Session 2 - Acute Inflammation Flashcards
What are 6 causes of acute inflammation?
Foreign bodies Immune reactions Infections Tissue necrosis Trauma Physical and chemical agents
What are the 5 signs of acute inflammation?
Redness Heat Swelling Pain Loss of function
What is rubor?
Redness
What is calor?
Heat
What is tumor?
Swelling
What is dolor?
Pain
What is inflammation?
Response of living tissue to injury
What are 2 phases of inflammation?
Vascular
Cellular
What happens during vascular phase with regard to blood flow?
Brief vasoconstriction for seconds
Longer lasting vasodilation, causing heat and redness
Increased permeability so fluid and cells can escape
What is Starling’s Law?
Movement of fluid is controlled by the balance of hydrostatic pressure and oncotic pressure
What is hydrostatic pressure?
Pressure exerted on a vessel wall by a fluid, pushing fluid away from blood vessels
What is oncotic pressure?
Pressure exerted by proteins, drawing fluid towards blood vessels
Why does heat and redness present during acute inflammation?
Vasodilation
Why does oedema present during acute inflammation?
Vasodilation increases capillary hydrostatic pressure, increased vessel permeability allows plasma proteins to move into interstitial, causing increased interstitial oncotic pressure, hence fluid moves out of vessel into interstitial fluid
What is stasis?
Reduced flow through vessel
Why does acute inflammation cause stasis?
Fluid moves out of vessel, increasing viscosity of blood
What is exudate?
Protein rich fluid occurring in inflammation when vascular permeability increases
What is transudate?
Ultrafiltrate of plasma occurring during organ failure as fluid moves due to increased capillary hydrostatic pressure and decreased capillary oncotic pressure, and vascular permeability is unchanged
What are 3 ways of increasing permeability of vessel walls?
Retraction of endothelial cells
Direct injury
Leukocyte dependent injury
What are 3 main components that makes vascular phase effective?
Interstitial fluid
Exudate
Lymph nodes
What is the role of interstitial fluid during acute inflammation?
Dilutes toxins
What are the 2 roles of exudate in acute inflammation?
Delivers proteins
- fibrin to limit spread of toxin
- immunoglobulins from adaptive immune response
What is the role of lymph nodes in acute inflammation?
Fluid drains to lymph nodes, stimulating adaptive immune response
What is the primary white blood cell involved in cellular phase of acute inflammation?
Neutrophils
What are the 4 steps of neutrophils escaping vessels?
- Margination
- Rolling
- Adhesion
- Emigration / diapedesis
What are the 2 main adhesion molecules used by neutrophils to escape from vessels?
Selections
Integrins
What do selectins do?
Responsible for rolling, expressed on activated endothelial cells and are activated by chemical mediators
What do integrins do?
Found on neutrophil surface, changes from low affinity to high affinity, responsible for adhesion
How do neutrophils move through the interstitium?
Chemotaxis, along an increasing chemical gradient of chemoattractants
How do neutrophils recognize what to phagocytose?
Opsonisation - toxin covered in C3b and Fc and neutrophils have the respective receptors on its surface
What are the 2 types of opsonins?
C3b and Fc
What are 2 ways neutrophils destroy pathogens?
Oxygen dependent
Oxygen independent
What are the 2 molecules that oxygen dependent killing mechanisms use?
Reactive oxygen intermediates and nitrogen intermediates
What are the 3 types of molecules used in oxygen independent killing mechanisms?
Lysosome
Hydrolytic enzymes
Defensins
What are 2 ways that cellular phase is effective in acute inflammation?
Removal of pathogens and necrotic tissue
Release of inflammatory mediators
What are inflammatory mediators?
Chemical messengers that control and coordinate inflammatory response
What are 3 examples of mediators that controls vasodilation?
Histamine
Serotonin
Prostaglandins
What are 3 mediators that increases vascular permeability?
Histamine
Bradykinin
Leukotrienes
What are 3 mediators that controls chemotaxis?
C5a
TNF-a
IL-1
What are 3 mediators that causes systemic responses?
Prostaglandins
IL-6
IL-1
What are 3 mediators that control pain?
Bradykinin
Substance P
Prostaglandin
What are 4 types of local complications of acute inflammation?
Swelling can cause compression of tubes, exudate compresses organs, loss of fluid, pain can lead to psychosocial consequences
What are 4 forms of systemic effects of acute inflammation?
Fever - pyrogens act on hypothalamus to increase temperature
Leucocytosis - mediators act on bone marrow to increased production of white cells
Acute phase response - reduced appetite, altered sleep to induce rest
Septic shock - dramatic drop in BP due to widespread vasodilation
What are 3 possible outcomes after acute inflammation?
- Complete resolution
- Repair with connective tissue (fibrosis)
- Progression to chronic inflammation (prolonged inflammation with repair)
What is hereditary angio-oedema?
Inherited deficiency of C1-esterase inhibitor
What is alpha-1 antitrypsin deficiency?
Low levels of alpha-1 antitrypsin, a protease inhibitor which deactivates enzymes released from neutrophils at the site of inflammation, so proteases act unchecked and destroy normal parenchyma tissue
What are the symptoms of alpha-1 antitrypsin deficiency?
Emphysema
What is chronic granulomatous disease?
Phagocytes cannot generate free radical superoxide, bacteria phagocytosed but phagocytes cannot kill them as they cannot do oxygen burst, results in many chronic infections
How does appendicitis occur?
Lumen is blocked by faecolith, accumulation of bacteria and exudate leads to increased pressure and eventually perforation
What are 2 organisms that cause pneumonia?
Streptococcus Pneumoniae
Haemophilus influenzae
What are 4 symptoms of pneumonia?
Shortness of breath
Cough
Sputum
Fever
What are 2 risk factors of pneumonia?
Smoking
Pre existing lung infection
What is bacterial meningitis?
Inflammation of meningitis
What are 3 causative organisms of bacterial meningitis?
Group B streptococcus
E. Coli
Neisseria meningitides
What are 4 symptoms of bacterial meningitis?
Headache
Neck stiffness
Photophobia
Altered mental state
What are abscesses?
Accumulation of dead and dying neutrophils with associated liquefaction necrosis
