Ch 8,9- Immunology & Digestive Flashcards
Composed of defenses always active against infection but lack ability to target specific invaders
Innate (nonspecific) immunity
Defenses that target a specific antigen
Adaptive or specific immunity
What structure produces all the leukocyes
Bone marrow
Stores blood and activates B-Cells (turns into plasma cells)
Spleen
_______ A division of adaptive immunity where antibodies dissolve and act in blood (rather than in cells)
Humoral Immunity
T-Cells are the agent of what type of the adaptive immunity
Cell mediated immunity
Two types of adaptive immunity
Cell mediated (T-Cells) and humoral immunity (Ab)
Provide a place for immune cells to communicate and mount an attack
Lymph nodes
Immune tissue found in close proximity to the digestive system
GALT (includes tonsils, adenoids, peyers patches, and appendix)
Site of t-cell maturation
Thymus
The procurer of leukocytes, erythrocytes, and platelets
Hematopoietic stems cells
Our first line of defense is the
Skin
Antibacterial enzymes called ________ can be found on the skin
Defensins
Several other mucous membranes like around the eye and oral cavity produce a nonspecific bacterial enzyme called
Lysozyme (Secreted in tears and saliva)
Role in GI in nonspecific immunity
Acid product, and gut flora
The ______ system consists of a number of proteins in the blood that act as a nonspecific defense against bateria
Compliment
(can be activated through a classical pathway (which requires the binding of an antibody to a pathogen) or an alternative pathway (which does not require antibodies)”
To protect against viruses, cells that have been infected with viruses produce
Interferons
Proteins that prevent viral replication and dispersion
Cause nearby cells to decrease production of both viral and cell proteins
Upregulate MHC class 1 and 3= increased antigen presentation
When a macrophage gets activated what 3 things occur
- Phagocytosis through endocytosis
- Digests invader with enzymes
- Presents peptides of invader to others cells using proteins called MHC
chemical substances that stimulate inflammation and recruit additional immune cells to the area.”
Cytokines
All nucleated cells in the body display what type of MHC molucules
MHC class 1
Often called endogenous pathway because it binds antigens from inside the cell. Allows immune system to monitor health of these calls.
________ molecules are mainly displayed by professional antigen-presenting cells like macrophages”
“MHC class II
(exogenous pathway)
because these antigens originated outside of cell
“While antibody production is the domain of the adaptive immune system, it is important to understand that cells of the innate immune system also present antigens.”
Antigen presenting cells include
Macrophages, dendritic cells, some b cells, certain activated epithelial cells
_______ is in all nucleated cells and presents endogenous antigens. _________ is in antigen-presenting cells and presents exogenous antigens.”
MHC 1, MHC-2
“Macrophages and dendritic cells also have special receptors known as _________, the best-described of which are
________
- pattern recognition receptors (PRR)
- toll-like receptors (TLR). ”
“PRRs are able to recognize the category of the invader (bacterium, virus, fungus, or parasite). This allows for the production of appropriate cytokines to recruit the right type of immune cells;”
“a type of nonspecific lymphocyte, are able to detect the downregulation of MHC and induce apoptosis in these virally infected cells. ”
Natural killer cells
“Cancer cells may also downregulate MHC production, so NK cells also offer protection from the growth of cancer as well.”
“Neutrophils can literally follow bacteria using _______—the sensing of certain products given off by bacteria and migration of neutrophils to follow these products back to the source (the bacterium itself).”
Chemotaxis
“Neutrophils can also detect bacteria once they have been marked with an antibody from a B-cell or _____
Excerpt From: Kaplan. “Kaplan MCAT Biology Review: Created for MCAT 2015 (Kaplan Test Prep).” iBooks.
opsonized
“contain bright red-orange granules and are primarily involved in allergic reactions and invasive parasitic infections.”
Eosinophils
-Release histamine=vasodilation and leaky capillaries
“contain large purple granules and are involved in allergic responses.”
Basophils
“Both basophils and _______ release large amounts of histamine in response to allergens, leading to inflammatory responses.”
Mast cells
Cells of innate immune system
Macrophages, mast cell, Granulocytes, Dendritic cells, NK cells
“B-cells mature in the _____. T-cells mature in the __________.”
Excerpt From: Kaplan. “Kaplan MCAT Biology Review: Created for MCAT 2015 (Kaplan Test Prep).” iBooks.
Bone Marrow, Thymus
“B-cells govern the ______ response while T-cells mount the ______ response.
Humoral, Cell mediated
Antibodies are also called
Immuneglobulins (Ig)
Once antigen bound to Ig what happens
Either
- Opsonization
- Agglutinate (large insoluble complexes that are phagoctizied)
- Neutralize pathogens
“For cell-surface antibodies, the binding of antigen to a B-cell causes activation of that cell, resulting in”
“its proliferation and formation of plasma and memory cells”
“when antigen binds to antibodies on the “surface of a mast cell, it causes what?
degranulation (exocytosis of granule contents), allowing the release of histamine and causing an inflammatory allergic reaction.”
“Antibodies are Y-shaped molecules that are made up of two identical _______ and two identical ________”
Heavy chains, Light chains
“Disulfide linkages and noncovalent interactions hold the heavy and light chains together”
“Each antibody has an ______ at the end of what is called the _______
antigen-binding region, variable region (domain)
“ antibodies come in five different isotypes
(IgM, IgD, IgG, IgE, and IgA).”
D-GAME
“Cells can change which isotype of antibody they produce when stimulated by specific cytokines in a process called
isotype switching.
“Upon exposure to the correct antigen, a B-cell will proliferate and produce two types of daughter cells.
Excerpt From: Kaplan. “Kaplan MCAT Biology Review: Created for MCAT 2015 (Kaplan Test Prep).” iBooks.
Plasma and memory Cells
Plasma cells produce large amounts of antibodies, whereas memory B-cells stay in the lymph node, awaiting reexposure to the same antigen.”
Initial B cell activation is called the ______ response. Takes 7-10 days. The memory cells jumping to action and producing specific atnobideis which will be rapid and robust are called ________
Primary, Secondary
“The development of these lasting memory cells is the basis of the efficacy of ____________
Vaccinations
“T-cells mature in the thymus, where they undergo both _____ and ______ selection.”
Positive, Negative
“Positive selection refers to maturing only cells that can respond to the presentation of antigen on MHC (cells that cannot respond to MHC undergo apoptosis because they will not be able to respond in the periphery).
Negative selection refers to causing apoptosis in cells that are self-reactive (activated by proteins produced by the organism itself).”
“The maturation of T-cells is facilitated by ______, a peptide hormone secreted by thymic cells.”
Excerpt From: Kaplan. “Kaplan MCAT Biology Review: Created for MCAT 2015 (Kaplan Test Prep).” iBooks.
Thymosin
“Once the T-cell has left the thymus, it is mature but naïve. Upon exposure to antigen, T-cells will also undergo clonal selection so that only those with the highest affinity for a given antigen proliferate.”
3 major types of t-cells
“helper T-cells, suppressor T-cells, and killer (cytotoxic) T-cells. ”
“CD4+ T-cells, coordinate the immune response by secreting chemicals known as
lymphokines
These molecules are capable of recruiting other immune cells (such as plasma cells, cytotoxic T-cells, and macrophages) and increasing their activity.
