Inflammation Lecture Notes

Flashcards covering the key concepts of Inflammation from the lecture notes.

Inflammation

The body's attempt at self-protection to remove harmful stimuli and begin the healing process.

Redness (Rubor)

A sign of inflammation caused by capillaries filled with more blood than usual.

Swelling (Tumor)

A sign of inflammation caused by an accumulation of fluid.

Heat (Calor)

A sign of inflammation where more blood in the affected area makes it feel hot to the touch.

Pain (Dolor)

A sign of inflammation; the inflamed area is likely to be painful due to chemicals stimulating nerve endings.

Loss of Function (Functio Laesa)

A sign of inflammation; there may be some loss of function in the affected area.

Neutrophils

Cell type important in inflammation; involved in infection and matrix phagocytosis.

Monocytes/Macrophages

Key players in inflammation; involved in debridement/matrix turnover and are a major source of stimulatory signals.

Lymphocytes

Cell type important in inflammation; recruited later and important in the early remodeling phase.

Innate Immune System Cells

Eosinophils, Monocytes/Macrophages, Natural Killer cells (NK), and Neutrophils.

Monocytes

Rapidly recruited into tissues following tissue damage or infection and differentiate into macrophages.

Macrophages

Can change their functional phenotype depending on environmental cues; have a central role in protecting the host but also in inflammatory and degenerative diseases.

B Cells (B Lymphocytes)

Derived from immature cells present in bone marrow; essential for humoral response. Main functions: make antibodies, present antigens to other immune cells, release immune-regulatory cytokines.

T Cells

Mature in the thymus; multifunctional cells involved in host defense. Several subsets each have a distinct function.

Helper T Cells

Orchestrate immune response.

Killer and Cytotoxic T Cells

Hunt down and destroy abnormal or infected cells.

Inflammatory Disorders

Arise when inflammation becomes uncontrolled and causes destruction of healthy tissue.

Autoimmune Disorders

Characterized by the body's immune responses being directed against its own tissues, causing prolonged inflammation and subsequent tissue destruction.

Chronic Inflammation

Shift in type of cells present at site of inflammation by simultaneous destruction and healing of tissue from inflammatory process.

Acute Inflammation

Short duration, minutes to days, increase blood flow, vascular permeability, protein exudate, predominantly innate immune system.

Chronic Inflammation

Long duration, days to years, predominantly adaptive immune system, proliferation of blood vessels, scarring and fibrosis, tissue atrophy and necrosis.

Mediators of Inflammation

Histamine, serotonin, endothelin, nitric oxide, lipid mediators and prostacyclins, products of the complement system, coagulation mechanism (thrombin), cytokines.

Termination of Acute Inflammation

Removal of the insult or stimulating agent and treatment; neutrophils have a short life span; mediators are short-lived and rapidly degrade, anti-inflammatory factors inhibit production of pro-inflammatory cytokines.

Chronic inflammation causative agents

Non-degradable pathogens persistent inflammation, infection with some types of viruses, persistent foreign bodies, overactive immune system reactions

Chronic inflammation major cells involved

Macrophages, lymphocytes, plasma cells, fibroblasts

Primary mediators in chronic inflammation

Reactive oxygen species, hydrolytic enzymes, IFN-y and other cytokines, growth factors

Chronic inflammation duration

Several months to years

Chronic inflammation outcomes

Destruction of tissue, thickening and scarring of connective tissue (fibrosis), death of cells or tissues (necrosis)

Acute Condition Inflammatory Disorders

Appendicitis, tonsillitis, bronchitis, sinusitis

Chronic Condition Inflammatory Disorders

Arthritis, hepatitis, IBD, Asthma and Obesity

Innate Immune System

Includes cells present within damaged/infected tissue and organs, generation of free radicals and oxidative stress, secretion of growth factors and cytokines.

Ageing and Inflammation Links

Oxidative stress, mitochondrial damage, immune-senescence, epi-genomics, metabolism, environmental and lifestyle

Causes of Inflammation

Chemical irritants, toxins, physical injury, allergens, burns, ionizing radiation, foreign bodies, stress, trauma, alcohol

Mediators of Inflammation: Vasodilation, increased permeability

Histamine, serotonin, endothelin, nitric oxide, lipid mediators and prostacyclins, products of the complement system, coagulation mechanism (thrombin)

Mediators of Inflammation: Chemotaxis Leukocyte adhesion

Thrombin, cytokines mediating inflammatory and effector functions, chemokines

Mediators of Inflammation: Tissue Remodelling

Chemokines, Chemotactic factors, Oxygen derived free radicals, Proteases