4: Cell injury and fate

Question 1

8 causes of stress on the body

Answer 1

Aging

Physical agents (trauma/radiation)
Infectious agents
Genetic defects

Chemical agents (weed killer, drugs)
Oxygen deprivation
Immunological reactions
Nutritional imbalances (e.g obesity, lack of food)

Question 2

4 most vulnerable parts of the cell

Answer 2

Cell membrane (immediate effects seen)
ATP generation *
Protein Synthesis
Genetic Apparatus

Question 3

When can morphological changes be seen in a cell

Answer 3

Following cell death, although cell can already be injured

Question 4

4 types of adaptation

Answer 4

Atrophy
Hypertrophy
Hyperplasia
Metaplasia

Question 5

Atrophy

Answer 5

Cell shrinks in size
Each cell loses material
Organ gets smaller
Elderly not using muscle - gets smaller

Question 6

Hypertrophy

Answer 6

Cell size increases
Organ therefore gets bigger
No new cells
e.g pregnancy

Question 7

Hyperplasia

Answer 7

Increase in NUMBER of cells
Pathological or physiological
Physiological -liver growing after resection
Pathological - cancer

Question 8

Metaplasia

Answer 8

Cell changes type
Reversible
Barrets oesophagus and bone development

Question 9

Dysplasia

Answer 9

Pre-cancerous cells showing features of malignancy but has not invaded the underlying tissue

Question 10

genetic and cytological features of cancer

Answer 10

Large nuceli
incr. nuceli to cytoplasm ratio
incr. number of mitoses

Question 11

An athlete showed myocardial cells of increased diameter. Cell count was normal. What is the adaptation shown and what could be its cause?

Answer 11

Hypertrophy, due to intense exercise

Question 12

Cell development after Dysplasia

Answer 12

Neoplasia (malignancy)

Question 13

Types of cell injury

Answer 13

Reversible
Irreversible

Question 14

Light microscopic features of reversible cell injury

Answer 14

Fatty change -white spots nothing inside
Cell swelling - white holes some cell space

Question 15

Light microscopic features of irreversible cell injury

Answer 15

Necrotic changes (4 types)
- unexpected

Question 16

4 types of necrosis

Answer 16

Coagulative necrosis
Liquefactive necrosis
Caseous necrosis
Fat necrosis

Question 17

Coagulative necrosis

Answer 17

Structure becomes fixed
e.g myocardial infarction

Question 18

Liquefactive necrosis

Answer 18

Tissue becomes liquified
e.g liquefactive cerebral infarct- brain doesn’t have much connectuve tissue to keep in place

Question 19

Caseous necrosis

Answer 19

Tissue looks Cheesy - oozy and structureless
e.g lung from Pulmonary TB

Question 20

Fat necrosis

Answer 20

Fat becomes liquified
e.g. in acute pancreatitis
Enzymes become activated in pancreas rather than duodenum –> liquifies fat

Question 21

Apoptosis

Answer 21

Intentional
needs energy
Does not cause inflammation
Can be physiological or pathological
usually a single cell

Question 22

Uses of apoptosis in the body (5)

Answer 22

Embryogenesis
Deletion of auto-reactive T cells in thymus
Withdrawal of a hormone
Cell deletion in proliferating populations
DNA damage causing cells to be eliminated

Question 23

Necroptosis

Answer 23

Spectrum of apoptosis and necrosis
energy dependent and has inflammation
-intentional

Question 24

8 main causes of cell injury

Answer 24

Genetic
Immunological
Nutritional imbalance
Chemical agents
Hypoxia
Ageing
Physical agents
Infectious agents

Question 25

4 cell mechanisms prone to injury

Answer 25

Cell membrane integrity
ATP generation
protein synthesis
genetic apparatus

• damage to any of these most likely leads to cell death

Question 26

A woman 30 weeks pregnant, what changes has her uterus undergone

Answer 26

Physiological Hypertrophy
- incr. size of existing muscle
- normal adaptive change