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Flashcards in 4. Cell injury Deck (48)
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1

Lethal cell injury

Causes cell death

2

Sublethal cell injury

produces injury not amounting to cell death
may be reversible or progress to cell death

3

Cell stress

can lead to adaptation which may be reversible
inability to adapt will lead to cell injury and death
excess stress leads straight to damage

4

Give an example of physiological cell stress

Exercise
Muscle cells increase in size as need more myofilaments to deal with increased work they have to do
Increases size of heart

5

Give an example of pathological cell stress

High blood pressure
Causes muscles to adapt (hypertrophy)
Increases size of heart

6

List 8 causes of cell injury

Oxygen deprivation
Chemical agents (Inc. drugs)
Infectious agents (Viruses, parasites etc)
Immunological reactions (Inc. Autoimmune)
Genetic defects
Nutritional imbalances
Physical agents
Aging

7

Myocardial infarction

Muscle death due to ischaemia
(Atheroma blocks artery)

8

Cellular response to injurious stimuli depends on

Type of injury
Duration
Severity

9

Consequences of injurious stimuli depend on

Type of cell
The cell's status e.g. dividing cells are more vulnerable than non-dividing

10

Which 4 intracellular systems are particularly vulnerable to injury?

Cell membrane integrity- separates self from non-self
ATP generation- cells NEED energy
Protein synthesis- essential for growth, enzyme systems
Integrity of the genetic apparatus- DNA & RNA=problems with cell division and protein synthesis

11

structural and biochemical components of a cell are integrally related, this means that

multiple secondary effects rapidly occur

12

Atrophy

Shrinkage in size of cells (or organs) by loss of cell substance (Cell size and Number)

13

5 Cellular adaptations to injury

Atrophy
Hypertrophy
Hyperplasia
Metaplasia
Dysplasia

14

Example of atrophy

Dementia: Loss of neurones
Muscle atrophy secondary to denervation

15

Hypertrophy

Increase in size of cells and consequently an increase in size of the organ

16

Types of hypertrophy and examples of each

Physiological e.g. Pregnancy, Exercise
Pathological e.g. High BP

17

What is hypertrophy caused by?

increased functional demand or specific hormonal stimulation

18

Hyperplasia

An increase in number of cells in an organ

19

Types of hyperplasia

Physiological
Pathological

20

Physiological hyperplasia

either hormonal or compensatory
e.g. Proliferative Endometrium

21

Pathological hyperplasia

usually due to excessive hormonal or growth factor stimulation
e.g. Carcinoma

22

Metaplasia

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

23

types of metaplasia

Physiological
Pathological

24

Physiological metaplasia example

At puberty and during pregnancy cervix expands, opens canal, columnar exposed to acid pH causing columnar to become Squamous
If no pregnancy, cervix closes Squamous become Columnar

25

How is the Cervix lined?

internally by columnar
Externally by stratified squamous epithelium.

26

Pathological metaplasia example

Barrett’s Oesophagus
Acid reflux causes Squamous to become Columnar.

27

How is the oesophagus normally lined?

with stratified squamous epithelium

28

What happens if Barrets oesophagus is treated with a PPI, which inhibits acid production?

Columnar revert to being Squamous

29

Dysplasia

Precancerous cells which show the genetic and cytological features of malignancy but not invading the underlying tissue. E.g.
High nuclear cytoplasmic ratio
Increased mitosis

30

What are the light microscope changes associated with reversible injury?

Fatty change
Cellular swelling