Abdomen

Question 1

1. What organs are palpable in the normal abdomen?

Answer 1

The aorta and in some cases the lower pole of the right kidney are the only organs that
are palpable in the normal abdomen.

The liver and spleen may be felt in pathological
states.

The neck of Pancreas
The neck of the Pancreas lies at L 1, on the transpyloric plane of Addison.

The Liver
The Liver is a large organ, much larger than people often appreciate. It runs along the
nipple line superiorly, the right 10th rib inferiorly and the left 5th intercostal space midclavicular line.

The Gallbladder
The Gallbladder lies at the 9th costal cartilage, in the midclavicular line.

The Spleen
The Spleen lies behind the 9th ;10th and 11
th ribs. It is susceptible to blunt chest wall and
abdominal trauma.

The aorta enters the abdomen at T12 in the midline running in the retroperitoneal space in
front of the vertebral column. It gives off 3 anterior branches:
Coeliac Axis (Upper part L1).
Superior mesenteric artery (Lower Part L1).
Inferior mesenteric artery (L3).
And 5 posterior (or lateral) branches.
Inferior Phrenic arteries (T12).
Suprarenal arteries(L1).
Renal arteries (L1-L2).
Gonadal arteries (L2).
Four paired lumbar arteries (L1-L4).
It then bifurcates into the common iliac arteries, and the median sacral artery at L4.

Question 2

2. What are the surface markings of the abdominal aorta?

Answer 2

The abdominal aorta commences at T12 or two fingers breadths above the transpyloric
plane of Addison in the midline, and runs in the retroperitoneal space to L4 or the
supracristal plane in the midline where it bifurcates.

Question 3

3. What investigation is this?

Answer 3

An abdominal aortogram. It is a form of digital subtraction angiography

Question 4

4. What branch is this?

Answer 4

This branch is the splenic artery.

Question 5

5. What artery is this?

Answer 5

The superior mesenteric artery.
You can see its branches: the ileal and jejunal branches, and the ileocolic, right and middle
colic arteries coming off it.

Question 6

6. What lies anterior to the aorta at L1?

Answer 6

The neck of the pancreas and the superior mesenteric artery.
This is the transpyloric plain of Addison. It represents the halfway point between the
suprasternal notch and the pubic symphysis.
From posterior to anterior, the significant structures crossed by the transpyloric plane in
the midline are:
The conus or termination of the spinal cord.
L1 vertebra.
Aorta.
Superior mesenteric artery.
Neck of the pancreas.
Superior mesenteric vein.
The pylorus of the stomach.
More laterally at this level:
Kidney hila.
Renal vein.
Hilum of the spleen.
Second part of duodenum.
Origin of the portal vein.
Duodenojejunal flexure.
Fundus of the gall bladder.
9th costal cartilage.

Question 7

7. What is the epiploic foramen of Winslow?

Answer 7

The epiploic foramen of Winslow is the communication between the greater and lesser
sacs of the peritoneal cavity. The lesser sac lies posterior to the stomach medially, and the
greater sac laterally.
Above is the caudate lobe of the liver, and below the 1
st
part of the duodenum.
In front is the lesser omentum (with the CBD, hepatic portal vein and common hepatic
artery in its free edge) and behind is the IVG. The lesser sac is a site for potential internal
herniation of the bowel.

Question 8

8. What is Pringle’s maneuver?

Answer 8

Pringle’s maneuver describes compression of the hepatic artery where it lies in the free
edge of the lesser omentum in the epiploic foramen of Winslow to stop bleeding from
the liver during laparotomy.

Question 9

9. What are the functions of the spleen?

Answer 9

The functions of the spleen can be remembered by the mnemonic ‘FISH’
• Filtration of encapsulated organisms and blood cells.
• Immunological function.
• Storage of platelets.
• Haematopoiesis in the foetus.

Question 10

10. Which organs may be damaged during a splenectomy?

Answer 10

There are several important structures that may be damaged during a splenectomy.
These are:
• Tail of the pancreas (in relation to the hilum of the spleen).
• Diaphragm above.
• Stomach.
• Left kidney.
• Splenic flexure of the colon.
The spleen is attached to the greater curvature of the stomach by the gastrosplenic
ligament, in which the short gastric and left gastro-epiploic vessels lie. The lienorenal
ligament attaches it to the left kidney (containing the splenic vessels and the tail of the
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pancreas).

Question 11

11. Where do Porto-systemic anastomoses occur?

Answer 11

Porto-systemic anastomoses occur where the systemic venous circulation meets the
portal venous circulation. There are five sites in the body:
• Retroperitoneum.
• Upper anal canal.
• Bare area of the liver.
• Lower end of the oesophagus.
• Periumbilical area of abdominal wall.
Portal hypertension causes dilatation of the veins at this anastomosis.
At the umbilicus this creates caput medusa; in the anal canal this can cause haemorrhoids.
At the lower end of the oesophagus this can cause varices, which place the patient at risk
of life-threatening haemorrhage.
(Oesophageal anastomosis is between the left gastric/portal and azygous/ hemiazygous/
systemic veins).

Question 12

12. What are the common sites for intra-abdominal collections to form?

Answer 12

The most dependent place for fluid to collect in the abdomen, when supine, is the
hepatorenal pouch of Rutherford-Morrison (the right subhepatic space).
Other common sites are:
• In the pelvis.
• Between loops of bowel.
• Right and left subphrenic spaces.
• Right and left paracolic gutters.

Question 13

Note:

Answer 13

It is important to know the surface anatomy of the abdominal organs.
One way of asking this that has been previously used is via a clinical case where a person
is stabbed at a certain point and you are asked what important structures the knife might
pass through.
Remember:
The neck of the pancreas.
L1.
Spleen.
9th 11
th rib posteriorly.
Liver.
The nipple line superiorly, the right 10th rib inferiorly and the left 5th intercostal space midclavicular line.
Gallbladder.
9th costal cartilage, midclavicular line.
Kidney.
Superior pole lies at the 12th rib posteriorly.

Question 14

Abdominal organs
This station tests your knowledge of abdominal organs….

1. Name the parts of the stomach?

Answer 14

The stomach is made up of four sections.
• The cardia, where the oesophagus enters.
• The Fundus.
• The body.
• The pylorus, which joins to the duodenum.

Question 15

2. How many parts does the duodenum have?

Answer 15

The duodenum is made up of four parts which form a ‘C’ shape around the head of the
pancreas.
The 2nd, 3rd and 4th parts are retroperitoneal.

Question 16

3. Into which part of the duodenum does the common bile duct enter?

Answer 16

The CBD enters the posteromedial wall of the 2
nd part of the duodenum at the ampulla of
Vater (flow of bile is regulated by the sphincter of Oddi).

Question 17

4. How could you tell the difference between the jejunum and the ileum?

Answer 17

The jejunum is larger, thicker, more vascular and a darker red than the ileum.
It has longer vasa recta and fewer arcades.

Question 18

5. How can you tell the difference between large and small bowel on an abdominal
   radiograph?

Answer 18

Large bowel has haustrae, which extend only a third of the way across the bowel from
each side, whereas small bowel has valvulae conniventes which traverse the complete
distance.

Occasionally, location can help; with small bowel tending to be more central (bewares a
drooping transverse colon!).

During an operative procedure, the colon can be further distinguished from small bowel
by the presence of the appendices epiploicae and taenia coli.

Question 19

6. How many parts does the pancreas have?

Answer 19

The pancreas consists of five parts: head, uncinate process, neck, body and tail.

Question 20

7. What are the functions of the pancreas?

Answer 20

The pancreas has both exocrine and endocrine functions.
The pancreatic acini perform the exocrine functions, producing and secreting digestive
enzymes.
The Islets of Langerhans perform the endocrine function:
• Alpha cells - produce and secrete glucagon.
• Beta cells - produce and secrete insulin.
• Delta cells - produce and secrete somatostatin.

Question 21

8. Describe the blood supply to the pancreas?

Answer 21

The pancreas has three main sources of blood supply:
The superior pancreaticoduodenal (from the gastroduodenal) and inferior
pancreaticoduodenal (from the superior mesenteric) arteries supply the head of the
pancreas.
Pancreatic branches from the splenic artery supply the remainder of the pancreas.
Venous drainage follows arterial supply, to the superior mesenteric and portal veins, and
the splenic vein respectively.

Question 22

9. What are the three main divisions of the coeliac axis?

Answer 22

The celiac axis divides into the left gastric artery, the common hepatic artery and the
splenic artery.

Question 23

10. What is the blood supply to the lesser curve of the stomach?

Answer 23

The right and left gastric arteries.

Question 24

11. What is the blood supply to the greater curve of the stomach?

Answer 24

The right and left gastro-epiploic arteries.

Question 25

12. From where does the left gastro-epiploic artery arise?

Answer 25

The left gastoro-epiploic artery is the largest branch of the splenic artery.
The right gastro-epiploic artery arises from the gastroduodenal artery.
They anastomosis along the greater curve of the stomach.
They both give off gastric branches that supply the anterior and posterior surface of the
stomach, and omental branches that supply the greater omentum.

Question 26

13. Which artery can bleed due to erosion by a duodenal ulcer?

Answer 26

Normally the gastroduodenal artery, which supplies the 1st and 2nd parts of the
duodenum.
More rarely an ulcer in the 3rd or 4th part of the duodenum could cause the
pancreaticoduodenal artery to bleed.

Question 27

14. What is Meckel’s diverticulum?

Answer 27

Meckel’s diverticulum is the remnant of the embryological vitellointestinal duct (which
connects the midgut to the yolk sac).
Commonly it obeys the ‘Rule of 2s’: occurs in 2% of the population; is 2 inches long; occurs
2 feet from the ileocaecal valve and is twice as common in males as in females. It should
be looked for during all appendicectomies when a normal appendix is found.
It is important as a Meckel’s can cause a number of complications:
Acute inflammation - can often mimic appendicitis, and should always be looked for at
laparoscopy when a normal appendix is found.
Ulceration and bleeding - often the diverticulum is lined with hydrochloric acid producing
gastric mucosa.
Perforation.
Intussusception.
Obstruction.
Littre’s Hernia - when found in an inguinal or femoral hernia sac.

Question 28

15. Where are the kidneys found?

Answer 28

The renal pelvis is found at the level of the L1 vertebra, with the kidney extending
between T12 to L3.
The kidneys are retroperitoneal structures surrounded by perinephric fat and Gerota’s
fascia.

Question 29

16. What are the relations of the kidney?

Answer 29

The immediate relations to the kidney are:
• Above - the diaphragm.
• Below - quadratus lumborum.
• Medially - psoas major.
• Laterally - transversus abdominis.
• Each kidney has numerous anterior relations

Question 30

17. Where are the adrenal glands found?

Answer 30

The adrenals lie antero-superior1y to the kidneys in a separate compartment of the
encompassing Gerota’s fascia.

Question 31

18. What are the layers of the adrenal glands?

Answer 31

Each adrenal gland has a medulla surrounded by an outer cortex.
The medulla secretes adrenaline and noradrenalin.
The cortex is further divided into 3 layers (remembered by ‘GFR’ from superficial to
deep):
• zona Glomerulosa - produces aldosterone.
• Zona Fasciculata.
• Zona Reticularis.
Both the zona fasciculata and reticularis secrete sex steroids and cortisol.

Question 32

Notes :

Answer 32

The following organs are intraperitoneal:
• Stomach.
• Duodenum (1
st
part), jejunum and ileum.
• Caecum, transverse and sigmoid parts of the colon.
• Tail of the pancreas.
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• Liver.
• Uterus and ovaries in the female.
The coeliac axis branches off the aorta and divides into the left gastric artery, the
common hepatic artery and the splenic artery to supply the stomach, pancreas, liver,
spleen and duodenum. The superior mesenteric artery arises anteriorly from the aorta
inferior to the celiac axis to supply part of the pancreas, the rest of the small bowel and
the colon as far as 2/3rds of the way along the transverse colon. The inferior mesenteric
artery supplies the remainder of the colon and rectum.