Cell Fate and Injury Flashcards

1
Q

What is Lethal and sublethal cell injury?

A

Lethal: Produces cell death

Sublethal: produces injury which may be reversible

( cell death can also be due to inability of cells to adapt )

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2
Q

What are the causes of cell injury? 8

A

Oxygen deprivation

Chemical agents

Infectious agents

Immunological reactions

Genetic defects

Nutritional imbalances

Physical agents

Ageing

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3
Q

Which intracellular mechanisms are vulnerable and injury could be lethal?

A

Cell membrane integrity
ATP generation
Protein synthesis
Integrity of genetic apparatus

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4
Q

How can a lost cell function have a big effect?

A

Components of a cell are integrally related which can lead to secondary effects.

Cellular function loss followed by cell death followed by morphological changes.

( No ATP –> No membrane … )

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5
Q
What is Atrophy? 
Give examples ( 2 )
A

Shrinkage of cell/organ size due to loss of cell substance

  • Dementia
  • Atrophy secondary to denervation
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6
Q

What is Hypertrophy and why may it occur?

A

Increase in cell/organ size which can be physiological or pathological.

Due to either Increased functional demand or specific hormonal stimulation

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7
Q

What is a physiological Hypertrophy example?

A

Uterus:

During pregnancy

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8
Q

What is an example of Pathological hypertrophy?

A

Myocyte response to increased load : hypertrophy

Common in athletes

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9
Q

What is Hyperplasia?

A

Increase in the number of cells in an organ which can be pathological or physiological

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10
Q

What is an example of physiological hyperplasia?

A

Hormonal or compensatory

Uterus
Proliferative Endometrium glands

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11
Q

What is an example of pathological hyperplasia?

A

Carcinoma

  • in a histology mitotic phases could be seen
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12
Q

What is Metaplasia?

A

Reversible change in which one adult cell type is replaced by another

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13
Q

What is an example of Physiological metaplasia?

A

Cervix:

Due to acidic pH of vagina, columnar epithelium –> Squamous

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14
Q

What is an example of Pathological metaplasia

A

Barrett’s Oesophagus:
Due to reflux from stomach squamous epithelium –>
columnar

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15
Q

What is Dysplasia?

A

Precancerous cells which show genetic and cytological features or malignancy

Do not invade underlying tissue

  • Histology: may show an increase in mitotic phase but will still be on the basement membrane ( oesophagus example )
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16
Q

How does Dysplasia differ from metaplasia in Barrett’s oesophagus?

A

In dysplasia the image of the cells looks darker due to having larger nuclei

17
Q

What are degenerative changes that can be seen by a light microscope?

A

Fatty change

Cellular swelling

18
Q

What is Alcoholic fatty change?

A

Hepatocytes will be surrounded by an increased number of fat cells - this is reversible

19
Q

Describe Ballooning degeneration as a characteristic of Alcoholic liver disease?

A

Damaged cytoskeleton leads to increased protein which causes cell to swell.

  • They may look like fat cell but you can see strands of cytoplasm
20
Q

What is Necrosis?

A

Cell death linked to inflammation
Affects group of cells
ATP independent

21
Q

What are changes associated with irreversible injury that can be seen by a light microscope?

Give a pathological example of each.

A
Coagulative necrosis ( structure becomes fixed )
e.g. Myocardial infarct

Liquefactive necrosis
e.g. Old cerebral infarct - not enough connective tissue to keep in place

Caseous Necrosis ( structureless ) 
e.g. pulmonary TB
Fat necrosis ( due to inappropriately activated lipase acids )
e.g acute pancreatitis
22
Q

What is Apoptosis

A

Physiological process which cases death of individual cells

Blebs form –> apoptotic body –> removed by phagocyte

  • do not leak contents out of blebs so there is not inflammation
23
Q

What are the causes of Apoptosis? ( 5 )

A
  • Embryogenesis
  • Deletion of auto-reactive T cells in thymus
  • Hormone dependent involution ( uterus after childbirth )
  • Cell deletion in proliferating populations
  • Mild injurious stimuli causing irreparable DNA damage
24
Q

What is Necroptosis?

A

Programmed cell death but associated with inflammation

e.g. viral infections cause