Lecture 21 Flashcards
immune complex type hypersensitivity: Involves soluble immune complexes (IgG, IgM, IgA) of antibody and antigen; Only involves complement binding Abs; Complexes are spread to joints/kidneys; Complexes precipitate and activate complement causing tissue damage
Type 3
Present in almost all tissues and are the mature form of monocytes.Orchestrate immune responses and help induce inflammation.Secrete signaling proteins that activate other immune cells.General scavenger cells in the body
macrophages
release of granules containing histamine and active agents
mast cell
3 stages of healing cascade
inflammation, proliferation, and remodeling
not true cells, cytoplasmic fragments w/ purple granules that contain chemical for blood clotting (enzymes, serotonin, Ca2+ ions, ADP, and PDGF), normally kept in “inactive” state by molecules secreted by endothelial cells of blood vessels; when activated, form temporary plug that helps to seal breaks in blood vessels
platelets
anuclear cell bodies derived from megakaryocytes, which circulate in the vasculature. undergo Adhesion, Activation, and Aggregation during coagulation.
Platelets (thrombocytes)
migration of leukocytes (mainly neutrophils or PMNs) into the site of injury (cellular recruitment and activation) associated with acute inflammation
cellular events
Cells of the immune system that store and release histamine
Mast Cells
is a monoamine neurotransmitter. Derived from tryptophan, primarily found in the gastrointestinal tract (GI tract), blood platelets, and the central nervous system. Released upon degranulation of platelets at site of injury. Functions as a smooth muscle constrictor to immediately act to limit the loss of blood volume
Serotonin
activated function of phagocytosis and activation of bactericidal mechanisms; antigen presentation
macrophages
antibody dependent hypersensitivity: cell membrane antigens altered to “non self”; could be from complement mediated lysis of host cells, antibody dependent cell mediated cytotoxicity, or direct binding by antibody to stimulate the cell
Type 2
balance between constrictor and dilator influences
vascular tone
contraction of smooth muscle cells of vessel walls to restrict the loss/flow of blood at site of injury; triggered by sympathetic nerves
vasoconstriction
is the most important mediator of a type IV reaction
IFNy
cell mediated hypersensitivity: Important mechanism to protect against intracellular pathogens (AIDS patients often get TB); Mediated by T cells rather than by antibody; Either CD4 Helper T cells or CD8 cytotoxic T cells
Type 4
anaphylactic hypersensitivity: includes Hayfever, bee sting, allergic asthma, penicillin, and aspirin: allergy and atrophy
Type 1