Liver Function And Pathology 2

Question 1

What is portal circulation?

Answer 1

The network of veins that drain through the liver before reaching the inferior vena cava

Question 2

What is systemic circulation?

Answer 2

Any veins that drain into the IVC NOT VIA THE LIVER

Question 3

What 3 blood vessels make up the portal vein that leads into the liver?

Answer 3

Superior mesenteric vein
Inferior mesenteric vein
Splenic vein

Question 4

What part of the gut does the Superior Mesenteric vein drain?

Answer 4

Ascending colon
Transverse colon (proximal 2/3s)

Small intestine (duodenum, jejenum, ileum)
Caecum

Question 5

What part of the gut does the Inferior Mesenteric Vein drain?

Answer 5

Descending colon
Sigmoid colon
Rectum (via rectal veins)

Question 6

What does the splenic vein drain?

Answer 6

Spleen into liver

Question 7

What is the flow of blood through the liver?

Answer 7

Portal vein (80%) + hepatic artery (20%) through portal triad -> sinusoids -> central vein -> hepatic veins

Question 8

What is portal hypertension?

What causes it?

Answer 8

The build up of blood in the portal venous system leading to high hydrostatic pressure here

Occurs due to the fibrotic changes seen in liver cirrhosis

Question 9

How does liver Cirrhosis cause portal hypertension?

Answer 9

The fibrotic changes in the liver means the liver cant expand as much so blood accumulates in portal system increasing the hydrostatic pressure

Question 10

What are the 3 main complications of portal hypertension?

Answer 10

Ascites

Splenomegaly

Varices

Question 11

Why does ascites develop with portal hypertension?

Answer 11

Build up of blood in portal system leads to increased hydrostatic pressure

Hydrostatic pressure > oncotic pressure in blood leading to fluid remaining in interstitium

Question 12

Why does Splenomegaly develop with portal hypertension?

Answer 12

The build up of blood in the portal system backs up into the splenic vein into the spleen

Question 13

What are Varices?

Answer 13

Dilated/distended veins that develop at sites of Portosystemic anastomosis

Question 14

What are portosystemic anastomosis?

Answer 14

Allow flow of blood from the portal system directly to the systemic circulation bypassing the liver when its difficult for blood to flow through the liver like in liver cirrhosis

Question 15

Describe the process of the formation of Varices with portal hypertension:

Answer 15

The increase in hydrostatic pressure in the portal system/circulation forces blood from the portal circulation directly to the systemic circulation via portosystemic anastomosis

These portosystemic anastomosis dilate/distend due to carry too much blood, they are now called Varices

Question 16

What are the 3 main locations where Varices can develop when theres portal hypertension?

Answer 16

Oesophageal Varices
Anorectal Varices
Umbilical Varices

Question 17

How do oesophageal Varices develop?

Answer 17

Portal hypertension
Normally left gastric vein drains lower oesophagus but the Varices divert blood to the azygous vein instead which drains to the SVC

So distension of the portosystemic anastomoses between the left gastric vein and the azygous vein

Question 18

Why are oesophageal Varices very dangerous?

Answer 18

Very vulnerable to rupture leading to massive haemorrhage (oesophageal mucosa thin)

Needs immediate endoscopic intervention to control bleeding and measures to lower portal hypertension

Question 19

What blood vessels do anorectal Varices form between?

Answer 19

Superior, middle and inferior rectal veins

Question 20

Why are anorectal Varices normally painless?

Answer 20

They are above the Pectineal line

Question 21

What is the name given to Umbilical Varices?

Answer 21

Caput medusae

Question 22

How do umbilical Varices/caput medusae present?

Answer 22

Dilated veins radiating from the umbilicus

Question 23

Why can umbilical Varices develop in an adult?

Answer 23

There’s still a connection in the adult between the umbilical vein remnant (ligamentum teres) abdominal wall and circulation

Question 24

What are the 2 bile ducts that branch directly from the livers bile ducts coalescing?

Answer 24

Left hepatic and right hepatic bile duct

Question 25

What bile duct forms from the left hepatic duct and right hepatic duct joining together?

Answer 25

Common hepatic duct

Question 26

What is the name of the bile duct that comes straight off the gall bladder?

Answer 26

Cystic duct

Question 27

What is the name of the bileduct which forms as a result of the joining of the common hepatic duct and the cystic duct?

Answer 27

Common bile duct

Question 28

What is hepatorenal syndrome?

Answer 28

Acute/rapid deterioration of kidney function due to liver cirrhosis causing portal hypertension The failing liver is causing a failing kidney

Question 29

What is the thought pathological mechanism of Heptorenal syndrome?

Answer 29

Portal hypertension leads to splanchinc (abdominal vein) vasodilation This leads to body perceiving systemic BP has dropped so it activates the RAAS to compensate Renal artery constriction occurs lead to reduced kidney perfusion and therefore reduced kidney function

Question 30

What other duct joins the Common Bile Duct?

Answer 30

Pancreatic duct

Question 31

What is the point at which the common bile duct drains into the duodenum called?

Answer 31

Ampulla of Vater

Question 32

What controls the release of secretions through the common bile duct into the duodenum through the Ampulla of Vater?

Answer 32

Sphincter of Oddi

Question 33

What are gallstones made of? Why can they form?

Answer 33

Cholesterol Bile pigments Form since the gall bladder concentrates bile by removing water when it’s storing it

Question 34

How can gallstones and renal stones be distinguished on an X-ray and why?

Answer 34

Renal stones show up white whereas gallstones not visible Renal stones have a Ca2+ component

Question 35

What are the risk factors for gallstone development?

Answer 35

Diet Lifestyle Woman Pregnancy

Question 36

What are 4 complications that can be caused by gallstones?

Answer 36

Biliary colic Acute cholecystitis Acute ascending cholangitis Acute pancreatitis

Question 37

What is biliary colic?

Answer 37

When theres sudden onset RUQ pain a couple of hours after eating a meal due to temporary blockage of the cystic duct by a gallstone NO INFLAMMATION

Question 38

What hormone is released following a meal which would cause the pain in biliary colic and why?

Answer 38

Cholecystokinin (CCK) This stimulates the gallbladder to contract which is what moves the gallstone blocking the duct

Question 39

How is biliary colic treated?

Answer 39

Analgesia Cholecystectomy (removal of gall bladder

Question 40

What is acute cholecystitis?

Answer 40

When the gallstone is permanently impacted into the wall of the cystic duct permanently blocking it

Question 41

How does acute cholecystitis present?

Answer 41

RUQ pain Fever INFLAMMATION (evidence of it)

Question 42

How is acute cholecystitis treated?

Answer 42

Antibiotics Analgesia Cholecystectomy

Question 43

What examination can be done to help diagnose acute cholecystitis? Explain how it works:

Answer 43

Murphys sign Put hand on patients right side of abdomen Get them to inhale, liver and gall bladder will sink below ribs, as it touches your hand patient will have a sharp painful inhalation showing gall bladder tenderness

Question 44

What is acute ascending cholangitis?

Answer 44

An infection of the billary tree which is caused by a gallstone blocking the common bile duct

Question 45

What leads to infection causing acute ascending cholangitis?

Answer 45

The stone blocks the common bile duct which completely blocks bile flow causing stasis of bile which leads to infection behind the stone

Question 46

What does acute ascending cholangitis present with? What are the presence of these 3 symptoms referred to as?

Answer 46

RUQ pain Inflammation Jaundice All 3 = Charcots triad

Question 47

How is acute ascending cholangitis treated?

Answer 47

Antibiotics Fluids Surgery

Question 48

What is acute pancreatitis?

Answer 48

Gallstone blocks the common bile duct at point which major pancreatic duct joins it or more distal to this

Question 49

Describe the pathological process of acute pancreatitis caused by a gallstone:

Answer 49

Gallstone blocks the common bile duct at point which major pancreatic duct joins it or more distal to this Leads to inc pressure in pancreatic duct so the protease enzymes become activated leading to auto digestion of the pancreas, this causes a MASSIVE INFLAMMTORY response (Acinar cells damaged and pancreatic necrosis)

Question 50

How does acute pancreatitis present?

Answer 50

Epigastric pain that radiates to the back Vomiting Elevated plasma pancreatic amylase and lipase levels Cullens and Grey turners (rare)