Liver, gallbladder, duodenum and pancreas

Question 1

What is the liver?

Answer 1

The liver is a peritoneal organ positioned in the right upper quadrant of the abdomen. It is the largest visceral structure in the abdominal cavity, and the largest gland in the human body.
An accessory digestive gland, the liver performs a wide range of functions; including synthesis of bile, glycogen storage and clotting factor production.

Question 2

Where is the liver located?

Answer 2

Predominantly located in the right hypochondrium and epigastric areas, and extends into the left hypochondrium.

Question 3

What are the surfaces of the liver?

Answer 3

Diaphragmatic surface – the anterosuperior surface, smooth and convex, fitting snugly beneath the curvature of the diaphragm.
Visceral surface – the posteroinferior surface, almost all covered in peritoneum, irregular and flat, in contact with the right kidney, right adrenal gland, right colic flexure, transverse colon, first part of the duodenum, gallbladder, oesophagus and the stomach.

Question 4

What are the different ligaments of the liver?

Answer 4

Falciform ligament
Coronary ligament
Triangular ligament
Lesser omentum

Question 5

What is the bare area of the liver?

Answer 5

The posterior aspect of the diaphragmatic surface is not covered by visceral peritoneum, and is in direct contact with the diaphragm itself (known as the ‘bare area’ of the liver).

Question 6

What is the falciform ligament?

Answer 6

this sickle-shaped ligament attaches the anterior surface of the liver to the anterior abdominal wall and forms a natural anatomical division between the left and right lobs of the liver. The free edge of this ligament contains the ligamentum teres, a remnant of the umbilical vein.

Question 7

What is the coronary ligament?

Answer 7

(Anterior and posterior folds) – attaches the superior surface of the liver to the inferior surface of the diaphragm and demarcates the bare area of the liver. The anterior and posterior folds unite to form the triangular ligaments on the right and left lobes of the liver.

Question 8

What is the triangular ligament?

Answer 8

The left triangular ligament is formed by the union of the anterior and posterior layers of the coronary ligament at the apex of the liver and attaches the left lobe of the liver to the diaphragm.
The right triangular ligament is formed in a similar fashion adjacent to the bare area and attaches the right lobe of the liver to the diaphragm.

Question 9

How does the lesser omentum interact with the liver?

Answer 9

Attaches the liver to the lesser curvature of the stomach and first part of the duodenum. It consists of the hepatoduodenal ligament (extends from the duodenum to the liver) and the hepatogastric ligament (extends from the stomach to the liver). The hepatoduodenal ligament surrounds the portal triad.

Question 10

What are the lobes of the liver?

Answer 10

Right
Left
Caudate
Quadrate

Question 11

Where are the accessory lobes of the liver?

Answer 11

Caudate lobe – located on the upper aspect of the visceral surface. It lies between the inferior vena cava and a fossa produced by the ligamentum venosum (a remnant of the fetal ductus venosus).
Quadrate lobe – located on the lower aspect of the visceral surface. It lies between the gallbladder and a fossa produced by the ligamentum teres (a remnant of the fetal umbilical vein).

Question 12

What is the blood supply to the liver?

Answer 12

Hepatic artery proper (25%) – supplies the non-parenchymal structures of the liver with arterial blood. It is derived from the coeliac trunk.
Hepatic portal vein (75%) – supplies the liver with partially deoxygenated blood, carrying nutrients absorbed from the small intestine. This is the dominant blood supply to the liver parenchyma, and allows the liver to perform its gut-related functions, such as detoxification.

Question 13

How is the liver venously drained?

Answer 13

Venous drainage of the liver is achieved through hepatic veins. The central veins of the hepatic lobule form collecting veins which then combine to form multiple hepatic veins. These hepatic veins then open into the inferior vena cava.

Question 14

How is the liver lymphatically drained?

Answer 14

The lymphatic vessels of the anterior aspect of the liver drain into hepatic lymph nodes. These lie along the hepatic vessels and ducts in the lesser omentum, and empty in the colic lymph nodes which in turn, drain into the cisterna chyli.
Lymphatics from the posterior aspect of the liver however, drain into phrenic and posterior mediastinal nodes which join the right lymphatic and thoracic ducts.

Question 15

What is an ultrasound?

Answer 15

Ultrasonic sound is passed into the body into a contact probe on the skin. Any surface or change in density of the bodies tissues will reflect some of the sound back to the probe and the time taken for it to be received is the distance from the reflecting surface to the probe. A picture is created and displayed on a screen.

Question 16

What is the portal triad?

Answer 16

Each anatomical lobule is hexagonal-shaped and is drained by a central vein. At the periphery of the hexagon are three structures collectively known as the portal triad:
Arteriole – a branch of the hepatic artery entering the liver.
Venule – a branch of the hepatic portal vein entering the liver.
Bile duct – branch of the bile duct leaving the liver.
The portal triad also contains lymphatic vessels and vagus nerve (parasympathetic) fibres.

Question 17

What are bile ducts?

Answer 17

Bile ducts: small tubes that connect the liver and small intestine. They allow fluid called bile to flow from the liver, through the pancreas, to the gut, where it helps with digestion.

Question 18

What is the gallbladder?

Answer 18

A gastrointestinal organ located within the right hypochondrial region of the abdomen. This intraperitoneal, pear-shaped sac lies within a fossa formed between the inferior aspects of the right and quadrate lobes of the liver.

Question 19

What is the function of the gallbladder?

Answer 19

concentrate and store bile which is produced by the liver. As part of the gustatory response, the stored bile is then released from the gallbladder in response to cholecystokinin.

Question 20

What’s the position of the gallbladder?

Answer 20

The gallbladder is entirely surrounded by peritoneum, and is in direct relation to the visceral surface of the liver.
It lies in close proximity to the following structures:
Anteriorly and superiorly – inferior border of the liver and the anterior abdominal wall.
Posteriorly – transverse colon and the proximal duodenum.
Inferiorly – biliary tree and remaining parts of the duodenum.

Question 21

What are the different parts of the gallbladder?

Answer 21

Fundus – the rounded, distal portion of the gallbladder. It projects into the inferior surface of the liver in the mid-clavicular line.
Body – the largest part of the gallbladder. It lies adjacent to the posteroinferior aspect of the liver, transverse colon and superior part of the duodenum.
Neck – the gallbladder tapers to become continuous with the cystic duct, leading into the biliary tree.
The neck contains a mucosal fold, known as Hartmann’s Pouch. This is a common location for gallstones to become lodged, causing cholestasis.

Question 22

What is the biliary tree?

Answer 22

The biliary tree is a series of gastrointestinal ducts allowing newly synthesised bile from the liver to be concentrated and stored in the gallbladder (prior to release into the duodenum).

Question 23

What is the flow of bile down the biliary tree?

Answer 23

Bile is initially secreted from hepatocytes and drains from both lobes of the liver via canaliculi, intralobular ducts and collecting ducts into the left and right hepatic ducts. These ducts amalgamate to form the common hepatic duct, which runs alongside the hepatic vein.
As the common hepatic duct descends, it is joined by the cystic duct – which allows bile to flow in and out of the gallbladder for storage and release. The common hepatic duct and cystic duct combine to form the common bile duct.
The common bile duct descends and passes posteriorly to the first part of the duodenum and head of the pancreas. Here, it is joined by the main pancreatic duct, forming the hepatopancreatic ampulla (the ampulla of Vater) – which then empties into the duodenum via the major duodenal papilla. This papilla is regulated by a muscular valve, the sphincter of Oddi.

Question 24

What is the blood supply of the gallbladder?

Answer 24

The cystic artery – a branch of the right hepatic artery (which itself is derived from the common hepatic artery, one of the three major branches of the coeliac trunk).

Question 25

What is the venous drainage of the gallbladder?

Answer 25

Venous drainage of the neck of the gallbladder is via the cystic veins, which drain directly into the portal vein. Venous drainage of the fundus and body of the gallbladder flows into the hepatic sinusoids.

Question 26

What is the innervation of the gallbladder?

Answer 26

The coeliac plexus carries sympathetic and sensory fibres, while the vagus nerve delivers parasympathetic innervation.

Question 27

What is the lymphatic drainage of the gallbladder?

Answer 27

Lymph from the gallbladder drains into the cystic lymph nodes, situated at the gallbladder neck.

Question 28

What causes biliary colic?

Answer 28

Bile is formed from a finely balanced mixture of chemicals which should keep all the individual components in solution. This solution often becomes imbalanced and ‘stones’ form in the gallbladder. The gallbladder contracts in response to fatty foods entering the duodenum and when it squeezes against the gallstones it can be painful.

Question 29

What causes hepatic encephalopathy?

Answer 29

The liver normally receives all the venous blood from the bowel. Ingested proteins which are digested and absorbed by the bowel often consist of chains of 3 or more amino acids. These are toxic to the brain as they can act as neurotransmitters. The liver removes all these proteins and reconfigures them into ‘safe’ molecules. In liver disease this process may fail or blood may bypass the liver through a porto-systemic shunt. The patient will develop neurological disease as a result.

Question 30

Where does pain from the gallbladder present?

Answer 30

The fundus of the gallbladder lies against the under surface of the diaphragm. Disease of the gallbladder may cause rubbing on the diaphragm. The pain produced will be carried by the phrenic nerve into C3, C4, C5. Pain felt over the right shoulder.

Question 31

Which structures can be found in the porta hepatis?

Answer 31

Macroscopically; portal vein, right and left hepatic artery, right and left hepatic duct Microscopically, lymphatics branches of the vagus and greater splanchnic nerves

Question 32

What structure degenerates to form the ligamentum venosum?

Answer 32

The ductus arteriosis; an embryological bypass for the liver which exists before the liver has fully formed.

Question 33

What is the surface marking of the fundus of the gallbladder?

Answer 33

The tip of the ninth costal cartilage. Where the midclavicular line crosses the costal margin. The most lateral attachment of the rectus abdominis onto the costal margin.

Question 34

What is the coeliac trunk? Label its branches

Answer 34

The coeliac trunk is the second branch of the abdominal aorta. It arises from the anterior aspect of the aorta, at the aortic hiatus of the diaphragm (T12 level). Gives rise to three major branches: the left gastric artery, the common hepatic artery and the splenic artery.

Question 35

What is the pancreas?

Answer 35

The pancreas is an abdominal glandular organ with both digestive (exocrine) and hormonal (endocrine) functions.

Question 36

Where is the pancreas located?

Answer 36

The pancreas is an oblong-shaped organ positioned at the level of the transpyloric plane. With the exception of the tail of the pancreas, it is a retroperitoneal organ, located deep within the upper abdomen in the epigastrium and left hypochodrium regions.

Question 37

What are the notable structures surrounding the pancreas?

Answer 37

The “C” shaped duodenum curves around and outlines the head of the pancreas.The aorta and inferior vena cava pass posteriorly to the head of the pancreas.The superior mesenteric artery lies behind the neck of the pancreas.

Question 38

What are the different parts of the pancreas?

Answer 38

Head – the widest part of the pancreas. It lies within the C-shaped curve created by the duodenum.
Uncinate process – a projection arising from the lower part of the head and extending medially to lie beneath the body of the pancreas.
Neck – located between the head and the body of the pancreas. It overlies the superior mesenteric vessels.
Body – centrally located, crossing the midline of the human body to lie behind the stomach and to the left of the superior mesenteric vessels.
Tail – the left end of the pancreas that lies within close proximity to the hilum of the spleen. It is contained within the splenorenal ligament with the splenic vessels. This is the only part of the pancreas that is intraperitoneal.

Question 39

What’s inside a pancreas?

Answer 39

It is composed of approximately one million ‘berry-like’ clusters of cells called acini, connected by short intercalated ducts.
The intercalated ducts unite with those draining adjacent lobules and drain into a network of intralobular collecting ducts, which in turn drain into the main pancreatic duct.

Question 40

What’s the blood supply to the pancreas?

Answer 40

The pancreas is supplied by the pancreatic branches of the splenic artery. The head is additionally supplied by the superior and inferior pancreaticoduodenal arteries which are branches of the gastroduodenal artery.

Question 41

What are the lymphatics of the pancreas?

Answer 41

They empty into the pancreaticosplenal nodes and the pyloric nodes, which in turn drain into the superior mesenteric and coeliac lymph nodes.

Question 42

What is a ERCP?

Answer 42

Endoscopic retrograde cholecystopancreatogram. An endoscope is passed through the mouth, oesophagus and stomach into the duodenum. A fine tube is passed through the duodenal papilla and a chemical which absorbs X-rays is injected to show the inside of the ‘tubes’.

Question 43

What is the Spleen?

Answer 43

The spleen is an organ located in the upper left abdomen, and is roughly the size of a clenched fist. In the adult, the spleen functions mainly as a blood filter, removing old red blood cells. It also plays a role in both cell-mediated and humoral immune responses.

Question 44

Where is the spleen located?

Answer 44

The spleen in located in the upper left quadrant of the abdomen, under cover of the diaphragm and the ribcage – and therefore cannot normally be palpated on clinical examination (except when enlarged). It is an intraperitoneal organ.

Question 45

What are the splenic ligaments?

Answer 45

Gastrosplenic ligament – anterior to the splenic hilum, connects the spleen to the greater curvature of the stomach.
Splenorenal ligament – posterior to the splenic hilum, connects the hilum of the spleen to the left kidney. The splenic vessels and tail of the pancreas lie within this ligament

Question 46

What is the spleen’s blood supply?

Answer 46

It receives most of its arterial supply from the splenic artery. This vessel arises from the coeliac trunk, running laterally along the superior aspect of the pancreas, within the splenorenal ligament.

Question 47

What is the spleen’s venous drainage?

Answer 47

Venous drainage occurs through the splenic vein. It combines with the superior mesenteric vein to form the hepatic portal vein.

Question 48

What is the spleen innervated by?

Answer 48

The nerve supply to the spleen is from the coeliac plexus.

Question 49

What’s the spleen’s lymphatic drainage?

Answer 49

The lymphatic vessels of the spleen follow the splenic vessels mentioned above and drain into the pancreaticosplenic lymph nodes, and ultimately the coeliac nodes.

Question 50

What are gallstones?

Answer 50

Small gallstones may pass through the cystic duct into the common bile duct. They may be too large to pass through the sphincter of Oddi. They may block the bile duct, pancreatic duct or both.

Question 51

What are the effects of gallstones?

Answer 51

Blockage of the bile duct leads to the build-up of pigments in the blood and the patient becomes jaundiced. It progresses to liver failure.

Blockage of the pancreatic duct will cause high pressure in the duct and digestive enzymes will leak out of the duct and start digesting the pancreatitis. It is fatal in 10% of cases. Fortunately a small knife can be passed down the endoscope to widen the sphincter and let the stone pass through.

Question 52

What is a pseudocyst?

Answer 52

In patients who survive pancreatitis the pancreas may leak fluid into the lesser sac. This will compress the stomach from behind and cause difficulty eating. A cyst is a fluid filled structure with an epithelial lining, this cyst has a mesothelial lining so it is a pseudocyst.

Question 53

Where can cancer of the pancreas spread to?

Answer 53

Carcinoma of the head of the pancreas can invade the bile duct or pancreatic duct and cause the same problems as gallstones. It can also grow around the portal vein, stopping blood flowing from the bowel to the liver (untreatable).

Question 54

What structures might a tumour of the head of the pancreas involve?

Answer 54

The hepatic portal vein, bile duct or pancreatic duct

Question 55

What structures join to form the common bile duct and what is its course?

Answer 55

The common hepatic and cystic duct. The common bile duct runs in the free edge of the lesser omentum and behind the first part of the duodenum, onto the posterior of the pancreas where it enters the pancreas to run alongside the pancreatic duct before opening into the duodenum.

Question 56

Where is the sphincter of Oddi located?

Answer 56

On the medial wall of the duodenum between the second and third parts.

Question 57

Which artery lies behind the first part of the duodenum?

Answer 57

Gastroduodenal artery

Question 58

What lies between the pancreas and the stomach?

Answer 58

The lesser sac

Question 59

How many pancreatic ducts are there? What is the embryological significance?

Answer 59

Two; one from the ventral pancreatic bud and one from the dorsal pancreatic bud.