Ch 70 The Liver

Question 1

What is the space in a liver lobule between the liver cell plates and the sinusoids?

Answer 1

Space of Disse: aka perisinusoidal spaces. Connected to lymphatic vessels to remove excess fluid and plasma proteins

Question 2

What is the purpose and origin of hepatocyte growth factor?

Answer 2

-Produced by mesenchymal cells in the liver and other tissues but NOT hepatocytes
-Stimulates hepatocyte division and growth
+/- influence from TNF and IL-6

Question 3

What is the function of transforming growth factor beta?

Answer 3

Inhibits liver cell proliferation, terminates regeneration

Question 4

What are Kupffer cells and where are they found? What is their function(s)?

Answer 4

Large phagocytic macrophages lining the hepatic venous sinuses.
-Cleanse blood of bacteria and debris

Question 5

Briefly, what are the four functions of the liver in carbohydrate metabolism?

Answer 5

1. Gluconeogenesis
2. Glycogen storage
3. Conversion of galactose and fructose to glucose
4. Forming intermediary compounds for CHO metabolism

Question 6

Briefly, what are the three functions of the liver regarding fat metabolism?

Answer 6

1. Fatty acid oxidation
2. Synthesizing cholesterol, phospholipids, and most lipoproteins
3. Synthesizing fat from proteins and carbs

Question 7

How does the liver deal with leftover Acetyl-CoA?

Answer 7

It cannot use all that is produced from beta oxidation of acetyl-Co-A (from fats), so it condenses two molecules each of Acetyl-CoA into Acetoacetic acid
= highly soluble acid that exits hepatic cells, goes to ECF and then is absorbed by other tissues, where it’s reconverted into acetyl-CoA and oxidized

Question 8

Briefly, what are the liver’s four main functions pertaining to protein metabolism?

Answer 8

1. Plasma protein formation
2. Converting ammonia into urea
3. Deamination of amino acids
4. Interconverting amino acids and synthesizing other compounds from them

Question 9

How does plasma protein depletion affect hepatic cell growth and division?

Answer 9

It causes rapid mitosis of hepatic cells and the liver grows larger, followed by rapid plasma protein output until the plasma protein levels are normal

Question 10

Which vitamins are stored in the liver, in descending order?

Answer 10

1. Vit A
2. Lots of Vit D and B12

Question 11

How is iron stored in the non-blood portion of the body? How?

Answer 11

As ferritin in the liver.
Apoferritin in hepatic cells combines reversibly with iron
*Liver is a blood-iron buffer

Question 12

Vitamin K is necessary for the formation (especially) of which clotting factors?

Answer 12

Prothrombin, Factor VII, IX, and X