Module 5 - Lymphatic Flashcards

Question

MALT – mucosa-associated lymphatic tissue

Answer 1

MALT – mucosa-associated lymphatic tissue – clusters of lymphocytes in mucous membranes of: GI tract – Peyer’s patches in ileum of sm. Intestine Respiratory airways Urinary tract Reproductive tract

Answer 2

MALT – Tonsils – multiple large aggregations Protect against invasion Producing lymphocytes and antibodies Form a ring at junction of oral cavity and pharynx – Waldeyer’s Ring 1 Pharyngeal (adenoid) 2 Palatine tonsils 2 Lingual tonsils

Answer 3

1 Pharyngeal (adenoid) Roof of posterior wall of nasopharynx – nasal meets throat

Answer 4

2 Palatine tonsils – largest Posterior region of oral cavity L & R – commonly removed create Crypts – deep and branching tunnels – B & T cells

Answer 5

2 Lingual tonsils – base of tongue

Answer 6

Innate Immunity – First Line Nonspecific resistance – catch all – variety of responses against variety of pathogens and toxins Physical barriers – first line defence Chemical Barriers

Answer 7

Physical barriers – first line defence Skin – epidermis – barrier against microbes – periodical shedding – perspiration Mucous membranes – line body cavities – secret mucus Mucus – traps microbes and foreign substances Lacrimal apparatus – cleans out eyes Saliva – washes away microbes from teeth and mouth Flow of urine – expels microbes Cilia – hair-like projections – traps microbes

Answer 8

Chemical Barriers Sebum – oil glands on skin – protective film – fatty acids inhibit growth of bacteria Lysozyme – in tears – enzyme breaks down cell walls of bacteria Gastric juice – strong acidity – hydrochloric acid, enzymes, and mucus Vaginal secretions – move microbes out – slightly acidic

Answer 9

Innate Immunity – Second Line Internal antimicrobial proteins Phagocytic and Natural Killer Cells Inflammation Fever

Answer 10

Internal antimicrobial proteins – discourage microbial growth – 4 types Interferons Complement system Iron-binding proteins Antimicrobial proteins

Answer 11

Interferons – proteins produced by infected lymphocytes, macrophages, and fibroblasts Diffuse to uninfected cells and bind to surface – synthesize antiviral proteins –block viral replication Enhance activity of phagocytes and NKs Inhibit cell growth and suppress tumour formation

Answer 12

Complement system – group of normally inactive proteins in blood plasma and membranes Enhance immunity Cause cytolysis/bursting of microbes Promotes phagocytosis Inflammation

Answer 13

Iron-binding proteins – reduce iron availability – bacteria cells can’t grow

Answer 14

Antimicrobial proteins – broad spectrum antimicrobial activity Kill microbes Attract dendritic cells and mast cells

Answer 15

Phagocytic Phagocytic Cells – perform phagocytosis – ingestion of microbes Neutrophils – stim by histamine Macrophages – stim by histamine Phagocytosis

Answer 16

Natural Killer Cells – microbes have penetrated physical barriers & by-passed blood barriers Natural Killer Cells NKs – 5-10% of lymphocytes in blood Lack membrane molecules that identify T & B cells Attack cell w/ abnormal or unusual plasma membrane proteins Apoptosis Cytolysis

Answer 17

Apoptosis – release granzymes – protein-digesting enzyme – force self destruction

Answer 18

Cytolysis NK cells bind to infected cell – release granules of toxic substances – Perforin Perforin – inserts into membrane – creates perforations – allows extracellular fluid to flow in – cell burst

Answer 19

Phagocytosis Chemotaxis – phagocytes are stim – to come Adherence – attachment to microbe Ingestion – plasma membrane extends and engulfs – sac surrounds microbe – phagosome Digestion – lysosome break down cell walls – enzymes degrade Killing

Answer 20

Inflammation – dispose of microbes & prevent spread Vasodilation & increase permeability Emigration of phagocytes from blood to interstitial fluid – clear cellular debris Tissue repair PRISH Pus – fluid – pocket of dead phagocytes – after engulf microbes – they die

Answer 21

PRISH P – pain – release of chemicals R – redness – more blood I – immobility – loss of some function S – swelling – accumulation of fluids H – heat – blood

Answer 22

Fever – abnormally high body temperature Causes by infection from bacteria & viruses High temp intensified Interferons – inhibits growth of some microbes Speeds up reactions to repair

Answer 23

Immunity – body’s ability to defend against specific invaders Specificity – looks for specific antigen Memory – previously encountered antigens

Answer 24

Antigens – foreign substances

Answer 25

Self-tolerance – immune system recognizes its own tissue

Answer 26

Adaptive Immunity Cell-mediated immunity (CMI) Antibody-mediated (humoral) immunity (AMI) Pathogens can provoke both types of immune responses

Answer 27

Cell-mediated immunity (CMI) – destruction of antigen by T cells Intracellular pathogens – fungi, parasites, & viruses Cancer cells & Foreign tissue transplants Cells attacking cells

Answer 28

Antibody-mediated (humoral) immunity (AMI) – destruction by antibodies B cells transform into plasma cells – synthesize & secrete specific proteins – antibodies Antibody can bind and inactivate specific antigens Works against extracellular pathogens – mostly bacteria body fluids & don’t enter cells Binds to antigens in body (humors) fluids – blood or lymph

Answer 29

Cell formation B cells – start and develop in red bone marrow T cells – start in red bone marrow as pre-T cells – migrate to thymus to mature

Answer 30

Immunocompetence – B & T cells carry out immune responses – antigen receptors - distinctive surface proteins

Answer 31

Clonal selection – rapid differentiation of lymphocytes in response to specific antigen Create clone cells that recognize the same antigens Effector cells Memory cells

Answer 32

Antigens Chemical substances recognized by antigen receptors Immunogenicity Reactivity Large complex molecules – proteins – can be: Nucleoproteins Lipoproteins Glycoproteins Polysaccharides

Answer 33

Immunogenicity – ability to provoke immune response Stim production of antibodies Stim proliferation of specific T cells

Answer 34

Reactivity – Ability of antigen to react specifically with antibodies or cells it provokes

Answer 35

Antigenic determinants – epitopes – specific portions of molecules – recognizable – trigger immune response

Answer 36

Routes of entry Bloodstream – injured blood vessel – flow to spleen Penetrate skin – enter lymphatic vessels – lodge in lymph nodes Penetrate mucous membranes – entrapped by MALT

Answer 37

Major histocompatibility complex antigens (MHC) – human leucocyte associated antigens Unique to every person Help T cells differentiate between self or foreign Recognize self-antigens on all cells – except RBCs Class I – all cells – built into plasma membranes Class II – some cells – surface of antigen-presenting cells

Answer 38

Antibodies Antigens induce plasma cells to secrete antibodies Immunoglobulin or Gamma Globulins – globulin protein family Specific antigen determinant triggers specific antibody 2 light chains – subtypes – K or Y 2 heavy chains – isotypes – MAGED – 5 types – markers Fab domains – change – antigens bind here – variable – this is how we have different antibodies Cells bind to constant portion – does not change b/w disulfide bond – connects chains – help together by covalent and noncovalent bonds

Answer 39

Life cycle: Lymphoid stem cells B-lymphocytes Plasma cells Antibodies

Answer 40

Neutralize antigens Immobilize bacteria Agglutinate antigens – reaction b/w antibody and antigens = clumps – identification of pathogens Activate complement proteins Help phagocytosis Fetal and newborn immunity – IgG

Answer 41

IgG – 2nd responses – opsonization (tasty 4 macrophages) – neutralize toxins – small molecule – 2 binding sites – 80% in serum

Answer 42

IgM IgA IgG IgE IgD

Answer 43

IgA – secreted in mucus, tears, saliva, colostrum – 4 binding sites – 13% in serum - secretory component

Answer 44

IgM – large molecule pentamer – 1st response – 6% in serum – 10 binding sites

Answer 45

IgD – B cell receptor – small molecule – 2 binding sites – 1% in serum

Answer 46

IgE – allergy and antiparasitic responses – small molecule – 2 binding sites – 0.002% in serum

Answer 47

Antigenic proteins are broken down to fragments to associate with MHC molecules Antigen-MHC complex is inserted into membrane – antigen presentation T cells can only recognize antigen-MHC complex as intruder if processed and presented Exogenous Processing – antigens in fluids outside body cells Endogenous Processing – antigens present inside body cells – viral proteins after virus infects

Answer 48

Exogenous Processing – antigens in fluids outside body cells Bacteria, Parasitic worms, Inhaled pollen or dust, & Viruses – not yet infected body Antigen-presenting cells APCs – process and present – dendritic cells, macrophages, & B cells – Epidermis – mucous membranes

Answer 49

Steps Ingestion – pathogen comes into cell + fuses with lysosome = phagolysosome Digestion of antigen into peptide fragments – lysosomes breaks down with acid Synthesis of MHC-II – Endoplasmic reticulum and ribosomes – produce MHC-II Packaging of MHC-II – Golgi – packages protein Fusion of vesicles – MHC-II binds with packaged to phagolysosome Binding of peptide fragment to MHC-II – antigen binds to MHC-II molecule Insertion of antigen-MHC-II complexes into plasma – leaves cell After processing – cell will be presented to lymphatic tissue – T cells bind – trigger adaptive response

Answer 50

Endogenous Processing – antigens present inside body cells – viral proteins after virus infects

Answer 51

Steps Digestion of antigen into peptide fragments – proteasome within cell splits antigen – go into endoplasmic Synthesis of MHC-I molecule – Endoplasmic reticulum and ribosomes produce MHC-I Binding of peptide fragments to MHC-I molecules – binds to antigen and moves out of endoplasmic Packaging of antigen-MHC-I molecules – Golgi packaged into vesicle Insertion of antigen-MHC-I complexes into membrane – pushes infection out of the cell to lymphatic tissue to trigger immune response

Answer 52

Cell-mediated Immunity Cell vs cell 1ST signal – T cell recognizes antigen-MHC complex 2ND signal – Antigen binds to receptors on inactive T cells after processed and presented by antigen-MHC complex – Co-stimulation Activation of T cells by specific antigen Clonal selection – rapid proliferation and differentiation – army of same cells

Answer 53

Co-stimulation – prevents immune response from accidently occurring – self tolerance – prevents autoimmune disease – Key and gear shift ex. Cytokines – interleukin-1 and -2 Pairs of plasma membrane molecules on surface of T cell and a second on surface of antigen presenting cell (APC)

Answer 54

Helper T cells (T4) = CD4 protein Key – APCs with MHC-II Gear – Interleukin-2 – trigger proliferation of T cells Result – clonal selection of other helper T cells, cytotoxic T cells, and B cells

Answer 55

Cytotoxic T cells (T8) = CD8 protein – kill target cell w/o self damage – immunological surveillance Key – APCs with MHC-I Gear – Interleukin-2 – Trigger proliferation of T cells Result – clonal selection

Answer 56

Memory T cells – recognize original invading antigen – enables quick reaction if repeated

Answer 57

Antibody-mediated Immunity Humoral immunity Produces antibodies to neutralize antigens Protects against pathogens freely circulating the body B Cells Detect on receptors Activation – Differentiate into plasma B cells – produce antibodies Bind to antigens all around Antibodies neutralize – dissolve (lyse) or engulfed (phagocytosed) – antigen is broken down into peptide fragments with MHC-II self-antigen and moved to surface of B cell Helper T cells see APC-MHC-II and co-stim B cell proliferation Virus gets blocked by antibodies – can’t enter cell

Answer 58

Immunologic Memory Ability of immune system to remember previous encounters with antigens Faster and more robust response at re-exposure Memory cells produced during primary response

Answer 59

Primary immune response New antigen – slow onset Lower antibody production Development of memory cells

Answer 60

Secondary immune response Re-exposed Memory cells rapidly available Higher antibody production

Answer 61

Naturally-acquired – body did it Passive – antibodies from mom to baby Active – Antigens enter body naturally – body forms antibodies

Answer 62

Artificially-acquired – doctor did it Passive – pre-formed antibodies are introduced Active – vaccines – little bit of virus is entering – body creates antibodies and memory cells

Module 5 - Lymphatic Flashcards

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