IM Flashcards by shahzeen I.Rasool

what is the difference in lymphoid and myeloid stem cells?

lymphoid: B and T cells
myeloid: basophils, eosinophils, neutrophils, macrophages, erythrocytes, platelets

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define an antigen

any molecule that can bind specifically to an antibody

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define an immunogen

any molecule that can induce an immune response

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define an antigenic determinant

the smallest unit of an antigen to which an antibody can be made or a T cell can respond to.

they cannot induce an immune response by themselves and need to be covalently attached to a carrier molecule in order to induce antibodies.

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define receptor

a molecule/complex of molecules which possess at least one recognition site. it binds to a determinant

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define specificity

the ability for a receptor to distinguish the identity of a determinant from other determinants

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which cell type is not part of the innate immune response?

a) Natural Killer cells
b) Macrophages
c) Dendrites
d) B cells
e) Mast cells

d) B cells

they are part of he adaptive immune response along with T cells

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which molecule is not part of the innate immunity?

a) Lysozymes
b) Complement
c) Chemokines
d) Antibody
e) Cytokines

d) Antibody

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what is the role of a complement molecule in the immune response?

to recruit inflammatory cells
opsonisation of pathogens
killing of pathogens

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which cell initiates adaptive immunity?

dendritic cell

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what activates T cells?

antigen and co-stimulatory molecules on a dendritic cell/macrophage

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define clonal expansion

the process by which lymphocytes, with a specific receptor, differentiate and proliferate once encountering an antigen. All daughter lymphocytes have the same receptor

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where do lymphocytes with varying receptor types form?

thymus and bone marrow

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what is clonal deletion?

the process by which lymphocytes are deactivated if they have receptors for self-antigens

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within a lymph node, where to T cells predominantly reside?

a) primary lymphoid follicle
b) paracortical areas
c) medullary cords
d) germinal centre
e) medullary sinus

b) paracortical areas

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within a lymph node, where to macrophages and plasma cells reside?

a) primary lymphoid follicle
b) paracortical areas
c) medullary cords
d) germinal centre
e) medullary sinus

c) medullary cords

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within a lymph node, where to B cells predominantly reside?

a) primary lymphoid follicle
b) paracortical areas
c) medullary cords
d) germinal centre
e) medullary sinus

a) primary lymphoid follicle

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what is the Waldeyer’s ring?

collection of adenoids, palatine tonsils, lingual tonsils

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what are M cells?

specialised cells found on Peyer’s patches. they take up an antigen and lead to the activation of T cells

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what are leukotrienes?

lipid mediators of inflammation
produced by macrophages and mast cells
cause smooth muscle contraction
increased permeability
mucosal secretion stimulation

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which cell types produce interferons?

leukocytes - antiviral
fibroblasts - antiviral
T cells and NK cells - macrophage activation

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which receptor type do viruses use to enter cells?

chemokine receptors

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what are chemokines?

small chemo-attractant molecules that stimulate the migration and activation of a cell

what is the action of T helper cells?

coordinate the immune response by direct cell-cell interactions and release of cytokines which aid B cells in antibody production

Define atopy

Atopy is the genetic tendency to overproduce IgE antibodies, likely to present as allergies eg asthma.

What are the five types of hypersensitivity?

Type I: immediate - IgE mediated Type II: Cytotoxic , antibody dependent - IgM or IgG mediated Type III; Immune complex driven - IgG, neutrophils mediated Type IV: Delayed, antibody independent (memory cells) - T cell and APC mediated Type V: stimulatory

Which IgE-mediated allergic reaction produces the response of oedema and irritation of nasal mucosa? a) Systemic anaphylaxis b) Acute urticaria c) Allergic rhinitis d) Asthma e) Food allergy

c) Allergic rhinitis

Which IgE-mediated allergic reaction produces the response of bronchial constriction, increased mucous production and airway inflammation? a) Systemic anaphylaxis b) Acute urticaria c) Allergic rhinitis d) Asthma e) Food allergy

d) Asthma

Which IgE-mediated allergic reaction is produced as a result of the allergens animal hair, insect bites? a) Systemic anaphylaxis b) Acute urticaria c) Allergic rhinitis d) Asthma e) Food allergy

b) Acute urticaria

Which IgE-mediated allergic reaction is produced as a result of drugs, peanuts, venoms? a) Systemic anaphylaxis b) Acute urticaria c) Allergic rhinitis d) Asthma e) Food allergy

a) Systemic anaphylaxis

True or False? Only lipids induce T-cell responses

FALSE only PROTEINS induce t cell responses

List the molecules released by mast cells upon activation and briefly list their function

- ENZYMES: remodelling of connective tissue matrix - TOXIC MEDIATORS (eg histamine) : toxic to parasites + increases vascular permeability + sm contraction - CYTOKINES - IL4, IL13: stimulate + amplify Th2 response - IL3,IL5,GM-CSF: promote production and activation of eosinophils - TNF-alpha: promote inflammation, cytokine production and endothelium activation -CHEMOKINES: attracts monocytes, macrophages and neutrophils - LIPID MEDIATORS: - leukotrienes: sm contraction + increases vascular permeability + mucus secretions - Platelet-activating factor: attracts leukocytes, activates neutrophils, eosinophils, platelets

Which molecule causes activation and production of eosinophils by bone marrow? a) Enzymes b) Histamine c) IL- 4, IL-13 d) IL-3, IL-5, GM-CSF e) leukotrienes C4, D4, E4

d) IL-3, IL-5, GM-CSF

Which molecules stimulate and amplify Th2 cell response? a) Enzymes b) Histamine c) IL- 4, IL-13 d) IL-3, IL-5, GM-CSF e) leukotrienes C4, D4, E4

c) IL- 4, IL-13

Which hypersensitivity type is antiboody indepenedant? a) 1 b) 2 c) 3 d) 4 e) 5

d) 4

What is the name given to the process by which self-destructive immune cells are destroyed in the primary lymphoid centres?

tolerance

What is grave's disease?

Autoimmune disease resulting from type II (V) hypersensitivity resulting in antibodies acting against the thyroid-stimulating hormone receptor

What is Rheumatoid arthritis?

Autoimmune disease resulting from type IV hypersensitivity where auto-reactive T cells act against antigens of joint synovium

What is Hashimoto's thyroiditis?

Autoimmune disease due to type IV hypersensitivity whereby antibodies and auto-reactive T cells act against thyroid antigens

What is systemic lupus erythematosus?

Autoimmune disease resulting from type IV hypersensitivity. | autoantibodies and auto-reactive T cells act against DNA

What is Myasthenia Gravis?

Autoimmune disease resulting from type II hypersensitivity whereby antibodies block Ach receptor binding sites.

What is hemolytic anaemia?

Autoimmune disease due to type II hypersensitivity whereby RBC are destroyed by complement and Fcr phagocytosis resulting in anaemia.

What is recurrent Apthous Stomatitis?

Autoimmune disease causing oral ulcerations. | cytoxic T cells and circulating T cells all sensitised to oral mucosal antigens

What is Cicatricial pemphigoid

Chronic autoimmune disease whereby autoantibodies and complement deposit on basement membranes of mucous membranes

What is pemphigus vulgaris ?

autoimmune disease causing painful blisters on skin, lining of mouth, nose, throat, genitals

What is rheumaitic fever?

autoimmune disease = inflammatory lesions of the joint, heart, CNS and subcutaneous tissue. the patients B and T cells are unable to differentiate between hosts own cells and pathogenic cells

Which tonsils make up Waldeyer's ring?

- palatine tonsils - lingual tonsils - tubal tonsils - adenoids (pharyngeal)

Which component makes the mucus layer in the mouth viscous?

mucin glycoproteins produced by goblet cells

Which cell produces antimicrobial peptides, lectins and cytokines in the oral cavity? a) goblet cells b) cilia cells c) paneth cells d) epithelial cells

c) paneth cells

What are the physical barrier components in the oral cavity?

- ADHERENT MUCIN LAYER slippery, sticky gel allowing transit of nutrients but not bacterial toxins and products secreted from salivary glands. Traps bacteria, prolonging exposure to host antibacterial substances. - DESQUAMATION shedding of cells. rate related to microbial burden - EPITHELIAL ANTIBODY RECEPTORS secretory component receptors found on buccal epithelium anchoring S-IgA/bacterial complexes which are then shed with the cells.

What is acquired enamel pellicle?

an acellular organic film formed from the selective adsorption of proteins derived from oral fluids onto the tooth surface. proteins include lysozyme, IgG, glucosyltransferase, amylases etc. it acts as a diffusional barrier, protecting the enamel from acid exposures of short durations

If a sample of living tissue shows the presence of neutrophils, what does it suggest about its health?

Neutrophils are not found in normal healthy tissue, therefore if found, it suggests disease.

What are the three types of dendritic cells?

- Langerhans cells - Interdigitating cells - Follicular dendritic cells

Which type of dendritic cell presents un-modified antigens to B cells in lymph nodes?

-follicular dendritic ells

Which statement is incorrect? a) all antigens except peptides must be processed into peptides before they can be presented y MHC molecules b) class II MHC molecules are found only on antigen presenting cells c) class I MHC molecules are involved in the cell-to-cell interaction between an infected cell and a CD8+ type cell d) exogenous antigens are synthesised within the antigen presenting cells where they bind to class I MHC molecules e) class I MHC are found on all nucleated cells

d) exogenous antigens are synthesised within the antigen presenting cells where they bind to class I MHC molecules ENDOGENOUS antigens are synthesised within the APC exogenous are endocytosed (phagocytosis) by APCs and presented by class II MHC