Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Phase 2 - Gastrointestinal > Liver and the Biliary Tract > Flashcards

Liver and the Biliary Tract Flashcards

1
Q

What is the composition of bile?

A
  • Bile acids and bile salts
  • Water (95%)
  • Electrolytes
  • Cholesterol
  • Phospholipids
  • Conjugated bilirubin
  • Bile pigments
  • Enzymes
  • Vitamins
  • Heavy metals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where is bile formed?

A

The hepatocytes of the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is bile and it’s pH?

A

A greenish-yellow alkaline that is stored and concentrated in the gallbladder.
pH7-8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the action of bile on fat?

A
  1. Acts as a detergent to fats - emulsifies large fat particles into smaller fat particles and form micelles to be attacked by lipase in pancreatic juice
  2. Aid transport of digested fat end-products to / through intestinal mucosal membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why is bile a better emulsifier than bile acids?

A

Bile is amphipathic - both hydrophilic and hydrophobic parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the functions of bile? (3)

A
  1. Aids digestion and absorption of fat (detergentation)
  2. Means for excretion for bilirubin (end product of haemoglobin destruction) and excess cholesterol synthesised by liver cells
  3. Exerts hormone-like effect to influence intestional metabolic pathways
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What role does the gallbladder have in bile formation?

A

Stores and concentrates bile about 5 times.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are bile acids formed from?

A

Cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the main primary bile acids

A

Cholic acid

Chenodeoxycholic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens to primary bile acids?

A

They are conjugated to bile salts by the addition of an amino acid group. They are then actively transported from the hepatocyte.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Once bile salts are formed, where do they get transported to?

A

Once the leave the liver, they travel through the hepatic duct and the common bile duct. Here, they either travel directly to the duodenum (where they act) or to the gallbladder via the cystic duct.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What stimulates gallbladder contraction and Sphincter of Oddi relaxation?

A

Vagal stimulation
CCK - Cholecytokinin
This is released from duodenal enteroendocrine cells in response to luminal fat presence.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How would you describe the contractions of the gallbladder?

A

Rhythmic contractions of gallbladder transmit peristaltic waves down common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the role of CCK in the bile system?

A

It promotes bile release into the duodenum. It’s released by enteroendocrine cells of the duodenum due to presence of luminal fat.
It causes gallbladder rhythmic contractions (contraction of the smooth muscle of the gallbladder) and relaxation of the Sphinter of Oddi (allowing bile into the duodenum).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What mediates relaxation of the gallbladder and closure of the sphincter of odds?

A

sympathetic nerves and the gut hormones Vasoactive Intestinal Polypeptide (VIP) and Somatostatin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What % of bile acids recirculate and are recycled?

  • 85%
  • 90%
  • 95%
  • 99%
A

95%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the enterohepatic circulation.

A

This is the circulation of bile substances (bile acids/bilirubin) and drugs. Bile acids are secreted from the liver in bile which enters the small intestine. They are then reabsorbed by enterocytes (mainly in the ileum) by active transport. They are then transported to the liver sinusoids via the portal vein.
The liver produces more bile acids to compensate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What facilitates the transport of bile acids back to the liver?

A

Albumin. They are bound to albumin in blood.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the order of the biliary tree from smallest to largest?

A 
Biliary canaliculi
Interlobular ducts
Septal bile ducts
Intrahepatic ducts
R. and L. hepatic ducts
Common hepatic duct
Common bile duct
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Explain the path of the common bile duct (location).

A

It passes behind the duodenum and through the head of the pancreas. It joins the main pancreatic duct and this opens into the 2nd part of the duodenum (descending d.).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Terminology : Cholecystitis

A

Gallbladder inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Terminology: Cholelithiasis

A

Gallstones within the gallbladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Terminology: Cholecystectomy

A

Removal of the gallbladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Terminology: Cholangitis

A

Gallstone within a bile duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What vol. of bile can the gallbladder store?

  • 25-45ml
  • 30-50ml
  • 35-55ml
  • 40-60ml
A

30-50ml

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where does the gallbladder sit?

A

Located under the liver in the gallbladder fossa on the interior surface on the right love of the liver.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the risk factors for developing gallstones?

A
  • Increasing age
  • Family history
  • Caucasian
  • Low fibre diet
  • Inflammatory bowel disease
  • Prolonged fasting (bile held for long time in gallbladder and being concentrated)

5 F’s: Female, Fair, Fertile, Forty, Fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What percentage of the population will develop gallstones?

A

7-15% of the population. 80% of these are asymptomatic which don’t require treatment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the different types of gallstones and give a short description of each?

A
  1. Cholesterol only
    - Solitary, large, oval, soft and clay-like. These sit in the gallbladder
  2. Bile Pigment
    - Associated with haem
  3. Mixed
    - Mostly cholesterol with some bile pigment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Describe gallstone pathogenesis (3 steps)

A

Cholesterol Supersaturation

  • Cholesterol is solubilised by bile and high cholesterol levels results in supersaturation.
  • Typically occurs w/ high oestrogen levels (obesity/pregnancy/liver disease) low b. acid levels (active Crohn’s)

Biliary Stasis
- Occurs during fasting / starvation

Increased bilirubin secretion

  • Conjugated bilirubin soluble in bile
  • Pigmented stones develop when: 1. Increased RBC breakdown (haematological conditions). 2. Failure of hepatic conjugation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Why does liver disease cause high oestrogen levels?

A

The liver breaks down oestrogen therefore would cause men to be in a higher oestrogen state.

32
Q

What complications could gallstones cause if in the gallbladder?

A

Biliary Colic
Acute Cholescystitis
Empyema
Cancer

33
Q

What complications could gallstones cause if in the common bile duct?

A

Obstructive jaundice
Cholangitis
Pancreatitis

34
Q

What complication could gallstones cause if in the small intestine?

A

Gallstone ileus

35
Q

What is biliary colic? (Inc. pain, LFTs)

A

Sudden pain due to a gallstone.
The stone is usually impacted in the neck of the gallbladder. The pain is epigastrium / right upper quadrant / through back.
Pain provoked by eating and vomiting is a sign
Normal LFT
Often settles if stone moves back into fundus

36
Q

What is acute Cholecystitis in relation to a gallstone? (Inc. symptoms, LFTs, treatment)

A

Gallstone in gallbladder leading to wall oedema / inflammation.
May cause a bacterial infection in the GB wall
Symptoms: pain, nausea, abdominal tenderness
LFT: inc. inflammatory markers
Treatment: antibiotics

37
Q

What is post-hepatic obstructive jaundice?

A 
Post-hepatic = after the liver
Obstructive = bile excretion impaired by obstruction / loss of bile ducts
Jaundice = Increased bilirubin in blood
38
Q

What are common causes of post-hepatic obstructive jaundice?

A
  • choledocholithiasis (gallstones in bile duct)

- pancreatic cancer (head of pancreas compresses common bile duct

39
Q

What are signs and symptoms of post-hepatic obstructive jaundice?

A
  • Scratch marks
  • Features of chronic liver disease
  • Pale stools
  • Dark urine (conj. bilirubin excreted in urine from blood)
  • yellow sclera
40
Q

What is choledocholithiasis and how would a patient present?

A
  • gallstones in the bile ducts (migrated from the gallbladder where stones usually form)
    May present with:
  • obstructive jaundice
  • cholangitis (need antibiotics)
  • acute pancreatitis
    Treat w/ cholecystectomy to prevent reoccurrence.
41
Q

What are the endocrine and exocrine functions of the liver?

A 
Exocrine role
- Bile production
Endocrine role
- IGF
- Angiotensinogen
- Hepcidin, beta-trophic
42
Q

Blood in the portal vein travels from where to where?

A

From the GI tract, gallbladder, pancreas and spleen to the liver

43
Q

What are the functions of the liver? (9)

A

Metabolic

  • Synthesis (e.g. clotting factors, albumin)
  • Breakdown (e.g. drugs)
  • Amino acid, carb and lipid metabolism
  • Plasma protein and enzyme synthesis
  • Bile production
  • Detoxification
  • Storage of proteins, glycogen, vitamins, metals
  • Activates Vit. D
  • immune function
  • Urea, heparin and Vit. A production
44
Q

What is the vasculature of the liver?

A

Hepatic artery

  • 30-40% blood supply
  • Supplies non-parenchymal structures w/ oxygen rich blood
  • From coeliac trunk

Hepatic portal vein

  • 60-70% blood supply
  • supplies partially deoxygenated blood
  • blood drained from SI (nutrients), spleen (RBC breakdown products) and pancreas

Connecting sinusoids
- large fenestrated capillaries

Hepatic vein

  • central veins of hepatic lobule form collecting/sub-lobular veins which combine forming hepatic veins
  • open into inf. vena cava
45
Q

What supplies oxygenated blood to the liver?

A

Hepatic artery

46
Q

What supplies nutrient rich and partially deoxygenated blood to the liver?

A

Hepatic portal vein

47
Q

What artery allows the liver to perform gut-related functions?

A

Hepatic portal vein

48
Q

What structures makes up the portal triad?

A

Hepatic artery (in), portal vein (in) and bile ducts (out)

49
Q

What is the role of connecting sinusoids?

A

Receive and mix blood from hepatic artery (O2 rich) and portal vein (nutrient rich) and deliver this to central veins

50
Q

Where is the liver situated?

A

Right hypochondrium and epigastric regions

51
Q

What are the lobes of the liver?

A

Right with two accessory lobes; Caudate and Quadrate

Left

52
Q

Which lobe of the liver is the largest?

A

Right

53
Q

On what surface of the liver are the accessory lobes located on?

A

Visceral surface

54
Q

How to differentiate between caudate and quadrate lobes?

A 
Caudate
- Upper aspect visceral surface
Quadrate
- Lower aspect
- Next to gallbladder
55
Q

What separates the caudate and quadrate lobe and what does it transport?

A

Porta hepatis fissure

- Transmits vessels, nerves and ducts leaving/entering liver except hepatic veins

56
Q

What separates the left and right lobes of the liver?

A

The attachment of falciform ligament which also attaches to the abdominal wall.

57
Q

What covers the liver?

A

A fibrous membrane - Glisson’s Capsule

58
Q

What’s the micro-anatomy of the liver and their functions?

A

Hepatocytes (liver cells) - produce bile
Bile canaliculi - ducts collecting bile
Hepatic sinusoids - Supply liver w/ oxygenated and nutrient-rich blood

59
Q

What are the surfaces of a hepatocyte?

A

3 surface types

Sinusoidal, Intercellular, Canalicular

60
Q

What cell type is a hepatocyte?

A

Cubodial epithelial cells lined with microvilli

61
Q

How are hepatocytes arranged?

A

Densely packed and segmented into hepatic laminae only one cell thick by sinusoids (vascular spaces)

62
Q

Role of hepatocytes

A

Multi-functional
Parenchymal (functional unit of an organ)
They carry the function of the liver i.e. take up glucose, amino acids e.t.c for metabolism, detoxification of blood, synthesise bile e.t.c.

63
Q

What are bile canaliculi and their function?

A

Tiny channels located between hepatocytes. They transport bile from hepatocytes to bile ducts
The bile in canaliculi flows in the opposite direction to blood in sinusoids.

64
Q

What are hepatic sinusoids?

A

Capillaries with larges fenestrations (pores) located between hepatic laminae.

65
Q

Where do hepatic sinusoids drain to?

A

They converge centrally, draining into a central vein which drains into the hepatic vein then the inferior vena cava.

66
Q

What is the Space of Disse?

A

Perisinusoidal space - the spaces between layers of hepatocytes and sinusoidal endothelial cells.

67
Q

What is the function of hepatic sinusoids?

A

Blood from the portal vein and hepatic artery mixes here, delivering oxygen and nutrient rich blood

68
Q

Where are Kupffer cells situated?

A

They are macrophages and situated on walls of hepatic sinusoids

69
Q

What is a hepatic lobule?

A

The structural unit of the liver. It is one way to explain the arrangement of hepatocytes into hexagons.

70
Q

What is the structure of a hepatic lobule?

A

Hexagonal cylinders of hepatocytes which are drained by a central vein.
Lobules are separated by interlobular septum = CT containing lymphatics and blood vessels.
At each corner of the hexagonal lobule is a hepatic triad (6 for each lobule)

71
Q

What are the parenchymal liver cells?

A
  • Hepatocytes
  • Endothelial cells
  • Kupffer cells (macrophages)
  • Perisinusoidal (fat storing) cells
  • Liver-associated lymphocytes
72
Q

What is the transportation sequence of bile?

A

Secreted by hepatocytes > collected by system of ducts > right and left hepatic ducts > common hepatic duct > joins with cystic duct (from gallbladder), forming common bile duct > runs to duodenum

50% bile is first stored in gallbladder before released into duodenum.

73
Q

How is bile concentrated in the gallbladder?

A

Epithelial cells actively transport sodium through gallbladder mucosa. Water and other electrolytes are then reabsorbed through the epithelial cells.

74
Q

What happens to the bile as it flows through the ducts?

A

Duct cells, lining bile ducts of the liver, release bicarbonate and water therefore diluting bile.

75
Q

What regulates secretion of bile?

A

CCK and secretin. Also, nerve impulses from vagus nerve.

76
Q

What is the role of secretin in bile secretion?

A

Secreted by endocrine cells in response to acidic chyme. It stimulates biliary duct cells in the liver to secrete more water and sodium bicarbonate (essential to neutralise stomach acid present in the duodenum). It also stimulates bile production.

Phase 2 - Gastrointestinal (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions