PP: Acute Inflammation Flashcards
What is acute inflammation?
Response of living tissue to injury.
Name 5 major causes and biological purposes of acute inflammation.
- Microbial infections
- Hypersensitivity reactions
- Physical agents (e.g. Heat, radiation)
- Chemicals
- Tissue necrosis
Name the 5 characteristic clinical signs of acute inflammation.
- Rubor (Redness)
- Calor (Heat)
- Dolor (Pain)
- Tumour (Swelling)
- Loss of function
How does blood flow change during acute inflammation?
- Transient vasoconstriction of arterioles
- Vasodilation of arterioles and then capillaries (this increases the blood flow)
- Increased vessel permeability (results in exudation of protein rich fluid into tissues and slowing of circulation STASIS which is why swelling is seen)
Where does fluid move if there is increased hydrostatic pressure inside the vessels?
Interstitial space
Where does the fluid move if the is increased osmotic pressure in the interstitium?
Increased flow out of the vessels into the interstitial space
What is the clinical consequence of vascular leakage?
Oedema
What is meant by exudate oedema?
Fluid loss in inflammation is due to a higher protein content in the interstitial spaces.
What is meant by transudate oedema?
Fluid is lost from the vessels due to increased hydrostatic pressure
Give 2 examples when transudate oedema would occur.
Cardiac failure or venous outflow obstruction
How do tissues change in acute inflammation in order to allow neutrophil emigration?
- Margination (status causes neutrophils to line up at the edge of vessels along the endothelium)
- Rolling (neutrophils roll along, sticking intermittently)
- Adhesion (They stick more avidly)
- Emigration
What is chemotaxis?
Movement along a concentration gradient of chemoattractants.
How do neutrophils phagocytose?
- Contact
- Recognition (facilitated by opsonins)
- Internalisation (Cytoskeletal changes, phagosomes fuse with lysosomes)
Name 2 killing mechanisms that neutrophils have.
- Oxygen dependant (produces superoxide and hydrogen peroxide)
- Oxygen independent (Lysozyme and hydrolases)
Which chemicals mediate increased blood flow?
Histamine and prostaglandins