Term
| What are the functions of the lymphatic system? |
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Definition
| Draining excess interstitial fluid, tissue fluid balance, transporting dietary lipids and lipid-soluble vitamins, carrying out immune responses. |
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Term
| What are the components of the lymphatic system? |
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Definition
| Lymphatic capillaries, lymphatic vessels, lymph nodes, lymphatic trunks, lymphatic ducts, primary lymphatic organs, secondary lymphatic organs and tissues. |
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Term
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Definition
| Similar in composition to interstitial fluid, mostly water, some proteins/fat/WBCs, found in lymphatic vessels and tissue. |
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Term
| What are the primary lymphatic organs what occurs there? |
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Definition
| Red bone marrow and thymus, stem cells divide and become immunocompetent there. |
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Term
| What are the secondary lymphatic organs and what occurs there? |
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Definition
| Spleen, lymph nodes, lymphoid tissues, most immune responses occur there. |
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Term
| What happens in red bone marrow? |
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Definition
| Hematopoiesis, B cells become immunocompetent here, T cells start development here then migrate to thymus, red bone marrow is found in spongy bone. |
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Term
| What happens in the thymus and where is it? |
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Definition
| T cell maturation occurs here, protrudes from mediastinum into lower neck, made of glandular tissue, atrophies with age. |
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Term
| How many lymph nodes are in the body? |
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Definition
| About 600, usually in groups. |
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Term
| What cells stay in lymph nodes and what are lymph nodes' function? |
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Definition
| B & T cells stay here, they filter lymph. |
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Term
| What is the spleen's functions and what is it made of? |
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Definition
| Largest single mass of lymphatic tissue in body, made of red pulp which breaks down RBC and stores platelets and produces blood cells in fetus, made of white pulp which filters pathogens and produces lymphocytes, immune functions decrease when spleen removed. |
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Term
| What are lymphatic nodules, where are they found? |
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Definition
| Egg-shaped masses, not surrounded by capsule, found throughout GI/urinary/reproductive/respiratory tracts, includes tonsils. |
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Term
| Describe innate immunity specifically the 1st line of defense. |
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Definition
| Present at birth, non-specific, non-adaptive, composed of skin/mucous membranes, prevents entrance and spread of pathogens, acidic skin from sweat and oil is part of it, normal skin bacteria secrete other acids that interfere with pathogen growth. |
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Term
| Describe the 2nd line of defense in innate immunity. |
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Definition
| Phagocytic cells, extracellular killing, inflammatory response, fever, interferons, complement system. |
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Term
| What are a couple antimicrobial substances? |
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Definition
Complement system: 30+ different proteins circulate in blood, antibodies combine with complement to form MAC, causes lysis of pathogen, stimulates histamine secretion, attracts phagocytes
Interferons: proteins produced by virus-infected cells, infected cells die but IFN inhibits viral reproduction in neighboring cells, not strain-specific, most effective against short-term infections, used to treat some cancers. |
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Term
| What are examples of phagocytic cells? |
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Definition
Neutrophils: 60-70% of WBCs, chemotaxis, live a few days and die when ingest pathogens
Monocytes: 3-8% of WBCs, turn into macrophages at infection sites, fixed, wander through interstitial fluid
Eosinophils: 2-4% of WBCs, slightly phagocytic, release chemicals to destroy pathogens
Natural Killer Cells: destroy body's own virus-infected cells, tumor cells, not phagocytic, destroy cell membranes through lysis, release perforins |
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Term
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Definition
| Chemotaxis, adherence, ingestion, digestion, killing. |
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Term
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Definition
| Stimulated by tissue damage and pathogen entry, dilated vessels become leaky leading to edema, mast cells release histamine and produce prostaglandins, 4 characteristics: redness, pain, heat, swelling |
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Term
| What are the 3 stages of inflammation? |
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Definition
| Vasodilation and increased permeability, emigration of phagocytes to damage site, tissue repair. |
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Term
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Definition
| Released by injured circulating basophils, released by injured mast cells located in CT, effects are vasodilation and capillary leakage. |
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Term
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Definition
| Released by damaged tissues/mast cells, increase blood flow to affected area, stimulate emigration of phagocytes, intensify and prolong pain associated with inflammation, inhibited by NSAIDs. |
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Term
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Definition
| Thermostat in hypothalamus stimulated to reset to higher temperature by pathogens/toxins/pyrogens from WBCs, interferes with pathogen growth, increases phagocytosis and tissue repairs, intensifies effects of interferons. |
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Term
| Describe adaptive immunity. |
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Definition
| Specific, uses self/non-self recognition, immunological memory, activated B and T cells (main lymphocytes involved). |
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Term
| What are the two types of adaptive immunity? |
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Definition
Cellular: cell-mediated
Humoral: antibody-mediated |
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Term
| Describe how T and B cells mature and what that does to them. |
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Definition
| Both originate in red bone marrow, B lymphocytes remain and mature in red bone marrow, T lymphocytes mature in thymus, this provides specificity to recognize and eliminate pathogens and use different antibodies for each antigen, provides diversity to recognize millions of antigens and wide variance of lymphocyte population. |
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Term
| What is the cell-mediated immunity? |
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Definition
| T lymphocytes, response to intracellular bacteria and viruses/fungi/protists/worms/transplanted tissues/cancer, direct lymphocyte action, no antibodies involved. |
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Term
| What is antibody mediated immunity? |
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Definition
| B-lymphocytes, response to toxins/free bacteria/viruses found in body fluids, antibodies produced to inactivate antigens, process aided by helper T cells |
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Term
| What is clonal selection? |
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Definition
Process by which lymphocyte proliferates and differentiates in response to specific antigen, lymphocytes undergo clonal selection to produce:
Effector cells - die after immune response
Memory cells - do not participate in initial immune response but respond to subsequent exposure |
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Term
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Definition
| Foreign substances that elicit specific antibody response, proteins or large polysaccharides, located on surface of or they are produce by: bacteria/viruses/fungi/protists/parasitic worms/pollen/insect venom etc. |
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Term
| What are epitopes in regards to antigens? |
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Definition
| Region to which antibody binds, most antigens have many epitopes. |
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Term
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Definition
| Major histocompatibility complex antigens = self-antigens, group of glycoproteins in cell membranes, 20 genes, 100 alleles for each gene, only identical twins have identical MHC markers, source of self/non-self recognition, thousands of MHC markers on each body cell except RBCs. |
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Term
| What is antigenic processing? |
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Definition
| Adaptive immune response requires phagocytosis by antigen-presenting cells. |
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Term
| Describe the process of exogenous antigens. |
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Definition
| Antigen-presenting cells process and present exogenous antigens in body fluids and then migrate to lymph nodes, APC presents antigen with MHC-II marker to T cell which usually triggers AMI response. |
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Term
| Describe the processing of endogenous antigens. |
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Definition
| Foreign antigens within body cell, antigen associates with MHC-I molecule, complex displayed on plasma membrane surface, antigen recognized by helper T cell, helper T cells differentiate into either activated helper T cells or memory T cells. |
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Term
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Definition
| Small protein hormones released from one cell that influence another cell, stimulate or inhibit many cell functions. |
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Term
| How does the cell-mediated immunity activate helper T cells? |
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Definition
| Called CD4 cells, used in both AMI and CMI, first signal is when T cell receptor recognizes antigen with MHC-II marker, second signal is when T cell receives costimulation, activated T cell proliferates and differentiates, leads to clonal selection |
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Term
| How are cytotoxic T cells activated? |
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Definition
| Called CD8 cells, called killer T cells, cell-mediated response only, defend against intracellular pathogens, recognize antigens with MHC-I markers, also need costimulation by IL-2 or other cytokines |
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Term
| How are invaders eliminated? |
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Definition
| Infected host cells display antigens on cell membrane, cytotoxic T cells bind to these antigens, release granzyme to trigger apoptosis, release perforin or granulysin to cause cytolysis, T cells attack other subsequent cells, attack tumor cells with tumor surface antigen. |
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Term
| What is immunological surveillance? |
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Definition
| Cytotoxic T cells, natural killer cells, macrophages, recognize surface antigens of viral-induced tumors on body cells, eliminate tumor cells due to cancer-causing viruses. |
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Term
| What are dangers with transplants and grafts? |
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Definition
Replacement tissue or organ is recognized as foreign
Autografts: own tissue
Isografts: same genetic background
Allografts: same species, different genetic background
Xenografts: other species
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Term
| How do B cells get activated and go into clonal selection? |
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Definition
| B cells present in lymph nodes/spleen/MALT, antigen in body fluids, binds to specific receptor on B lymphocyte, B cell receives costimulation from helper T cells, B cell reproduces creating large number of clones, stimulated B cells form plasma cells which create antibodies and memory B cells and stimulate T cells which attack antigen. |
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Term
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Definition
| Molecules that bind to specific antigen and are produced by B lymphocytes, one antibody to one antigen, plasma cells produce 2000 antibodies, active for 4-5 days, help eliminate antigen, antibodies recognize epitopes. |
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Term
| Describe the antibody structure. |
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Definition
| Antibodies are immunoglobulin proteins, Y shaped, 4 polypeptide chains, 2 light, 2 heavy, fixed region are same for all, variable regions are tips of Y's and vary from one antibody to the next and are regions that attach to epitopes. |
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Term
| What are the 2 major features of IgG antibodies? |
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Definition
| Most abundant circulating antibody, crosses placenta from mother to baby. |
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Term
| Where is IgA antibody found? |
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Definition
| Mucus, saliva, tears, sweat, colostrum. |
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Term
| What are 2 major features of IgM antibodies? |
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Definition
| Appear in response to initial infections, anti-A and anti-B antibodies produced in response to ABO blood types. |
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Term
| What are IgE antibodies produced in response to? |
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Definition
| Produced in response to allergic reaction. |
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Term
| What is immunological memory? |
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Definition
| Memory B and T lymphocytes, survive for long periods, not active during primary responses. |
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Term
| Describe the primary immune response of immunological memory. |
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Definition
| Clonal selection after body's first exposure to antigen, 10-17 day lag time. |
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Term
| Describe the secondary immune response of immunological memory. |
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Definition
| Acquired immunity, body's responst to antigen after previous exposure, faster response, more prolonged, more numerous antibodies. |
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Term
| Describe naturally acquired and artificially acquired active immunity. |
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Definition
Naturally acquired: body produces antibodies after recovering from illness
Artificially acquired: receive immunization |
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Term
| Describe naturally acquired and artificially acquired passive immunity. |
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Definition
Naturally acquired: IgA and IgG from mother to baby
Artificially acquired: receive antibodies from people already vaccinated |
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Term
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Definition
| Acquired immunodeficiency syndrome, caused by HIV-1 and HIV-2 which rapidly mutate and hide in macrophages and T cells. |
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Term
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Definition
| Blood, semen, vaginal secretions, mother to baby through vaginal delivery or breastfeeding. |
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Term
| What are the signs/symptoms of AIDS? |
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Definition
| Mild mono-like, helper T cell count falls, secondary infections, AIDS wasting syndrome, AIDS dementia. |
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Term
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Definition
| Male homosexual sex, shared IV needles, heterosexual sex, 25% babies of infected mothers contract infection, blood transfusions. |
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Term
| Describe the immune response to HIV. |
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Definition
| Mostly invisible, some antibodies are formed, rapid mutational changes of antigens, causes destruction of helper T cells. |
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Term
| Describe allergic reactions. |
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Definition
| Immune hypersensitivity to environmental agents, many types of hypersensitivity. |
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Term
| What is a type I allergic reaction? |
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Definition
| Anaphylaxis, ometimes life-threatening reaction to injected or ingested antigens, IgE produced and binds to mast cells, mast cell degranulation releases histamine causing sudden vasodilation/drop in BP/airway constriction, treat with epinephrine to dilate airways and strengthen heartbeat, milder symptoms such as itching/swelling/hives. |
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Term
| What is a type II allergice reaction? |
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Definition
| Cytotoxic, immune system attacks body cells, IgG/IgM produced, often leads to activation of complement proteins. |
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Term
| What is a type III allergic reaction? |
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Definition
| Immune-complex, failure to remove antibody-antigen complexes from blood vessel walls or tissues, IgA/IgM/complement system activated. |
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Term
| What is a type IV allergic reaction? |
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Definition
| Cell-mediated, appears 12-72 hours after exposure, macrophage or other cell overactivity. |
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Term
| Describe autoimmune diseases. |
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Definition
| Loss of self-tolerance, immune system reacting against itself, examples are rheumatoid arthritis/grave's disease/myasthenia gravis/MS. |
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Term
| What is infectious mononucleosis? |
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Definition
| Acute infection of B cells by epstein-barr virus, up to 50-85% of kids have had EBV exposure by age 4, peak incidence b/w 15-19 years old, kissing disease, sore throat/fever, incubation time is 30-50 days. |
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Term
| What is edema and what are contributing factors? |
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Definition
| 30% increase in interstitial fluid volume, increased BHP, decreased plasma protein concentration, increased capillary permeability, increased extracellular volume, blocked lymphatic vessels. |
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