Inflammation Flashcards
Inflammation
Nonspecific, predictable response of living tissues or entire body to injury
Causes of inflammation
- Chemical agents
- Physical factors
- Microbes/pathogens
- Any stimuli that disturb homeostasis
- Immune causes: autoimmune disease
Acute vs chronic inflammation
- Acute: sudden onset, lasting hours to days
2. Chronic: lasting weeks to months to years
How does a fever occur and what are the effect of a fever?
Fever occurs by resetting of hypothalamic thermostat and may intensify effects of interferons, inhibit bacterial growth and speed up repair reactions
Cardinal signs of inflammation
- Calor (heat)
- Rubor (redness)
- Tumor (swelling)
- Dolor (pain)
- Functio laesa (disturbed function)
Chemotaxis vs cytotoxicity
- Chemotaxis (move PMNs to area of inflammation)
2. Cytotoxicity (T cells toxic to bacteria/viruses)
Stages of disease progression
- Vasoconstriction-lasting only seconds
- Vasodilation
- Edema
- Pain
Histamine
- Quickly released by mast cells (type of WBC)and platelets
- Increased blood vessel permeability and diapedesis
- Vasodilatior and broncho constrictor
- Lasts less than 30 minutes (inactivated by histaminase)
Bradykinin
- Slow acting
- Induces pain (dolor)
- Vasodilator
- Facilitates movement of WBCs
- Opsonisation: facilitated phagocytosis of bacteria
- Chemotaxis: migration of leukocytes
Most important arachidonic acid derivatives
- Leukotrienes
- Prostaglandins
- Thromboxane
Leukotrienes
Increase vascular permeability and promote Chemotaxis, typically found in anaphylactic shock and bronchospasm (bronchial asthma)
Prostaglandins
stimulate vasodilation, increase vascular permeability and cause smooth muscle contraction. Mediate pain and fever
Thromboxane
promotes platelet aggregation (thrombosis: clotting)
Transudate
caused by hydrostatic or osmotic pressure changes (mild injury)
thin, watery fluid; contains small amounts of proteins
Exudate
caused by inflammation (severe injury)
contains more protein and polymorphonuclear neutrophils (PMNs)
Phagocytosis
PMN cells eat microbes or cellular debris
Polymorphonuclear neutrophils (PMNs) or leukocytes
- Most numerous WBCs in blood (60-70%)
- First cells to appear in acute inflammation
- Promote inflammation
- Recruit new leukocytes
- Cause symptoms of inflammation
Eosinophils
- 2-3% of circulating WBCs
- Appear 2-3 days after PMNs
- Longer lifespan than PMNs, present in chronic inflammation
- Prominent in allergic reactions (i.e. hay fever, asthma)
- Respond to parasitic infection
Basophils
- Less than 1% of circulating WBCs
- Most prominent in allergic reactions
- Precursors to mast cells (histamine)
Macrophages
- Appear 3-4 days after onset of infection/injury
- Long lifespan, present in chronic inflammation
- Important for phagocytosis
Main phagocytic cells
macrophages and PMNs
Platelets
- No nucleus
2. Cytoplasm contains granules
