Lecture 2 - Response To Cellular Stress Flashcards

1
Q

What are labile cells?

A

Labile cells are cells that multiply constantly throughout life (e.g. epithelial cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are stable cells?

A

Stable cells are cells that multiply only when needed (myocardial cells, liver, the proximal tubules of the kidney and endocrine glands
- Moves through cell cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are quiescent cells?

A

Quiescent cell are cells in a reversible state which do not divide but retains the ability to re- enter cell proliferation (e.g satellite cells in muscle)
- Leaves cell cycle (G0)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are causes of cellular stress? (7)

A

• Oxygen deprivation
• Physical trauma
• Chemical trauma
• Infectious agents
• Immunological agents
• Genetic derangements
• Nutritional imbalances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the most common cause of cell injury?

A

Hypoxia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are causes of hypoxia?

A

Inadequate oxygenation
Loss of O2 carrying capacity
• Decreased Haemoglobin
• Decreased RBC production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is ischaemia?

A

Restriction of blood supply - most devastating cause of hypoxia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the most common cause of general injury to the body?

A

Ischaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens during ischaemia?

A

Waste products cannot be removed. An accumulation of waste products results in pain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is hypoxic hypoxia?

A

Hypoxia insufficient O2 available to lungs which means the lungs are not able to deliver enough O2 to the blood passing through them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are potential causes of hypoxic hypoxia?

A

– Drowning
– Blocked airway
– Reduced 02 in atmosphere e.g. high altitude
– Secondary to lung damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is anaemic hypoxia?

A

Hypoxia due to decreased concentration of functional haemoglobin or decreased number of RBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What can be the cause of decreased concentration
of functional haemoglobin?

A

Sickle cell anaemia
Thalassemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What can be the cause of decreased number of RBCs?

A

Decreased or delayed production
Increased or early degeneration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is ischaemic hypoxia?

A

Hypoxia due to an inadequate blood supply to the tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are types of Ischaemic Hypoxia?

A

Generalised
Localised
Gradual
Acute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is an example of generalised ischaemic hypoxia?

A

Heart Failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is an example of localised ischaemic hypoxia?

A

Vessel obstruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is an example of gradual ischaemic hypoxia?

A

Arteriosclerosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is an example of acute ischaemic hypoxia?

A

Embolus: infarction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the different types of physical trauma?

A

Mechanical
Thermal
• Hypothermia
• Hyperthermia
Electrical
Radiation
Damages DNA
Changes in atmospheric pressure
• Blast injury
• Decompression sickness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the different types of chemical trauma?

A

Hypertonicity
Poisons
Strong acids and alkalis
Environmental pollutants
Recreational drugs.

23
Q

What are the effects of MDMA in cellular death?

A

Increase in serotonin which are involved in temperature
regulation.
Increased temperature
Increased water consumption
Cells swell -> burst and die
– Liver cells
– Lung cells
– Brain cells
• Respiration rate declines
• Heart rate increases
• Blood pressure decreases

24
Q

What are the different types of infectious agents? (5)

A

• Fungi
• Viruses
• Parasites
• Protozoa
• Bacteria

25
Q

Where can Helicobacter pylori be found?

A

In the upper GI tract

26
Q

What is Helicobacter pylori linked to and why?

A

Gastric ulcers as it neutralises acid environment of stomach and damages epithelial cells

27
Q

What is anaphylactic reaction?

A

Allergic response to allergen
– Drugs
– Insect bites/stings
– foods

28
Q

What are the two types of genetic derangments?

A

Mutations - affect protein synthesis
Mendelian single gene disorders

29
Q

What are the different types of mutations?

A

Point mutations
Deletions and insertions
Trinucleotide repeat mutations

30
Q

What is an example of a point mutation?

A

Sickle cell anaemia
• (CTG->CUG) Glutamic acid to valine

31
Q

What are the different types of mendelian single gene disorders?

A

Autosomal dominant
Autosomal recessive
X-linked

32
Q

What is an example of an autosomal dominant mendelian single gene disorder?

A

Huntington

33
Q

What is an example of an autosomal recessive mendelian single gene disorder?

A

Cystic fibrosis

34
Q

What is an example of an X-linked mendelian single gene disorder?

A

Duchenne’s muscular dystrophy

35
Q

What is Thalassemia?

A

Inherited mutations that decrease the rate of synthesis of α or β-globin chains leading to haemoglobin deficiency.

36
Q

What is α-thalassemia usually due to?

A

α-thalassemia usually due to a deletion of part of the α-globin gene

37
Q

What is the cause of Huntington disease?

A

Autosomal dominant
– Manifested in heterozygote
– Repeat expansion of CAG in HD gene to > 35 copies
– Gain of function of HD gene
– Increased number of repeats leads to earlier age of onset

38
Q

What happens during Huntington’s disease?

A

Loss of medium spiny striatal neurons that normal dampen motor activity (basal ganglia)

39
Q

What are the different types of cellular adaption?

A

• Hypertrophy
• Hyperplasia
• Metaplasia
• Atrophy

40
Q

What is hypertrophy?

A

Increase in the SIZE of individual cells and ultimately the entire organ

41
Q

What is hypertrophy associated with?

A

Increased accumulation of protein
Increased workload

42
Q

What is hyperplasia?

A

Increase in the number of cells caused by an increased rate of cellular division

43
Q

What is metaplasia?

A

Reversible replacement of one mature cell type by another, less differentiated cell

44
Q

What happens cellularly during Barrett’s oesophagus?

A

Squamous cells become metaplastic and turn into columnar cells in response to this stress.

45
Q

What happens during Barrett’s oesophagus?

A

Ongoing reflux of acid from stomach into the oesophagus causes long term stress on these epithelial cells, causing metaplasia

46
Q

What is atrophy?

A

Reduction in cell size due to decreased protein synthesis and increased protein degradation due to either normal physiologic or pathologic conditions.
- may result in organ shrinkage

47
Q

What are the cell changes that occur during atrophy?

A

Cell changes:
– Reduced endoplasmic reticulum
– Reduced mitochondria
– Reduced myofilaments

48
Q

What are the causes of atrophy?

A

• Decreased workload
• Decreased use
• Decreased blood supply
• Decreased nutrition
• Decreased hormonal stimulation
• Aging
• Decreased nervous stimulation
– E.g. poliomyelitis

49
Q

What is Poliomyelitis (Polio)?

A

Polio is caused by the Polio virus which damages the anterior horn of motor neurons. This leads atrophy of the limbs due to loss of nerve innervation.

50
Q

What is reversible adaptation to stress characterised by at the LM level?

A

At the LM level, reversible adaption is characterised by cellular swelling and fatty change (lipid vacuoles in cytoplasm)

51
Q

What causes cellular swelling in reversable adaption to stress?

A

Failure of ATP dependent ion pumps in plasma
membrane

52
Q

Where does fatty change during reversible adaption to stress occur?

A

Occurs in cells involved in or dependent on fat metabolism for energy

53
Q

What is reversible adaptation to stress characterised by at the EM level?

A

– Swelling of RER
– Detachment of ribosomes
– Swelling of mitochondria
– Plasma Membrane blebs
– Chromatin condensation (nucleus)