1.2.1 Liver, Portal Circulation, Biliary System and Spleen

Question 1

Embryological development of the gut region
- In the 5th week of development, the gut tube and associated structures are suspended by dorsal and ventral mesenteries
o Dorsal mesogastrium – suspends the ______
o Ventral mesogastrium – contains the liver at the foregut region. Ventral mesogastrium is divided into __________ and the _________ – remnant of the embryologic ventral mesentery liver to the anterior abdominal wall

Answer 1

GI tract;

lesser omentum, falciform ligament

Question 2

Liver and its relations

• The liver is located underneath the diaphragm, followed by the lesser omentum, stomach, greater omentum and then intestinal loops
  o The pancreas is in the posterior abdominal wall and is a retroperitoneal structure (except for tail)
• Develops in the ventral foregut mesentery
  o Connected to the anterior abdominal wall by the falciform ligament
  o Connected to the stomach by the lesser omentum
  o Part of the liver is in direct contact with the diaphragm – bare area of the liver not covered by peritoneum
• The liver is the largest gland in the body, lying mainly in the ___________ of the abdomen
  o Mostly under the cover of the ribcage from the _______ – cannot be palpated in a normal person where there is no enlargement (hepatomegaly)
  o Extends across the right hypochondrium through the epigastrium into the left hypochondrium

Answer 2

RUQ region; 7th rib to the 11th rib

Question 3

Anatomical lobes of the liver – 2 main and 2 accessory lobes divided eternally be peritoneal reflections
- The anatomical boundary between the 2 lobes is the falciform ligament
- The bare area of the liver is enclosed by the _________ – in direct contact with the diaphragm
o Anterior and posterior layers of the coronary ligament form _________ at the corners of the lobes

Answer 3

coronary ligament; triangular ligaments

Question 4

Relations of the liver to organs
- Right lobe – _______ impression, ________ impression and duodenal impression (from the 1st part of the duodenum)
- Left lobe – gastric impression (from the fundus of the stomach)
o Underneath the gallbladder, there is also an impression – fossa for gall bladder

Answer 4

right kidney; colic

Question 5

Right sagital fissure of the liver is the continuous groove formed anteriorly by fossa for ____ and posteriorly by groove of _________

Answer 5

gall bladder; vena cava

Question 6

Left sagital fissure is formed anteriorly by fissure for ____ and posteriorly by fissure for the ______

Answer 6

round ligamentum; ligamentum venosum

Question 7

Functional subdivisions of the liver - dividing the liver according to the blood supply (right
or left hepatic artery) and function
- On the visceral aspect, the _________ lobe is part of the left vascular lobe whereas the ______ lobe is supplied by branches from both hepatic arteries (supplied by the branches from both hepatic arteries, independent from the trifurcation of the porta triad)
- Grooves for the foetal veins (ligamentous venosum and teres) mark out minor parts of the functional left lobe – which divides into the quadrate and caudate lobes
- The __________ of the liver separates the quadrate and caudate lobes – carries the hepatic artery, portal vein, common bile duct and lymphatics

Answer 7

quadrate; caudate; porta hepatis (hilus)

Question 8

Anatomical relations of the liver

• The liver is covered by the costal margin except in the upper epigastrium where it is bare – but it is still not palpable in that region due to the _____________
• Convex diaphragmatic surface – corresponds to concavity of inferior surface of ________
• Complex visceral surface – right kidney and adrenal gland, inferior vena cava, abdominal oesophagus, stomach, duodenum and right colic flexure

Answer 8

rectus abdominis muscle; diaphragm

Question 9

Spaces of the liver

Subdiaphragmatic recesses:
- Superior extension of the _______ of the peritoneal cavity between the diaphragm and ______ aspect of the liver, separated into left and right by the falciform ligament

Subhepatic space: Portion of supracolic compartment of greater sac immediately inferior to liver

Hepatorenal recess/subhepatic recess (Morrison’s pouch)

• ________of subhepatic space between right visceral space and right kidney: fluid drains from omental bursa through the _______, communicating anteriorly with the right subphrenic recess
• Potential space significant in conditions in which fluid collects within the abdomen

Answer 9

greater sac; anterosuperior; Posterosuperior; extension epiploic foramen

Question 10

Visceral surface of Liver
o IVC is closely related to posterior aspect of the liver as the hepatic veins drain directly into it – IVC runs in a deep groove
o Ventral aspect – gallbladder is closely related to the _____ area, _________ area and renal area

Answer 10

colic; duodenal

Question 11

Blood supply to the liver – mainly comes from the coeliac trunk
- The ___________, derived from the coeliac axis, supplies arterial blood to the liver (20 to 30% of total supply)
- The portal vein drains the venous blood from the GI tract and spleen into the liver – providing the other 70 to 80% of the blood supply to the liver
- The coeliac trunk gives off 3 branches – left gastric artery, common hepatic artery and splenic artery
o Main artery supplying the liver is the common hepatic artery – branches into the hepatic artery proper and the __________ which supplies the lesser curvature of the stomach
o Hepatic artery branches further into the right and left hepatic artery – supplies the right and left functional lobes respectively
o From the __________, the cystic artery arises to supply the gallbladder

Answer 11

hepatic artery; right gastric artery; right hepatic artery

Question 12

Portal venous system drains the whole of the gut
structures – blood from the
gut drains into the liver via the portal vein
o The portal vein is actually the major blood supply to the liver

The portal vein is formed from the superior mesenteric vein and the splenic vein (which the _______________
drains into)
- Venous blood from the liver drains directly into the inferior vena cava just beneath the diaphragm via 3 short hepatic veins which are the _________
o Attachment to ____ holds the liver in position

Answer 12

inferior mesenteric vein;

right, middle and left hepatic veins;

IVC

Question 13

What are the 4 important anastomeses between the portal system and the systemic veins occuring along the GI tract

Answer 13

• left gastric vein (portal vein) and oesophageal vein (branch of azygos vein)
• superior rectal vein (portal vein) and inferior rectal vein which is a branch of internal pudendal veins (systemic)
• paraumbilical vein (portal) and epigastric veins (systemic)
• visceral veins (portal) and posterior abdominal wall veins (systemic)

Question 14

2 of the important sites of anastomoses are between the _____________________, as well as the inferior rectal vein (systemic) and superior rectal vein (portal) in the anal region.

o Varicose veins – any damage to the liver tissue causing scarring and fibrosis may obstruct blood flow via the liver, leading to portal hypertension
o Blood may flow through systemic veins of the anastomoses, resulting in dilated and weakened
veins especially in the lower oesophageal, rectal and
paraumbilical regions (occasionally) – may lead to a rupture, causing internal haemorrhage

Answer 14

oesophageal vein (systemic) and left gastric vein (portal)

Question 15

Biliary duct system – transport of hepatic secretions (bile) into the duodenum

• The right and left hepatic ducts from the right and left lobes of the liver join together to form the common hepatic duct, which then joins with the cystic duct (from the gallbladder) to form the bile duct
  o When bile is not needed, a sphincter at the distal end of the bile duct closes and pushes the bile back into the gallbladder for concentration and storage

Gallbladder – intraperitoneal, pear-shaped sac lies within a fossa formed between the inferior aspects of the right and quadrate lobes of the liver
o Fundus, body, infundibulum, neck
o ________ surface is not covered by peritoneum but other parts are covered by peritoneum

The common bile duct passes behind the 1st part of the duodenum and head of pancreas, joins with the pancreatic duct join to form the __________, which opens in the 2nd part of the duodenum through the major duodenal papilla.
o The terminal part of the hepato-pancreatic ampulla, bile and pancreatic ducts have smooth muscle sphincters – _______ which controls the flow of secretions into the duodenum
o The bile duct sphincter is always present – the other 2 sphincters may be absent or weak

Answer 15

Hepatic; hepatopancreatic ampulla of Vater; ampullary sphincter of Oddi

Question 16

What does the portal triad consist of?

Answer 16

hepatic artery, portal vein, common bile duct

Question 17

Neoplasms of the _____ of the pancreas can obstruct the bile duct or pancreatic duct

Cholecystoenteric fistula – gallbladder is close to the _________, so a gallstone developing in the gallbladder can result in ulceration of the gallbladder wall
o Further ulceration can penetrate through the wall and
irritate the duodenal wall, forming an ulcer on the
duodenal wall
o The 2 ulcers can connect, allowing for the gallstone to pass into the duodenum directly

Answer 17

head ; 1st part of the duodenum

Question 18

Spleen – largest lymphoid organ in the body
- Fist-sized and suspended in the dorsal foregut mesentery by the _________ligaments
- Lies posteriorly on the left midaxillary line under the 9th to 11th rib – closely related to the ______(anteriorly), _______ (medially),_______ (splenic flexure) (inferiorly) and the tail
of the pancreas
o Not palatable
o Traumatic rupture of the spleen causes severe haemorrhage

Soft, vascular mass with a relatively delicate fibroelastic capsule covered with a layer of visceral peritoneum (except at the splenic hilum) – site of lymphocyte proliferation, immune surveillance and response and response
o Identification, removal and destruction of expended RBCs and broken down platelets, iron and globin cycling
o Serves as a blood reservoir – self-transfusion during haemorrhage to an extent

Answer 18

gastrosplenic and splenorenal

stomach; left kidney; left colic flexure

Question 19

Surfaces and ligaments of spleen – ________reaches the hilum of the spleen (with the splenic artery going into the hilum)
- Diaphragmatic surface – smooth and convexly curved to fit concavity of the diaphragm and curved bodies of adjacent ribs
- Close relationship to ribs serves as protection, but may be detrimental during rib fractures – traumatic rupture of the spleen may result from trauma to the left side due to laceration by ribs
o Bleeding may result in marked increase in intraabdominal pressure, leading to rupture of the thin capsule and overlying peritoneum of the spleen, disrupting the soft pulp, leading to profuse bleeding and shock

• From the hilar surface of the spleen, there is a
  superior border, anterior border and inferior
  border
  o Anterior and superior borders are _____ and often notched while inferior border and the posterior end is _______

Answer 19

tail of the pancreas; sharp; rounded

Question 20

Hilum of the spleen contains the tail of the pancreas , splenorenal ligament and gastrosplenic ligament
o Splenorenal ligament – connects the spleen to the left kidney and contains the splenic vessels from the tail of the pancreas
o Gastrosplenic ligament – connects the spleen to the stomach and contains the ________
o These gastric vessels supply part of the
stomach on the left side
- Both these ligaments are part of the mesentery (greater omentum) that connects the spleen to the respective structures
- __________ and the left (splenic) flexure of the colon prevents the downward displacement of the spleen

Answer 20

short gastric vessels; Phrenicocolic ligament

Question 21

Calot’s triangle – small anatomical space at the porta hepatis, orientated so that its apex is directed at the liver
- Clinical importance during laparoscopic cholecystectomy (removal of the gall bladder) – triangle is carefully dissected by the surgeon, and its contents and borders identified
o Allows the surgeon to take into account any anatomical variation and permits safe ligation and division of the cystic duct and ________
o Right hepatic artery – must be identified by the surgeon prior to ligation of the cystic artery
- What are the borders of the triangle?

Answer 21

cystic artery; cystic duct, hepatic duct and liver