Pathological processes

Question 1

What are the two types of cell death?

Answer 1

Apoptosis and necrosis

Question 2

Which cell components are most susceptible to injury?

Answer 2

Mitochondria, proteins, nucleus (DNA) and cell membranes

Question 3

What is hypoxia?

Answer 3

Hypoxia is a deficiency of oxygen that can result in a reduction in aerobic oxidative respiration

Question 4

What characteristics do hypoxic tumours show?

Answer 4

1. Increased aggressiveness
2. Resistance to therapy
3. Increased metastasis
4. Poor patient prognosis

Question 5

What is hypoxaemic hypoxia?

Answer 5

Low arterial oxygen content

Question 6

What is anaemic hypoxia?

Answer 6

Decreased ability of haemoglobin to carry oxygen

Question 7

What is ischaemic hypoxia?

Answer 7

Interruption to blood supply

Question 8

What is histiocytic hypoxia?

Answer 8

Inability to utilise oxygen in cells due to disabled oxidative phosphorylation enzymes

Question 9

What is a hypersensitivity reaction?

Answer 9

When host tissue is injured secondary to an overly vigorous immune reaction

Question 10

What are the main free radicals?

Answer 10

hydroxyl, superoxide and hydrogen peroxide

Question 11

When are free radicals produced?

Answer 11

1. Metabolic reactions - Oxidative phosphorylation
2. Inflammation - Oxidative burst of neutrophils
3. Radiation
4. Contact with unbound metals within the body - iron
5. Drugs and chemicals - in the liver during the metabolism of paracetamol

Question 12

Which three vitamins are antioxidants?

Answer 12

A, C and E

Question 13

Which enzymes neutralise free radicals?

Answer 13

Superoxide dismutase, Catalase

Question 14

What do free radicals do to lipids in cell membranes?

Answer 14

Lipid peroxidation

Question 15

Proteins that mend misfolded proteins and maintain cell viability are called…

Answer 15

Heat shock proteins (unfoldases or chaperonins)

Question 16

What is a method of diagnosing cell death based on increased permeability of the cell membrane?

Answer 16

Dye exclusion assays

Question 17

What is oncosis?

Answer 17

Cell death with swelling

Question 18

What are the two main types of necrosis?

Answer 18

Coagulative and liquefactive (colliquitive)

Question 19

When does coagulative necrosis occur?

Answer 19

When there is more protein denaturation than the release of active proteases e.g. ischaemia of solid organs, free radical damage

Question 20

When does liquefactive necrosis occur?

Answer 20

When enzyme degradation is substantially greater than denaturation e.g. ischaemia in loose tissues, the presence of many neutrophils, release of reactive oxygen species

Question 21

What is caseous necrosis?

Answer 21

A type of coagulative necrosis. The tissue contains amorphous debris.

Question 22

Which type of necrosis is associated with tuberculosis?

Answer 22

Caseous necrosis

Question 23

What is fat necrosis?

Answer 23

It results from the action of lipases released into adipose tissue. Free fatty acids accumulate and precipitate as calcium soaps (saponification)

Question 24

What is gangrene?

Answer 24

Necrosis visible to the naked eye

Question 25

What is infarction?

What is infarct?

Answer 25

Necrosis caused by a reduction in arterial blood flow. Infarct is an area of necrotic tissue which is the result of loss of arterial blood supply

Question 26

What is dry gangrene?

Answer 26

Coagulative necrosis modified by exposure to air. More commonly caused by arterial occlusion

Question 27

What is wet gangrene?

Answer 27

Liquefactive necrosis modified by infection. More commonly caused by venous obstruction

Question 28

What is gas gangrene?

Answer 28

A type of wet gangrene where the infection is with anaerobic bacteria that produce gas