Inflammation Flashcards
What are the 5 main signs on inflammation?
Redness, heat, swelling, pain and loss of function.
What are the steps for inflammation?
Change in local blood flow, structural changes in microvascalature, recruitment of immune cells and proteins.
2 examples of inflammatory signals when a wound occurs?
Non apoptotic cell death and foreign material.
After damage to tissue occurs and inflammatory signals are released, what happens?
Vasodilators are released - histamines and nitric oxide.
What do vasodilators result in?
Vascular changes. Increased permeability. Dilation. Plasma leakage.
How does increased vascular permeability and leakage act as a barrier to pathogens?
Increased swelling. Pathogens have to travel further.
Apart from histamines what other molecules are found at injury?
Prostaglandins, cytokines, chemokines and complement proteins.
What is exudate?
Fluid, proteins and cells that have seeped out of a blood vessel.
When it comes to immune cell recruitment what do chemokines do?
Chemokines diffuse out to form a gradient. Leukocytes expressing complementary chemokine receptors migrate towards chemokine source.
What is neutrophil extravasation?
Neutrophil extravasation is the movement of neutrophils out of the circulatory system and towards the site of tissue damage or infection.
What is the first step of neutrophil extravasation?
Leukocyte such as a macrophage releases cytokines that activate adhesion molecules (selectins) on endothelial surface.
What is the second step of neutrophil extravasation?
Integrins in low affinity state on neutrophils bind to selectins. This is referred to as rolling adhesion.
What is the third step of neutrophil extravasation?
Chemokines promote low to high affinity switch integrin switch.
What is the fourth step of neutrophil extravasation?
Cytoskeletal rearrangement to migrate out of endothelium.
How do neutrophils recognise gram negative bacteria?
Use their receptors to recognise lipopolysaccharide molecules on surface of gram negative bacteria.