Pathology and Inflammation Flashcards

Flashcards covering vocabulary terms related to pathology, injury, inflammation and related topics.

Etiology

The cause of disease

Pathogenesis

The mechanisms causing disease

Pathology

Molecular and morphologic changes to cells or tissues

Clinical manifestations

Signs and symptoms

Prognosis

The anticipated course of disease

Epidemiology

Incidence, prevalence and distribution

Homeostasis

Cells in a normal healthy state

Adaptation

Reversible modulation of structure/function to avoid injury

Adaptation

A response to stress or increased demand that maintains the cells functions by a new steady state

Reversible/ sublethal injury

A response to stimuli that compromises cellular function

Irreversible injury/ lethal injury

A response to stimuli that compromises cellular function to the point that it cannot recover

Physiological adaptation

Cellular response to normal stimulation - hormones - endogenous chemicals

Pathological adaptation

Cellular response to stimulation secondary to underlying disease/ to avoid injury by modulation of structure and/or function

Hypertrophy

Increased cell size - increased organ size

Hyperplasia

Cell number - organ size

Atrophy

Decreased cell size/ number - decreased organ size

Metaplasia

Change in cell type

Hypertrophy

Increased size of cells resulting in increased size of organ

Hyperplasia

Increase in number of cells in an organ or tissue

Atrophy

Reduced size organ resulting from decrease in cell size and number

Metaplasia

Replacement of one differentiated cell type with another

Hypoxia

Oxygen deficiency

Ischemia

Loss of blood supply to tissue

Reversible injury

Recovery if damaging stimulus is removed - Compromise cell function - May compromise organ function

Irreversible injury and cell death

When the cell cannot recover and it dies

Necrosis

Increased eosinophilic staining - denatured protein and loss of RNA - Vacuolation - digested cytoplasmic organelles - Swelling of ER and mitochondria

Karyolysis

Nuclear lysis - decreased basophilia from DNA breakdown

Pyknosis

Nuclear shrinkage and increased basophilia (condesed)

Karyorrhexis

Nuclear fragmentation

Coagulative necrosis

Denaturation > digestion - most common type - due to severe ischemia - occurs in solid organs (except brain)

Liquefactive necrosis

Denaturation > digestion - complete digestion of dead cells - associated with infection (bacterial and fungal)

Caseous necrosis

Fragmented lysed cells with amorphous granular appearance - Tissue architecture obliterated - Associated with infection with mycobacterium tuberculosis

Fat necrosis

Refers to focal areas of fat destruction - enzymes liquefy membranes of fat cells - release fatty acids which combine with calcium to cause patchy white lesions (fat saponification) - most common in acute pancreatitis

Fibrinoid necrosis

Occurs in blood vessels in response to deposition of immune complexes - necrosis associated with leakage of fibrin and inflammatory cells

Gangrenous (Lower limb) necrosis

Usually describes coagulative necrosis that occurs in a lower limb which has lost its blood supply - liquefactive necrosis may accompany a bacterial infection -wet gangrene

Apoptosis

Regulated form of cell death which may be both physiological and pathological

Phagocytes

Macrophages professional phagocytes that reside reside in tissue - throughout the body - Neutrophils-short-lived cells, abundant in blood but nor present in normal tissue

Regeneration

Tissues composed of cells with proliferative captivity AND - The underlying structure of the tissue has not been too severely damaged

Repair by scar formation

Tissue composed of cells with limited or no proliferative capacity OR - The underlying structure of the tissue is lost

itis

A suffix meaning inflammation

Lymphocytes

Large nucleus which almost fills the entire cell

Neutrophil

Irregular shaped nucleus (can look like to has many nucleus)

Monocytes

Has colourless parts which are the lysosomes along with the nucleus

Acute inflammation

Rapid onset short duration - fluid plasma protein and cellular exudate - neutrophilic leukocyte accumulation

Chronic inflammation

Insidious onset - long duration - lymphocytes and macrophages - scarring

Edema

Due to an accumulation of fluid in the body's tissues

Phagocytosis

The process by which a phagocyte (a type of white blood cell) surrounds and destroys foreign substances (such as bacteria) and removes dead cells.

Toll like receptors

Recognise patterns that are unique to viruses and other pathogens

PAMP

Pathogen-associated molecule patterns

DAMP

Damage associated molecular patterns

Recruitment

Vasodilation - Vascular permeability - Stasis - Cellular - margination - rolling adhesion - transmigration - Migration/ chemotaxis

Transudate

Increased hydrostatic pressure - accumulation of interstitial fluid - ultrafiltrate - Low protein concentration, few cells

IL

Interleukin

Leukocyte

White blood cell

Margination

Slowed blood flow-stasis - Leukocytes are pushed to the ‘margins’ of the blood vessels

Rolling

Weak transient adhesion - Reduces rolling velocity - Mediated by selectins (bind sugars)

Adhesion

Mediated by integrins - Expressed on leukocyte plasma membrane - Low affinity until activated by chemokines

Migration

Transmigration or diapedesis-movement of leukocytes between cells at the intercellular junctions

Chemotaxis

A chemical gradient produced by exogenous (infection) and endogenous (host factors) sources

Opsonization

Being prepared for recognition and removal

Alpha helix transmembrane receptors

Recognise bacterial peptides and inflammatory mediators produced in response to microbes or injury

Lysosomal acid proteases

Functions at low pH in lysosome

Resolution

Injury short lived - Minimal damage - Regeneration and repair of damaged tissue - regain function

Resolution

Regain function

Lipoxins

Inhibitors of inflammation

Fibrosis

Substantial tissue destruction and scar deposition

Plasma derived mediators

Inter-related enzymatic cascades - Complement system - Kinin system - Coagulation/ fibrinolytic system

Cell derived chemical mediators

Produced by tissue macrophages - dendritic cells - mast cells - endothelial cells - Leukocytes

Histamine

Preformed granules - released by variety of stimuli

Newly synthesized mediators

Arachidonic Acid metabolites-prostaglandin and leukotrienes - AA metabolites (eicosanoids) mediate most inflammatory steps - Prostaglandins and Leukotrienes

Acute phase response

Pathologic manifestations

Leukocytosis

Increased leukocyte count

Leukopenia

Decreased leukocyte counts

Sepsis

Severe microbial infection (microorganism or their products in the blood)

Edemea

First observed - caused by the protein called ultrafiltrattransidate -a associated with vasodilation

Morphology-Serous Inflammation

Characterised as a watery, cell poor effusion

Fibrinous Inflammation

Characterised by the deposition of fibrin in the extracellular space as a result of increased extravascular permeability

Organisation

scar is formed through the deposition of collagen

Suppurative (purulent)

Characterised by the production of pus, an inflammatory exudate composed of neutrophils and dead cells

Unceration

Necrosis and inflammation on or near the surface

Chronic inflammation

Continues when offending agent from acute inflammation cannot be removed

Immune mediated diseases (hypersensitivity)

Primary chronic inflammation - Injury that involves chronic inflammation without an initial acute inflammatory response

Rheumatoid Arthritis

Associated with autoimmune - Dense inflammatory infiltrates (frequently forming lymphoid follicles) of CD4+ helper T cells, B cells, plasma cells

Chronic inflammation

Prolonged inflammation (weeks, months, years)

Lymphocytes

Mobilized by immune stimulus (infection) and non-infection mediated inflammation- Recruited into peripheral tissues

THI

Secrete IFN-Y - Classical macrophage activation - Defense against bacteria, viruses and autoimmune disease

TH2

Secrete IL-4, IL-5, IL-13 - Alternative macrophage activation - Defense against helminthic parasites and allergic inflammation

TH17

Secrete IL-17 - Leukocyte recruitment

Chronic ulcer

Macroscopic features of inflammation

Repair

Proliferation of fibroblasts and endothelial cells

Granulomatous inflammation

Aggregates of activated macrophages - epithelioid cells - will develop epithelial-like appearance (large, pin, flat)

Caseating granuloma

Central mass of necrotic material (caseous)

non caseating granuloma

Non caseating granuloma can become present in many tissues and organs

Foreign body granuloma

Incited by inert foreign material that can not be removed

Immunity

Provides protection against infection

Innate immunity

General - Epithelial barrier - Phagocytes - Antigen Presenting Cells - NK-cells - Plasma protein (c’)

Adaptive immunity

Specialised - Humoral immune response-extracellular pathogens - Antibodies neutralise microbes, block infection, promotes phagocytosis

Autoimmunity

An reaction to self antigens can cause disease

Self-tolerance

Lack of immune responsiveness to one’s own tissue antigens, is fundamental property of immune system

Immunological tolerance

Occurs when lymphocytes are unresponsive to antigen