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Flashcards in Liver Structure and Function Deck (40)
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1
Q

What are the lobes of the liver?

A
  • 2 Major lobes: Right > Left
  • 2 Minor lobes: Caudate, Quadrate
2
Q

What blood vessels exit/enter the liver?

A

hepatic portal vein, hepatic artery

3
Q

What else other than blood vessels exit/enter the liver?

A

•, lymphatic vessels, ducts (right/left hepatic ducts Þ common hepatic duct), nerves (hepatic nerve plexus) via Porta on inferior surface

4
Q

What is the common bile duct composed of?

A

Common hepatic duct + cycstic duct of gall bladder

5
Q

What joins onto the common bile duct?

A

Pancreatic duct - forming the major duodenal papilla (sphincter of oddi)

6
Q

What is the liver covered in?

A

Connective tissue capsule and visceral peritoneum except for bare area.

The bare area is surrounded by coronary ligament and is found on the diaphragmatic surface

7
Q

Define porta hepatis

A

The porta hepatis or transverse fissure of the liver is a short but deep fissure, about 5 cm long

8
Q

What structure provides support in the liver?

A

The connective tissue capsule provides a branching network of septa into the body of the liver

(·Vessels, ducts and nerves follow septa throughout liver)

9
Q

How are hexagonal lobules formed?

A

Septa divide

10
Q

What is the portal triad?

A

Hepatic portal vein

Hepatic artery

Hepatic duct

11
Q

Where are portal triads located?

A

At the corner of each hexagonal lobule

12
Q

How does the blood from a lobule enter the IVC?

A

Travels to the central vein of the lobule - hepatic vein - IVC

13
Q

Define Hepatic chords, Bile canaliculus and hepatic sinusoids

A

Hepatic chords are chains of hepatocytes that radiate out from the central vein like spokes on a wheel.

Cannaliculi ie between cells within each chord

Hepatic sinusoids are blood chanels that fill the space between hepatic chords

14
Q

What do the bile cannaliculi eventually form?

A

The bile duct

15
Q

What feeds into hepatic sinusoids?

A

The hepatic portal vein, the hepatic artery and some of the products of hepatocytes (basically everything that needs to go to the central vein)

16
Q

What is the direction of transport of materials from the hepatic sinusoids?

A

Some travel to the central veins

Others travel to the hepatocytes (probably excess nutrients and toxins)

17
Q

What is the transport from the central vein?

A

Travels to hepatic veins

18
Q

What is contained within the blood coming from the hepatic portal vein?

A
19
Q

What is contained in the blood coming from the hepatic artery?

A

O2 - rich nutrient depleted blood

20
Q

What substances are found within the hepatocytes?

A

Bile

Nutrient storage

Glycogen

Fat

Vitamins (B12,A,D,E,K)

Copper

Iron

Nutrient interconversion

Detoxification

21
Q

What is the movement of bile that has been synthesised by hepatocytes?

A

Travels to cannaliculi to hepatic ducts

22
Q

What is the alimentary role of the liver?

A

Production and secretion of bile

23
Q

What are the components of bile?

A
24
Q

What is responsible for the formation of Bile acid, Lethicin, Cholesterol, Bile pigments, toxic metals?

A

Secreted by hepatocytes

25
Q

What is responsible for the formation of bicarbonate?

A

Duct cells

26
Q

What are bile pigments?

A

Breakdown products of haemoglobin from old/damaged erythrocytes

27
Q

Where does bilirubin come from?

Which is the predominent bile pigment

A

Extracted from blood by hepatocytes and secreted into bile (forms yellow bile)

28
Q

What causes faeces to become brown?

A

Bacterial enzymes modify bilirubin to produce brown pigments

29
Q

What causes urine to be yellow?

A

Billirubin is reabsorbed

30
Q

What are bile acids synthesised from?

A

Cholesterol (0.5 g/day)

31
Q

How is bile modified before secretion?

A

Bile acids are conjugated with glycine or taurine

(increases solubility)

32
Q

How are bile salts recycled?

A

Via enterohepatic circulation (95 % is recycled, 5% is lost in faeces)

33
Q

What happens to the bile produced when the sphincter of Oddi closes?

A

Prevents bile entering the second part of the duodenum.

Bile now backs up into the gall bladder where it Is stored and concentrated

34
Q

What is the pathway from the liver back to the liver?

A

Liver - bile duct - duodenum - ileum - hepatic portal vein - liver

35
Q

Where is the gallbladder located?

A

On the inferior surface of the liver

36
Q

Describe the mucosa in the gallbladder

A

Folded - rugae - for expansion

37
Q

What is inbetween the gallbladder and the common bile duct?

A

The cystic duct

38
Q

What happens to the gallbladder when CCK is released in the duodenum?

A

Sphincter of Oddi relaxes and the gallbladder contracts

Bile now solubilises fat

CCk also promotes pancreatic enzyme secretion (lipase)

39
Q

What type of diet will result in less concentrated bile?

A

A fatty diet because the gallbladder is always emptying so will never get a chance to concentrate

40
Q

Summary of secretin and cholecystokinin

A