Abdominal viscera: Liver, Pancreas and Spleen

Question 1

Describe the development of the liver, pancreas and spleen

Answer 1

Liver and gallbladder develop as an outpouching of the foregut in ventral mesentery.

The spleen develops from mesoderm in dorsal mesentery.

The pancreas develops from both a dorsal and ventral bud from the foregut that develops in the mesentery. The ventral bud forms the head and uncinate process, rotates around the bile duct during development to join dorsal bud. Dorsal bud forms majority of the head, neck body and tail.

During development the stomach rotates clockwise and to the left, pushing the spleen to the left and it expands. At the same time the duodenum, dorsal mesentery and dorsal bud of pancreas swings to the right and fuses with the body wall. Massive growth of the liver in the ventral mesentery and fusion to the superior surface of the diaphragm.

Question 2

What structures come from the foregut?

Answer 2

Stomach, distal oesophagus, liver, gallbladder, pancreas.

Question 3

what is an annular pancreas?

Answer 3

Annular pancreas occurs when the ventral bud of the developing pancreas splits into two and encircles the duodenum. Can present with failure to thrive, vomiting and poor gastric emptying.

Sometimes detected in US as increase in amniotic fluid as obstruction stops fetus swallowing amniotic fluid.

Question 4

How does development of the stomach, liver, pancreas and dudodenum finish?

Answer 4

Stomach rotates to left and clockwise by 90 degrees

Liver grows out of ventral mesentery

Pancreas and duodenum become secondarily retroperitoneal.

Question 5

What is the transverse mesocolon?

Answer 5

Transverse mesocolon is double layered fold of peritoneum (mesentery) that attaches the transverse colon to the posterior abdominal wall.

Question 6

What are the boundaries of the lesser sac?

Answer 6

Superiorly bound by the liver.

Lesser sac is formed anteriorly by the lesser omentum stretching from the lesser curvature of the stomach to the inferior border of the liver.

Inferiorly bound by the greater omentum, hanging off the greater curvature of the stomach and attaching to the posterior abdominal wall. Posteriorly and inferiorly by the transverse mesocolon.

Posterior wall of the lesser sac is parietal peritoneum overlying the pancreas, kidneys and adrenal glands.

Question 7

What is the greater sac?

What are the two regions of the greater sac?

Answer 7

Greater sac is all of the peritoneal cavity not included in the lesser sac.

Lies anterior to the liver, lesser omentum, greater omentum.

Split into the supra and infracolic compartments.

Supracolic sits above the level of the transverse colon and anterior to the greater omentum.

Infracolic sits below the transverse colon and behind the greater omentum.

Question 8

Where does the liver sit within the abdominal cavity?

(surface anatomy)

Answer 8

Liver extends from the 5th rib to the 10 th rib, mostly in the right hypochondrium, but extends to the MCL in the left hypochondrium.

Its inferior border follows the subcostal border, it is in direct contact with the diaphragm and moves inferiorly on inspiration.

Question 9

What is the bare area?

What is the falciform ligament and what structure ran within this?

Answer 9

Bare area is an area on the superior surface of the liver that is in direct contact with the diaphragm, grows out of the ventral mesentery during development. Rest of the visceral surface of the liver is covered in visceral peritoneum.

Anterior remnant of ventral mesentery that attaches the liver to the anterior abdominal wall is the Falciform ligament.

Within the falciform ligament is the ligamentum teres, remnant of the umbilical vein.

Question 10

What is the only route into the lesser sac?

Answer 10

Only route into the lesser sac is via the epiploic foramen which is continous with the greater sac.

Question 11

Describe the ligaments of the liver

Answer 11

Liver has multiple ligaments:

Anteriorly the falciform ligament which contains ligamentum teres, remnant of the umbilical vein.

On the superior surface have anterior and posterior coronary ligaments which border the bare area, and laterally the R and L triangular ligaments.

On the visceral surface the liver is split into right and left lobes by fossa for the IVC and Gallbladder which lie to the right.

To the left of the IVC and gallbladder are the ligamentum venosum superiorly and the ligamentum teres inferiorly.

Also have the hepatogastric ligament connecting liver to the stomach and the hepatoduodenal ligament, connected the liver to the duodenum.

Question 12

What are the lobes of the liver?

What impression are left on the liver?

Answer 12

liver split into R and L lobes, on the visceral surface by fossa for IVC and the gallbladder.

R lobe is the largest lobe, left lobe is smaller.

The caudate lobe is the smaller superior lobe bound on the R by the IVC and on the left by the ligamentum venosum.

The quadrate lobe is the smaller inferior lobe bound on the R by the gallbladder and on the left by the ligamentum teres.

Impressions left on the liver: To the left is the gastric impression and the oesophageal impression. On the right it the impression of the right kidney and the right suprarenal gland.

Question 13

What is the porta hepatis?

Answer 13

The porta hepatis is formed by the hepatic artery, the hepatic portal vein and the bile duct as they enter/ exit the liver.

Question 14

What is the relevance of segementation of the liver?

Answer 14

Liver is divided into 8 functionally independent segments, each with its own arterial and venous supply, and bile drainage. Clinically relevant as a segment of the liver can be resected without affecting the function of the other segments.

Question 15

What is the blood supply to the liver?

Answer 15

70% from the hepatic portal vein which is formed by the union of the splenic vein with the IMV and SMV.

30% from the hepatic artery which is a branch off the coeliac trunk.

Coeliac trunk divides into left gastric, splenic and common hepatic artery.

Common hepatic artery then divides into R and L hepatic arteries, the R hepatic artery gives off the cystic artery which supplies the gallbladder.

Question 16

What structure does the hepatic artery run in?

What does it run with?

What is the pringle manouvre?

Answer 16

The hepatic artery runs with the hepatic portal vein and the common bile duct in the free edge of the lesser omentum.

The pringle manouvre is a pinching manouvre, whereby the free edge of the lesser omentum is pinched during surgery after trauma to prevent blood loss from the hepatic vessels.

Question 17

What regions are drained by the HPV?

What vertebral level does it form at?

Answer 17

HPV formed by the union of the splenic vein, IMV and SMV posterior to the neck of the pancreas at T11.

Receives blood from the spleen, pancreas, stomach, small intestine and large intestine.

Question 18

What are some of the tribituaries to the hepatic portal vein?

Answer 18

Tribitaries include the R and L gastric veins draining lesser curvature of the stomach and the abdominal oesophagus.

cystic veins from the gallbladder

paraumbilical veins associated with the obliterated umbilical vein and anastomose with veins on the anterior abdominal wall.

Question 19

What is portal hypertension?

How can it present?

Answer 19

Portal tension occurs when there is increased pressure within the portal venous system, often due to liver disease either cirrhosis or cancer which restricts blood flow, increasing resistance and causing backflow into the portal system.

This can present with splenomegaly and varices at regions of portosystemic anastomosis.

Question 20

What are the three regions of portosystemic anastomoses?

Answer 20

1) gastro-oesophageal junction between the azygous vein and the left gastric vein which gives off branches that drains the abdominal oesophagus. Portal HTN forms oesophageal varices these are at high risk of trauma and bleeding -> requires emergency tx.
2) rectal varices between the superior rectal vein given off by the IMV and the middle and inferior rectal veins given off by the internal iliac vein.
3) paraumbilical veins on the anterior abdominal wall that anastomose with veins on the anterior abdo wall. Paraumbilical are associated with the obliterated umbilical vein, when portal HTN occurs blood is shunted back into these veins forming caput medusae.

Question 21

Describe the bile drainage from the liver and gallbladder?

Answer 21

Bile drained from L and R bile ducts that form the common hepatic duct. The common hepatic duct runs in the free margin of the lesser omentum. This is then joined by the cystic duct and forms the common bile duct which passes posterior to the duodenum before emptying into the second part of the duodenum along with the pancreatic duct at the major duodenal papilla.

Question 22

What is severe pain in the gallbladder called?

What is it caused by?

what is inflammation of the gall bladder called?

Answer 22

Severe pain in the gallbladder is called biliary colic and is caused by contraction of the gallbladder (induced by CCK from small intestine) against an obstructed outflow in the gallbladder neck. Gallstones can lodge within the gallbladder neck (cholelithiasis) or lodge within the bile duct (choledocolithiasis). When the gallbladder contracts against obstructed lumen there is severe pain.

Gallstones represent and infection and inflammation risk, inflammation of the gallbladder is called cholecystitis.

Question 23

Where does pain from an cholecystitis refer to?

Answer 23

Pain will present on the anterior abdominal wall in the right hypochondrium region and in the epigastric region due to direct irritation of the parietal periotoneum in the area of the inflammed gallbladder.

Pain will also refer to the right shoulder due to irritation of the diaphragm which is innervated by the phrenic nerve C3-5.

Question 24

How can gallstones cause jaundice?

Answer 24

If a gallstone lodges within the bile duct at the region of the sphincter of oddi, it can obstruct pancreatic outflow as well as obstructing outflow of bile containing bilirubin from the liver and gallbladder store. Leads to hyperbilirubinaemia and yellowing of the skin/ sclera/ mucuous membranes and itchy skin.

Question 25

Where does the gallbladder sit? (surface anatomy)

Answer 25

Gallbladder sits at the tip of the 9th costal cartilage on the R.

Question 26

What are the peritoneal recesses?

Answer 26

The periotoneal recesses are regions of potential fluid accumulation or abscess formation that lie between the liver and the diaphragm or the liver and the R kidney/ R adrenal gland.

The subphrenic recess is between the liver and the diaphragm.

The hepatorenal recess or Morrison’s pouch is the recess formed posteriorly by the liver and the R kidney / R adrenal gland.

These recesses are gravity dependent and in a supine patient fluid can accumulate within them forming an abscess.

Question 27

Where does the pancreas sit in the abdominal cavity?

Surface anatomy?

Answer 27

Pancreas sits in the epigastric region and extends into the left hypochondrium.

It lies mostly posterior to the stomach with its head in the C of the duodenum.

Its neck body and tail sit behind the stomach, the tail extends into the splenic hilum. The pancreas neck sits in the transpyloric plane at L1.

Its tail is the only intraperitoneal part, the rest of the pancreas is secondarily retroperitoneal.

Question 28

What are the parts of the pancreas?

Where is pancreatitis pain referred to?

Where can fluid from pancreatitis accumulate?

Answer 28

Parts of the pancreas are the uncinate process, head, neck, body and tail.

Pancreatitis pain is referred to the back and epigastric region.

Fluid from pancreatitis can accumulate in the lesser sac.

Question 29

Describe the ductal system of the pancreas

Answer 29

Pancreatic duct begins in the tail of the pancreas, passes through the body and into the head of the pancreas.

Pancreatic duct joins the bile duct forming the hepatopancreatic ampulla (ampulla of vater) which is surround by the sphincter of oddi. Empties into the 2nd part of the duodenum at the major duodenal papilla.

Accessory pancreatic duct sits just above drains into the duodenum at the minor duodenal papilla, above the major dudodenal papilla.

Main and accessory pancreatic ducts normally communicate with each other.

Question 30

What can be the first sign of a pancreatic tumour?

Answer 30

First sign of a pancreatic tumour can be jaundice which obstructs the major duodenal papilla, preventing bile and pancreatic drainage.

Can also be caused by gallstone lodging in the hepatopancreatic ampulla region/ major duodenal papilla.

This is called obstructive jaundice.

Question 31

Describe the blood supply of the pancreas

Answer 31

The pancreas is supplied by the branches of the coeliac trunk:

Coeliac trunk splits into splenic artery, left gastric and the common hepatic artery.

The splenic artery runs over the superior surface of the pancreas and supplies the body and tail.

The common hepatic artery gives off the gastroduodenal artery before splitting into R and L hepatic arteries.

The gastroduodenal artery gives off the superior pancreaticoduodenal artery which anastomoses with the inferior pancreaticodudodenal artery which comes off the SMA.

Venous drainage is via the superior mesenteric vein (drains the head) and the splenic vein. Join to form the HPV carried to the liver.

Lymph drainage follows arterial supply to the coeliac node, to the thoracic duct to the supraclavicular nodes.

Question 32

Where does the spleen sit in the abdominal cavity?

What are its relations?

clinical relevance?

Answer 32

Spleen sits in the upper left quadrant or the left hypochondrium.

Anatomical relations are:

anteriorly the stomach, the tail of the pancreas (hilum), the left kidney, the left colic flexure.

Spleen sits on the posterolateral abdominal wall at ribs 9-12 (9-10 or 11- 12) and extends into the costodiaphragmatic recess into which the lungs can expand during inspiration.

Rib fractures can perforate the spleen and cause mass bleeding.

Question 33

What ligaments are associated with the spleen?

Answer 33

Spleen connected to the stomach via the gastrosplenic ligament and the left kidney by the splenorenal ligament, both of which are part of the greater omentum.

Gastrosplenic ligament contains the short gastric and gastroomental vessels.

The splenorenal ligament contains the splenic vessels.

Question 34

what is the spleen covered in? what region is not covered? What does this region contain?

Answer 34

Spleen is covered in peritoneum, except at the hilum which contains the splenic vein and artery.

Question 35

What is the blood supply to the spleen?

What is the lymph drainage?

Answer 35

From the coeliac trunk, the splenic artery. Splenic artery divides into segmental branches with each one supplying different segment of the spleen.

Splenic tissue bleeds profusely if damaged and heals poorly, tends to lead to removal.

Drainage via the splenic vein which joins the SMV and IMV and forms the HPV.

Lymph drainage follows arterial supply, to the coeliac node, thoracic duct, to supraclavicular nodes.

Question 36

where will the spleen be palpated if it is enlarged?

What causes splenomegaly?

Answer 36

due to its relation posteriorly to the ribs when the spleen enlarges it pushes downwards and forwards to the L iliac fossa.

Spleen enlargement can occur from leukaemia, lymphoma and indectionsthat cause generalised lymphadenopathy and spleen enlargement.