Liver Structure and function

Question 1

List the functions of the liver (6)

Answer 1

Amino acid, carbohydrate and lipid metabolism
Storage of proteins, glycogen, vitamins and metals
Plasma protein and enzyme synthesis
Detoxification
Production of bile
Immune functions

Question 2

In what region of the abdomen is the liver found in?

Answer 2

Right upper quadrant

Question 3

List the lobes of the liver

Answer 3

Right
Left
Cuadate
Quadrate

Question 4

Caudate – located on ____ aspect of the visceral surface

Quadrate – located on ____ aspect of visceral surface

Answer 4

Caudate = upper 
Quadrate = lower

Question 5

what are the parenchymal cels fo the liver called

Answer 5

hepatocytes

Question 6

hepatocytes are arranged into ____?

Answer 6

lobules

Question 7

Each lobule is _____-shaped as is drained by a _____.

Answer 7

hexagonal

central vein

Question 8

What structures make up the portal triad and where are they found?

Answer 8

 Arteriole (branch of hepatic artery entering liver)
 Venule (branch of hepatic portal vein entering liver)
 Bile Duct (branch of bile duct leaving the liver)

They are found at the 6 edges of each lobule

Question 9

At what anatomical area do these structures enter/leave the liver?

Answer 9

These all enter/exit the liver at the “porta hepatis”. Porta = gateway

Question 10

what are the 2 distinct sources of blood supply to the liver ?
what percentage of the blood supply does each source make up?
What areas do they both supply?

Answer 10

Hepatic artery (30-40%) - supplies non-parenchymal structures
Hepatic Portal Vein (60-70%) - supplies the liver parenchyma

Question 11

What type of blood does each blood source supply to the liver?

Answer 11

Hepatic artery - Oxygenated blood

Portal vein - Nutrient-rich, partially deoxygenated blood

Question 12

What are connecting sinusoids?

Answer 12

vascular channels that receive blood from the hepatic artery and portal vein at the periphery of lobules and deliver it to central veins

Question 13

Sinusoids have a ______ ______ cell lining and are flanked by plates of _________

Answer 13

fenestrated endothelial

hepatocytes

Question 14

Venous drainage of the liver is achieved via ?

Answer 14

hepatic veins

Question 15

describe the passage of venous blood out of the liver

Answer 15

Central veins form collecting veins which then combine to from multiple hepatic veins. These hepatic veins open into the inferior vena cava.

Question 16

What is the area called that separates Hepatocytes from sinusoids ?

Answer 16

Space of Disse

Question 17

what feature do Hepatocytes have that extend into the Space of Disse?

Answer 17

Microvilli

Question 18

What do hepatocytes do?

Answer 18

They exchange material with blood at sinusoidal surface

Question 19

What are the 3 types of surface found on hepatocytes?

Answer 19

1. Sinusoidal
2. Intercellular
3. Canalicular

Question 20

What are the 2 ways in which sinusoids are different to normal capillary endothelium?

Answer 20

o	Fenestrated (have holes in them)
o	Lack a complete basement membrane

Question 21

list the 5 types of parenchymal liver cells

Answer 21

	Hepatocytes
	Endothelial cells
	Kupffer cells  
	Perisinusoidal (aka Ito) cells: 
	Liver-associated lymphocytes

Question 22

what are Kupffer cells a form of? what do they do?

Answer 22

form of macrophages

They are involved in phagocytosis

Question 23

describe Ito/perisinusoidal/stellate cells and where are they found?

Answer 23

fat-storing cells found in perisinusoidal space (Space of Disse)

Question 24

what is the Glisson’s capsule?

Answer 24

A thick, fibrous, INNER layer that covers the liver

Question 25

What is the there layer that surround the liver besides Glisson's capsule?

Answer 25

Outer serous layer derived from peritoneum

Question 26

What is parenchymal reticulin made up of? where is it found?

Answer 26

made up of type 3 collagen found around the central hepatic vein supports parenchymal tissue of liver

Question 27

List the parts of the biliary system

Answer 27

Bile canaliculi Bile ductules Bile ducts

Question 28

Describe the passage of bile once it has been secreted

Answer 28

Bile is secreted by hepatocytes and the bile canaliculi empty into a series of progressively larger bile ductules and ducts. These eventually become the Common Hepatic Duct.

Question 29

List the contents of bile

Answer 29

* Bilirubin * Bile acid/salts * Mucin

Question 30

what is jaundice caused by?

Answer 30

a build-up of bilirubin

Question 31

Define cirrhosis

Answer 31

Cirrhosis is a diffuse and irreversible process resulting in architectural disturbance, characterised by nodules of hepatocytes separated by fibrosis

Question 32

Describe the pathogenesis and possible causes of cirrhosis

Answer 32

Persistence of ‘injury-causing agent’ e.g. obesity, alcohol, virus, autoimmune disease Damage to hepatocytes and progressive loss of liver cells, Leads to: Liver inflammation = (Fibrous) scarring Hepatocyte regeneration =hyperplastic nodules Architectural abnormality Eventually irreversible & cirrhosis develops

Question 33

List the possible complications of cirrhosis

Answer 33

Portal hypertension Liver failure Liver (hepatocellular) cancer

Question 34

Describe the effects of liver failure

Answer 34

Altered intermediary metabolism e.g. impaired synthesis of urea and glycogen – could cause hypoglycaemia Reduced albumin & other transport proteins Coagulation disorders Reduced complement so prone to infection Jaundice Altered xenobiotic metabolism e.g. drugs Circulatory and endocrine disturbances

Question 35

List causes of cirrhosis

Answer 35

``` Alcohol Non-alcoholic fatty liver disease • Obesity • High blood pressure • Diabetes Hepatitis B/C virus (B is most common) Autoimmune hepatitis Biliary disease Haemochromatosis (genetic condition where there is an overload of iron) ```

Question 36

How does cirrhosis result in portal hypertension?

Answer 36

Cirrhosis increases resistance to blood flow through the liver This increases pressure in portal circulation

Question 37

what changes does portal hypertension cause?

Answer 37

Portal-systemic shunts and varices (enlarged, swollen veins) Ascites (abnormal build up of fluid in abdomen) Splenomegaly (enlargement of spleen due to increased pressure)