Inflammation I

Question 1

what is inflammation

what are the types

Answer 1

a biological reaction to NOXIOUS STIMULUS such as microbes, burns and trauma
- fundamentally PROTECTIVE, but can be harmful if it leads to tissue injury
Types: acute, chronic

Question 2

what are the 4 cardinal signs of inflammation

what is the 5th one

Answer 2

• Rubor (Redness)
• Tumor (Swelling)
• Calor (Heat)
• Dolor (Pain)

5th sign: Functio Laesa (Loss of function)

Question 3

describe acute inflammation

Answer 3

rapid host response to deliver leukocytes and plasma proteins eg such as ANTIBODIES to the sites of infection or tissue injury

Question 4

what does acute inflammation protect the body from

Answer 4

• infection
• trauma (blunt/penetrating)
• burns/frostbite (thermal/chemical)
• allergic reaction
• tissue necrosis

Question 5

how quickly does acute inflammation last

what does it consist of

Answer 5

hours to days

consists of: vascular and cellular reaction

Question 6

what are the 3 major components of acute inflammation

Answer 6

1) VASCULAR DILATION: inc blood flow
2) STRUCTURE CHANGES: in microvasculature to allow plasma proteins and leukocytes to leave circulation
3) EMIGRATION: of leukocytes from microvasculature, their accumulation in the injury site and their activation to eliminate the offending agent

Question 7

what is the vascular reaction as a result of inflammation

Answer 7

• vessel dilation and INC blood flow
• leakage of plasma fluid and protein
• leukocyte EMIGRATION and accumulation in the site of injury

Question 8

what is the purpose of VESSEL DILATION
what does VESSEL DILATION result in
what is it induced by

Answer 8

• inc blood flow
• result in HEAT and REDNESS (hyperaemia)
• induced by: HISTAMINE, BRADYKININ, NO

Question 9

what is the source and function of histamine as a mediator of vascular reactions

Answer 9

source:
mast cells, basophils, platelets
function: arteriole dilatation, inc of venous permeability

Question 10

what is the source and function of bradykinin as a mediator of vascular reactions

Answer 10

source:
Kinin system
function: vasodilatation, inc vascular permeability, PAIN

Question 11

what is the source and function of nitric oxide as a mediator of vascular reactions

Answer 11

source:
endothelial cells
function:
vasodilation

Question 12

increased vascular permeability is a hallmark of what

Answer 12

acute inflammation

Question 13

what is the purpose of inc vascular permeability

Answer 13

• allows plasma fluid and protein to escape from circulation into extracellular tissue (causes oedema)

Question 14

what are mechanisms of increasing vascular permeability

Answer 14

• endothelial cell contraction to INC INTRACELLULAR SPACES
• endothelial cell injury and detachment
• INC transport of fluid and protein through the endothelial cells

Question 15

what is extravasation

Answer 15

movement of leukocytes from VESSEL LUMEN to interstitial lumen to INTERSTITIAL TISSUE

Question 16

what are the endothelial adhesion molecules used by leukocytes

Answer 16

P-selectin
E-selectin
CD34
ICAM-1 
VCAM-1

Question 17

describe chemotaxis of leukocytes

Answer 17

a process in which leukocytes EMIGRATE to the site of injury, driven by substances called CHEMOATTRACTANTS

Question 18

what are the initially phagocytic cells

what do they do

Answer 18

neutrophils, followed by monocytes

- produce inflammatroy mediators that maintain the inflammatory response

Question 19

what is chemotaxis

Answer 19

process by which leukocytes are attracted by CHEMOTACTIC AGENTS to the site of injury once outside the blood vessel

Question 20

what are the 2 types of chemoattractants

give examples of each

Answer 20

endogenous and exogenous 
exogenous: 
- bacterial products 
endogenous:
- complement components 
- cytokines
- products of lipoxygenase pathway (leukotriene B4)

Question 21

what do leukocytes use for recognition

Answer 21

LEUKOCYTE RECEPTORS:

• Toll-like receptors (TLRs) for MICROBIAL PRODUCTS
• G-protein coupled receptors for SHORT BACTERIAL PEPTIDES CONT N-FORMYLMETHIONYL RESIDUES
• Opsonin receptors for antibodies, complements, lectins
• Cytokine receptors

Question 22

what is phagocytosis

Answer 22

removal of offending agents

Question 23

what are the stages of phagocytosis

Answer 23

1) recognition and attachment
2) engulfment ( engulfed particle fuses with lysosome to form PHAGOLYSOSOME, degranulation)
3) killing (ROS, other lysosomal enzymes)

Question 24

what are the acute inflammatory cytokines

Answer 24

TNF-alpha
IL-1
IL-6
chemokines

Question 25

what are the sources of the acute inflammatory cytokines

Answer 25

TNF-alpha: macrophages, mast cells, T-lymphocytes
IL-1: macrophages, endotheilial cells, epithelial cells
IL-6: macrophages,other cells
chemokines: macrophages, endothelial cells, T lymphocytes, mast cells, other cells

Question 26

what is fibrinous inflammation

Answer 26

characterised by FIBRINOUS EXUDATE which can lead to SCAR FORMATION and LIMITATION OF FUNCTION

Question 27

what is purulent inflammation

Answer 27

pus filled fluid consisting of NEUTROPHILS and DEAD CELLS

- typically caused by Staph. infections

Question 28

what is serous inflammation

Answer 28

copious EFFUSION of non-viscous SEROUS FLUID

eg skin blister

Question 29

what is ulcerative inflammation

Answer 29

NECROTIC loss of tissue from the surface, exposing LOWER layers leading to ulcer formation

Question 30

what are the possible outcomes of acute inflammation

Answer 30

• complete resolution (injury is limited/short lived or little tissue damage)
• healing by CONNECTIVE TISSUE REPLACEMENT(fibrosis) (if substantial tissue damage, fibroblats grow into area of damage)
• progression to CHRONIC inflammation