Cell Injury & Fate

Question 1

What are the two types of cell injury?

Answer 1

Lethal and sublethal

Question 2

What is lethal cell injury?

Answer 2

Produces cell death

Question 3

What is sublethal cell injury

Answer 3

Reversible cell damage can progress to cell death

Question 4

What is an example of direct cell injury?

Answer 4

Myocardial infarction

Question 5

How does a myocardial infarction occur?

Answer 5

Direct cell injury due to ischaemia, causes cell death through infarction, hypertrophy insufficiently compensates increased demand
Sub-lethally damaged cells can be recovered

Question 6

What are the 8 causes of cell injury?

Answer 6

Oxygen deprivation, chemical agents
Infectious agents
Immunological agents
Genetic agents
Nutritional imbalance
physical agents
aging
HICGINPA

Question 7

What three factors contribute to the cellular response to injurious injury?

Answer 7

Severity
Duration
Type

Question 8

What consequences of injurious stimuli depend upon?

Answer 8

Type of cell

Status

Question 9

Which intracellular mechanisms are vulnerable to injury?

Answer 9

Cell membrane integrity
ATP generation
Protein synthesis
Integrity of the genetic apparatus

Question 10

What is atrophy?

Answer 10

Shrinkage in the cellular size, by the loss of cell substance

Question 11

What is an example of atrophy?

Answer 11

Dementia
Amyloid Beta, phosphorylation of tau, dissociates from the MF and accumulates into filamentous neurofibrillary tangles, reduction in neural function, apoptosis

Question 12

What is hypertrophy?

Answer 12

Enlargement of cells, consequently resulting in an increase in size of the organ
Hypertrophy response to physiological or pathological stresses

Question 13

What is hyperplasia?

Answer 13

An increase in the number of cells in an organ

Question 14

Whatis metaplasia?

Answer 14

Reversible change whereby an adult type cell is replaced by another

Question 15

What lines the cervix?

Answer 15

Squamous epithelium

Question 16

What lines the internal endocervical canal?

Answer 16

Columnar epithelium

Question 17

During cervical expansion what happens to the exposed columnar epithelial cells?

Answer 17

The columnar epithelium cells react to external factors (Vaginal pH) and change into squamous epithelial
These changes are reversible

Question 18

What is barrets Oesophagus?

Answer 18

Acid reflux induces metaplasia

Squamous lined epithelium exchanged into columnar epithelium

Question 19

What is dysplasia?

Answer 19

Precancerous cells which show genetic and cytological feature, not invading underlying tissue

Cells do not express malignancy, have not invaded the basal lamina

Question 20

What is the clinical significance of cervical cancer screening?

Answer 20

Aims to identify cells in the dysplastic stage marks patients with an increased risk of cancer

Question 21

What stage does alcohol-induced fatty liver begin at?

Answer 21

Steatosis

Question 22

What does ethanol consumption do to the liver?

Answer 22

Ethanol metabolism to shift the redox state of liver and inhibit beta oxidation due to sterol regulatory element binding protein I being activated
Lipogenic enzymes

Question 23

What does ethanol metabolites do?

Answer 23

Activates element binding protein 1 (lipogenic enzymes)

Fatty deposits cause fatty liver disease

Question 24

What is ballooning degeneration?

Answer 24

Hepatocytes increase in size

Question 25

What is necrosis?

Answer 25

Confluent (Region of cells) associated with inflammation

Question 26

What is coagulative necrosis?

Answer 26

Substance changes, molecular structure does not Tissue retains the same structure Nuclei are absent, neutrophil polymorphs present The architecture of dead tissue is preserved

Question 27

What is coagulative necrosis associated with?

Answer 27

Ischemia infarction

Question 28

What are the four types of necrosis?

Answer 28

Liquefactive, caseous, fat and coagulative

Question 29

What is liquefactive necrosis?

Answer 29

Results in a transformation of the tissue into a liquid viscous mass Cellular death proceeds into lysosomal digestion, formation of pus filled cysts

Question 30

What is caseous necrosis?

Answer 30

Activated cytolytic T lymphocytes kill M TB infected macrophages, resulting in collateral damage. Host degenerates self tissue to control uninhibited multiplication of bacilli.

Question 31

What composition is the necrotic area?

Answer 31

Granular

Question 32

What is fat necrosis?

Answer 32

Release of lipases digests and hydrolyzes triglycerides to free fatty acids and glycerol FFAs combine with calcium in the extracellular fluid and deposits. Blue area is calcium

Question 33

What ion do FFAs combine with in the extracellular fluid?

Answer 33

Calcium

Question 34

What is apoptosis?

Answer 34

Controlled and programmed cell death

Question 35

What is the distinctive comparison between apoptosis and necrosis?

Answer 35

Necrosis is associated with inflammation Apoptosis concerns the death of individual cells Active cell death requires ATP Both physiological and pathological

Question 36

How is the intrinsic pathway of apoptosis triggered?

Answer 36

Response to internal stimuli (biochemical stress, DNA damage)

Question 37

Which gene is activated that halts the cell cycle?

Answer 37

P53 gene, initiates gene repair

Question 38

What is BCL-2?

Answer 38

Consists of pro and anti apoptotic members balance determines the direction of apoptosis Establishes molecular switch

Question 39

What is the extrinsic apoptotic pathway?

Answer 39

Triggers apoptosis in response to external stimuli, by ligand binding at death receptors on the cell surface

Question 40

What family of receptors do death receptors concern with?

Answer 40

Tumour necrosis factor receptor

Question 41

what is the execution phase in regards to apoptosis?

Answer 41

Cascade activiation of caspases

Question 42

What is the initiator caspase?

Answer 42

Caspase 8

Question 43

What does caspase 8 do?

Answer 43

The initiator caspase cleaves pro-caspases into active executioner caspases PRO --> EXECUTIONER

Question 44

What are the functions of executioner caspases?

Answer 44

Cause the degradation of cellular structures (cytoskeleton and nucleus)

Question 45

What is pyknosis?

Answer 45

Nuclear shrinkage

Question 46

What is karyorrhexis?

Answer 46

Fragmentation

Question 47

What do dead cells phagocytose in?

Answer 47

Phagocytosis into membrane vesicles --> apoptotic bodies

Question 48

Why is there no inflammation?

Answer 48

Vesicles result in no cytoplasmic leakage

Question 49

What are the causes of apoptosis?

Answer 49

Embryogenesis: Death of intermediate cells between fingers Deletion of autoreactive T cells in the thymus Shedding of the endometrium Response to DNA damage that irreparable