Liver and Integration of Metabolism Flashcards Preview

FHB Block 3 > Liver and Integration of Metabolism > Flashcards

Flashcards in Liver and Integration of Metabolism Deck (19):
1

The liver plays an important role in the metabolism of drugs and xenobiotics. Describe how the liver metabolizes drugs and xenobiotics to ensure they will be excreted in the urine

In order for the kidney to eliminate drugs and xenobiotics, the compounds must be made hydrophilic. There is a two phase reaction that takes place in the liver to convert drugs to their hydrophilic form.

2

Identify the enzyme complex responsible for the oxidation reactions in phase I metabolism of drugs and xenobiotics

Phase 1: The introduction of OH or COOH groups, usually through the oxidation of the parent compound. The enzymes responsible for this are present a an enzyme complex of

NADPH-cytochrome P450 reductase and hemoproteins

aka cytochrome p450

3

The liver plays an important role in the metabolism of carbohydrates. Identify the major pathways of carbohydrate metabolism that are active in the liver

Glycolysis, glycogenolysis, gluconeogenesis, glycogenesis

4

Compare the rates of glycogen synthesis and degradation following a period of feeding.

Glycogen synthesis >> glycogen degradation following a period of feeding

5

Describe insulin's role in regulating hepatic glycogen metabolism and gluconeogensis

Insulin, released when glucose levels are high, stimulates the storage or glucose as glycogen in the liver

6

Describe glucagon's role in regulating hepatic glycogen metabolism and gluconeogenesis

Glucagon, released when blood glucose levels drop, stimulates gluconeogenesis

7

Explain the impact of hepatic liver disease on blood glucose levels.

When the liver is damaged, it can not properly regulate blood glucose levels. This leads to hypoglycemia during times of fasting

8

The liver plays an important role in the metabolism of lipids. Review the role of the liver in lipid metabolism

The liver is responsible for the beta oxidation

9

Identify the plasma lipoproteins that are synthesized and/or metabolized in the liver

VLDL and HDL are synthesized in the liver

Chylomicron remnants are sent to the liver to deliver CE
IDL and LDL delivers cholesterol to the liver and other cells

10

The liver produces most of the circulating plasma proteins. Explain why liver disease and long term starvation can result in generalized edema.

Not producing enough proteins in the blood/not enough albumin.

This leads to high hydrostatic pressure (and low oncotic pressure) so fluid leaks out into the interstitium.

Cirrhosis --> portal hypertension --> ascites.

11

Identify at least four protein that are synthesized predominantly in the liver.

Plasma proteins: albumin
Clotting factors: fibrinogen, prothrombin, transferrin

12

Where is urea produced?

The liver

13

What happens when the liver can no longer process amino groups into urea?

Hyperammonemia --> brain damage

14

WHat is the role of the liver in the handling of amino acids

The liver plays an important role in the synthesis and inter-conversion of amino acids.

15

What type of vitamins are stored in the liver?

Fat soluble vitamins

16

What metals are stored in the liver?

Iron and copper.

The liver is important in the storage and hemostasis of iron and copper.

17

What is another name for vitamin A?

Retinol

18

What is the major role of the liver in vitamin D handling

Although the major vitamin D stores are in the adipose and skeletal muscle, some is stored in the liver.

The liver is responsible for the initial activation of D3; it converts this form to 25-hydroxycholecalciferol and synthesizes the vitamin D binding protein

19

How does the liver affect thyroid hormones?

Conversion from T4 to T3 (functional form)