Inflammation Flashcards
3 lines of defence
1- skin and mucous membranes
Skin is physical barrier and waterproof
Mucous membranes secrete things and trap viruses and bacteria
Eg, tears wash away particles, eyelashes trap particles, blink reflex, enzymes neutralise harmful substances and skin stops entry of pathogens
2- inflammation
Non-specific, natural, innate immunity and rapid response
3- immunity
Specific, acquired immunity, adaptive and slow response
Define inflammation
Body’s non specific protective response to tissue damage, disease or injury in attempt to destroy, dilute or wall off injurious agent and injured tissue
5 cardinal signs of inflammation
Acronym: We See Really Painful Legs
Warmth / calor - increased blood flow, either specific or whole body (Pyrexia)
Swelling/ tumor- oedema, leaky fluid
Redness/ rubor- increased blood flow
Pain/ dolor - locally by compression of nerve endings + chemical release
Loss of function / function leasa
Why do we have inflammation?
Prevents minor infections from becoming unmanageable
Prepares damaged tissue for repair
5 factors that cause inflammation
Injury / trauma- physical (sports), thermal (ice burns), radiation (flash burns), electrical and chemical
Infection- virus, bacterium, rickettsiae, fungi, Protozoa or worms
Infarction- lack of oxygen to damaged tissue eg, MI leads to ischaemia
Immune reactions- foreign protein hypersensitivity like allergies and auto immune conditions like RA or ankylosing spondylitis or chrons disease
Nutrient deprivation
ITIS
Means inflammation
Eg Conjunctivitis - eye inflammation Arthritis- inflammation in joints Tendinitis- inflamed tendons Appendicitis - inflamed appendix Peritonitis - inflamed abdominal cavity Pericarditis- inflamed heart Capsulitis - inflamed capsules of joints
Mechanism of inflammation
Vicky Can’t Pick Lemons
Vascular response- changes in blood flow and protein rich exudation
Cellular response - leucocyte emigration
Phagocytosis - starts clear up process of causative agent
Lymphatic drainage - rid of excess fluid and gives protection
Steps in vascular response
TRANSIENT VASOCONSTRICTION- few seconds
MORE PROLONGED VASODILATION
INCREASE BLOOD FLOW AND HYDROSTATIC PRESSURE
OPENING OF CAPILLARY BEDS
INCREASED VASCULAR PERMEABILITY
BRADYKININ- amino acid so Capillary endothelium retracts (crenallation). Causes muscles in blood vessel walls to constrict so gaps are larger in vessels.
Leaking plasma- protein rich exudate
Oedema formation - fluid retention at injury site
Haemoconcentration - more proteins lost from blood , blood gets thicker and more concentrated
Stasis - blood flow slows and then stops
Cellular response
Basically, neutrophils get to site first, they are small and travel quickly in blood. Drawn by chemotaxis. Neutrophils also produce chemotactic chemicals.
then monocytes, which last longer but take longer to arrive as larger
Turns into macrophages
WBC travel on inside normally
Chemotaxis - WBCs to rim of vessel in MARGINATION
Endothelial cells positive charge and WBC negative
ROLL of WBCs as cant move smoothly
ADHESION- WBCs stick to vessel walls
PAVEMENTING- Flattens WBCs at walls
All due to chemotaxis
WBCs struggle to get through gaps in blood vessels and form projections called pseudopods
WBCs wriggle in amoeboid actions
WBCs pass through gaps by emigration and diapedesis cell walking (from blood vessel into extracellular fluid to site of injury)
Chemotaxis encourages more WBCs to area to destroy damaged cells or pathogen
Phagocytosis
Neutrophils and monocytes become macrophages at injury site
Macrophage ingests + destroys antigen, remove damaged tissue etc.
Macrophages die in process
This is non specific
Lymphatic drainage
Lymph system beside vascular, runs through lymph nodes like femoral triangle, popliteal fossa, cubital fossa etc.
Lymphatic system drains tissue fluid, products of inflammation and antigens not dealt with
Antigen presenting cells present to immunity - 3rd line of defence
WHY RUBOR?
Increased blood flow to area via vasodilation
Why calor?
More blood flow to area via vasodilation. It can be local or pyrexia (whole body increases in temperature)
Function leasa
Because of tissue damage, swelling and pain
Dolor
More vascular permeability and fluid = compressed tissue and compresses nerves. Chemical mediators elicit pain on nerve endings
Pain prevents more inflammation
Diabetics have reduced pain
