Pathophysiology of inflammation Flashcards
What are the 5 symptoms of inflammation?
Rubor- redness Calor- heat Tumor- swelling Dolor- pain Loss of function
What are the 5 causes of inflammation?
Microbial infection Allergy Physical agents Chemicals Tissue necrosis
What 3 substances are released after a trigger of inflammation?
Histamine, prostaglandins and leukotrienes
What do PAMPs and DAMPs do after being triggered to release?
PAMPs- alert immune cells to destroy intruding pathogens
DAMPs- promote pathological inflammatory response
What cells are PAMPs and DAMPs recognised on and what do these cells do?
Sentinel cells
This refers to cells in the body’s first line of defence and patrol the body for the signs of infection
What are the 4 types of cytokines and what do they do?
1) Interleukins
Signal between white blood cells
Can be pro-inflammatory and anti-inflammatory
2) Interferons
Interfere with viral replication
3) Chemokines Control the migration of white blood cells Have adhesion molecules Attract circulating cells Most chemokines are neutrophils
4) Colony stimulating factors
Stimulate formation of maturing colonies of white blood cells
How do white blood cells, cytokines, prostaglandins and histamine contribute to fluid exudate?
White blood cells -> cytokine -> histamine -> fluid exudate
Prostaglandins -> fluid exudate
What 3 cascades does fluid exudate directly cause?
1) Coagulation cascade
Prevents blood by clotting by the release of thrombin
2) Fibronolytic cascade
Breaks down the clotting and releases plasmin
3) Kinin cascade Maintains vascular response Releases kallikrein-> bradykinin Bradykinin: A vasodilator that causes pain and stimulates NO synthesis as NO keeps the blood vessel open
What cascade is indirectly activated by fluid exudate?
Complement cascade Releases histamine Opsonizes Activates phagocytic cells Contributes to the lysis of bacteria Chemotactic- attracts cells
What are the steps of phagocytosis?
1) The phagocyte recognises the pathogen due to opsonisation
2) The pathogen interacts with the phagocyte receptor
3) The phagocyte envelopes with the pathogen inside. Lysosomes break down the pathogen due to the presence of proteolytic enzymes and hydrogen peroxide
What are some benefits and harms of inflammation
Benefits:
Delivery of antibodies, nutrients and oxygen, drugs such as antibodies
Stimulates adaptive immunity
Harms:
Digestion of normal tissues
Swelling (in airways)
Inappropriate inflammatory to harmless stimulus (hypersensitivity)
What are some ways to treat inflammation?
RICE
(rest, ice, compression, elevation)
NSAIDs
These reduce inflammation by stopping production of prostaglandins
Aspiration of fluid
Injection of corticosteroids
What are 2 examples of antigen-presenting cells?
Dendritic cells- detect pathogens, antigen presentation, activate adaptive immunity
Macrophages- Engulf tissue debris, dead cells, antigen presentation
What are the 2 types of macrophages and what do they do?
M1- pro inflammatory
M2- tissue repair and healing
What happens after antigens are processed by APCs?
They are presented with major histocompatibility complex
Major histocompatibility complex: proteins found on surfaces of cells that help the immune sysrem recognise foreign substances
Where do the APCs travel to get to the lymphocytes?
In the lymphatic system to the lymphoid tissue to present antigen to lymphocytes
What are the 2 types of lymphocytes, where are they formed and what do they do?
B cells- mature in bone marrow, make antibodies
T cells- mature in thymus, cell mediated immunity
What are the 2 stages of adaptive immunity?
Induction phase
Effector stage
What are the 2 types of effector stages?
Humoral immunity and cell mediated immunity
What happens in humoral immunity?
B cells make antibodies
What are the 5 types of antibodies and what do they do?
IgG- memory antibody
IgM- first antibody to appear in response to antigen
IgE- mediates allergies
IgA- works on mucous membranes
IgD- makes up 1% of proteins in plasma proteins of B-lymphocytes
What happens in cell mediated immunity?
Cytotoxic T cells kill intracellular microorganisms
Activate macrophages
What are the four possible outcomes of inflammation?
Complete healing
Abscess formation
Excessive necrosis
Scarring
What are the difference in cells in chronic and acute inflammation
Chronic inflammation:
Lymphocytes, plasma cells, macrophages
More granulation and scaring
Acute inflammation:
Mostly neutrophils
What are the benefits and harms of inflammation medication?
Benefits:
Relieves symptoms of inflammation
Reduce tissue damage due to chronic inflammation
Harms:
Prevents healing by allowing activity by suppressing pain
Suppresses other inflammatory responses to infections
