Inflammation

Question 1

What is an inflammatory response

Answer 1

Innate immune reaction that ensures immune cells & other substances are brought to infected areas so that:

Foreign organisms can be destroyed/inactivated
Injured tissue/cell remnants can be removed
Favourable conditions for healing process are provided

Question 2

What is an acute infection

Answer 2

Normal response to most forms of injury/infection
Lasts days
Repair of damage/removal of infection removes stimulus

e.g. infection by microorganisms, hypersensitivity, physical (burns, UV light etc.), chemical irritants, tissue necrosis

Question 3

What is a chronic infection?

Answer 3

Starts of similar to acute
Wound may not heal due to foreign body or continuing infection
Lasts weeks-years
e.g. persistent infection (e.g. myobacterium tuberculosis), persistent presence of non-living material (e.g. suture material), immune mediated diseases (hypersensitivity & arthritis)
Granulomas form - aggregates of chronically stimulated inflammatory cells

Question 4

Inflammatory response steps

Answer 4

1.Detection of stimuli
Immune cells detect presence of harmful stimuli

2. Release of cytokines
   Macrophages & dendritic cells release cytokines in response to detected stimuli
   Cytokines also produced by endothelial cells & fibroblasts present in damaged tissue
3. Recruitment of immune cells
   Cytokines act as chemical messengers & activate immune cells (neutrophils, monocytes & lymphocytes) to site of infection
4. Increased vascular permeability
   Cytokines (histamine) cause blood vessels to become more permeable so immune cells can pass through
   Leads to swelling, warmth & redness
5. Activation of immune cells
   Cytokines (IL-1 & IL-6) stimulate immune cells to become more active & eliminate harmful stimuli
6. Amplification of immune response
   Cytokines act as feedback signals to amplify immune response
7. Resolution of inflammation
   Once harmful stimuli have been eliminated cytokines (IL-10 & IL-4) damped inflammatory response & promote tissue repair

Question 5

Outline the effects of inflammation

Answer 5

Redness (Rubor)
Heat (Calor)
Swelling (Tumor)
Pain (Dolor)
Lack of function