Liver and Pancreas

Question 1

The liver is the largest internal organ, how much does it weigh

Answer 1

Roughly 1.5kg in adults

Question 2

Where is the liver located?

Answer 2

In the right quadrant of the abdomen, just below the diaphragm

Question 3

The liver consists of four lobes, what are these?

Answer 3

two major and two small inferior

Question 4

What is the parietal peritoneum?

Answer 4

Parietal peritoneum is that portion that lines the abdominal and pelvic cavities.

Question 5

What is the visceral peritoneum?

Answer 5

Visceral peritoneum covers the external surfaces of most abdominal organs, including the intestinal tract.

Question 6

What is the liver covered by?

Answer 6

A thin capsule and mesothelium of the visceral peritoneum

Question 7

What is a mesothelium?

Answer 7

A membrane composed of simple squamous cells that form the lining of several body cavities

Question 8

The liver receives a dual blood supply, explain.

Answer 8

It receives a dual blood supply from the hepatic artery which carries oxygen from the heart and hepatic portal vein which carries nutrient rich blood from the GI tract

Question 9

Where does venous drainage of blood occur in the liver?

Answer 9

via the hepatic vein into the vena cava

Question 10

What are the six main functions of the liver

Answer 10

1. fat metabolism
2. carbohydrate metabolism
3. protein metabolism
4. storage
5. intermediary metabolism
6. secretion

Question 11

During fat metabolism, the liver is responsible for oxidising triglycerides to produce what?

Answer 11

energy

Question 12

During fat metabolism, the liver is responsible for synthesising what three substances?

Answer 12

lipoproteins, cholesterol and phospholipid

Question 13

During carbohydrate metabolism, the liver is responsible for converting carbohydrates and proteins into what?

Answer 13

fatty acids and triglyceride

Question 14

During carbohydrate metabolism, what three methods are used by the liver in order to regulate blood glucose concentrations?

Answer 14

Glycogenesis, glycogenolysis and gluconeogenesis

Question 15

What is glycogenesis?

Answer 15

Glycogenesis is the process of glycogen synthesis, in which glucose molecules are added to chains of glycogen for storage.

Question 16

What is glycogenolysis?

Answer 16

Glycogenolysis is the biochemical breakdown of glycogen to glucose whereas glycogenesis is the opposite, the formation of glycogen from glucose.

Question 17

What is glyconeogenesis?

Answer 17

Gluconeogenesis (GNG) is a metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates.

Question 18

The liver holds the function of protein metabolism, give some examples of plasma proteins it is responsible for synthesising

Answer 18

albumin and clotting factors

Question 19

The liver is responsible for the synthesis of non essential

Answer 19

amino acids

Question 20

Under protein metabolism, the liver functions to detoxify what, and give an example

Answer 20

Detoxification of metabolic waste products such as the deamination of amino acids and urea production

Question 21

What does the liver function to store

Answer 21

glycogen, vitamins and iron

Question 22

How is the liver involved in intermediary metabolism?

Answer 22

Because it is involved in the detoxification of drugs and toxins such as alcohol

Question 23

What secretory purpose does the liver hold

Answer 23

the synthesis and secretion of bile

Question 24

What are the key liver cells called?

Answer 24

Hepatocytes

Question 25

How are the hepatocytes arranged in the liver

Answer 25

Arranged as thin plates, only one cell thick

Question 26

How would one describe the hepatocytes in terms of shape and nuclei?

Answer 26

Large cuboidal or polyhedral cells, round central nuclei, prominent nucleoli

Question 27

Why is the cytoplasm of hepatocytes eosinophilic?

Answer 27

The cytoplasm has numerous mitochondria. Eosin is a pink colour and is an acidic dye - negatively charged that binds to positively charged particles like the mitochondria and many components of the cytoplasm

Question 28

Hepatocytes are often seen as which types of cells? Uninucleate, binucleate or multinucleate?

Answer 28

BINUCLEATE BABES - they are commonly seen

Question 29

More than half of the hepatocytes contain twice the normal complement of chromosomes, what are they referred to as?

Answer 29

tetraploid

Question 30

When looking at a histology slide of a collection of hepatocyes, we may see irregular unstained areas. Why is this?

Answer 30

This is because the glyocogen and lipid are removed during processing

Question 31

The liver is a very solid organ. The outer surface is covered by a capsule composed of collagenous tissue called

Answer 31

the Glisson's capsule

Question 32

The Glisson's capsule which is a collagenous tissue covering the outside layer of the liver is surrounded by what cell layer?

Answer 32

Mesothelial cell layer from the peritoneum

Question 33

What is the basic functional unit of the liver called

Answer 33

Hepatic lobules

Question 34

What do hepatic lobules contain?

Answer 34

Portal tracts

Question 35

What does each portal tract of the hepatic lobule of the liver contain? Which three main structures?

Answer 35

The hepatic portal vein, the hepatic artery and a bile ductule

Question 36

What surrounds each of the portal tracts?

Answer 36

Plates of hepatocytes

Question 37

How is the structural integrity of the liver maintained?

Answer 37

By a meshwork of reticulin fibres

Question 38

Reticulin fibres contain which type of collagen fibres?

Answer 38

Collagen type 3 fibres

Question 39

What specifically do the reticulin fibres which are made of type 3 collagen fibres provide support to?

Answer 39

To the hepatocytes and sinusoidal lining cells

Question 40

What are the reticulin fibres stained with?

Answer 40

Silver - shows reticulin as a black-stained material.

Question 41

What is a hepatic lobule

Answer 41

The structural unit of the liver

Question 42

What type of shape does a hepatic lobule have

Answer 42

A hexagonal shape

Question 43

What is a hepatic lobule centred around?

Answer 43

A terminal hepatic venule

Question 44

Blood flows from the portal vein and hepatic artery in the portal tract to where?

Answer 44

To the central veins

Question 45

Where does blood flow along in the hepatic lobules of the liver

Answer 45

Along sinusoids lined with endothelial cells

Question 46

The close association sinusoids have with hepatocytes allows what to occur?

Answer 46

Absorption of nutrients and secretion of hepatic products

Question 47

What is the alternative model of the liver called?

Answer 47

The hepatic acinus

Question 48

The alternative model for the liver louble referred to as the hepatic acinus is a berry shaped unit of liver parenchyma centered on a

Answer 48

portal tract

Question 49

The hepatic acinus lies between two or more

Answer 49

terminal hepatic venules

Question 50

In the hepatic acinus model, blood flows from the portal tracts through the _____ to the _____

Answer 50

sinusoids and venules

Question 51

The hepatic acinus model is divided into how many zones?

Answer 51

Three zones

Question 52

The three different zones of the hepatic acinus model is because each zone has

Answer 52

different metabolic functions

Question 53

Describe the location of zone 1

Answer 53

It is closest to the portal tract so it receives the most oxygenated blood

Question 54

Describe the location of zone 3

Answer 54

Zone 3 is found closest to the central vein

Question 55

Describe the oxygen concentration of zone 3 and which enzymes are therefore present

Answer 55

Least oxygen, so high in esterases and low in oxidative enzymes

Question 56

What is an esterase?

Answer 56

An esterase is a hydrolase enzyme that splits esters into an acid and an alcohol in a chemical reaction with water called hydrolysis.

Question 57

What type of endothelium does the sinusoid have in the hepatic lobule?

Answer 57

Fenestrated

Question 58

Do the sinusoids present in the hepatic lobules have a basement membrane?

Answer 58

No homie

Question 59

There are microvilli present in the hepatocytes of the liver for what reason?

Answer 59

To increase the surface area for metabolic exchange

Question 60

What is the space of disse?

Answer 60

The location in the liver between a hepatocyte and a sinusoid

Question 61

What does the space of disse bathe the hepatocyte surface with?

Answer 61

With plasma, microvilli of the hepatocytes extend here to allow exchange

Question 62

Where does the space of disse plasma drain into?

Answer 62

Into lymphatics in portal tract

Question 63

What are the three types of cells lining the sinusoids?

Answer 63

Endothelial cells Kupffer cells Stellate cells

Question 64

Describe the endothelial cells that line the sinusoids

Answer 64

Most numerous, flat darkly stained nuclei, thin fenestrations - large pores

Question 65

Describe the kupffer cells

Answer 65

Large plum cells with ovoid nuclei

Question 66

What is the function of the kupffer cells

Answer 66

Monocyte-phagocyte system and removal of spent erythrocytes

Question 67

What are the main functions of the stellate cells?

Answer 67

Fat storage, lipid droplets - vit A. Production of ECM and collagen

Question 68

Bile is produced by all

Answer 68

hepatocytes

Question 69

The apical surfaces of hepatocytes form what thin tube like structure into which bile is secreted?

Answer 69

Bile canaliculi

Question 70

Bile canaliculi form a network of channels through the

Answer 70

hepatocyte plates

Question 71

Bile flow progresses in which direction compared to that of the blood?

Answer 71

Opposite direction

Question 72

Bile canaliculi of adjacent hepatocyte plates merge to form which structure

Answer 72

canals of Hering

Question 73

What are the canals of Hering lined by?

Answer 73

Cuboidal epithelial cells - cholangiocytes

Question 74

What do the canals of hering join together to form?

Answer 74

Bile ductules in the portal areas

Question 75

Where do bile ductules drain?

Answer 75

Into the bilary tree

Question 76

What does the intrahepatic bile collecting system consist of?

Answer 76

Bile canaliculi, bile ductules and bile ducts

Question 77

What do the intrahepatic bile colllecting system merge to form?

Answer 77

The left and right hepatic ducts

Question 78

The left and right hepatic ducts join to form the

Answer 78

common hepatic duct

Question 79

On leaving the liver, the common hepatic duct is joined by which duct?

Answer 79

the cystic duct

Question 80

The cystic duct and hepatic duct drain into the gall bladder forming which structure?

Answer 80

The common bile duct

Question 81

What do common bile ducts join to

Answer 81

The pancreatic duct

Question 82

The common bile ducts and pancreatic ducts join to form which structure

Answer 82

the short ampulla of vater

Question 83

where does the short ampula of vater enter

Answer 83

the duodenum

Question 84

How would one describe the structure of the gall bladder?

Answer 84

A hollow, pear shaped muscular sac attached to the lower surface of the liver

Question 85

What type of epithelial cell surrounds the gall bladder?

Answer 85

Simple columnar epithelium

Question 86

What is the volume capacity of the bile duct in humans?

Answer 86

100mL

Question 87

How does the gall bladder end up contracting and releasing the bile into the duodenum?

Answer 87

The presence of lipid in the duodenum promotes secretion of cholecystokinin (CCK) by neuroendocrine cells of duodenal mucosa

Question 88

How would you describe the wall of the gall bladder?

Answer 88

Mucosa of wall is highly folded and lined with a simple columnar epithelium

Question 89

How many muscle layers does the gall bladder have?

Answer 89

Only one

Question 90

What is the serosa present in the gall bladder?

Answer 90

A serous membrane (also referred to as a serosa) is one of the thin membranes that cover the walls and organs in the thoracic and abdominopelvic cavities

Question 91

What two structures are absent in the histology of the gall bladder?

Answer 91

No muscularis mucosa and submucosa