Metabolism 11 (Exam 4) Flashcards

1
Q

What is the liver often called?

A

The body’s major biochemical factory

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

Why are sharks buyoant?

A

The liver makes lots of LDLs for them!

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

How do hepatocytes access venous blood?

A

Portal vein

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

How do hepatocytes access arterial blood?

A

Hepatic artery

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

What is the capillary network in the liver called? What does it permit?

A

Sinusoids

Permits exchange between the hepatocytes and blood

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

Once blood drains from the liver, where does it go?

A

It drains into the hepatic vein which connects to the inferior vena cava

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

What is the primary cell of the liver? What is its function?

A

Hepatocyte

It has quite high metabolic and secretory functions that are complemented by phagocytic activity in resident macrophages

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

What % of total body weight does the liver make up?

A

2%

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

What is the liver’s functional unit

A

lobule

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

What is a lobule?

A

cylindrical structure several mm in length and diameter

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

How many lobules are in the liver?

A

50,000-100,000

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

The individual bile ducts converge to form what? What does that do?

A

Hepatic duct

The hepatic duct delivers bile to the duodenum

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

Explain liver blood flow starting with the portal vein

A

Portal vein –> small portal venules –> flat branching hepatic sinusoids (between the plates) –> central vein

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

Where are hepatic arterioles present?

A

In the interlobular septa

They frequently terminate into hepatic sinusoids

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

What are the three cell types of the liver?

A

Hepatocytes, Liver sinusoidal endothelial cells, and large kupffer cells

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

What are the large pores in the liver endothelial lining called? what do they do?

A

Fenestra

Allow plasma proteins to fit through

17
Q

What are the spaces of Disse

A

they are perisinusoidal spaces between the endothelial lining and the hepatic cells

18
Q

What do the spaces of Disse connect to?

A

They connect with lymphatic vessels in the interlobular septa. Excess fluid in these spaces is removed via lymphatics

19
Q

What are kupffer cells also known as?

A

Reticuloendothelial cells

Resident macrophages

20
Q

What do kupferr cells do?

A

Capable of phagocytizing bacteria and foreign matter

21
Q

How fast is liver blood flow from the portal vein into the liver sinusoids?

A

Pretty fast
~1,000 ml/min
Additional 300 ml/min from the hepatic artery
Total is ~27% of CO

22
Q

Explain how the liver has very low vascular resistance even despite the high volume

A

Pressure in the portal vein averages 9 mmHg

Pressure in the hepatic vein from the liver into the vena cava averages 0 mmHg

23
Q

How can the liver function as a blood reservoir?

A

It’s a large, expandable organ
Its normal blood volume is ~450 mL (10% of total blood volume)
High atrium pressure can expand the liver to another 0.5-1 mL of blood

24
Q

How does liver lymph compare to normal lymph?

A

It has 3 times the amount of protein

25
Q

How do the hepatic sinusoids compare to other capillaries in terms of permeability?

A

the hepatic sinusoids have pores that are very permeable so lymph draining has about 6g of protein/dL (only slightly less than the protein in the plasma)

26
Q

What does the high permeability and flow of the hepatic sinusoids allow?

A

It allows for about half of all lymph in the body to be generated in the liver

27
Q

What is portal hypertension in small animals?

A

Elevated pressure within the portal venous system

28
Q

Describe what prehepatic portal hypertension in small animals looks like.

A

Portal vein obstruction and hepatic arteriovenous fistula

Symptom: Ascites (the accumulation of fluid in the peritoneal cavity)

29
Q

Describe what Intrahepatic portal hypertension in small animals looks like.

A

Likely fibrosis caused by toxins or infections, AKA cirrhosis

30
Q

Describe what posthepatic portal hypertension in small animals looks like.

A

Posthepatic causes involve the heart, cranial vena cava, and hepatic veins

31
Q

Partial hepatectomy (excision of the liver) (up to 70%) will result in?

A

It causes the remaining lobes to enlarge and restore the liver to original size (regeneration)
It’s pretty rapid, believed to involve the hepatocytes replicating once or twice before re-entering quiescent state