Session 2 Flashcards
What is acute inflammation?
The response of living tissue to injury
What are some characteristics of acute inflammation?
Innate
Stereotyped
Immediate/Early
Short Duration (mins, hours, days)
Acute inflammation is controlled by…
Chemical mediators
Acute inflammation serves to limit…
The tissue damage
Give 5 causes of acute inflammation
Microbial infections Hypersensitivity reactions Physical agents (e.g. Heat, light, radiation) Chemicals Tissue necrosis
What are 5 clinical features of acute inflammation?
Rubor Tumour Calor Dolor Loss of function
What is rubor?
Redness
What is tumour?
Swelling
What is calor?
Heat
What is dolor?
Pain
Acute inflammation involves which 3 changes in tissues?
Changes in blood flow
Exudation of fluid into tissues
Infiltration of inflammatory cells
Describe the changes in blood flow seen in acute inflammation with regards to the size of the arterial/capillary lumen
Initially vasoconstriction of arterioles
Then vasodilation of arterioles and then capillaries
How long does the initial transient vasoconstriction of arterioles in acute inflammation last for?
First few seconds of acute inflammation
Vasodilation of arterioles and capillaries contributes to which symptoms of acute inflammation?
Calor
Rubor
How is the permeability of blood vessels affected in acute inflammation? What consequences does this have? What happens to the viscosity of the blood as a result of this?
Increased permeability
Exudation of protein rich fluid into tissues and tumour seen
Increased viscosity
Name an immediate early response chemical mediator seen in acute inflammation
Histamine
When does histamine begin its action in acute inflammation? Histamine is produced from which cells?
Immediately (first 30 mins)
Mast cells, basophils and platelets
Name 3 things that histamine causes…
Vascular dilatation
Increase in vascular permeability
Pain
Name some other chemical mediators of acute inflammation?
Leukotrienes, bradykinin
Fluid loss from vessels is determined by ___________ law - the balance of __________ and ___________ __________ pressures.
Starling’s
Hydrostatic
Colloid Osmotic
What effect will increased hydrostatic pressure in a vessel have on fluid flow to tissues?
What effect will increase colloid osmotic pressure in the interstitial have on fluid flow to tissues?
Increased fluid flow out of vessels
Increased fluid flow out of vessels
How does arteriolar dilatation seen in acute inflammation affect hydrostatic pressure in capillaries?
How does increased permeability of vessel walls seen in acute inflammation affect the protein content of the interstitial fluid?
What consequence can both of these factors result in?
Increased
Increased protein content (colloid osmotic pressure)
OEDEMA
The fluid in oedema can be either…
Transudate
Exudate
What is a transudate? What is an exudate?
Give an example of where each is seen.
Fluid in oedema that has the same protein content as plasma
Cardiac failure
Fluid in oedema that has a higher protein content than plasma
Only in inflammation
How does oedema affect lymphatic drainage?
Results in increased lymphatic drainage
Give 5 mechanisms by which vessels can become ‘leaky’
Contraction of endothelial cells Cytoskeletal reorganisation Direct injury - e.g. Sunburn, chemicals Leukocyte dependent injury Increased transcytosis
How does contraction of endothelial cells and cytoskeletal reorganisation result in leaky vessels?
Give an example of a chemical that causes contraction of endothelial cells
Give an example of a chemical that causes cytoskeletal reorganisation
Leads to gaps in the walls of vessels
Histamine, leukotrienes
Cytokines IL-1 and TNF
How does leukocyte dependent injury make blood vessels leaky?
Leukocyte produce toxic oxygen species and enzymes which damage the vessels
Give an example of a chemical that results in increased transcytosis?
VEGF
What is an important protein component of the protein rich exudate seen in acute inflammation?
Fibrin
What is the role of fibrin in the protein rich exudate seen in acute inflammation?
Where is this particularly important?
Forms a sticky meshwork to localise inflammation
Serosal surfaces - e.g. Pleural cavity, pericardium - so whole cavity isn’t filled with fluid
What is another term for a neutrophil? What is the appearance of these cells under the microscope?
Polymorph
Come in multiple shapes with multi-lobed nuclei
What type of blood cell is a neutrophil?
White blood cell - type of granulocyte
What is a granulocyte?
A WBC with secretory granules in its cytoplasm