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88 Cards in this Set
- Front
- Back
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what's the role of lymphocytes in the immune system? |
they detect problems & travel to the site of injury |
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what's the differences between non-specific & specific? |
NON-SPECIFIC: they always work the same why & work against any type of invading agent SPECIFIC: they protect against specific pathogens & provide immunity |
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what's the importance of lymphocytes & how are they distributed in the body? |
they detect problems & travel into the site of injury/infection.
80% of lymphocytes are in organs, lymph, tissues, etc. and 20% are in blood. |
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what's lymph? |
a fluid similar to plasma but doesn't have the plasma proteins that transport hormones, nutrients & waste products |
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what are lymphatic vessels? |
vessels that carry lymph from peripheral tissues to the venous system |
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what are lymphatics? |
superficial lymphatics are vessels that are located in skin, mucous membranes, and serous membranes that line body cavities. deep lymphatics are larger vessels that accompany deep arteries & veins. both empty into thoracic cacity & right lymphatic duct |
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what are lymphoid tissues? |
connective tissue in the lymphoid system rich with lymphocytes |
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what are lymphoid organs? |
lymph nodes, thymus, spleen --- they're separated from surrounding tissues by a fibrous connective tissue capsule. |
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what are lymphatic capillaries? |
capillaries where the lymphoid system begins that only collect fluids, cells and solutes (don't distribute them) because they're one-way valves |
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what's the thoracic duct? |
duct in lymphatic system that collects lymph drainage from thoracic cavity |
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what's the cisterna chili? |
the first duct where lymph is collected |
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what's the right lymphatic duct? |
where lymph is collected |
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what's lymphedema? |
blockage of lymph drainage from a limb that causes severe swelling & interferes with immune system function |
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what are T cells? |
thymus-dependent. they make up 80% of lymphocytes |
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what are the 3 types of T cells? |
CYTOXIC: attack infested cells & produce cell-mediated immunity HELPER T CELLS: stimulate function of T cells & B cells SUPPRESSOR T CELLS: inhibit function of T cells & B cells |
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what are B cells? |
bone-marrow derived. make up 10-15% of lymphocytes. they change into plasma cells which produce & secrete antibodies but don't fight them directly. |
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what are NK cells? |
natural killer cells, make up 10-15% of lymphocytes. they attack foreign cells, virus infected cells & cancer cells |
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what are plasma cells? |
they produce & secrete antibodies and are differentiated from B cells |
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what are antigens? |
targets that identify any pathogen or foreign compound |
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what are NK cells also called? |
large granular lymphocytes |
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what's the life span of a lymphocyte? |
they can survive for many years |
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how do lymphocytes circulate? |
most are stored, not circulating. they wander through tissues |
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what's lymphopoiesis? |
lymphocyte production that involves bone marrow, thymus and peripheral lymphoid tissues |
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what are lymphoid nodules? |
areolar tissue with densely packed lymphocytes |
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what's the germinal center? |
where lymphocytes are replicated and divide |
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what does MALT stand for? |
mucosa-associated lymphoid tissue |
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what's MALT? |
lymphoid tissues associated with the digestive system |
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what are aggregated lymphoid nodules? |
nodules clustered deep to the intestinal epithelial lining |
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where are tonsils found & what's their location? |
in the respiratory tract in the wall of the pharynx. their function is to trap bacteria & viruses that we breathe in |
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what are the 5 types of tonsils? |
left & right palatine tonsils, pharyngeal tonsils & 2 lingual tonsils |
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what are lymph nodes? |
lymphoid organs that filter & purify lymph before returning to the venous circulation. they remove debris, pathogens & 99% of antigens |
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what are trabeculae? |
walls in lymph nodes that separate B cells |
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what's the hilus? |
where artery, vein & nerve meet in the spleen |
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what are afferent & efferent lymphatics? |
AFFERENT: where lymph enters the node EFFERENT: where lymph exits the node |
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how does lymph flow? |
fro lymphatic capillaries to larger lymphatic vessels containing one-way valves |
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what are dendritic cells? |
cells that process antigens & present it to T cells on the surface |
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what's the outer & deep cortex of the node? |
OUTER: section of the node with mainly B cell follicles DEEP: section of the node with mainly T cells |
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what is the medulla and the medullary cords? |
medulla is in node & contains large blood vessels, sinuses & the medullary cords, which are cord of lymphatic tissue that contain antibody-secreting plasma cells |
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what's the function of a lymph node? |
it's distributed to monitor peripheral infections & respond before infections reach vital organs |
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what's lymphadenopathy? |
when lymph nodes are abnormal sized, consistency or number and become swollen or enlarged |
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what's the thymus function? |
a lymphoid gland/organs that helps create T cells |
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what are the thymic lobules? |
there's a dense (with lymphocytes) outer cortex and a pale central medulla |
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how is the thymus divided up, and what structure seperates them? |
into two lobes, the left and right. the septa separates them |
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what's the cortex & medulla of the thymus? |
CORTEX: where lymphocytes divide MEDULLA: where T cells migrate to |
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what are reticular epithelial cells? |
cells that are found in thymus medulla and form layers called thymic corpuscle cells |
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what are Hassall's corpuscles? |
concentric layers of reticular epithelial cells |
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what is the hormone secreted by the thymus? |
thymosin: promotes development of lymphocytes |
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what's the gastrosplenic ligament? |
where the spleen attaches to the stomach |
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what is pulp, red pulp, and white pulp of the spleen? |
PULP is what's inside fibrous capsules. RED PULP contains many RBC's WHITE PULP contains many lymphocytes
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what are trabecular arteries & veins of the spleen? |
where the arteries & veins branches off in the spleen |
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what's a splenectomy? |
surgical procedure to remove the spleen |
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what are the functions of the spleen? |
to remove abnormal cells by phagocytosis, stores iron that's recycled from RBC's, and initiates immune responses by B cells and T cells |
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what are the 6 types of nonspecific defenses? |
physical barriers, phagocytes, immunological surveillance, interferons, complement system, inflammatory response, and fever |
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what do physical barriers do? |
they prevent the approach of & deny access to pathogens |
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what are the two types of phagocytes and what does each do? |
MICROPHAGE leave the bloodstream and go to tissues to fight infections. MACROPHAGE are distributed throughout the body & make up reticuloendothelial system |
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what do phagocytes do? |
remove debris & pathogens |
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what are the 2 types of macrophages? |
FIXED MACROPHAGES (histiocytes) stay in specific tissues or organs. they have microglia (found in CNS) and Kupffer cells (found in liver sinusoids) FREE MICROPHAGES travel freely throughout the body. they have alveolar macrophages, which are phagocytic dust cells. |
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what's chemotaxis & adhesion in phagocytes? |
CHEMOTAXIS is movement in response to a chemical stimulus and ADHESION is binding to pathogens surfaces |
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what does immunological surveillance do? |
destroys abnormal cells |
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what's NK cell activation? |
when an NK cell attaches to abnormal cell & kills by releasing perforins (proteins that are released out of vesicles of NK cells that lyse abnormal plasma membrane) |
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what are tumor-specific antigens (TSA)? |
antigens that are located on tumors that elicit a specific response in their host. they don't occur on normal cells of the same origin though, only tumors. |
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what is immunological escape? |
the immune system's inability to eliminate transformed cells before & after tumor development |
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what are interferons? |
proteins released by activated lymphocytes & macrophages |
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what are antiviral proteins? |
proteins that mediate interferon inhibition of virus replication in virus infected cells |
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what are alpha, beta, and gamma interferons? |
ALPHA stimulate NK cells & are made by leukocytes. BETA slow inflammation and are made by fibrocytes. GAMMA stimulate macrophage activity & are secreted by T & NK cells. |
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what are cytokines? |
chemical messenger proteins released by tissue cells to coodinate local activities |
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what are complement proteins? |
proteins found in plasma that complement antibody system |
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how does the complement system work? |
inflammation is stimulated, phagocytes are attracted, phagocytosis occurs & target membrane is destroyed |
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what is opsonization and what are opsonins? |
opsonization is enhancement of phagocytosis. opsonins are complements that work with antibodies |
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what's membrane attack complex (MAC)? |
5 complement proteins join & destroy target plasma membrane |
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what's inflammatory response? |
increased bloodflow, phagocytes activated, specific defenses activated, temp increased, etc. |
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how does the inflammatory response system respond to an injury? |
a localized response is triggered by any stimulus that kills cells or injured tissue |
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what's a fever? |
a maintained body temp about 99 F or 37 C |
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what are pyrogens and endogenous pyrogens? |
pyrogens are any material that causes hypothalamus to raise body temp. endogenous pyrogens are released by macrophages |
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what's cell-mediated immunity? |
defense against abnormal cells & pathogens inside the cell - Tcells |
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what's antibody-mediated immunity? |
defense against antigens & pathogens in body fluids |
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what are the 4 forms of immunity? describe each. |
1. innate - present at birth 2. acquired - acquired after birth 3. active - develop after exposure to antigen **naturally acquired (environmental exposure) and induced (vaccine exposure) 4. passive - antibodies are transferred from one source to another **naturally acquired (got it from mother) and induced (by an injection of ANTIBODIES)
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what are the four properties of immunity? |
1. specificity: T&B cells only respond to specific antigen & ignores all others 2. versatility: body produces many types of lymphocytes to fight different antigens & clones itself 3. memory - active lymphocytes that stay stored or in circulation to provide immunity against new exposure 4. tolerance - immune system ignored "normal" antigens of your body |
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what are the 3 types of T cells what does each do? |
cytoxic t cells: attack injected cells helper t cells: stimulate t & b cell function suppressor t cells: inhibit t & b cell function |
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describe the mechanisms of t cell activation |
antigen presenting cells activate t cells, which destroy & seek target cells by releasing perforin, secreting lymphotoxin, and activating killer genes |
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what's the difference between MHC class I & MHC class II? |
MHC class I carries antigens to surface & signals the red flag. it's found in all cells & displays abnormal peptides on the surface of the cell. MHC class II is found on lymphocytes & antigen presenting cells only, displays antigenic fragments on the surface. |
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describe B cell activation |
they attack antigens by producing specific antibodies. the activated B cell divides into plasma and memory B cells. |
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what's the difference between plasma and memory cells? |
plasma cells synthesize & secrete antibodies into interstial fluid. memory b cells are like memory T cells except they remain in the reserve to fight the next infection. |
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describe the structure of an antibody |
they have heavy & light chained portions, constant regions (determine antibody class) and variable regions (determine specificity) |
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what are the types of antibodies? explain each |
IgA (saliva & tears), IgG (attack bacteria & viruses), IgE (inflammation & allergies), IgM and IgD |
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what is the function of antibodies & how do they perform their function? |
they bind to antigens, which triggers multiple pathways to antigen destruction. they're released into plasma. **when they respond to non-self antigens=normal respond. when they respond to their own antigens=autoimmune response |
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what are primary and secondary responses to antigen exposure? |
PRIMARY - the 1st exposure to the pathogen when antigens activate B cells, plasma cells differentiate, & antibody levels (antibody titer) slowly rise. peak response takes 2 weeks to develop SECONDARY - the next exposure that activates memory B cells in massive quantities to fight infection/disease |
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what's sensitization of antibodies? |
the prep process for preparing B cells for activation where antigens bind to B cell receptors. |
