Histopathology of Inflammation Flashcards
What is inflammation?
It is a reaction of VASCULARISED living tissue to local injury.
Why are blood vessels important for inflammation?
It is the blood vessels which aid the stereotypically seen accumulation of fluid in inflamed tissues which is the delivering of the inflammatory cells to the tissues.
In repair or inflamed tissues, what type of scar tissue is produced if the parenchyma can not regenerate and it is a :
1) Non-CNS tissue
2) CNS tissue
1) fibroblastic scar tissue is formed (fibroblasts producing collagen)
2) glial scar tissue is formed
What are the X4 cardinal signs of inflammation?
1) rubor (redness) = due to increased blood flow to the area
2) tumour (swelling) = due to collection of oedema fluid
3) calor (heat) = think calor gas!
4) dolor (pain) = oedema fluid stretches cutaneous nerve endings in the inflamed tissue
Which subdivision of the immune system mediates acute inflammation?
The innate, NOT adaptive!
What X2 vascular changes occur during acute inflammation?
What do both of these result in?
1) firstly = transient arteriole vasoconstriction
2) secondly = vasodilation and increased blood flow
These result in increased permeability of the microvasculature and exudation is fluid and plasma proteins into the tissue (oedema)
What is the name given to acute inflammation where the accumulation of fluid is the main feature, such as with a blister?
Acute SEROUS inflammation
What are exudates?
What are transudates?
Which does oedema in inflammation contain?
Exudates
= inflammatory extravascular oedema that has a HIGH PROTEIN CONCENTRATION
transudates
= ultrafiltration LOW IN PROTEIN caused by increased hydrostatic pressure in the vessels
Inflammatory oedema is exudate and contains proteins.
How do blood cells usually move through the blood vessels?
What effect do they employ?
The use through the centre of the vessel lumen via the farheas-linquist effect.
How a blood flow affected in acute inflammatory lesions?
The blood vessel epithelial cells release adhesion molecules onto their surface which causes neutrophils to interact with the epithelial surface instead of moving centrally through the blood vessel lumen.
Which organelles within the endothelial cells are responsible for releasing adhesion molecules during acute inflammation?
What is an example of an adhesion molecule?
Weibel-palade bodies
P-selectin / E-selectin / ICAM-1
What happens to the neutrophils as they interact with the vessel epithelia?
What is this process called?
The roll along the epithelia in a process called marginationm(moving of the inflammatory cells (neutrophils) from the centre of the blood vessel to the margins to interact and roll along them).
As the neutrophils roll against the epithelia they lose momentum and stick.
What happens next in the inflammatory response?
What is this process called?
The injured tissues secrete chemokines to entice the neutrophils via chemotaxis to the site of injury. This is called diapedesis.
What is the difference between diapedesis and extravasation?
Diapedesis = movement across the endothelium
Extravasation = movement of cells into the tissues from the blood following a chemokine gradient
Both vaguely the same!
What is the name given to acute inflammation where the accumulation of neutrophils is the main feature, such as with a appendicitis?
Acute suppurative inflammation
