Session 1 - Pictures and Drug Overdose

Question 1

What can be seen on this image?

Answer 1

Coagulative necrosis

Question 2

Name three features of coagulative necrosis

Answer 2

Dead tissue has solid consitency

Ghost outline of cells

Appearance lasts a few days before phagocytes invade and ingest dead material

Question 3

What can be seen?

Answer 3

Liquefactive necrosis

Question 4

Why does this type of necrosis occur?

Answer 4

Release of active enzymes such as proteases by neutrophils in response to bacterial infection.

Question 5

What is the type of necrosis demonstrated in the picture?

Answer 5

Caseuous necrosis

Question 6

How can caseuous necrosis occur?

Answer 6

* Tissue appears amorphous

* Associated with infections such as tuberculosis

Question 7

What is the type of necrosis shown here?

Answer 7

Fat necrosis

Question 8

How can fat necrosis occur?

Answer 8

* Occurs in pancreatitis > release of lipases > damage adipocytes

Question 9

What is the cause of this necrosis?

Answer 9

Infarction causing white necrosis

Question 10

What causes this type of necrosis?

Answer 10

• Occurs with the occlusion of an “end” artery (sole source of arterial blood to a segment of an organ). If occluded, the tissue will die and appear white due to lack of blood

Question 11

What is this type of necrosis caused by?

Answer 11

Red infarction

Question 12

Why does this type of infarction occur?

Answer 12

Tissue filled with blood due to extensive haemorrhage. Limited blood supply, not enough for tissue to survive so lots of blood. Can be caused by occlusion of one of a pair of arteries.

Question 13

What is the pathway for alchol metabolism?

Answer 13

Ethanol –> (alcohol dehydrogenase, CYPZE1, catalase) –> Acetaldehyde –> (aldehyde dehydrogenase) –> Acetate

Question 14

How can excess alcohol abuse be detected in blood?

Answer 14

• Elevated mean cell volume (large red blood cells) due to direct toxic effects of alcohol on bone marrow, or folate defiency.
• Raised AST and ALT, due to damage to hepatocytes
• Gamma-GT (aminotransferase) - Raised in regular moder and heavy drinkers
• Alcoholic hepatitis, eleveated serum bilirubin, aminotransferases, alkaline phosphatases

Question 15

What affect does alcohol have on liver presentation?

How are these changes caused?

Answer 15

Fatty change

Acute hepatitis

Alcoholic cirrosis

• Caused by toxicity

Question 16

What change to liver cells can been seen here, and what is the clinical name for it?

Answer 16

Fatty change

Steatosis

Question 17

What affect can alcohol have on nervous system?

Answer 17

• Wernicke syndrome, due to thiamine defiency
• Results in ataxia (loss of voluntary muscle control), disturbed cognition, nystagmus (involuntary eye movement)
• Korkasoff syndrome
• Thiamine defiency + toxicity
• Sever memory loss
• Peripheral neuropathy
• Epilepsy

Question 18

What affect can alcohol have on cardiovascular system?

Answer 18

Cardiomyopathy

Hypertension

Beri Beri heart disease

Question 19

What affect does alcohol have on GI tract?

Answer 19

Pancreatitis, leads to vitamin defiency (unable to breakdown fat, fat soluble vitamins cannot be absorbed)

Question 20

What is foetal alcohol syndrome?

Answer 20

Acetaldehyde crosses over placental barrier and damages foetal brain. Causes mental retardation.

Question 21

What happens after an OD of paracetamol?

Answer 21

Glutathione depleted and NAPQI binds with suplhdryl groups on liver membrane, causing necrosis and liver failure

Question 22

Give three examples of patients will suffer from paracetamol OD at lower doses and why

Answer 22

Lower glutathione in first place

• Alcohol with the OD
• Malnourished
• HIV positive

Question 23

What are the physiological effects of paracetamol overdose?

What is the antidote?

Answer 23

Liver failure at 36-96 hours and death

N-acetylcysteine, which increases availability of hepatic glutathione

Question 24

What is a method of determining severity of liver damage?

Answer 24

Prothrombin time (PT), clotting in blood

Measure Creatinine and blood pH

Question 25

What are the consequences of an aspirin overdose?

Answer 25

Acidosis (acetysalicylic acid)

Increase in lactose, ketones and pyruvate also contributes to acidosis