Bio 251 - EXAM 2 (CSN - Joshua Stomel)

Which of the following statements about how the skin prevents disease is false?

a) salt in sweat retards microbial growth

b) the skin is the most common route for organisms to penetrate the body

c) oil glands on the skin make it waterproof

d) native microbes that live on your skin help protect you from infection

b) the skin is the most common route for organisms to penetrate the body

This antimicrobial protein is found at high levels in lacrimal secretions (tears)

a) lysozyme

b) defensins

c) sebum

d) C3b

a) lysozyme

Which component of the compliment system would stimulate neutrophils to phagocytize an attached cell?

a) C5a

b) C5b

c) C3a

d) C3b

d) C3b

Which of the following would prevent a microbe from activating the Alternative pathway of the compliment system?

a) a bacteria that has an enzyme that degrades antibodies

b) a bacteria that has a thick cell wall

c) a bacteria that can prevent C3b from binding to it

d) a bacteria that contain no mannose

c) a bacteria that can prevent C3b from binding to it

Which of the following is NOT a feature of the skin that allows it to serve as a barrier to infection?

a) melanin in the skin is toxic to a bacteria

b) sweat creates a sling environment that prevents non-halotolerant bacteria from growing

c) tight junctions in keratinocytes make the skin waterproof

d) resident flora produce bacteriocins

a) melanin in the skin is toxic to a bacteria

The immune system cell most commonly associated with allergies is:

a) neutrophil

b) eosinophil

c) basophil

d) macrophage

c) basophil

Which of the following would be an example of a PAMP?

a) GaGs on the surface of eukaryotic of a PAMP

b) C3b bound to bacteria

c) peptidoglycan

d) tissue factor

c) peptidoglycan

This cytokine is released by virally infected cells, anti-viral

interferon

Suppose that someone's blood stem cells in their marrow ware dividing and developing into B cells. What cytokine might be responsible for this?

a) chemokines

b) tumor necrosis factor

c) colony stimulating factor

d) interferon

c) colony stimulating factor

Which of the following cells would likely have Toll-like receptors (TLRs)?

a) mast cells

b) dendritic cells

c) neutrophils

d) T-lymphocytes

e) hepatocytes

mast cells, dendritic cells

Which of the following would be most likely to be detected by a Rig-like receptor (RLR)

a) bacterial DNA

b) helminth proteins

c) double stranded RNA

d) LPS

c) double stranded RNA

What event during inflammation is responsible for swelling?

a) diapedesis

b) increasing vascular permeability

c) vasodilation

d) increased sensitivity of nociceptors

b) increasing vascular permeability

Put the steps of Phagocytosis in order.

Chemotaxis

Exocytosis

Recognition and Attachment

Engulfment (endocytosis)

Destruction and Digestion

Phagosome maturation and phagolysosome formation

Chemotaxis

Recognition and Attachment

Engulfment (endocytosis)

Phagosome maturation and phagolysosome formation

Destruction and Digestion

Exocytosis

What are examples of Antigen Presenting Cells?

Mast cells, Dendritic cells, Macrophages, B-cells

Which of the following is NOT a way that antibodies assist the immune system in getting rid of pathogens?

a) labelling pathogens for phagocytosis (opsonization)

b) poking holes in the cell membrane and lysing bacteria directly

c) binding to viral coat proteins and preventing them from being able to enter cells

d) binding to flagella and fimbrae and preventing movement and adherence

b) poking holes in the cell membrane and lysing bacteria directly

Which of the following pathogens could initiate an antibody response without Helper T-cells?

a) HIV

b) Gram- organisms

c) Gram+ organisms

d) Helper T-cells are not normally for an antibody response

b) Gram- organisms

Which of the following statements about B-cells is false?

a) B-cells mature in the bone marrow

b) B-cell receptors are all identical

c) When activated, B-cells differentiate into plasma cells

d) B-cells present foreign antigens on an MHCII

b) B-cell receptors are all identical

Suppose you are observing a patient who has a bacterial infection that begins to subside fairly quickly after becoming symptomatic. An analysis of their blood shows high levels of IgM specific to the bacteria, but undetectable levels of IgG and IgD. Two months after being discharged, the patient returns with another infection by the same bacteria. What would be reasonable to conclude?

The patient's immune reaction happened through the T-independent pathway

Know the following:

IgM, IgG, IgA, IgE, IgD

IgM- first antibody produced in response to an infection

IgG- antibody that penetrates the placenta; abundant in blood and fluids; antibody of memory

IgA- found in body secretions: mucus, tears, saliva, breastmilk for infants

IgE- involved in allergic reactions

IgD- poorly understood function

Suppose that an antibody binds to a toxin molecule and prevents the toxin from binding to a receptor where it would have a negative effect. This is an example of:

a) cross-linking

b) opsonization

c) immobilization

d) neutralization

d) neutralization

In the thymus, T-cells that bind self antigens are:

a) stimulated to proliferate (divide)

b) sent to the spleen

c) eliminated through negative selection

d) shunted back into the thymus for a second round of selection

c) eliminated through negative selection

An HIV positive individual with low CD4 T-cell count is infected with a normally non-fatal virus and later dies. What likely occurred?

a) they were unable to release histamine and could don't mount an inflammatory response

b) their immune system became hyper-active through the T-independent pathway and they died due to a cytokine storm

c) they were unable to generate antibodies through the T-dependent pathway due to lack of helper T-cells

d) their macrophages were unable to stimulate Helper T-cells due to insufficient MHC II

c) they were unable to generate antibodies through the T-dependent pathway due to lack of helper T-cells

Once you have recovered from influenza, you have acquired immunity to that strain. This is an example of

a) natural active immunity

b) artificial active immunity

c) natural passive immunity

d) artificial passive immunity

a) natural active immunity

When would an inactivated vaccine be preferable to an attenuated vaccine?

a) when cost is a factor

b) when the patient has a well developed immune response

c) when rapid immunization must be obtained

d) in a disaster situation where electricity is unavailable

d) in a disaster situation where electricity is unavailable

Which of the following cells would posses NEITHER an MHCII NOR an MHCI

a) red blood cell

b) hepatocyte

c) dendritic cell

d) neutrophil

a) red blood cell

The immune system cell most commonly associated with allergies is:

a) neutrophil

b) eosinophil

c) basophil

d) macrophage

c) basophil

Which of the following would be a common treatment for an autoimmune disorder?

a) epinephrin

b) antihistamines

c) steroids

d) theyroidectomy

c) steroids

Suppose that someone has a contact dermatitis latex allergy. Would you expect this condition to be diagnosable via a basophil degranulation assay?

a) Yes, because latex allergies are localized type 1 hypersensitivities

b) Yes, because although latex allergies are not IgE dependent they still operate through a basophil induced inflammation

c) No, because as a localized reaction latex allergies only work through mast cells

d) No, because latex allergies work through cytotoxic T cells

d) No, because latex allergies work through cytotoxic T cells

Mother/fetus Rh factor incompatibility is an example of what hypersensitivity:

a) Type 1

b) Type 2

c) Type 3

d) Type 4

b) Type 2

What would likely be an appropriate treatment for a systemic type 1 hypersensitivity

a) Epi-pen

b) RhoGAM

c) Anti-histamine cream

d) there is no effective treatment for type 1 hypersensitivities

a) Epi-pen

Which of the following would be an example of a primary immunodeficiency?

a) someone in the advanced stages of AIDS

b) someone on immunosuppressive therapy for an organ transplant

c) someone with a mutation in the gene that codes for the C3 protein of the compliment system

d) all of these primary immunodeficiencies

c) someone with a mutation in the gene that codes for the C3 protein of the compliment system

Which of the follow statements is false?

a) herd immunity only protects a population if most of the members have been vaccinated

b) inactivated vaccines primarily work through humoral immunity

c) children do not need vaccines if they breastfeed from a vaccinated mother

d) vaccines are often ineffective in immunocompromised patients

c) children do not need vaccines if they breastfeed from a vaccinated mother

What are the three pathways of the compliment system?

Classical, Lectin, and Alternative pathway

Which of the following is NOT a way that the compliment system acts to protect you?

a) stimulating inflammatory response

b) preventing viral replication

c) opsonization

d) direct lysis of cells

b) preventing viral replication

(T/F) The compliment system can be activated by antigen presenting cells

False

What is a chemokine?

chemotaxis of immune cells

What are colony-stimulating factors (CSFs)?

multiplication and differentiation of leukocytes

What is an interferon?

cytokine with anti-viral function

What is an interleukin?

involved in regulation and coordination of the immune system

What is tumor necrosis factor (TNF)?

stimulates inflammation and apoptosis

Suppose someone has a very high fever that threatens to kill them. Which chemical would it be most useful to suppress?

a) bradykinin

b) prostaglandin

c) histamine

d) CRP

b) prostaglandin

What serves as chemical signals between cells and stimulate a wide range of nonspecific defenses?

cytokines

Bacteriocins and defensins are types of which of the following?

a) leukotrienes

b) cytokines

c) inflammation-eliciting mediators

d) antimicrobial peptides

d) antimicrobial peptides

What is a chemical mediator that is secreted onto the surface of the skin?

sebum

Identify the complement activation pathway that is triggered by the binding of an acute-phase protein to a pathogen.

a) classical

b) alternative

c) lectin

c) lectin

Histamine, leukotrienes, prostaglandins, and bradykinin are examples of what?

chemical mediators that promote inflammation

What are bacteriocins?

antimicrobial peptides produced by normal microbiota

TLRs (toll-like receptors)

found on surface of sentinel cells, used to find infectious molecules/cell, OUTSIDE the cell

NLRs (NOD-like receptors)

found in cytoplasm of most cells, detects INSIDE the cell (flagella, peptidoglycan)

RLRs (RIG-like receptors)

found in cytoplasm to detect VIRAL components (ds RNA)

Neutrophils

most abundant circulating WBC

NK cells- kills cells that fail to display self antigens on their surface

Macrophages- phagocytic sentinel cell

Basophils

releases histamine in response to infection, involved in allergic reactions

Macrophages

sentinel cells that phagocytize foreign substances, dead cells, debris

Eosinophils

has an anti parasitic function

B cells

a lymphocyte processed in bone marrow and responsible for producing antibodies.

Cytotoxic T-cells

destroy cells infected with intracellular pathogens, made in thymus

NK cells (natural killer cells)

a lymphocyte that kills cells that do not present antigens/proteins (virally infected/cancerous)

Type 1 hypersensitivity

IgE mediated, triggering mast cell degranulation ex) food/drug allergies

Type 2 hypersensitivity

IgG and IgM antibodies directed against cellular antigens, leads to cell damage ex) red blood cell damage after transfusion w/ mismatched blood

Type 3 hypersensitivity

immune complexes of IgG and IgM antibodies and antigens are deposited in tissues, cascades into tissue damage ex) rheumatoid arthritis

Type 4 hypersensitivity

T cell mediated , TH1 cells secrete cytokines, which activate macrophages and cytotoxic T cells

Which of the following is the type of cell largely responsible for type I hypersensitivity responses?

a) erythrocyte

b) mast cell

c) T cell

d) antibody

b) mast cell

Type I hypersensitivities require which of the following initial priming events to occur?

a) sensitization

b) secondary immune response

c) cellular trauma

d) degranulation

a) sensitization

Which of the following are the main mediators/initiators of type II hypersensitivity reactions?

a) antibodies

b) mast cells

c) erythrocytes

d) histamines

a) antibodies

Which of the following is a common treatment for type III hypersensitivity reactions?

a) anti-inflammatory steroid treatments

b) antihistamine treatments

c) hyposensitization injections of allergens

d) RhoGAM injections

a) anti-inflammatory steroid treatments

Which of the following is NOT an example of a type 4 hypersensitivity?

a) latex allergy

b) contact dermatitis (contact w/ poison ivy

c) a positive tuberculin skin test

d) hemolytic disease of the newborn

d) hemolytic disease of the newborn

Allergy shots work by shifting antibody responses to produce ________ antibodies.

IgG

Primary immunodeficiency

congenital; usually genetic errors that impair development (antibody deficiencies)

secondary immunodeficiency

acquired later in life; result of infection (sometimes viral) or other stress on system (AIDs, malnutrition)

natural active immunity

immunity gained through illness and recovery

natural passive immunity

immunity gained from antibodies through placenta or breastmilk

artificial active immunity

immunity gained through a vaccine

artificial passive immunity

immunity gained from an animal or another person

Bacteriostatic

a substance that inhibits bacteria from spreading

Bacteriocidal

a substance that kills bacteria

Sterilization

removal of ALL microbial life, including virus but not prions

disinfection

getting rid of MOST pathogens from a non-living object (kitchen)

antisepsis

getting rid of pathogens from skin or another living entity

Sanitization

removal of pathogens from objects to meet public health standards

degerming

removing, NOT killing, organisms through mechanical action (hwndwwashing)

Pasteurization

use of heat to destroy pathogens and reduce the number of spoilage microorganisms in foods and beverages

preservation

action that inhibits microbial growth in the future

T-independent activation

-the activation of B cells without helper T cells, only produces IgM, but DANGEROUS

-no class switching and no memory TH cells

T-dependent activation

high affinity B cells with class-switched antibodies

Which of the following would have an MHC II?

a) neutrophils

b) macrophages

c) dendritic cells

d) basophils

e) mast cells

f) monocytes

macrophages, dendritic cells, monocytes

Which of the following chemical control agents is no longer in common use?

a) peroxides

b) halogens

c) aldehydes

d) heavy metals

d) heavy metals

ALCOHOLS

intermediate-level disinfectant that denatures proteins and disrupts cell membranes, not a sterilant

PHENOLICS

low- to intermediate-level disinfectants, used in household applications

HALOGENS

intermediate level disinfectant, damages enzymes by oxidation and denaturation, bleach, chlorine

SURFACTANTS

soaps, detergents, quads: degerming agents

selective toxicity

antibiotics that target components of bacteria and not the host, interferes with biological structures & processes

Penicillin

inhibits cell wall synthesis

Tetracycline

inhibit protein synthesis, cause discolored teeth

Chloramphenicol

inhibit protein synthesis, drug of last resort: aplastic anemia

Ciporfloxacin

inhibit nucleic acid synthesis, last resort

Rifampin

Antituberculosis, blocks RNA polymerase

Sulfa drugs

Inhibits the synthesis of folic acids

Isoniazid

inhibits mycolic acid synthesis

Explain, in physiological detail, how the body reacts to PB

On first exposure to the allergen, APCs process and present the allergens on MHC II to helper T cells. B cells are also able to process and present these on an MHC II to helper T2 cells that releases cytokines. The cytokines then stimulate differentiation and proliferation in the IgE-secreting plasma cells. The IgE antibodies then bind to mast cells, sensitizing them for subsequent exposure to the allergen. On second exposure, the allergens cross-links IgE antibodies on the mast cells causing activation. This then releases granules and inflammatory molecules that causes signs and symptoms type 1 hypersensitivity reactions.