Cell Injury And Fate

Question 1

What are the two types of cell injury?

Answer 1

Sublethal and lethal

Question 2

What is lethal cell injury?

Answer 2

one that produces cell death

Question 3

what is sublethal injury?

Answer 3

Produces injury but not amounting to cell death - may be reversible or even progress to cell death

Question 4

What are seven causes of cell death?

Answer 4

1. Oxygen deprivation
2. Chemical agents
3. Infectious agents
4. Immunological reactions
5. Genetic defects
6. Nutritional imbalances
7. Physical agents eg trauma or rdiation
8. Aging

Question 5

The cellular response to injurious stimuli depends on…

Answer 5

1. type of injury
2. duration
3. severity of injury

Question 6

The consequences of an injurious stimuli depend on?

Answer 6

1. Type of cell

2. cell status

Question 7

What are 4 intracellular systems which are particularly vulnerable to cell injury?

Answer 7

1. Cell membrane integrity
2. ATP generation
3. Protein synthesis
4. Integrity of genetic apparatus

Question 8

What is meant by atrophy?

Answer 8

Shrinkage in size of a cell / organ by the loss of cell substance eg shrinking brain in dementia patient

Question 9

What is meant by hypertrophy?

Answer 9

Increase in the size of the cells

Question 10

What is a pathological example of hypertrophy?

Answer 10

‘Pathological’ cardiac hypertrophy is a condition that is characterized by the thickening of the heart muscle, a decrease in the size of the chambers of the heart, and a reduced capacity of the heart to pump blood to the tissues and organs around the body.

Question 11

What is an example of physiological hypertrophy?

Answer 11

increase in the size of cells of the uterus during pregnancy to accomodate for the foetus

Question 12

What is meant by hyperplasia?

Answer 12

An increase in he number of cells in an organ

Question 13

What is the main cause of pathological hyperplasia

Answer 13

usually due to excessive hormonal or growth factor stimulation

Question 14

Describe a physiological example where hyperplasia can occur?

Answer 14

increased oestrogen stimulation drives the increased proliferation of the endometrial glands leading to increased number of endometrial cells

Question 15

What is a pathological example of hyperplasia?

Answer 15

carcinoma = too many cells leading to disease

Question 16

what is metaplasia?

Answer 16

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

Question 17

Describe a pathological example of Metaplasia?

Answer 17

Barretts Oesophagus - The oesophagus is normally lined with squamous epithelium cells, acid reflux causes these to change to columnar epithelial cells

Question 18

Describe a physiological example of metaplasia?

Answer 18

During pregnancy - cervix expands and due to the acid pH of the vagina, the columnar cells becomes squamous

Question 19

What is meant by dysplasia?

Answer 19

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

Question 20

Why do cells undergoing dysplasia appear darker on a slide?

Answer 20

Due to an increased nuclear:cytoplasm ration

Question 21

What are the two forms of light microscopic changes associated with reversible injury?

Answer 21

fatty change and cellular swelling

Question 22

What is a common cause of fatty change

Answer 22

Alcohol

Question 23

What might be seen on a film on cells undergoing fatty change?

Answer 23

Accumulation of lipids in the cytoplasm - seen on film as large clear droplets filling the cytoplasm

Question 24

Which condition is fatty hepatic change usually associated with?

Answer 24

Alcoholic liver disease

Question 25

What is meant by cellular swelling?

Answer 25

When the cytoskeleton of cells are damaged leading to protein accumulation that results in cell swelling = degenerative changes

Question 26

What are the two features of alcoholic liver disease?

Answer 26

Fatty change and cellular swelling

Question 27

What is necrosis?

Answer 27

Confluent cell associated with inflammation

Question 28

What are the four types of necrosis?

Answer 28

1. Coagulative necrosis 2. Fatty necrosis 3. Liquefactive necrosis 3. Caseous necrosis

Question 29

What is meant by coagulative necrosis?

Answer 29

Accidental cell death typically caused by ischaemia or infarction

Question 30

What might muscle cells which have undergone myocardial infarction look like?

Answer 30

Inflammatory reaction to dead muscle cells results in lots of macrophages, but no nuclei as cells are dead

Question 31

What is liquefactive necrosis?

Answer 31

When the tissue becomes liquefied which results in a transformation of the tissue into a liquid viscous mass

Question 32

What type of necrosis occurs with cerebral infarction

Answer 32

Liquefactive necrosis

Question 33

What is caseous necrosis?

Answer 33

A unique form of cell death in which the tissue maintains a cheese like appearance

Question 34

What is fat necrosis?

Answer 34

Condition when damage to area of fat occurs - fat replaced with oily contents of the fat

Question 35

Which condition is highly associated with fat necrosis?

Answer 35

Acute pancreatitis

Question 36

Describe the fat necrosis seen in acute pancreatitis?

Answer 36

This is when pancreatic enzymes are activated in the pancreas, rather than the duodenum - results in lipases digesting pancreatic tissue into fatty acids and triglycerides which bind to Ca2+ ions and form salts which precipitate get deposited in the pancreas

Question 37

What is apoptosis?

Answer 37

Programmed cell death

Question 38

What are the five causes of apoptosis?

Answer 38

Embryogenesis. Deletion of auto-reactive T cells in the thymus. Hormone-dependent physiological involution. Cell deletion in proliferating populations. A variety of mild injurious stimuli that cause irreparable DNA damage that, in turn, triggers cell suicide pathways.

Question 39

Describe how a cell would undergo apoptosis?

Answer 39

1. Cell undergoes injury 2. Genetic errors arise from injury 3. Attempts are made to repair the error but errors still remain 4. Additional injury = Leads to apoptosis

Question 40

What are the key differences between apoptosis and necrosis?

Answer 40

Apoptosis might by physiological, necrosis is not Apoptosis is an active, energy dependant process Necrosis is associated with inflammation, apoptosis is not

Question 41

Why is ATP needed for Apoptosis?

Answer 41

ATP is needed to maintain cell membrane integrity and package apoptotic bodies

Question 42

What are physiological examples of apoptosis?

Answer 42

Elimination of self reactive T cells

Question 43

What is necropoptosis?

Answer 43

Programmed cell death, associated with inflammation

Question 44

How does a cell actually die through necrosis?

Answer 44

Enzymatic digestion and leakage of cellular components = cell membrane loses integrity

Question 45

How does a cell die through apoptosis?

Answer 45

Phagocytosis of apoptotic bodies and fragments

Question 46

What is a cause of necropoptosis?

Answer 46

Viral infections