Cell Injury and Fate

Question 1

What happens to cells that experience increase in demand beyond elastic point

Answer 1

When the cells cannot meet the demand, cell injury or cell death occurs

Question 2

What is sublethal cell injury

Answer 2

Damage to the cell that does not directly kill the cell. It can be reversible and repaired or result in death with more injurious stimuli

Question 3

What are the 8 causes of cell injury

Answer 3

Oxygen deprivation, chemical agents, infectious agents, immunological responses, genetic defects, nutritional imbalance, physical agents and ageing

Question 4

Why what three things is the amount of cell injury induced by injurious stimulus determined

Answer 4

The type of injury, the duration of the injurious stimulus and the severity of the injurious stimulus

Question 5

What two things does the consequence of injurious stimulus depend on

Answer 5

Depends on the type of cell and the status of the cell, for example replicating cell

Question 6

Which four intracellular systems are particularly vulnerable to cell injury

Answer 6

Cell membrane integrity dependent on electrochemical equilibrium, ATP generation dependent on oxygen, protein synthesis dependent on ribosome integrity and genetic apparatus dependent on DNA stability

Question 7

What is lost before morphological changes can be seen in cells

Answer 7

Cell function is lost before morphological changes indicative of cell death can be seen

Question 8

What is atrophy and in what two diseases may this be seen often

Answer 8

Atrophy is the shrinkage of cells in size by loss of cell volume, which is seen dementia and after denervation of muscle tissue

Question 9

What is hypertrophy and what causes it

Answer 9

Hypertrophy is an increase in size of cells, which can be caused by an increased physiological requirement or hormonal stimulation

Question 10

Is muscle gain due to hypertrophy or hyperplasia

Answer 10

Muscle gain is largely due to hypertrophy and not hyperplasia

Question 11

What is an example of physiological and pathological hypertrophy

Answer 11

Physiological hypertrophy occurs in the uterus during pregnancy, while hypertension can lead to cardiac muscle hypertrophy to meet the pathologically increased demand

Question 12

What is hyperplasia and what causes it

Answer 12

Hyperplasia is an increase in the number of cells in an organ, which can be both physiological and pathological and occurs under hormonal stimulation

Question 13

What is an example of physiological and pathological hyperplasia

Answer 13

An example of physiological hyperplasia is the oestrogen stimulated growth of the uterine endometrium, pathological example are cancers

Question 14

What is metaplasia and what is an example in the cervix and oesophagus

Answer 14

Metaplasia is a reversible change in the morphology of cells which can occur due to environmental changes. In the cervix during pregnancy as the cervix expands the end of the endocervical columnar epithelium changes to squamous epithelium due to acidity of vagina. Barret’s oesophagus can occur in people with acid reflux, the epithelium will experience much more acidity than in normally does and this can lead to oesophagal cells become columnar where they were squamous.

Question 15

What is dysplasia and what is the distinction between pre-cancerous and cancerous cells

Answer 15

Dysplasia is when cells change morphilogically and genetically to noticeably abnormal cells but do not (yet) invade other tissues. In cancerous cells, these abnormal cells do invade surrounding tissues by migrating through the basement membrane of the tissue.

Question 16

How can dysplastic cells often be distinguished in a histological examinations

Answer 16

Dysplastic cells often have an abnormal cytoplasm to nucleus ratio

Question 17

What two histological changes can be seen in hepatocytes in degenerative alcoholic liver disease

Answer 17

Hepatocytes containing fatty granules and swelling of hepatocytes which is called ballooning degeneration

Question 18

Which four types of changes in light microscopic histology are seen in irreversible cell injury

Answer 18

Coagulative necrosis, liquifactive necrosis, caseous necrosis, fat necrosis

Question 19

What is an example of coagulative necrosis

Answer 19

In myocardial infarction coagulative necrosis of myocytes can occur

Question 20

What type of necrosis is characteristic of brain damage

Answer 20

Liquefactive necrosis is characteristic of brain damage

Question 21

What type of necrosis is characteristic of pulmonary tuberculosis

Answer 21

Caseous necrosis is characteristic of pulmonary tuberculosis

Question 22

What type of necrosis is characteristic of acute pancreatitis

Answer 22

Fat necrosis is characteristic of acute pancreatitis

Question 23

Why do histological examinations of acute pancreatitis contain blue regions

Answer 23

Calcium has been deposited by fatty acids binding to calcium and precipitate in the pancreatic tissue

Question 24

What is difference between apoptosis and necrosis

Answer 24

Apoptosis is death of individual cells without inflammation, where in necrosis cells die and confluence and this induces inflammation

Question 25

What is the difference in how cells die in apoptosis and necrosis

Answer 25

In apoptosis parts of the cell bud of with integral membrane in apoptotic bodies, whereas in necrosis the membrane loses integrity and cellular components leak out and enzymatic degradation occurs

Question 26

What are three examples of physiological apoptosis in the body

Answer 26

Formation of the body structures during embryogenesis, deletion of self-reactive T cells in the thymus, hormone dependent physiological apoptosis for example in menstruation

Question 27

How is the genome preserved through apoptosis

Answer 27

In response to mild injurious stimuli that irreversibly damage DNA, the cell undergoes apoptosis in a suicide pathway to ensure that proliferating cells only contain the appopriate genome

Question 28

Why is ATP required for apoptosis

Answer 28

ATP is required to package cellular organelles and maintain membrane integrity of the apoptotic bodies to be cleared by macrophages

Question 29

What is necroptosis and what is an example when this happens

Answer 29

Necroptosis is an energy dependent process of programmed cell death in which the dying cells bleb off but do induce an inflammatory response like in necrosis, often seen in viral infections