Phagocytes were first discovered and named by
A. Pasteur.
B. Koch.
C. Lister.
D. Metchnikoff.

D. Metchnikoff.

In which organism were phagocytes first reported?
A. Bacteria

B. Amoeba

C. Red blood cells

D. Starfish larvae

D. Starfish larvae

Which is not a component of innate immunity?
A. Skin

B. Inflammation

C. Fever

D. Antibody

D. Antibody

Which is not involved in adaptive immunity?
A. antibody
B. T cell
C. B cell
D. tear flow

D. tear flow

Skin and mucous membranes are mostly involved in
A. adaptive immunity.
B. autoimmunity.
C. irregular immunity.
D. innate immunity.

D. innate immunity.

Skin and mucous membranes
A. are the first line of innate immunity.
B. are the first line of adaptive immunity.
C. act as physical barriers to infection.
D. contain antimicrobial secretions.
E. are the first line of innate immunity, act as physical barriers to infection, AND contain antimicrobial secretions.

E. are the first line of innate immunity, act as physical barriers to infection, AND contain antimicrobial secretions.

Interferons, complement, lysozyme, and lactoferrin are all examples of
A. specific antimicrobial factors.
B. immune enzymes.
C. nonspecific antimicrobial factors.
D. cytokines.

C. nonspecific antimicrobial factors.

Normal microbiota
A. are the organisms that typically reside on and in your body.

B. protect against infection by pathogens.

C. enhance infection by pathogens.
D. play no role in affecting pathogen growth.
E. are the organisms that typically reside on and in your body AND protect against infection by pathogens.

E. are the organisms that typically reside on and in your body AND protect against infection by pathogens.

Iron
A. is required by microorganisms.
B. binds to lactoferrin.
C. is necessary for the functioning of some enzymes.
D. All of the choices are correct.

D. All of the choices are correct.

Factors that work generically against any foreign substance entering the host are described as
A. innate immunity.
B. specific immunity.
C. irregular immunity.
D. immune metabolism.

A. innate immunity.

The cells primarily involved in all immune responses are the
A. erythrocytes.
B. platelets.
C. osteocytes.
D. leukocytes.

D. leukocytes.

In humans, the stem cells from which all blood cells arise are found in the
A. peripheral circulation.
B. lymphatic vessels.
C. lymph nodes.
D. bone marrow.

D. bone marrow.

All blood cells originate from the
A. erythrocyte.
B. leukocytic stem cell.
C. eosinophilic stem cell.
D. hematopoietic stem cell.

D. hematopoietic stem cell.

Which of the following is a phagocytic cell found in the human body?
A. Erythrocyte

B. Neutrophil

C. Megakaryocyte

D. T cell

B. Neutrophil

The leukocyte that contains histamine is the
A. lymphocyte.
B. monocyte.
C. macrophage.
D. basophil.

D. basophil.

16. Allergic reactions mainly involve
A. macrophages.
B. monocytes.
C. neutrophils.
D. mast cells.

D. mast cells.

Which of the following are referred to as mononuclear phagocytes?
A. Lymphocytes and basophils

B. Mast cells and eosinophils

C. Basophils and eosinophils

D. Monocytes and macrophages

D. Monocytes and macrophages

The "voices" of a cell, which carry messages, are

A. surface receptors.
B. platelets.
C. cytokines.
D. antigens.

C. cytokines.

Toll-like receptors
A. are cytokines.
B. each recognize a specific "danger" molecule.
C. are embedded in cellular membranes.

D. are part of adaptive immunity.
E. each recognize a specific "danger" molecule AND are embedded in cellular membranes.

E. each recognize a specific "danger" molecule AND are embedded in cellular membranes.

Complement
A. may be activated through three pathways.
B. disrupts the cytoplasmic membrane of invading bacteria and foreign cells.
C. is part of the specific defense system.
D. is a group of blood proteins.
E. may be activated through three pathways, disrupts the cytoplasmic membrane of invading bacteria and foreign cells, AND is a group of blood proteins.

E. may be activated through three pathways, disrupts the cytoplasmic membrane of invading bacteria and foreign cells, AND is a group of blood proteins.

The complement pathway that requires antibodies to be activated is the
A. alternate pathway.
B. classical pathway.
C. properdin pathway.
D. inflammatory pathway.

B. classical pathway.

23. A group of interacting serum proteins that provide a nonspecific defense mechanism is
A. complement.
B. interferon.
C. glycoprotein.
D. lysozyme.

A. complement.

The complement pathway that is activated by mannan-binding lectins is the
A. classical pathway.
B. alternative pathway.
C. C3 pathway.
D. lectin pathway.

D. lectin pathway.

The complement pathway that is activated by binding of C3b to cell surfaces is the
A. classical pathway.
B. alternate pathway.
C. C3 pathway.
D. mucociliary pathway.

B. alternate pathway.

The key molecule upon which all complement pathways converge is
A. C1.
B. C2.
C. C3.
D. C6.

C. C3.

The leukocyte responsible for adaptive immunity is the
A. lymphocyte.
B. monocyte.
C. eosinophil.
D. neutrophil.

A. lymphocyte.

C3a and C5a are involved in
A. inflammation.
B. interferon production.
C. properdin activation.
D. attraction of phagocytes.

E. inflammation AND attraction of phagocytes.

E. inflammation AND attraction of phagocytes.

C3b is involved in
A. opsonization.
B. interferon production.
C. properdin activation.
D. endotoxin production.

A. opsonization.

The complex resulting from complement activity that leads to cell lysis is the
A. prostaglandin complex.
B. leukotriene activating complex.
C. membrane attack complex.
D. histamine complex.

C. membrane attack complex.

30. Which of the following are most susceptible to complement lysis?
A. Gram-positive bacteria
B. Gram-negative bacteria
C. Bacteriophages

D. Prions

B. Gram-negative bacteria

The low molecular weight protein produced by animal cells in response to viral infections is
A. complement.
B. lysozyme.
C. histamine.
D. interferon.

D. interferon.

Interleukins are
A. produced by leukocytes.
B. important in both innate and adaptive immunity.
C. involved in directly killing tumor cells.
D. protein molecules.
E. produced by leukocytes AND protein molecules.

E. produced by leukocytes AND protein molecules.

The presence of long double-stranded RNA (> 30 bp)
A. indicates infection by an RNA virus other than a retrovirus.
B. indicates infection by a virus.
C. indicates exposure to mutagens.
D. induces synthesis of interferon.
E. indicates infection by an RNA virus other than a retrovirus AND induces synthesis of interferon.

E. indicates infection by an RNA virus other than a retrovirus AND induces synthesis of interferon.

Interferons function to make cells
A. prevent viral replication.

B. lyse when exposed to virus.
C. non-motile when infected with virus.
D. resistant to phagocytosis.

A. prevent viral replication.

Which of the following cytokines is most antiviral in its action?
A. Interleukin-1

B. Interleukin-2

C. Interferon

D. Lysozyme

C. Interferon

Which of the following statements about interferon is incorrect?
A. It only works on a few specific types of virus.
B. It makes cells resistant to viral infection.
C. It is a species specific molecule.
D. It does not directly inactivate viruses.

A. It only works on a few specific types of virus.

Which activity of the virally invaded cell triggers production of interferon?

A. Activation of rRNA

B. Movement of nuclear proteins to the cytoplasm

C. Production of glycolipids

D. Production of dsRNA

D. Production of dsRNA

The cellular organelle responsible for the digestion of ingested infectious agents is the
A. endoplasmic reticulum.
B. Golgi apparatus.
C. phagolysosome.
D. lysosome.

C. phagolysosome.

Following digestion of a microorganism by phagocytes, the debris is excreted by
A. ingestion.
B. exocytosis.
C. extrusion.
D. budding.

B. exocytosis.

The four cardinal signs of inflammation are:
A. Flare, wheals, fever, cough

B. Rash, pus, heat, rubor

C. Heat, pain, vesicles, fever

D. Redness, heat, swelling, pain

D. Redness, heat, swelling, pain

The first host response to a nonspecific tissue injury is described as
A. inflammation.
B. reaction.
C. antibodies.
D. trauma.

A. inflammation.

The first kind of leukocyte lured to the site of inflammation is the
A. neutrophil.
B. monocyte.
C. macrophage.
D. basophil.

A. neutrophil.

The attraction of leukocytes to the area on inflammation is referred to as
A. parasitism.
B. infection.
C. phototaxis.
D. chemotaxis.

D. chemotaxis.

One of the strongest indications of infectious disease is
A. a rash.
B. pustules.
C. vesicles.
D. fever.

D. fever.

Pyrogens are
A. fever-inducing substances.
B. fever-inhibiting substances.
C. phagocytosis-enhancing substances.
D. complement activators.

A. fever-inducing substances.

During apoptosis, a cell will

A. die because it is damaged and, as a result, cause an inflammatory response.

B. self-destruct and, as a result, cause an inflammatory response.

C. self-destruct without causing an inflammatory response.

D. die because it is accidentally damaged, and, as a result, cause an inflammatory response.

A. die because it is damaged and, as a result, cause an inflammatory response.

Fever
A. enhances bacterial growth.
B. inhibits bacterial growth.
C. speeds up the body's reactions.
D. triggers complement.
E. inhibits bacterial growth AND speeds up the body's reactions.

E. inhibits bacterial growth AND speeds up the body's reactions.

What two functions do phagocytes serve in immune responses?

A. Production of antibodies AND engulfment/destruction of foreign cells

B. Engulfment/destruction of foreign cells AND alerting the other cells of the immune system to an invader

C. Alerting the other cells of the immune system to an invader AND serving as a physical barrier against microbial invasion

D. Production of antibodies AND serving as a physical barrier against microbial invasion.

B. Engulfment/destruction of foreign cells AND alerting the other cells of the immune system to an invader

How do cytokines function?
A. They bind directly to microbes to enhance their chance of being ingested (phagocytosed).
B. They are secreted in the phagolysosomes of neutrophils to effect killing of ingested microbes.
C. They are secreted by one cell type. They then bind to a receptor on target cell causing a signal within that cell that turns on (or off) certain genes to achieve a response.

D. They work as a series of serum proteins to produce a hole in microbes to directly lyse them.

C. They are secreted by one cell type. They then bind to a receptor on target cell causing a signal within that cell that turns on (or off) certain genes to achieve a response.

Toll-like receptors (TLRs) bind molecules on pathogens. Why is this helpful to the immune response?
A. It provides a highly specific response to very small and highly unique areas on an individual pathogenic microbe, providing the most specific and selective response possible.
B. It provides a general response to broad categories of molecules/cells that should NOT be in our system, as we don't have these molecules on our own cells.
C. These secreted molecules help bind pathogens and then direct them to receptors on the immune system cells that are best capable of eliminating them from our systems. TLRs are delivery mechanisms for the immune responses.
D. TLRs are capable of directly lysing (destroying) the microbes, helping our immune responses by eliminating pathogens.

B. It provides a general response to broad categories of molecules/cells that should NOT be in our system, as we don't have these molecules on our own cells.

Smoking impairs the ciliated cells of the middle portion of the respiratory tract. Many analgesic drugs (painkillers) impair peristalsis (the churning motion of the digestive tract). The result of either of these activities leads to an increased risk of infection in their respective areas. Why?
A. The actions of the cells in these areas help to propel pathogens out of the area, serving as a part of the physical barrier system. When they are impaired/slowed, bacteria and other pathogens have an easier time adhering to the tissues in the area and causing an infection.
B. Ciliated cells also line the digestive tract, and these cells secrete strong natural antibacterial compounds. When they are impaired, bacteria can more easily infect these areas.
C. Chemicals in cigarette smoke and the chemicals in painkillers impair our immune systems, making us generally more predisposed to infections (regardless of the tissue area).
D. Chemicals in cigarette smoke and the chemicals in painkillers impair the ability of our immune system cells to move into areas that are infected. As such, they can't perform their job of eliminating microbes as well as they should and infections result more easily.

A. The actions of the cells in these areas help to propel pathogens out of the area, serving as a part of the physical barrier system. When they are impaired/slowed, bacteria and other pathogens have an easier time adhering to the tissues in the area and causing an infection.

A physician is attempting new therapies for HIV patients who are suffering from an impaired immune response. He decides to try using a recombinant form of colony-stimulating factor cytokine (CSF). Why?
A. CSF is a strong inducer of antiviral activities in our cells, and may help our immune system fight off the effects of HIV for a longer period of time.
B. CSF will hyperstimulate the activities of the macrophages, leading to ingestion and destruction of HIV-infected cells.
C. CSF will help to stimulate the production of new lymphocytes-the very cells that are infected and depleted during an HIV infection. This may help to keep the patients' immune responses "normal" for a longer period of time before they succumb to full-blown AIDS.

D. CSF will drive up the production of lactoferrin, a strong antiviral compound produced in our mucus membrane secretions.

C. CSF will help to stimulate the production of new lymphocytes-the very cells that are infected and depleted during an HIV infection. This may help to keep the patients' immune responses "normal" for a longer period of time before they succumb to full-blown AIDS.

A cell infected by viruses may die due to the actions of interferons. The same result would occur WITHOUT interferon-any cell infected by a virus would die directly from the virus. Is there any apparent benefit to the host organism from the interferon action?
A. No-interferon is just an evolutionary leftover from a much earlier form of antiviral activity. It has no function now.
B. Yes-when the interferon acts on a virally infected cell, it shuts down protein production (which shuts down virus replication). Without interferon, virus will kill the cell eventually, but only after it has replicated many times over. Interferons may kill the host cell, but they will also prevent it from being used to replicate virus.

C. Yes-by killing host cells, you limit the number of cells that are available targets for viral infection. This is a good way of preventing viral infection.
D. No-viruses will replicate in cells regardless of the effects of interferons, so their action of killing the cell has no benefit to the host organism during the infection process.

B. Yes-when the interferon acts on a virally infected cell, it shuts down protein production (which shuts down virus replication). Without interferon, virus will kill the cell eventually, but only after it has replicated many times over. Interferons may kill the host cell, but they will also prevent it from being used to replicate virus.

Syphilis was once treated by intentionally infecting the patient with the parasite that causes malaria, a disease characterized by repeated bouts of fever, shaking, and chills. Why might this treatment cure syphilis?
A. Malaria parasites produce strong antibacterial compounds (since they're eukaryotic in nature-they are trying to eliminate their competition for resources). This helps to eliminate ALL bacteria in and on the human body for a short period of time.
B. Malaria parasites track down and feed upon ALL bacterial cells in the human body as a part of their life cycle. This makes them a "natural antibiotic" of sorts, and highly effective at clearing the bacterial infection of syphilis.

C. One of the side effects of malarial infection is a massive overproduction of macrophages-so many that they become the dominant cell type in the blood (even over red blood cells!). This drives up the ability to ingest and destroy any microbe, including the bacterium that causes syphilis.
D. The effect of driving up the body temperature for periods of time can shut down the temperature-sensitive replication of the bacterium that causes syphilis. This gives the immune system time to eliminate it properly.

D. The effect of driving up the body temperature for periods of time can shut down the temperature-sensitive replication of the bacterium that causes syphilis. This gives the immune system time to eliminate it properly.