Phys 35 Flashcards

Which cells provide cellular innate defense?

A. Plasma cells and memory cells

B. Helper and cytotoxic T cells

C. Follicular and plasma B cells

D. NK cells and phagocytes

Which gastrointestinal mechanism provides innate immunity?

A. Peyer patch class switching

B. Gastric acid and digestive enzymes

C. Memory B-cell activation

D. Antigen-specific IgG secretion

Which pairing identifies adaptive immunity’s divisions?

A. Complement and phagocytic

B. Active and passive

C. Cellular and inflammatory

D. Humoral and cell-mediated

A vaccine produces circulating antigen-specific antibodies. Which adaptive arm predominates?

A. Cell-mediated immunity

B. Humoral immunity

C. Innate cellular immunity

D. Passive mucosal immunity

Activated lymphocytes directly destroy infected cells. Which adaptive arm is responsible?

A. Cell-mediated immunity

B. Humoral immunity

C. Innate chemical immunity

D. Passive antibody immunity

What initiates both adaptive immune pathways?

A. Cytokines

B. Immunoglobulins

C. Antigens

D. Complement fragments

Where are lymphocytes found most extensively?

____ ____

Which list contains recognized lymphocyte locations?

A. Liver, kidney, dermis, cartilage, muscle

B. Pancreas, myocardium, adrenal, tendon, retina

C. Spleen, GI submucosa, thymus, marrow

D. Thyroid, renal cortex, muscle, cartilage

Which organ preprocesses B cells during mid-fetal life?

Which statement best describes a clone of lymphocytes?

A. Cells derived from one precursor with identical specificity
B. Cells from multiple precursors sharing cytokine responses
C. Cells with different receptors targeting one pathogen
D. Different lymphocyte types located in one lymph node

Which cell releases IL-1 to promote lymphocyte proliferation?

A. Plasma cells

B. Helper T cells

C. Macrophages

D. Memory B cells

After digesting an organism, how can macrophages stimulate lymphocytes?

A. Secrete preformed immunoglobulin

B. Present degraded antigen directly

C. Release histamine into lymph

D. Form antigen-specific plasma cells

Which cells secrete cytokines that activate antigen-specific B cells?

A. Neutrophils
B. Plasma cells
C. Natural killer cells
D. Helper T cells

Some activated lymphoblasts avoid plasma-cell differentiation. What do they form?

A. Helper T cells

B. Memory B cells

C. Natural killer cells

D. Follicular dendritic cells

What normally reactivates a dormant memory B cell?

A. Unrelated cytokine exposure

B. Any bacterial invasion

C. Complement pathway activation

D. Same antigen reappears

Memory B cells produce which secondary-response characteristic?

A. Faster, stronger antibody response

B. Slower, weaker antibody response

C. Immediate innate-only response

D. Reduced antigen specificity

Antibodies belong to which plasma-protein category?

A. Alpha globulin chemokines

B. Beta globulin complement proteins

C. Gamma globulin immunoglobulins

D. Albumin-derived binding proteins

Which antibody regions form the antigen-binding site?

A. Heavy-chain constant regions

B. Light-chain constant regions

C. Heavy and light constant regions

D. Heavy and light variable regions

Which antibody region binds a specific antigen?

A. Variable region

B. Constant region

C. Fc receptor

D. Hinge region

Which antibody region determines tissue behavior?

A. Antigen-binding site

B. Variable region

C. Constant region

D. Epitope-binding loop

A larger affinity constant (Ka) indicates what?

A. Stronger antigen binding

B. Faster antibody breakdown

C. Greater tissue diffusion

D. Increased complement inhibition

Which immunoglobulin predominates in circulation?

Which antibody predominates during primary responses?

Pentameric IgM has how many binding sites?

A. Two

B. Ten

C. Four

D. Twenty

Antibodies bind antigen-bearing particles into clumps. Which mechanism occurred?

A. Neutralization

B. Precipitation

C. Lysis

D. Agglutination

Soluble antigen-antibody complexes become insoluble. Which process occurred?

A. Agglutination

B. Precipitation

C. Neutralization

D. Opsonization

Antibodies cover a toxin’s active sites. Which mechanism occurred?

A. Precipitation

B. Agglutination

C. Neutralization

D. Chemotaxis

Which mechanism disrupts a microbial membrane?

A. Precipitation

B. Complement-mediated lysis

C. Agglutination

D. Neutralization

Antibodies may enhance pathogen destruction by activating what?

A. Coagulation cascade

B. Complement system

C. Kallikrein system

D. Renin pathway

Which description best defines complement?

A. One antibody subclass

B. A lymphocyte receptor family

C. A membrane lipid complex

D. A plasma protein cascade

Complement proteins normally circulate in what state?

A. Bound to antibodies

B. Active membrane enzymes

C. Secreted within vesicles

D. Mostly inactive precursors

What initiates the classical complement pathway?

A. Spontaneous C3 hydrolysis

B. Microbial mannose residues

C. Antigen-antibody complexes

D. Bacterial endotoxin alone

When an antibody binds its antigen, the ____ portion becomes available for binding by C1q, which begins the classical complement pathway.

Which complement protein first binds the Antibody constant region?

A. C3

B. C1

C. C5

D. C9

Which complement structure produces cellular lysis?

A. C3 convertase

B. Membrane attack complex

C. C1 complex

D. C5 convertase

Which proteins form the membrane attack complex?

A. C1 through C4

B. C2 through C5

C. C3a through C5a

D. C5b through C9

C3b most strongly enhances phagocytosis by which cells?

A. Neutrophils and macrophages

B. Mast cells and basophils

C. B cells and plasma cells

D. Eosinophils and platelets

Which fragments activate mast cells and basophils?

A. C3a and C5a

B. C3b and C4b

C. C1q and C2a

D. C5b and C9

Which event represents complement-mediated inflammation?

A. Antibody gene rearrangement

B. Plasma-cell class switching

C. T-cell receptor editing

D. Leukocyte recruitment and degranulation

T cells recognize antigens only when bound to what?

A. Antibodies

B. Complement proteins

C. Fc receptors

D. MHC proteins

Which cells are the three major APCs?

A. NK cells, neutrophils, eosinophils

B. Plasma cells, mast cells, CTLs

C. Macrophages, B cells, dendritic cells

D. Basophils, platelets, erythrocytes

Which cell is the most potent APC?

A. Macrophage

B. B lymphocyte

C. Dendritic cell

D. Helper T cell

Which molecule creates pores during T-cell killing?

A. Granzyme

B. Perforin

C. Histamine

D. Complement C3

Which T-cell type regulates most immune functions?

A. Cytotoxic T cells

B. Regulatory T cells

C. Helper T cells

D. Memory B cells

Helper T cells regulate immunity through which mediators?

A. Immunoglobulins

B. Complement fragments

C. Acute-phase proteins

D. Lymphokines

Which cells suppress helper and cytotoxic T cells?

A. Regulatory T cells

B. Plasma cells

C. Dendritic cells

D. Natural killer cells

Regulatory T cells primarily prevent what outcome?

A. Antibody production

B. Excessive self-tissue damage

C. Antigen presentation

D. Complement activation

Which lymphokine promotes cytotoxic T-cell proliferation?

A. IL-4

B. IL-5

C. IL-2

D. IL-6

Which cytokine positively reinforces helper T-cell activation?

A. IL-4

B. IL-5

C. IL-2

D. GM-CSF

Which cytokines act as B-cell growth factors?

A. IL-4, IL-5, IL-6

B. IL-1, IL-2, IL-3

C. TNF, IFN-γ, IL-2

D. C3a, C4a, C5a

Which set contains helper T-cell lymphokines?

A. C3a, C3b, C5a, C5b

B. IgA, IgD, IgE, IgG

C. IL-2–IL-6, GM-CSF, IFN-γ

D. Histamine, heparin, leukotrienes

Defective lymphocyte preprocessing may cause which condition?

A. Passive immunity

B. Autoimmune disease

C. Complement deficiency

D. Atopic sensitization

Autoimmune glomerulonephritis may target which structure?

A. Renal tubular epithelium

B. Glomerular basement membranes

C. Ureteral smooth muscle

D. Renal arterial endothelium

Myasthenia gravis targets which structure?

A. Acetylcholine receptors

B. Voltage-gated calcium channels

C. Glomerular basement membranes

D. Myelin basic protein

Which disease causes multisystem autoimmunity?

A. Myasthenia gravis

B. Poison ivy dermatitis

C. Atopic rhinitis

D. Systemic lupus erythematosus

Which intervention provides passive immunity?

A. Live attenuated vaccination

B. Toxoid immunization

C. Natural pathogen exposure

D. Transferred antibodies or lymphocytes

Delayed allergic reactions are mediated by what?

A. IgE antibodies

B. T lymphocytes

C. Complement proteins

D. Plasma cells

Poison ivy dermatitis represents which response?

A. Delayed cell-mediated hypersensitivity

B. Immediate IgE hypersensitivity

C. Immune-complex hypersensitivity

D. Antibody-mediated cytotoxicity

Atopic allergies are primarily associated with what?

A. Cytotoxic T cells

B. IgE antibodies

C. IgG antibodies

D. Regulatory T cells

Which description best defines an allergen?

A. Antigen activating complement directly

B. Antigen reacting specifically with IgE

C. Cytokine recruiting eosinophils

D. Antibody binding mast cells

IgE has strong affinity for which cells?

A. Mast cells and basophils

B. Neutrophils and macrophages

C. Platelets and erythrocytes

D. B cells and CTLs

Allergen cross-linking of cell-bound IgE causes what?

A. Antibody class switching

B. Complement inhibition

C. T-cell deletion

D. Mast-cell degranulation

Which mediators are released during IgE degranulation?

A. Perforin, granzyme, Fas ligand

B. IgG, IgM, secretory IgA

C. C3b, C5b, C8, C9

D. Histamine, proteases, leukotrienes, heparin

Which substances recruit eosinophils and neutrophils?

A. Chemotactic factors

B. Immunoglobulin light chains

C. MHC proteins

D. Perforin molecules

IgE-mediated mediator release produces which effects?

A. Vasoconstriction and reduced permeability

B. Bradycardia and reduced blood flow

C. Decreased leukocyte recruitment

D. Vasodilation, permeability, granulocyte recruitment

A patient develops transient raised, pruritic skin lesions after eating shellfish. Which reaction occurred?

A. Hay fever

B. Bronchial asthma

C. Urticaria

D. Systemic anaphylaxis

Which treatment is most appropriate for uncomplicated urticaria?

A. Antihistamine

B. Epinephrine

C. Bronchodilator

D. Corticosteroid inhaler

An injected allergen causes hypotension and widespread vascular leakage. What is the diagnosis?

A. Hay fever

B. Urticaria

C. Allergic asthma

D. Anaphylaxis

Which medication is first-line for anaphylaxis?

A. Diphenhydramine

B. Epinephrine

C. Albuterol

D. Montelukast

Why can systemic anaphylaxis rapidly become fatal?

A. Pulmonary fibrosis develops

B. Antibodies destroy erythrocytes

C. Widespread vascular reactions occur

D. Nasal secretions obstruct breathing

An allergen triggers nasal swelling and watery secretions. Which disorder is present?

A. Hay fever

B. Urticaria

C. Anaphylaxis

D. Allergic asthma

Which mediator primarily causes fluid leakage in hay fever?

A. Heparin

B. Leukotriene

C. Perforin

D. Histamine

Which treatment commonly improves hay fever symptoms?

A. Epinephrine

B. Antihistamines

C. Cytotoxic therapy

D. Complement inhibitors

An allergen reaction localized to bronchioles causes dyspnea. Which condition is present?

A. Allergic asthma

B. Hay fever

C. Urticaria

D. Anaphylaxis

Which mediator class strongly promotes allergic bronchospasm?

A. Immunoglobulins

B. Interferons

C. Leukotrienes

D. Complement opsonins

Why are antihistamines relatively ineffective in allergic asthma?

A. IgG drives bronchospasm

B. Complement blocks histamine

C. Neutrophils consume histamine

D. Leukotrienes dominate bronchoconstriction

In allergic asthma, mast cells release both _____ and _____. Histamine contributes, but _____ cause stronger, longer-lasting airway narrowing, increased mucus, and swelling.

Which anatomical site is primarily affected in allergic asthma?

A. Nasal cavities

B. Bronchioles

C. Cutaneous venules

D. Systemic arteries

Which macrophage cytokine promotes lymphocyte proliferation?

A. IL-2

B. IL-4

C. IL-1

D. IL-10

An antigen-specific B cell enlarges after activation. What has it become?

A. Lymphoblast

B. Plasmablast

C. Plasma cell

D. Memory cell

Which cell directly precedes the mature plasma cell?

A. Lymphoblast

B. Memory B cell

C. Helper T cell

D. Plasmablast

Plasmablasts arise through differentiation of which cells?

A. Plasma cells

B. Lymphoblasts

C. Macrophages

D. Regulatory cells

Approximately how many antibodies can one plasma cell produce each second?

A. 2,000

B. 200

C. 20,000

D. 20

Which feature best characterizes a secondary antibody response?

A. Delayed and weaker

B. Limited to several weeks

C. Rapid and more potent

D. Predominantly nonspecific

A secondary response may begin within what interval?

A. Several weeks

B. Several months

C. Several days

D. Several hours

Compared with primary responses, secondary antibodies persist for what duration?

A. Several days

B. Many months

C. Only several weeks

D. Less than one week

Which antibody regions differ among antigen specificities?

A. Variable regions

B. Constant regions

C. Disulfide bridges

D. Hinge carbohydrates

Where are antibody variable regions located?

A. Fc chain centers

B. Constant-region foci

C. Light and heavy ends

D. Constant-region termini

The remainder of each antibody chain forms which region?

A. Variable region

B. Hinge region

C. Fab region

D. Constant region

Which forces hold antibody chains together?

A. Hydrogen bonds and noncovalent bonds

B. Noncovalent and covalent bonds

C. Ionic interactions and covalent bonds

D. Hydrophobic forces and noncovalent bonds

Which covalent linkage joins antibody chains?

A. Disulfide bonds

B. Peptide bonds

C. Phosphodiester bonds

D. Glycosidic bonds

Which interaction contributes to antigen-antibody binding?

A. Phosphodiester bonding

B. Peptide cross-linking

C. Hydrophobic bonding

D. Covalent glycosylation

Which force involves attraction between partial charges?

A. Ionic attraction

B. Hydrophobic interaction

C. Disulfide bonding

D. Hydrogen bonding

Which force involves attraction between charged groups?

A. Ionic attraction

B. van der Waals forces

C. Hydrogen bonding

D. Hydrophobic bonding

Which weak interaction results from transient dipoles?

A. Ionic attraction

B. van der Waals forces

C. Disulfide bonding

D. Hydrogen bonding

A higher Ka generally indicates which property?

A. Tighter antigen binding

B. Faster antibody degradation

C. Reduced antigen specificity

D. Weaker molecular interactions

Antibodies protect through which two broad mechanisms?

A. Phagocytosis and cytokine secretion

B. Direct attack and complement activation

C. Chemotaxis and T-cell killing

D. Fever and acute inflammation

Which antibody action recruits a separate plasma-protein cascade?

A. Direct neutralization

B. Antigen precipitation

C. Complement activation

D. Surface agglutination

A transfusion reaction causes antigen-bearing erythrocytes to form visible clumps. Which antibody action occurred?

A. Precipitation

B. Neutralization

C. Agglutination

D. Opsonization

Antibodies bind soluble tetanus toxin until large insoluble complexes form. Which process occurred?

A. Precipitation

B. Agglutination

C. Neutralization

D. Lysis

Antibodies prevent a toxin from binding its cellular receptor. Which mechanism occurred?

A. Opsonization

B. Precipitation

C. Agglutination

D. Neutralization

An antibody directly disrupts a pathogen’s membrane. Which process occurred?

A. Neutralization

B. Lysis

C. Precipitation

D. Agglutination

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Which complement fragment coats bacteria for phagocytosis?

A. C3a

B. C5a

C. C3b

D. C5b

Which cells strongly engulf C3b-coated bacteria?

A. Mast cells and basophils

B. Neutrophils and macrophages

C. B cells and plasma cells

D. Eosinophils and platelets

What is the principal effect of opsonization?

A. Increased antibody secretion

B. Reduced leukocyte migration

C. Direct toxin neutralization

D. Enhanced microbial engulfment

Which components form the complement lytic complex?

A. C3a through C5a

B. C5b through C9

C. C1q through C4b

D. C2a through C5b

What is another name for C5b–C9?

A. C3 convertase

B. C5 convertase

C. Classical recognition complex

D. Membrane attack complex

Which complement fragment strongly promotes chemotaxis?

A. C5a

B. C3b

C. C5b

D. C9

C5a recruits which cells toward infection?

A. B cells and plasma cells

B. Mast cells and basophils

C. Neutrophils and macrophages

D. Platelets and erythrocytes

Which complement fragments are traditionally called anaphylatoxins?

A. C1q, C2a, C3b

B. C3b, C4b, C5b

C. C5b, C6, C7

D. C3a, C4a, C5a

Anaphylatoxins activate which immune cells?

A. Neutrophils and macrophages

B. Mast cells and basophils

C. B cells and plasma cells

D. Cytotoxic and helper T cells

Which T-cell population is most numerous?

A. Cytotoxic T cells

B. Regulatory T cells

C. Helper T cells

D. Memory T cells

Which cytokine stimulates cytotoxic and regulatory T-cell proliferation?

A. IL-2

B. IL-4

C. IL-5

D. IL-6

A vaccine contains organisms unable to replicate. Which category is this?

A. Toxoid vaccine

B. Conjugate vaccine

C. Inactivated vaccine

D. Live attenuated vaccine

Chemical treatment destroys toxin activity while preserving antigenicity. What is produced?

A. Conjugate

B. Toxoid

C. Adjuvant

D. Antiserum

Which group contains live attenuated vaccines?

A. Tetanus, diphtheria, pertussis

B. Hepatitis B, HPV, anthrax

C. Rabies, hepatitis A, influenza shot

D. Measles, yellow fever, oral polio

What vascular effect does histamine produce locally?

A. Arterial constriction

B. Blood-vessel dilation

C. Reduced permeability

D. Venous thrombosis

What effect can histamine produce on smooth muscle?

A. Irreversible paralysis

B. Complete relaxation

C. Local contraction

D. Cellular necrosis

Which mediator causes prolonged bronchiolar smooth-muscle spasm?

A. Leukotrienes

B. Histamine

C. Heparin

D. Perforin

Where does the allergen-reagin reaction occur in asthma?

A. Nasal cavities

B. Skin venules

C. Systemic arteries

D. Pulmonary bronchioles

Where does the allergen-reagin reaction occur in hay fever?

A. Bronchioles

B. Nose

C. Skin

D. Intestines

Severe leukotriene-mediated bronchospasm may cause death through what mechanism?

A. Pulmonary hemorrhage

B. Systemic thrombosis

C. Suffocation

D. Cardiac rupture