Cell injury Flashcards Preview

MCD - Cell pathology > Cell injury > Flashcards

Flashcards in Cell injury Deck (23)
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1
Q

List the EIGHT causes of cell injury

A
Oxygen deprivation 
Inflammation 
Chemical Agents 
Genetics 
Infection 
Nutritional imbalances 
Physical Agents 
Ageing

oxygen is crucial in going around north pole

2
Q

What four intracellular mechanisms are particularly vulnerable to cell injury?

A
  • Cell membrane integrity
  • Protein synthesis
  • ATP Generation
  • Integrity of the genetic apparatus
3
Q

Define Atrophy.

A

Shrinking in the size of a cell or organ by the loss of cell substance.

4
Q

Define Hypertrophy.

examples of causes?

A

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

  • Can be caused by increased functional demand or specific hormonal stimulation
    eg. cardiomyocytes adaptation to increased stress is hypertrophy
5
Q

Define Hyperplasia

A

Increase in the number of cells in an organ

Can be physiological or pathological

eg. cancer = pathological hyperplasia

6
Q

Define Metaplasia

A

A REVERSIBLE change in which one adult cell type is replaced with another

eg. barretts oesophagus

7
Q

Define Dysplasia.

name a screening which identifies this?

what is the relation between metaplasia and dysplasia?

A

Pre-cancerous cells which show the genetic and cytological features of malignancy but not invading the underlying tissue

  • cervical cancer screening
  • normally metaplasia leads onto dysplasia
8
Q

Define Ulcer.

A

A local defect, or excavation of the surface, of an organ or tissue, produced by sloughing of necrotic inflammatory tissue

9
Q

What are the two physiological causes of hyperplasia?

A

Hormonal (e.g. oestrogenic wave of proliferation)

Compensatory

10
Q

What are two light microscopic changes associated with reversible injury?

A

Fatty change
Cellular swelling

these are degenerative

11
Q

Define Necrosis

A

Confluent cell death associated with inflammation

whole areas of cells die

12
Q

What are the four types of necrosis?

A

Coagulative,
Liquefactive,
caseous
Fat

13
Q

What disease is fat necrosis associated with and why?

A

Acute pancreatitis -

  • release of lipases that break down triglycerides into free fatty acids and glycerol.
  • Free fatty acids associate with calcium deposits
  • each deposit is an area of fat necrosis
14
Q

Describe some uses of apoptosis

A
  • Embryogenesis - lumen of intestine is created by the apoptosis of the cells
  • Removal of auto-reactive T and B cells
  • Cell deletion in proliferating populations
  • Hormone dependent physiological involution - e.g. shedding of endometrium
15
Q

Describe three differences between apoptosis and necrosis.

A
  • Apoptosis is an active process (required energy)
  • Apoptosis can be physiological
  • Apoptosis is not associated with inflammation
16
Q

what does the cellular response to the injury depend on?

A
  • type of injury
  • duration
  • severity
17
Q

why is the cell membrane important?

A
  • the cell membrane distinguishes the self form non self
18
Q

what does trophy mean?

what does plasia mean?

A
trophy = size 
plasia = number
19
Q

what is coagulative necrosis?

A
  • The substance changes but the shape of the molecule DOES NOT change
  • eg all the nuclei disappear
20
Q

what is Liquefactive Necrosis?

A
  • when all the cells liquify

- eg the brain might liquify

21
Q

what is Caseous Necrosis

A
  • ‘Cheesy’ necrosis
  • Associated with Pulmonary TB
  • The necrotic area is GRANULAR
22
Q

what is the purpose of apoptosis ?

A
  • If the cell can repair itself it will
  • If the injury is too severe or the repair systems are lacking
  • When a cell recognises that it can’t repair itself, it goes for apoptosis
23
Q

what is apoptosis ?

A
  • death of single cells
  • there is no inflammation
  • active cell death
  • apoptosis is a neat process
  • The nucleus shrinks and little bits of the
    cell break off
  • NO
    INFLAMMATION
  • phagocytosed by macrophages