Ch. 25 Liver Function - Part 1

Question 1

Give the four major functions of the liver

Answer 1

Metabolism of carbohydrates, lipids, proteins, and bilirubin
Detoxification of harmful substances
Storage of essential compounds
Excretion/Secretion of substances to prevent harm

Question 2

If the liver is nonfunctional for any reason, death will occur within approximately 24 hours due to _____

Answer 2

Hypoglycemia

Question 3

Which of the following statements is/are TRUE:
The liver is
A. 1.2 to 1.5 kg in a healthy adult
B. located beneath and attached to the diaphragm
C. Protected by the lower rib cage
D. Held in pace by ligamentous attachments

Answer 3

All

Question 4

Divides the liver into two unequal parts

Answer 4

Falciform ligament

Question 5

The right lobe of the liver is 6x (larger/smaller) than the left lobe

Answer 5

Larger

Question 6

Enumerate the liver’s two sources of blood

Answer 6

Hepatic artery

Portal vein

Question 7

Which among the livers two sources of blood:
Is a branch of the aorta
Supplies oxygen-rich blood
Provides for 25% of the total blood supply to the liver

Answer 7

Hepatic artery

Question 8

Which among the livers two sources of blood:
Supplies nutrient-rich blood from the digestive tract
Provides for 75% of total blood supply

Answer 8

Portal vein

Question 9

Results from the merging of the Hepatic artery and the Portal vein

Answer 9

Hepatic sinusoid

Question 10

The hepatic sinusoid is lined with _____ capable of removing potentially toxic substances from the blood

Answer 10

Hepatocytes

Question 11

It is through this passage that blood leaves the liver

Answer 11

Central canal (Central vein)

Question 12

The collecting system of veins that drain the approximately 1500 mL of blood from the liver empties into what vein

Answer 12

Hepatic vein

Question 13

It is where the excretory system of the liver begins

Answer 13

Bile canaliculi

Question 14

These are small spaces between the hepatocytes that form intrahepatic ducts, where excretory products of the cell can drain

Answer 14

Bile canaliculi

Question 15

Microscopic and functional units of the liver

Answer 15

Lobules

Question 16

They are responsible for all metabolic and excretory functions performed by the liver

Answer 16

Lobules

Question 17

Two major cell types in the liver:

Answer 17

Hepatocytes

Kupffer cells

Question 18

Each six-sided lobule of the liver has portal triads that contains

Answer 18

Hepatic artery
Portal vein
Bile duct

Question 19

These make up 80% of the volume of the liver; large cells that radiate outward from the central vein in plates to the periphery of the lobule

Answer 19

Hepatocytes

Question 20

Responsible for the regenerative properties of the liver.

Answer 20

Hepatocytes

Question 21

These are macrophages that line the sinusoids of the liver. These acts as phagocytes capable of engulfing bacteria, debris, toxins, and other substances flowing through the sinusoids

Answer 21

Kupffer cells

Question 22

The major heme waste product

Answer 22

Bilirubin

Question 23

It is the only organ that has the capacity to rid the body of heme waste products

Answer 23

Liver

Question 24

Principal pigment in bile. Derived from the breakdown of red blood cells

Answer 24

Bilirubin

Question 25

Approximately _____ days after the emergence from the reticuloendothelial tissue, red blood cells are phagocytized and hemoglobin is released.

Answer 25

126

Question 26

What is the composition of bile?

Answer 26

Bile acids or salts Bile pigments Cholesterol Other substances extracted from the blood

Question 27

The body produces approximately __L of bile per day and secretes __L of what is produced

Answer 27

3, 1

Question 28

Degradation of Hemoglobin produces:

Answer 28

Heme Globin Iron

Question 29

Among the three components produced from the degradation of hemoglobin, which would be bound by transferrin and returned to the liver or bone marrow for reuse?

Answer 29

Iron

Question 30

Among the three components produced from the degradation of hemoglobin, which would be degraded to its constituent amino acids, which are then reused by the body?

Answer 30

Globin

Question 31

Among the three components produced from the degradation of hemoglobin, which would be converted to bilirubin in 2 to 3 hours?

Answer 31

Heme

Question 32

Before bilirubin is transported to the liver, what amino acid binds to it?

Answer 32

Albumin

Question 33

Bilirubin bound to albumin is called _____. It is insoluble in water, and cannot be removed from the body until it is has been conjugated by the liver.

Answer 33

Unconjugated or Indirect bilirubin (B1)

Question 34

What carrier protein picks up bilirubin once it has been separated from albumin and has flowed through the sinusoidal spaces of the liver

Answer 34

Ligandin

Question 35

It carries the unconjugated bilirubin from the liver to the endoplasmic riticulum

Answer 35

Ligandin

Question 36

Site where the conjugation (esterification) of bilirubin happens

Answer 36

Endoplasmic reticulum

Question 37

The enzyme present during esterification; which transfers a glucuronic acid molecule to each of the two propionic acid side chains of bilirubin to form bilirubin diglucuronide

Answer 37

Uridyldiphosphate glucuronyl transferases (UDPGT)

Question 38

The form of bilirubin that is water soluble and is able to be secreted from the hepatocyte into the bile canaculi. Once in the hepatic duct, it combines with secretions from the gallbladder through the cystic duct and is expelled through the common bile duct to the intestines.

Answer 38

Conjugated biirubin (B2)

Question 39

Acts upon the conjugated bilirubin in the intestines and produces mesobilirubin

Answer 39

Intestinal bacteria

Question 40

Mesobilirubin is reduced to form mesobilirubinogen and then _____ (a colorless product).

Answer 40

Urobilinogen

Question 41

Roughly 80% of the formed urobilinogen is oxidized to an orange colored product called _____, which is then extcreted in feces

Answer 41

Urobilin/Stercobilin

Question 42

The substance that gives stool its brown color

Answer 42

Stercobilin

Question 43

The majority of the remaining 20% of urobilinogen will be absorbed by _____ to be recycled through the liver and re-excreted

Answer 43

Extrahepatic circulation

Question 44

What will happen to the lesser fraction of the remaining 20% of urobilinogen in the liver?

Answer 44

The lesser fraction of the remaining 20% of urobilinogen will enter systemic circulation and will subsequently be filtered by the kidney and excreted in the urine.

Question 45

Approximately how many mg of bilirubin is produced per day?

Answer 45

200 to 300 mg

Question 46

Almost all the bilirubin formed is eliminated in the _____

Answer 46

Feces

Question 47

What is the usual level of total bilirubin in the serum of a healthy adult?

Answer 47

0.2 - 1.0 mg/dL

Question 48

When carbohydrates are ingested and absorbed, the liver can do three things which are:

Answer 48

1. Use the glucose for its own cellular energy requirements 2. Circulate the glucose for use at the peripheral tissues 3. Store glucose as glycogen

Question 49

Principal storage form of glucose

Answer 49

Glycogen

Question 50

It is the major player in maintaining stable glucose concentrations due to its ability to store glucose and degrade glycogen

Answer 50

Liver

Question 51

The term used to describe the storing of glucose in the form of glycogen

Answer 51

Glycogenesis

Question 52

Degrading glycogen to obtain glucose; could occur at times where there is an increased need for glucose (fasting or stress). Breakdown of glycogen to glucose for use as energy.

Answer 52

Glycogenolysis

Question 53

The process wherein the liver creates glucose (Glucose-6-phosphate) from nonsugar carbon substrates like pyruvate, lactate, and amino acid.

Answer 53

Gluconeogenesis

Question 54

The liver metabolizes lipids and lipoproteins and gathers free fatty acids from the diet, and those produced by the liver itself. These are then broken down to form _____, which can enter several pathways to form triglycerides, phospholipids, or cholesterol

Answer 54

Acetyl-CoA

Question 55

The greatest source of cholesterol in the body comes from _____

Answer 55

What is produced by the liver, not from dietary sources.

Question 56

TRUE/FALSE. All proteins are synthesized by the liver. Explain

Answer 56

False. Immunoglobulins and adult hemoglobin are not synthesized in the liver

Question 57

It is one of the most important proteins synthesized by the liver

Answer 57

Albumin

Question 58

This results in the exchange of an amino group on one acid with a ketone group on another acid.

Answer 58

Transamination (via Transaminase)

Question 59

After transamination, _____ degrades them to produce ammonium ions that are consumed in the synthesis of urea and urea is excreted by the kidneys

Answer 59

Deamination

Question 60

This serves as a gatekeeper between substances absorbed by the gastrointestinal tract and those released into systemic circulation.

Answer 60

Liver

Question 61

The process wherein every substance that is absorbed in the gastrointestinal tract must first pass through the liver is referred to as:

Answer 61

First pass

Question 62

What are the body's two mechanisms for detoxification of foreign materials (drugs and poisons) and metabolic products (bilirubin and ammonia)

Answer 62

1. Bind the material reversibly so as to inactivate the compound 2. Chemically modify the compound so it can be extcreted

Question 63

The most important mechanism in the liver; responsible for the detoxification of many drugs through oxidation, reduction, hydrolysis, hydroxylation, carboxylation, and demethylation.

Answer 63

Drug-metabolizing system

Question 64

Many of the drug-metabolizing systems take place in the liver microsome via what isoenzyme?

Answer 64

Cytochrome P-450 isoenzymes

Question 65

Metabolism of glucose to lactate or pyruvate for production of energy

Answer 65

Glycolysis

Question 66

What are the processes by which the liver detoxifies drugs?

Answer 66

oxidation, reduction, hydrolysis, hydroxylation, carboxylation, and demethylation.

Question 67

Many of the detoxification processes of the liver takes place in the _____ via the cytochrome P-450 isoenzyme.

Answer 67

Liver microsome