Cell fate and injury

Question 1

What are the two kind of stresses the body can experience?

Answer 1

Physiological- part of normal life e.g. strenuous exercise

Pathological- resulting from disease

Question 2

What are the two types of cell injury?

Answer 2

Lethal and sub-lethal

Question 3

What are the 8 causes of cell injury?

Answer 3

Oxygen deprivation
Chemical agents
Infectious agents
Immunological reactions
Genetic defects
Nutritional imbalances
Physical imbalances
Physical agents
Ageing

Question 4

What causes myocardial infarction?

Answer 4

Oxygen deprivation causes death of tissue

Often by blocked coronary artery

Question 5

What does the cellular response to injurious stimuli depend upon?

Answer 5

The type of injury
Its duration
Its severity

Question 6

What do the consequences of an injurious stimulus depend upon?

Answer 6

The type of cell
Its status (rapid turnover?)

Question 7

Which 4 intracellular systems are particularly vulnerable?

Answer 7

Cell membrane integrity
ATP generation
Protein Synthesis
Integrity of the genetic apparatus

Question 8

Why might a patient die before myocardial infarction occurs?

Answer 8

Cellular function is lost before cell death occurs

Which occurs before the morphological changes are seen

Question 9

What is Atrophy?

Answer 9

Shrinkage in the size of the cell or (Organ) by the loss of cell substance

Question 10

When is atrophy seen?

Answer 10

Atrophy of the brain as a result of dementia

Muscle atrophy secondary to nerve being cut

Question 11

What is hypertrophy?

Answer 11

Increase in the size of cells and consequently an increase in the size of the organ
Can be physiological or pathological
Caused by either increased functional demand to specific hormonal stimulation

Question 12

Given an example of hypertrophy

Answer 12

Uterus during pregnancy

Question 13

What is hyperplasia?

Answer 13

Increase in the number of cells in an organ
Physiological or pathological
Hormonal or compensatory (e.g. enlarged kidney in live donors)
Pathological usually due to excessive hormonal or growth factor stimulation

Question 14

Given an example of hyperplasia?

Answer 14

Proliferative endometrium during menstrual cycle

Carcinoma

Question 15

What is metaplasia?

Answer 15

A reversible change in which one adult cell type is replaced by another
Pathological or Physiological

Question 16

Given an example of metaplasia?

Answer 16

Cervix increase in bulk during pregnancy, exposure of glandular epithelium (columnar) which then becomes squamous epithelium
Barrett’s oesophagus- squamous epithelium becomes columnar as a result of acid reflux

Question 17

What is dysplasia?

Answer 17

Precancerous cells which show the genetic and cytological feature or malignancy but not invasion the underlying tissue

Question 18

Give an example of Dysplasia

Answer 18

Seen in Barrett’s oesophagus

Increased nuclear cytoplasmic ratio

Question 19

Name two types of reversible injury?

Answer 19

Fatty change

Cellular swelling

Question 20

Given an example of reversible injury

Answer 20

Alcoholic fatty change in the liver

Question 21

What is necrosis?

Answer 21

Confluent cell death associated with inflammation

Question 22

What are the 4 types of necrosis?

Answer 22

Coagulative
Liquefactive
Caseous
Fat

Question 23

What is coagulative necrosis?

Answer 23

Cells keep their shape despite death

Question 24

What is liquefactive necrosis?

Answer 24

Highly characteristic of death in the brain

Tissue turns to fluid

Question 25

What is caseous necrosis?

Answer 25

Liquidy, cheese-like (brie)

Seen in lungs with TB

Question 26

What is fat necrosis?

Answer 26

Characteristic of acute pancreatitis
Lipase from pancreases begins to digest fats around the pancreas
FFA’s bind to calcium and precipitate

Question 27

What is Apoptosis?

Answer 27

Cell death of a single cell with no inflammation

Active energy dependent process

Question 28

What are the 5 causes of apoptosis?

Answer 28

Embryogenesis e.g when has are formed fingers stuck together
Deletion of auto-reactive T cells in the thymus
Hormone-dependent physiological involution
Cell deletion in proliferating populations
A variety of mild injurious stimuli that cause irreparable DNA damage, that triggers cell suicide pathways

Question 29

What is necroptosis?

Answer 29

Energy dependent programmed cell death with inflammation

many causes e.g. viral infections