Liver Structure & Function Flashcards

1
Q

In what section of the abdomen is the liver found?

A

The upper right quadrant

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

Name the 4 lobes of the liver

A

Major - Right & left

Minor - Caudate & Quadrate

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

Where do structures enter and leave the liver?

A

A section on the inferior surface called the porta hepatis. Basically a fissure about 5cm long.

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

What structures enter/exit the liver at the porta hepatis?

A

(o) Blood - Hepatic artery + portal vein
(o) Lymphatics
(o) Left & Right Hepatic Ducts
(o) Nerves - hepatic nerve plexus

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

What covers the liver.

A

Visceral Peritoneum & connective tissue capsule

Except at the bare area

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

What is the bare area?

A

A small area on the liver’s diaphragmatic surface surrounded by the coronary ligament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens to the connective tissue capsule at the porta hepatis?

A

it forms a branching network of septa passing into the liver to support it.

Vessels, ducts & nerves follow these septa.

These septa divide the liver into hexagonal lobules

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

How does the portal triad relate to the lobules of the liver?

A

Each hexagonal lobule has a branch of the hepatic portal vein, artery and duct at its corners.

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

Explain the structure of the hexagonal lobules of the liver?

A

1) Central Vein at the centre
2) Hepatic cords of hepatocytes radiating out from central vein
3) Lumen called bile canaliculus runs between the cords
4) blood channels called hepatic sinusoids also run between cords

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

explain the passeage of bile

A

Bile salts secreted by hepatocytes

  • -> Into bile canaliculi
  • -> Into bile ductules
  • -> Into Hepatic Ducts
  • -> Common hepatic duct
  • -> Merge with cystic Duct to become common bile duct
  • -> Merge with pancreatic duct to become hepatopancreatic ampulla
  • -> Passes through sphincter of Oddi and out the major duodenal papilla into duodenum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where do the hepatic sinusoids drain from/to? and whats their purpose?

A

they drain blood from the hepatic portal vein & artery, through the sinusoids and into the central vein.

They allow all the hepatocytes to be in contact with the blood and do their stuff

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

Where do the central veins run to?

A

The hepatic veins

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

What is the function of hepatocytes?

A
  • Bile Synthesis
  • Nutrient Storage
  • Nutrient Interconversion
  • Detoxification
  • Storage of glycogen, fat, vitamins and mineral (e.g. copper & iron)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the components of bile and their sources?

A

Synthesized in Liver:

  • Bile Acids
  • Lecithin
  • Cholesterol

Parts of broken haemoglobin:
- Bile Pigments (bilirubin)

Taken from blood during detoxification in liver:
- Toxic Metals

Produced in ductal cells:
- Bicarbonate

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

Whats the purpose of bile?

A
  • Solubilises fat
  • Disposes of toxins
  • Neutralises Acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the various bile pigments and where do they come from?

A

(o) Bilirubin - Yellow
- Comes from breakdown components of old/damaged erythrocytes
- extracted from the blood by hepatocytes & secreted into bile

(o) Bilirubin modified by bacteria - Brown
- Modification occurs in the large intestine
- Causes faeces to be brown

(o) Reabsorbed Bilirubin excreted in urine- Yellow
- Yellow Urine

17
Q

What is the Gall bladder?

A

A saclike structure about 8/4cm against inferior surface of liver

18
Q

Describe the walls of the gallbladder?

A

Mucosa - Folded into rugae like stomach
Muscularis - Smooth Muscle contracts to push out bile
Serosa (connective Tissue)

19
Q

What drains bile from the gallbladder?

A

Cystic Duct -> Common bile duct -> Hepatopancreatic Ampulla -> Major Duodenal Papilla -> Duodenum

20
Q

What controls bile release into the dudenum?

A

The sphincter of Oddi, when it contracts it forces bile into the gallbladder.
When it relaxes it allows bile and pancreatic juice into the duodenum

21
Q

What controls the sphincter of Oddi?

A

Cholecystokinin

22
Q

Explain the pathway of CCK:

A

Fats & Amino Acids in duodenum

  • > CCK released from duodenal cells
  • >
    • Decreased Gastric Emptying
  • Increased pancreatic enzyme secretion
  • Gall bladder contraction
  • Sphincter of Oddi relaxation
23
Q

What is bile made from and how much is made a day

A

Synthesized from cholesterol at a rate of about 0.5g/day

24
Q

How are bile acids made soluble?

A

Prior to secretion they are conjugated with glycine or taurine to make bile salts

25
Q

How does the gall bladder concentrate bile?

A

IT draws out the Na and H2O