MOD S3 Flashcards
What are some causes of acute inflammation?
Microbial infections Hypersensitivity reactions (aka allergies) Physical agents Chemical agents Tissue necrosis
What is acute inflammation?
The response of living tissue to injury, initiated to limit tissue damage
What are the macroscopic signs of inflammation?
Calor - heat
Rubor - redness
Tumor - swelling
Dolor - pain
+ loss of function
What are the microscopic features of acute inflammation?
Vasodilation Gaps form in endothelium Exudation Margination and emigration Macrophages and lymphocytes
Describe the changes in blood flow in acute inflammation
Transient vasoconstriction of arterioles (a few secs)
Vasodilation of arterioles and then capillaries
Increased blood vessel permeability
Stasis- increased concentration of RBCs in small vessels and blood viscosity
What are some chemical mediators of vasodilation?
HISTAMINE
Prostoglandins
C3a
C5a
Describe histamine
-Released ~30 mins into acute inflammation
-Many stimuli
-Released by mast cells, basophils and platelets
-Causes:
>Vasodilation
>Transient increase in vascular permeability
>Pain
What are some chemical mediators of increased vascular permeability?
HISTAMINE
Prostoglandins
Kinins
What determines fluid flow across blood vessel walls?
Starling’s Law
The balance of hydrostatic and colloid osmotic pressure
An increase in either will increase fluid movement out of blood vessel
What is a build up of tissue fluid called?
Oedema
What does oedema lead to?
Increased lymphatic drainage
What is a transudate?
Fluid loss from blood vessels due to hydrostatic pressure only
Has a low protein content
Caused by cardiac failure or venous outflow obstruction
What is exudate?
Fluid loss from blood vessels
Seen in inflammation
Has a high protein content
What are some chemical mediators of leukocyte emigration?
Leukotrienes
IL-8
C5a
What is another name for a neutrophil?
A polymorph