Liver

Question 1

Define hepatic acinus and indicate which area is most susceptible to anoxic injury or injury by toxins requiring enzymatic activation. What direction does blood move through the acinus or hepatic lobule?

Answer 1

Define hepatic acinus and indicate which area is most susceptible to anoxic injury or injury by toxins requiring enzymatic activation. What direction does blood move through the acinus or hepatic lobule?

Acinar are organized on the basis of blood flow

Zone 1 - Periportal
Zone 2 - Midzonal
Zone 3 - Periacinar

Zone 3 is most susceptible

Blood flows from Zone 1 to Zone 3 (Periportal -> Centrilonbular)

Question 2

Zones 1, 2 and 3 of the hepatic acinus correspond to what area in the hepatic lobule? Which has the highest level of oxygen?

Answer 2

Zones 1, 2 and 3 of the hepatic acinus correspond to what area in the hepatic lobule? Which has the highest level of oxygen?

Zone 1 - Periportal (Highest O2)
Zone 2 - Midzonal
Zone 3 - Periacinar

Question 3

Define icterus. What two basic pathophysiologic abnormalities lead to icterus?

Answer 3

Define icterus. What two basic pathophysiologic abnormalities lead to icterus?

aka Jaundice

Yellow discoloration of tissue as a result of elevated bilirubin in the blood.

Bilirubin derived from leak from damaged hepatocytes, bile ducts or from hemolysis of blood

Question 4

List the routes by which an infectious agent can reach the liver (5)

Answer 4

List the routes by which an infectious agent can reach the liver

Direct implantation (penetrating trauma through abdomen)’
Invasion of the capsule from adjacent peritonitis
Hematogenous via hepatic artery or portal and umbilical veins
Ascending via common bile duct
Migrating nematode parasites

Question 5

Ito cells (“hepatic stellate cells”):

a. contribute to fibrosis in disease
b. “pericyte” function of sinusoids regulate sinusoidal blood flow
c. Vitamin A storage
d. Express GF and may play role in hepatic regeneration

Answer 5

Ito cells (“hepatic stellate cells”):

All of the above

Question 6

Why do infectious agents such as bacteria often induce a multifocal necrotizing hepatitis?

Answer 6

Why do infectious agents such as bacteria often induce a multifocal necrotizing hepatitis?

Question 7

List several causes of a fatty liver

Answer 7

List several causes of a fatty liver

Dietary excess
Animals with high energy demands
Dietary restriction in animals
Ketosis in ruminants
Starvation
Diabetes mellitus
Hypoxia of hepatocytes
Intoxication
Deficiency in cobalt and B12
Hyperlipemia of ponies

Question 8

What is the appearance of fatty liver in cattle and cats?

Answer 8

What is the appearance of fatty liver in cattle and cats?

Hepatomegaly

Muscle wasting

Excessive stores of body fat

Infiltration of marrow with fat

Question 9

What is the basic abnormality associated with portosystemic shunt?

Answer 9

What is the basic abnormality associated with portosystemic shunt?

Abnormal vessel allows blood in portal venous system to bypasss liver and drain into systemic circulation

Intrahepatic - persistent ductus venous

Extrahepatic - single anastomosis between portal vein and caudal vena cava or azygos vein

Question 10

Portosystemic shunt

What does the liver look like?