click below
click below
Normal Size Small Size show me how
MCAT Bio. Ch. 8
Term | Definition |
---|---|
Innate Immunity (Nonspecific Immunity) | Composed of defenses that are always active but cannot target a specific invader and cannot maintain immunologic memory |
Adaptive Immunity (Specific Immunity) | Composed of defenses that take time to activate, but that target a specific invalder and can maintain immunologic memory |
Immune Cells Come From: | The bone marrow |
The Spleen And Lymph Nodes Are Sites Where: | Immune responses can be mounted, and in which B-cells are activated |
Thymus Is The Site Of: | T-cell maturation |
Gut-associated Lymphoid Tissue (GALT) Includes: | The tonsils and adenoids |
Leukocytes (White Blood Cells) Are Involved In: | Immune defenses |
The Skin Acts As: | A physical barrier and secretes antimicrobial compounds like defensins |
Mucus On Mucous Membranes: | Trap pathogens. In the respiratory system, the mucus is propelled upward by cilia and can be swallowed or expelled. |
Tears And Saliva Contain: | Lysozyme, an antibacterial compound |
The Stomach Produces Acid, Which: | Kills most pathogens. Colonization of the gut helps prevent overgrowth by pathogenic bacteria through competition. |
Complement System Can Punch Holes In: | The cell walls of bacteria which makes them osmotically unstable |
Interferons Are Given Off by Virally Infected Cells And Help: | Prevent viral replication and dispersion to nearby cells |
Macrophages Ingest: | Pathogens and present them on major histocompatibility complex (MHC) molecules. They also secrete cytokines. |
MHC Class I (MHC-I) Is Present In: | All nucleated cells and displays endogenous antigen (proteins from within the cell) to cytotoxic T-cells (CD8+ cells) |
MHC Class II (MHC-II) Is Present In: | Professional antigen-presenting cells (macrophages, dendritic cells, some B-cells, and certain activated epithelial cells) and displays exogenous antigen (protein from outside the cell) to helper T-cells (CD4+ cells) |
Dendritic Cells Are: | Antigen-presenting cells in the skin |
Natural Killer Cells: | Attack cells not presenting MHC molecules which includes virally infected cells and cancer cells |
Granulocytes Include: | Neutrophils, eosinophils, and basophils |
Neutrophils Ingest: | Bacteria, particularly opsonized bacteria (those marked with antibodies). They can follow bacteria using chemotaxis |
Eosinophils Are Used In: | Allergic reactions and invasive parasitic infections. They release histamine, which causes an inflammatory response |
Basophils Are Used In: | Allergic reactions |
Mast Cells Are Related Cells To Basophils Found: | In the skin |
Humoral Immunity Is Centered On: | Antibody production by plasma cells which are activated B-cells |
Antibodies Target A Particular: | Antigen. They contain two heavy chains and two light chains. They have a constant region and a variable region. |
The Tip Of The Variable Region Of An Antibody Is: | The antigen-binding region |
When Activated, The Antigen-binding Region Undergoes: | Hypermutation to improve the specificity of the antibody produced. |
Cells May Be Given To Switch: | Isotypes of antibody (IgM, IgD, IgG, IgE, IgA) |
Circulating Antibodies Can Opsonize: | Pathogens (which means to mark them for destruction), cause agglutination (clumping) into insoluble complexes that are ingested by phagocytes or neutralize pathogens |
Cell-surface Antibodies Can Activate: | Immune cells or mediate allergic reactions |
Memory B-cells Lie In Wait For: | A second exposure to a pathogen and can then mount a more rapid and vigorous immune response (secondary response) |
Cell-mediated (Cytotoxic) Immunity Is Centered On: | The functions of T-cells |
T-Cells Undergo Maturation In The Thymus Through Positive Selection, Which Is: | Only selects for T-cells that can react to antigen presented on MHC |
T-Cells Undergo Maturation In The Thymus Through Negative Selection, Which Is: | Causes apoptosis in self-reactive T-cells |
The Peptide Hormone, Thymosin, Promotes: | T-cell development |
Helper T-Cells (Th or CD4+) Respond To: | Antigen on MHC-II and coordinate the rest of the immune system, which secretes lymphokines to activate various arms of immune defense. |
Th1 Cells Secrete Interfuron Gamma, Which: | Activates macrophages |
Th2 Cells Activate: | B-cells |
Cytotoxic T-cells (Tc, CTL, or CD8+) Respond To: | Antigen on MHC-I and kill virally infected cells |
Suppressor (Regulatory) T-cells (Treg) Tone Down The Immune Response After: | An infection and promote self-tolerance |
Memory T-Cells Serve A Similar Function To: | Memory B-cells |
In Autoimmune Conditions, A Self-antigen Is Recognized As: | Foreign and the immune system attacks normal cells |
In Allergic Reactions, Nonthreatening Exposures Incite: | An inflammatory response |
Immunization Is A Method Of Inducing: | Active immunity (activation of B-cells that produce antibodies to an antigen) prior to exposure to a particular pathogen |
Passive Immunity Is The: | Transfer of antibodies to an individual |
The Lymphatic System Is: | A circulatory system that consists of one-way vessels with intermittent lymph nodes |
The Lymphatic System Connects To The Cardiovascular System Via: | Thoracic duct in the posterior chest |
The Lymphatic System: | Equalizes fluid distribution, transports fats and fat-soluble compounds in chylomicrons, and provides sites for mounting of immune responses |