Exam 2- Innate Immilunity: Inflammation Flashcards
Cytokines
Signaling molecules that influence behavior of immune and other types of cells.
Cause fever
Most important: interleukins or interferons
proinflammatory or antiinflammatory in nature depending on whether they induce or inhibit the inflammatory response. They usually diffuse over short distances, and bind to and affect the appropriate target cell.
Chemotaxis
The movement of leukocytes from the vessel into into a damaged area.
Chemotactic factors are biochemical substances that attract leukocytes to the site of inflammation.
move along a concentration gradient (from an area of lesser concentration of the factor to an area of greater concentration of the factor).
Mast cell degranulation
release of the granular contents of mast cells. Mast cells are cellular bags of granules located in skin, GI tract, and respiratory tract.
They initiate the inflammatory response. In response to stimulus, biochemical mediators in the mast cell (histamine, chemotactic factors, and cytokines), are released and exert their effects immediately.
Histamine
a vasoactive amine that causes temporary, rapid constriction of the large vessel walls and dilation of the postcapillary venules and increased vascular permeability.
H1 is pro-inflammatory and H2 is anti-inflammatory.
H1 receptors are present on smooth muscle cells, especially those of the bronchi, and cause bronchial contraction when stimulated.
H2 receptors abundant in stomach mucosa and induce secretion of gastric acid as part of the normal physiology of the stomach.
Interferon
Antiviral cytokines
Platelets
Clot the area and wall it off to prevent spread of inflammation and bacteria. Need calcium for this.
Eosinophils
Defend against parasites.
Degrade vasoactive substances released by mast cells.
Mast cells
Release chemicals that initiate the inflammatory response.
Release preformed inflammatory mediators immediately by degranulation.
Nonphagocytic innate
Natural killer cells
Eliminate virus-infected cells
Macrophages
Phagocytize microorganisms and cellular debris.
Secrete chemicals that promote tissue healing.
Activate adaptive immunity.
Secrete chemicals to attract fibroblasts.
Phagocytosis innate
Neutrophils
Phagocytize microorganisms and cellular debris soon after injury.
Secrete chemicals that call in longer-acting phagocytes.
Phagocyte innate
First line of defense
Anatomical barriers
Collectins
Chemical defenses produced by the king and epithelium.
Ex: surfactant
Defensins
Type of chemical barrier
Kinins
Chemicals involved in the inflammatory response.
Pattern recognition receptors
How one innate immune cell can recognize many different types of pathogenic bacteria.
Complement cascade
When activated, forms membrane attack complex that causes cell lysis.
Steps of inflammation
Brief vasoconstriction Vasodilation Increased vascular permeability Leakage of plasma into tissues Local edema
PAMP
A molecular pattern that is associated with pathogenic microorganisms.
DAMP
Molecular pattern that is associated with injured or stressed host cells.
Innate immunity
Nonspecific, meaning that one cell or other element will defend against many different typesI’m of antigens. Inflammation. 2nd like of defense. 1st immune response.
Aka natural or native immunity.
Adaptive immunity
Specific, meaning that one cell will defend against only one particular antigen.
Opsonins
Molecules that mark antigens for destruction by innate immune cells.
Diapedes
Cells leaving the blood vessel to the site of injury. Move chemotaxis to the area where the chemotactic cytokines are in the highest concentration.
Fibroblasts
Secrete collagen, which forms scar tissue.
Activated by chemicals released by macrophages.
Granuloma
Walked-off infectious agent in chronic inflammation
Age-related changes that affect tissue healing
Loss of capillaries that normally bring blood to the area.
Adaptive immunity
Activated after some delay. Remembers the pathogen and acts more rapidly upon subsequent exposure. Works against one specific antigen.
Fibrinous exudate
Thick and clotted
Purulent exudate (supperative)
Containing many WBCs
Hemorrhagic exudate
Containing many RBCs
Serous exudate
Watery, with few proteins and cells.
Healing by primary intention
Edges easily approximate.
Ex: surgical incision
Healing by secondary intention
Larger wounds that have greater tissue loss.