Topic 3: Cell injury and inflammation Flashcards Preview

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Flashcards in Topic 3: Cell injury and inflammation Deck (33):
1

Reversible cell injury

-no cell death
-transient ischemic attach, bee sting, asthma, alcohol, minor contusion, tendinopathies, DOMS, compartment syndrome

2

Irreversible cell injury

-lethal
-stroke, acid burn, excessive alcohol, asthma, traima, muscle strains, fractures, acute tendon ruptures

3

What is apoptosis?

endogenosly induced cell death.
Programmed: natural
Unscheduled: SIPs, infection, inflammation

4

What is necrosis?

exogenously induced cell death, compromise of cell membrane integrity --> release of DAMPs

5

What is cell senescence?

catabolic --> anabollic phenotype
results in expression of SASPs (secretory associated secretory pattern)

6

How does a pro-inflammatory environment come about?

increased/sustained stress --> increase in amount of cells expressing SASPs --> pro-inflammatory cytokines --> pro-inflammatory environment

7

What are some SASP factors?

renal disease, type 2 diabetes, osteoporosis, CV disease, cancer, psycho-emotional stress, hypertension, sedentary disease

8

What are the functions of inflammation?

-degrade, eliminate, isolate source of homeostatic disturbance
-able to adapt to altered conditions
-restoration of function to normostasis

9

What is normostasis?

optimal cell, tissue and organ functoin

10

What is stress response?

-cell/tissue stress due to noxious conditions
-expression of cytokines
-reversible: atrophy, hypertrophy, hyperplasia, metaplasia, dysplasia

11

What is para-inflammation?

-cell/tissue stress due to prolonged/heightened noxious conditions
-exudate formation and recruitment of non-resident immune cells (NOT seen in stress response)
-allows tissue to adapt to conditions (short term), restore homeostasis (long-term)
-adaptive; localised or systemic

12

What are some examples of adaptive para-inflammation?

DOMS, post-exercise, tendinopathies, bone stress injuries

13

What are some examples of maladaptive para-inflammation?

CVD, CNS degeneration (Alzheimer's), macula degeneration, type 2 diabetes, metabolic disease

14

What are factors leading to maladaptive para-inflammation?

cell senescence, SIPS --> SASP, lifestyle factors, increased lifespan, overweight/obesity, prolonged stress, dysregulated sleep, malnutrition/malnourishment

15

What is inflammation?

-activated by overt injury or infection
-stress and para-inflammation not sufficient

16

What are some examples of acute inflammation?

ligament sprain, muscle tear, bone fractures, contusions, burns, viral infections

17

What are the three components of inflammation?

increased blood flow, exudation (plasma and leucocytes out of circulation), immune cells to injury site

18

What is chronic inflammation?

tissue destruction and healing occurring at the same time

19

What are the main signs of chronic inflammation?

macrophages, fibroblast recruitment and activation, adaptive immunity activation

20

What are some causes of chronic inflammation?

-failure to eliminate cause of infection
-autoimmunre response
-prolonged exposure to potentially toxic agent

21

What is the difference between dysregulated para-inflammation and chronic inflammation?

PA: less vascular system activation --> less oedema and less non-resident immune cells
CI: vascular systems activated --> oedema and non-resident immune cells

22

What are the key features of acute inflammation?

increase blood flow, increase capillary permeability, neutrophil migration, diapedesis, chemo-taxis, leucocyte recruitment + activation

23

What are the key features of chronic inflammation?

macrophage and T and B cell circulation, tissue destruction, tissue repair

24

What are inducers of inflammation?

tell immune system something is wrong

25

What are exogenous inducers?

PAMPs, virulence factors, allergens, noxious irritants, foreign bodies

26

What are endogenous inducers?

produced from stressed/distressed/damaged tissue, DAMPs

27

What are sensors of inflammation?

-innate and drive inflammatory response
-PRRs detect PAMPs and DAMPs
-eg paranchymal cells, ECM, tissue-resident macrophages and mast cells, epithelial cells, platelets

28

What are mediators of inflammation?

-released by sensors to activate and drive response
-cytokines - histamine, vasoactive amines, complement, lipid mediators, chemokines, vasoactive peptides, pro-inflammatory cytokines

29

What are the roles of mediators?

vasodilation, vascular permeability, immune cell adhesion, chemotaxis, pain

30

What are effectors of inflammation?

-restore homeostasis

31

What are the cellular events of inflammation?

activation of endothelial cells --> gathering of immune cells --> adhesion of immune cells --> migration of immune cells --> endothelial retraction --> phagocytosis

32

What are the vascular events of inflammation?

vasoconstriction, vasodilation, increase vascular permeaility, hyperaemia, oedema

33

What is the purpose of oedema?

continuity between vascular and lymphatic systems