Summary's chapter 3 Flashcards
Is inflammation always disadvantageous?
No, it is also a beneficial host response to foreign invaders and necrotic tissue.
What is a good memory aid to remember the steps of inflammation?
The 5 Rs:
- Recognition of the injurious agent
- recruitment of leukocytes
- removal of the agent
- regulation (control) of the response
- Resolution (repair).
What are causes of inflammation?
Infections, tissue necrosis, foreign bodies, trauma and immune responses.
What cells can sense the presence of microbes and necrotic cells?
Epithelial cells, tissue macrophages and dendritic cells leukocytes etc.
What can be the outcome of acute inflammation?
Elimination of the noxious stimuli followed by decline of the reaction and repair of the damaged tissue or persistent injury resulting in chronic inflammation.
Fill in the gap
… (1) is induced by inflammatory mediators such as
histamine, and is the cause of … (2) and
… (3) of blood flow.
- vasodilation
- erythema
- stasis
By which mediators is increased vascular permeability induced?
Histamine, kinins and other mediators.
What is the result of increased vascular permeability?
It allows plasma proteins and leukocytes, the mediators of host defense, to enter sites of infection or tissue damage. Exudation results in edema.
Except vascularisation, what other system is involved in inflammation?
Lymph vessels and nodes, they often show redness and swelling.
What cells are recruited from the blood into the extravascular tissue where infectious pathogens or damaged tissues may
be located, migrate to the site of infection or tissue injury, and
are activated to perform their functions?
Leukocytes.
Name the steps of leukocyte recruitment.
- Loose attachment to and rolling on endothelium
- Migration through interendothelial gaps.
Which cytokines (among others) promote expression of selectins and integrins ligands on endothelium?
TNF, IL-1
What kind of proteins increase the activity of integrins for their ligands and also promote directional migration of leukocytes?
Chemokines
Which immune cells predominate in early inflammatory infiltrates and by which immune cells are they replaced?
Neutrophils, they get replaced by monocytes and macrophages.
How do leukocytes eliminate microbes and dead cells?
By phagocytosis (through destruction in phagolysosomes)
By what is destruction of microbes and dead cells caused?
By free radicals (ROS, NO).
What is another function of neutrophils?
They can extrude their nuclear contents to form extracellular nets that trap and destroy microbes.
What is the physiologic role of inflammation? What is the pathologic consequence of inflammation?
The mechanisms that function to eliminate microbes and dead cells (physiologic role), are also capable of damaging normal tissues (pathologic consequence).
What is the function of vasoactive amines (mainly histamine)?
Vasodilation and increased vascular permeability
What are metabolites of arachidonic acid?
Leukotrienes and prostaglandins.
Where are arachidonic acid metabolites involved in?
Vascular reactions, leukocyte chemotaxis..
What are principal cytokines in acute inflammation?
TNF, IL-1 and chemokines.
What does complement system activation lead to?
It leads to the generation of multiple breakdown product, which are responsible for leukocyte chemotaxis, opsonization and phagocytosis and cell killing.
What is the function of kinins?
They mediate vascular reactions and pain.
Fill in the gap:
… (1) is caused by microbes that resist elimination, immune
responses against self and environmental antigens, and some
toxic substances (e.g., silica); underlies many medically important diseases.
- chronic inflammation
What kind of inflammation is morphologically specific for chronic inflammation?
Granulomatous
Through which cytokines is fever induced (through stimulation and production of PGs in hypothalamus)?
TNF, IL-1
What is leukocytosis?
Cytokines stimulate production of leukocytes from precursors in the bone marrow.
Tissues consist of continuously dividing cells, normally quiescent cells that are capable of proliferation and non-dividing cells. The regenerative capacity of a tissue depends on …
the proliferative potential of its constituent cells.
What is a classic example of repair by regeneration?
Regeneration of the liver
How does repair occur?
By deposition of connective tissue and scar formation if the injured tissue is not capable of regeneration or if the structural framework is damaged and cannot support
regeneration.
What are main steps in repair by scarring?
Clot formation, inflammation, angiogenesis and formation of granulation tissue, migration and proliferation of fibroblasts, collagen synthesis,
and connective tissue remodeling
What cells are critical for orchestrating the repair process,
by eliminating offending agents and producing cytokines and
growth factors that stimulate the proliferation of the cell types
involved in repair?
Macrophages
What are the main phases of cutaneous wound healing?
Inflammation, formation of granulation tissue and ECM remodeling.
How can cutaneous wounds heal?
By primary union (first intention) or secondary union (secondary intention).
What conditions can alter wound healing?
Infection and diabetes. The type, volume, and location of
the injury are important factors that influence the healing
process.
What can cause keloids in the skin?
Excessive production of ECM
What leads to tissue fibrosis?
Persistent stimulation of collagen synthesis in chronic inflammation
