal
cavity.
• The peritoneum looks like a
balloon.
• The intra-abdominal organs
have different relations with
the peritoneum:
- Enclosed within a fold of
peritoneum (intraperitoneal)
and so freely mobile.
- Present behind the
peritoneum and so they are
fixed; retroperitoneal.
• Parietal peritoneum:
The part of peritoneum that lines
the abdominal wall.
• Visceral peritoneum:
The part of peritoneum that
surrounds the abdominal organs
(viscera).
• Peritoneal cavity:
Is a potential space between the
parietal and visceral peritoneum
that contains a very thin film of
fluid.
Increase in the amount of this fluid
is called ascites.
Peritoneal Reflections
The folds of peritoneum are called:
1- Omentum: if related to the stomach.
2- Mesentry: if related to the small intestine.
3- mesocolon: if related to the large intestine.
4- ligaments: eg.
Ligaments of the
liver, falciform, right
and left triangular.
Ligaments of the
spleen; gastrosplenic
and lienorenal.
The main contents of the
peritoneal folds are:
1- blood vessels supplying the related organ.
2- autonomic nerve plexus.
3- lymphatics and lymph nodes..
4- extraperitoneal connective tissue.
5- the organs themselves ( for freely mobile
organs).
• The peritoneum (peritoneal sac) is a closed
sac in male however in females it is not
completely closed as the two lateral ends of
the Fallopian tubes open in it.
The peritoneal cavity is divided
into two main sacs:
Greater sac.
Lesser sac.
The two sacs are
connected together
through the epiploic
foramen (foramen of
the lesser sac)
Greater sac:
• It is the part of
peritoneum that is
present just behind
the anterior
abdominal wall.
Lesser sac (omental bursa):
It is a small diverticulum
of the peritoneal sac
that lies behind the
stomach.
Boundaries of the lesser sac:
Anterior wall:
• From above downwards;
1- lesser omentum.
2- peritoneum covering the
posterior surface of the
stomach and 1st inch of
duodenum.
3- anterior 2 layers of the
greater omentum.
• Posterior wall:
The lower part formed
by the posterior 2
layers of the greater
omentum.
The upper part is formed
by the peritoneum
covering the following
structures:
 Body of
pancreas.
 Upper part of
abdominal aorta.
 Left crus of
diaphragm.
 Left kidney and
left suprarenal
gland.
Boundaries of the lesser sac:
• Left border:
formed by the
gastrosplenic &
lienorenal
ligaments.
• Right border:
the epiploic foramen
(foramen of
Winslow).
Epiploic foramen:
• It is a slit-like opening
connecting the greater
with the lesser sac.
Boundaries of the epiploic foramen:
Anteriorly:
Free margin of lesser
omentum containing
bile duct, portal vein &
hepatic artery.
Posteriorly:
IVC
Superiorly:
Caudate lobe of the
Liver.
Inferiorly:
1st part of duodenum
Lesser Sac (omental bursa) – Clinical Correlations
• The lesser sac has important clinical significance. As it is located
posterior to the stomach, the posterior wall of the stomach is in
contact with the sac.
• Thus any posterior ulceration of the stomach will cause fluid to
pass into this sac.
• Also an injured pancreas or inflamed pancreas will cause
pancreatic secretions to enter the lesser sac. This can cause a
pancreatic pseudocyst.
• Also sometimes the loop of the small intestine will enter the
epiploic foramen and go into the lesser sac.
• The boundaries of the epiploic foramen contain important vessels,
hence surgical removal of the intestine is deemed dangerous.
Nerve supply of the peritoneum:
• Parietal peritoneum:
Supplied by somatic nerves that supply the
abdominal wall (lower 5 intercostal &
subcostal nerves) & diaphragm (phrenic
nerve).
The parietal peritoneum is senstive to pain,
temperature and touch.
• The visceral peritoneum:
Supplied by autonomic nerves that supplies
the viscera.
It is only sensitive to traction and distension
of the viscera.