Microbiology, Ch 14, Nester's 9th

Which is not a component of innate immunity? - Skin - Inflammation - Fever - Antibody

- Antibody

Please select the TRUE statement regarding Toll-like receptors (TLRs). - A number of different TLRs have been described, all of which are found in the phospholipid membranes of endosomes and phagosomes. - TLRs allow cells to detect patterns associated with microbes, indicating that the innate immune responses involve some specificity (although not the specificity of adaptive immunity). - TLRs represent a very important early-warning system for viral infections. They allow any virally infected cell to alert neighboring cells that a virus is present. - TLRs anchored in the membrane of endosomes generally detect components of the outermost layers of microbial cells, including lipopolysaccharide (LPS), lipoproteins, and flagellin. - All of these statements are true of TLRs.

- TLRs allow cells to detect patterns associated with microbes, indicating that the innate immune responses involve some specificity (although not the specificity of adaptive immunity).

How do cytokines function? - They are secreted by lysozomes into the phagosomes of neutrophils to enhance the killing of ingested microbes within those organelles. - They are secreted by one cell type, then work as a series of serum proteins to produce holes in the cytoplasmic membranes of microbes to directly lyse them. - They are secreted by microbes that have been engulfed by phagocytes, causing those cells to produce destructive enzymes and undergo apoptosis. - They are secreted by one cell type, 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. - They are produced by several cell types and bind directly to microbes to enhance their chance of being ingested, in a process called opsonization.

- They are secreted by one cell type, 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.

The chains of an antibody molecule are bonded to one another by: - disulfide bonds. - hydrogen bonds. - ionic bonds. - oxygen bonds.

- disulfide bonds

Toll-like receptors are found on: - lymphocytes. - mast cells. - macrophages. - neutrophils.

- macrophages

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

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

Influenza is caused by: - orthomyxovirus. - H. influenza. - cytomegalovirus. - adenovirus.

- orthomyxovirus. Not ch 14. That's ok.

Interleukins are: - involved in directly killing tumor cells. - produced by leukocytes AND protein molecules. - produced by leukocytes. - protein molecules. - important in both innate and adaptive immunity.

- produced by leukocytes AND protein molecules.

Your first patient of the day is complaining of pain in the area of his new tattoo. When you examine the tattoo, you note that the area around it is firm, red, and swollen. There is no evidence of pus, and your patient has a normal pulse, and no fever. You tell your patient that you have seen this type of response to a tattoo before, and that it is called a granulomatous reaction. You give him more information on the condition. You tell your patient that when he got his tattoo, his first line of defense of his innate immunity was breached because his skin was damaged by the process. He asks you to explain what is included in the first line of defense and you tell him: - skin, mucous membranes, and lymphocytes. - mucous membranes. - skin and mucous membranes. - skin - white blood cells.

skin and mucous membranes.

In which organism were phagocytes first reported? - humans - Starfish larvae - Amoeba - Bacteria - Red blood cells

starfish larvae - Russian scientist Metchnikoff

Your sister recently had her first child, a boy who she names Owen. Unfortunately, Owen seems to get sick really often, and after some investigation, he is diagnosed with an extremely rare genetic disorder called leukocyte adhesion deficiency (LAD). People with LAD suffer from repeated bacterial infections because their leukocytes have adhesion defects—they cannot adhere to the endothelium and as a result are unable to leave the blood vessels to move into tissues containing microbial invaders. Without this inflammatory response, the person experiences severe tissue infections and frequently has neutrophilia (high levels of neutrophils in the blood). You help your sister understand this disease, using your knowledge of the immune system. Which of the following is NOT a leukocyte? - Neutrophil - B cell - Basophil - Macrophage - These are all leukocytes

they are all leukocytes

Which of the following are enzymes found in neutrophil granules, saliva, and milk that react with hydrogen peroxide to form antimicrobial compounds? A) Peroxidases B) Lactoferrins C) Transferrins D) Peroxidases AND lactoferrins E) Lactoferrins AND transferrins

A

Which of the following is the correct sequence of events in the interferon response? 1. IFN induces synthesis of inactive antiviral proteins (iAVPs). 2. Virus enters host cell (cell 1) and replicates, producing long dsRNA. 3. Activated AVPs induce apoptosis of infected cell. 4. dsRNA induces synthesis and secretion of IFN to neighboring cells. 5. Entry of virus into cell armed with iAVPs (cell 2) activates these proteins. A) 2, 4, 1, 5, 3 B) 1, 2, 3, 4, 5 C) 3, 1, 2, 5, 4 D) 5, 4, 1, 2, 3 E) 2, 1, 4, 3, 5

A

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. E) IFNs regulate several immune responses.

A

Which of the following are referred to as mononuclear phagocytes? A) Monocytes and macrophages B) Lymphocytes and basophils C) Mast cells and eosinophils D) Basophils and eosinophils E) Neutrophils and macrophages

A - The mononuclear phagocyte system includes monocytes, macrophages/histiocytes, and dendritic cells. Macrophages/histiocytes are tissue-based cells that have an important phagocytic function and produce a variety of bioactive substances that play roles in inflammation and fibrosis.

Please select the correct sequence for the steps of phagocytosis: 1. Conditions in the phagosome change, increasing its antimicrobial activities. 2. The phagocytic cell binds microbial invaders and engulfs them, internalizing them in a phagosome. 3. Phagocytic cells are recruited to the site of an injury by chemoattractants. 4. Within the phagolysosome, various factors work together to destroy an engulfed invader. 5. The phagosome fuses with enzyme-filled lysosomes, forming a phagolysosome. A) 1, 2, 3, 4, 5 B) 2, 4, 3, 5, 1 C) 3, 2, 1, 5, 4 D) 1, 3, 5, 2, 4 E) 1, 5, 2, 4, 3

C

Which of the following cytokines is most antiviral in its action? A) Interleukin-1 B) Interleukin-2 C) Interferon D) Tumor necrosis factor E) Colony-stimulating factor

C

The "voices" of a cell, which carry messages, are: A) surface receptors. B) cytokines. C) platelets. D) antigens. E) adhesion molecules.

Cytokines - chemical messengers "any of a number of substances, such as interferon, interleukin, and growth factors, which are secreted by certain cells of the immune system and have an effect on other cells."

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) die because it is accidentally damaged, and, as a result, cause fever. D) self-destruct without causing an inflammatory response. E) divide to repair damaged tissue, leading to an inflammatory response.

D

Your first patient of the day is complaining of pain in the area of his new tattoo. When you examine the tattoo, you note that the area around it is firm, red, and swollen. There is no evidence of pus, and your patient has a normal pulse, and no fever. You tell your patient that you have seen this type of response to a tattoo before, and that it is called a granulomatous reaction. You give him more information on the condition. Your patient wonders what giant cells are and how they form. You explain that giant cells: A) are very large cells with a single nucleus; they are formed by the fusion of many neutrophils during a chronic inflammatory response. B) are macrophages that have large extensions in their cytoplasmic membranes which both increases their size and enhances their phagocytic ability. C) are any cells in body that have a diameter of greater than 10-3 m. D) are very large cells with multiple nuclei; they are formed by the fusion of many macrophages during a chronic inflammatory response. E) cells that have engulfed a large number of particles that get stored inside the cell, causing it to absorb water and swell.

D

Your sister recently had her first child, a boy who she names Owen. Unfortunately, Owen seems to get sick really often, and after some investigation, he is diagnosed with an extremely rare genetic disorder called leukocyte adhesion deficiency (LAD). People with LAD suffer from repeated bacterial infections because their leukocytes have adhesion defects—they cannot adhere to the endothelium and as a result are unable to leave the blood vessels to move into tissues containing microbial invaders. Without this inflammatory response, the person experiences severe tissue infections and frequently has neutrophilia (high levels of neutrophils in the blood). You help your sister understand this disease, using your knowledge of the immune system. Which of the following do you think would be a possible way to cure a person with LAD? A) Giving the person inflammatory mediators daily to enhance the vasodilation process during inflammation. B) Giving the person a single blood transfusion with blood containing healthy leukocytes. C) Keeping the person on multiple antimicrobial medications for their whole life to fight any potential infections. D) Giving the person a hematopoietic stem cell transplant—this would replace the person's defective leukocytes with healthy leukocytes. E) Keeping the person in a completely microbe-free environment so that they are never at risk of contracting a microbial infection.

D

Fever allows the body to fight microbial invaders by which of the following mechanisms? - Fever prevents microbes with lower optimum temperatures from growing, giving the immune system time to eliminate those cells. - Fever increases the inflammatory response, but reduces the production of interferons unless the invader is a dsRNA virus. - A moderate fever reduces the inflammatory response but stimulates phagocytic activity in neutrophils and eosinophils. - Fever increases the multiplication of lymphocytes and enhances the release of substances that attract basophils that then engulf the microbial invader. - Fever plays all of these roles in the body.

Fever prevents microbes with lower optimum temperatures from growing, giving the immune system time to eliminate those 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? 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). 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. 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. 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. The actions of the cells in these areas help to propel pathogens into the stomach, where they are destroyed by acid. When they are impaired/slowed, bacteria and other pathogens do not get destroyed by and can cause an infection.

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.

Which of the following is NOT true of phagocytosis? - Within a phagolysosome, O2 consumption decreases dramatically, allowing an enzyme to produce reactive oxygen species (ROS), which are toxic. - The phagocytic cell binds microbial invaders and engulfs them by means of pseudopodia, internalizing them in a phagosome. - The phagolysosome releases undigested debris to the outside of the cell by fusing with the phagocyte's cytoplasmic membrane. - If a phagocyte encounters something too large to engulf, it releases its toxic contents as a means of destroying that invader. - Phagocytic cells are recruited to the site of an injury by chemoattractants such as complement C3b.

Within a phagolysosome, O2 consumption decreases dramatically, allowing an enzyme to produce reactive oxygen species (ROS), which are toxic.

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. E) All of the answer choices are correct.

alternate pathway The alternative pathway of the complement system is an innate component of the immune system's natural defense against infections. The alternative pathway is one of three complement pathways that opsonize and kill pathogens. The pathway is triggered when the C3b protein directly binds a microbe.

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

exocytosis

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

fever

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

inflammation

C3a and C5a are involved in inflammation. interferon production. properdin activation. enhancement of phagocytosis. inflammation AND enhancement of phagocytosis.

inflammation AND enhancement of phagocytosis.

The complement pathway that is activated by mannan-binding protein is the: A) classical pathway. B) alternative pathway. C) C3 pathway. D) lectin pathway. E) properdin pathway.

lectin pathway The lectin pathway is responsible for an antibody-independent pathway of complement activation that is initiated by binding of the mannose-binding lectin (MBL) to carbohydrates on the surface of pathogens.

White blood cells are called:

leukocytes

The cells primarily involved in all immune responses are the: A) erythrocytes. B) platelets. C) leukocytes. D) lymphocytes. E) chondrocytes.

leukocytes - white blood cells

The cells responsible for adaptive immunity are the: A) lymphocytes. B) monocytes. C) eosinophils. D) neutrophils. E) leukocytes.

lymphocytes - B and T cells

Allergic reactions mainly involve: A) macrophages. B) monocytes. C) mast cells. D) neutrophils. E) eosinophils.

mast cells - basophils too, had that been a choice.

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. E) macrophage antibody complex.

membrane attack complex MAC is composed of a complex of four complement proteins (C5b, C6, C7, and C8) that bind to the outer surface of the plasma membrane, and many copies of a fifth protein (C9) that hook up to one another, forming a ring in the membrane.

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

neutrophil

T/F - Lymphocytes are the cells primarily responsible for the adaptive immune responses.

True

T/F - Pattern recognition is involved in innate immunity.

True

T/F - White blood cells also called leukocytes are important in immunity.

True

C3b is involved in: A) opsonization. B) interferon production. C) properdin activation. D) endotoxin production. E) inflammation.

A

Please select the correct sequence for the steps of phagocytosis: 1. Conditions in the phagosome change, increasing its antimicrobial activities. 2. The phagocytic cell binds microbial invaders and engulfs them, internalizing them in a phagosome. 3. Phagocytic cells are recruited to the site of an injury by chemoattractants. 4. Within the phagolysosome, various factors work together to destroy an engulfed invader. 5. The phagosome fuses with enzyme-filled lysosomes, forming a phagolysosome.

3, 2, 1, 5, 4

Which is not involved in adaptive immunity? A) Tear flow B) Antibody production C) T cells D) B cells E) Tear flow AND B cells

A) Tear flow

Your first patient of the day is complaining of pain in the area of his new tattoo. When you examine the tattoo, you note that the area around it is firm, red, and swollen. There is no evidence of pus, and your patient has a normal pulse, and no fever. You tell your patient that you have seen this type of response to a tattoo before, and that it is called a granulomatous reaction. You give him more information on the condition. You tell your patient that tattoo ink can sometimes cause the skin reaction he is experiencing; red ink in particular can cause this because it commonly contains mercury and/or other heavy metals. Your patient has developed a granuloma at the site of his tattoo. When he asks you what a granuloma is, you tell him: A) a collection of macrophages, giant cells, and T cells. B) a collection of neutrophils, giant cells, eosinophils and red blood cells. C) a mass of macrophages, activated complement proteins, and keratin. D) an acute inflammation response involving mast cells and dendritic cells. E) a collection of microbes, keratin, and white blood cells.

A) a collection of macrophages, giant cells, and T cells.

Pyrogens are: A) fever-inducing substances. B) fever-inhibiting substances. C) phagocytosis-enhancing substances. D) complement activators. E) pus-producing substances.

A) fever-inducing substances.

What is the consequence of fever? A) inhibits bacterial growth AND speeds up the body's reactions B) enhances bacterial growth AND speeds up the body's reactions C) inhibits bacterial growth AND triggers complement activation D) speeds up the body's reactions AND triggers complement activation E) enhances bacterial growth AND triggers complement activation

A) inhibits bacterial growth AND speeds up the body's reactions

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

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

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. E) adaption.

A) innate immunity.

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. E) form endospores.

A) prevent viral replication.

What two functions do phagocytes serve in immune responses? A) Production of antibodies AND engulfment/destruction of foreign cells. 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. E) Alerting the other cells of the immune system to an invader AND production of antibodies. 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. E) Alerting the other cells of the immune system to an invader AND production of antibodies.

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

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 diedirectly fromthevirus.Isthere 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. Virus infections are always treated with medications. B) Yes; when the interferon acts on a virally infected cell, it shuts down virus replication. Without interferon, the virus will eventually kill the cell, but only after it has replicated many times. IFNs may kill the host cell, but they will also prevent it from being used to replicate virus. C) Yes; by killing host cells, the number of cells that are available targets for viral infection is limited. 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. E) Yes; IFN is needed to activate complement which stimulates otherwise phagocytes in the host so that they recognize and destroy not only the virus but also any infected cells. Without complement, all phagocytes are inert.

B

Given the name "leukocyte adhesion deficiency," which of the following steps in the inflammation process given below do you think is/are not carried out in a person with this condition? 1. Tight junctions between endothelial cells are disrupted, allowing fluid to leak from the vessels into the tissue. 2. The phagocytes bind to the endothelial cells and exit the blood vessel by a process called diapedesis. 3. Once in the tissues, phagocytic cells engulf and destroy any microbial invaders. 4. The increase of fluids in the tissues causes the swelling and pain associated with inflammation. 5. The diameter of local blood vessels increases due to the action of inflammatory mediators. A) 1 B) 2 C) 3 D) 1 and 2 E) 2, 3, and 5

B

When microbes are introduced into normally sterile body sites, or when tissues are damaged, inflammation occurs. The purpose of this is to contain a site of damage, localize the response, eliminate the invader, and restore tissue function. Select the correct sequence of events for an inflammation response. 1. The phagocytes then produce other adhesion molecules that strengthen their attachment to the endothelial cells. 2. Tight junctions between endothelial cells are disrupted, allowing leakage from the vessels into the tissue. 3. Endothelial cells of the blood vessels produce adhesion molecules that loosely "grab" phagocytic cells. 4. In response to various chemoattractants, the phagocytes leave the blood vessels and move into the surrounding tissues. 5. The diameter of local blood vessels increases due to the action of inflammatory mediators, slowing blood flow in the area. A) 1, 2, 3, 4, 5 B) 5, 2, 3, 1, 4 C) 3, 2, 4, 1, 5 D) 1, 3, 5, 2, 4 E) 4, 5, 1, 2, 3

B

Your first patient of the day is complaining of pain in the area of his new tattoo. When you examine the tattoo, you note that the area around it is firm, red, and swollen. There is no evidence of pus, and your patient has a normal pulse, and no fever. You tell your patient that you have seen this type of response to a tattoo before, and that it is called a granulomatous reaction. You give him more information on the condition. You go on to explain to your patient that his skin and mucous membranes are protected from microbes by a number of antimicrobial substances. You inadvertently make a mistake during this explanation. Which of the following definitions is INCORRECT? A) Lysozyme—enzyme that degrades the peptidoglycan layer of the bacterial cell wall. B) Defensins—short chains of carbohydrates that have strong antimicrobial properties. C) Peroxidases—enzymes found in neutrophils, saliva, and milk that react with H2O2 to form antimicrobial compounds. D) Transferrin—an iron-binding protein found in blood and tissue fluids that deprives microbes of Fe, inhibiting their growth. E) Perspiration—source of salty residue on the skin that inhibits all microbes except those that are salt-tolerant.

B

Which is not a component of innate immunity? A) Skin B) Antibody C) Inflammation D) Fever E) Mucus membranes

B) Antibody - it's a part of adaptive immunity

How are macrophages and neutrophils similar, and how are they different? A) Macrophages and neutrophils both circulate in the blood. Macrophages are phagocytic cells while neutrophils are granulocytes but not phagocytes. B) Macrophages and neutrophils are both phagocytic cells. Macrophages reside in the tissues while neutrophils typically circulate in the blood. C) Macrophages and neutrophils are both abundant cell types in tissues. Macrophages are phagocytic cells while neutrophils are not. D) Macrophages and neutrophils are both phagocytic cells. Macrophages are granulocytes while neutrophils are effector cells. E) Macrophages and neutrophils are both leukocytes. Macrophages are granulocytes and neutrophils are lymphocytes.

B) Macrophages and neutrophils are both phagocytic cells. Macrophages reside in the tissues while neutrophils typically circulate in the blood.

The body's own cells do not trigger the alternative pathway of complement system activation. Why is this? A) Host cells produce convertase 3b which changes C3b into C3a that does not activate the complement pathway. B) Molecules in host cell membranes bind regulatory proteins that will inactivate any C3b molecules that attach to the membrane. C) C3b triggers the alternative pathway in prokaryotes but not in eukaryotes. D) Molecules in host cell membranes bind regulatory proteins that will stimulate the binding of C3b molecules to bacterial cells. E) Molecules in host cell membranes bind any MACs, deactivating them and preventing the activation of the alternative pathway.

B) Molecules in host cell membranes bind regulatory proteins that will inactivate any C3b molecules that attach to the membrane.

The four cardinal signs of inflammation are: A) Flare, wheals, fever, cough B) Redness, heat, swelling, pain C) Rash, pus, heat, rubor D) Heat, pain, vesicles, fever E) Heat, pain, redness, fainting

B) Redness, heat, swelling, pain

Which statement about skin and mucous membranes is NOT correct? A) They are the first line of innate immunity. B) They are the first line of adaptive immunity. C) They act as physical barriers to infection. D) They contain antimicrobial secretions. E) They separate us from our environment.

B) They are the first line of adaptive immunity.

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

B) classical pathway

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

B) innate immunity.

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

B. phagolysosome

Your first patient of the day is complaining of pain in the area of his new tattoo. When you examine the tattoo, you note that the area around it is firm, red, and swollen. There is no evidence of pus, and your patient has a normal pulse, and no fever. You tell your patient that you have seen this type of response to a tattoo before, and that it is called a granulomatous reaction. You give him more information on the condition. Your patient doesn't understand all of the cell names that you have used. You educate him on the role of each cell type. One cell type that plays a role in adaptive immunity rather than innate immunity. Which cell is this? A) Neutrophils—type of phagocytic cell in the blood that quickly move to infected tissues, where they engulf and destroy invading microbes. B) Macrophages—type of phagocytic cell that resides in tissues, engulfing invaders and debris, and producing pro-inflammatory cytokines. C) Dendritic cells—antigen-presenting cells that "show" antigens to T cells, playing an essential role in their activation. D) Eosinophils—primary role is to rid the body of parasitic worms; also involved in allergy. E) Mast cells—tissue cells that are important in the inflammatory response and immediate allergic reactions.

C

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

C) Metchnikoff. - he was studying starfish larvae

Which of the following are phagocytic cells found in the human body? A) Erythrocytes AND neutrophils B) Neutrophils AND megakaryocytes C) Neutrophils AND macrophages D) Megakaryocytes AND leukocytes E) Macrophages AND erythrocytes

C) Neutrophils AND macrophages - erythrocytes are red blood cells, megakaryocytes are where platelets come from, leukocytes means all the white blood cells and not all WBCs are phagocytes.

Which statement about complement proteins is FALSE? A) They may be activated through three different pathways. B) They disrupt the cytoplasmic membrane of invading bacteria and foreign cells. C) They are part of the specific immune defense system. D) They are a group of blood proteins produced by the liver. E) They are part of the innate immune response.

C) They are part of the specific immune defense system.

The presence of long double-stranded RNA (> 30 bp): A) indicates infection by any virus. B) indicates exposure to mutagens. C) induces synthesis of interferon. D) indicates infection by a retrovirus. E) indicates complement activity.

C) induces synthesis of interferon.

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

C) nonspecific antimicrobial factors.

Toll-like receptors (TLRs) bind molecules on pathogens. Why is this helpful to the immune response? a) TLRs are capable of directly lysing (destroying) the microbes, helping our immune responses by eliminating pathogens. b) 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. c) 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. d) These secreted molecules help bind pathogens and then direct them to receptors on the immune system cells that can eliminate them from our systems. TLRs are delivery mechanisms for the immune responses.

C. 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.

The key molecule upon which all complement pathways converge is ________. A) C1 B) C2 C) C3 D) C6 E) C9

C3

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? - CSF is a strong inducer of antiviral activities in our cells, and may help our immune system fight off the effects of an HIV infection for a longer period of time. - CSF will drive up the production of lactoferrin and transferrin, strong antiviral compounds produced in our mucus membrane secretions that trap and destroy viruses. - CSF is a cytokine that allows cells to communicate. If levels of CSF are elevated, HIV-infected cells can alert other healthy cells so that they produce protective IFNs. - CSF will help to stimulate the production of new lymphocytes, the very cells that are affected by HIV. This may help to keep the patients' immune responses "normal" for a period of time. - CSF will hyperstimulate the activities of the macrophages, leading to aggressive ingestion and successful destruction of HIV-infected cells.

CSF will help to stimulate the production of new lymphocytes, the very cells that are affected by HIV. This may help to keep the patients' immune responses "normal" for a period of time.

Please identify the INCORRECT definition regarding innate immunity. A) First line defenses—the barriers that separate and shield the interior of the body from the surrounding environment (skin and mucous membranes). B) Sentinel cells—host cells that help the immune system detect signs of invasion by producing cytokines when their PRRs recognize an invading microbe. C) Inflammatory response—coordinated innate response involved in containing a site of damage, localizing the response, eliminating the invader, and restoring tissue function. D) Innate lymphoid cells—a group of lymphocytes that have increased specificity in their mechanism of antigen recognition (example: natural killer (NK) cells). E) RIG-like receptors—a group of pattern recognition receptors within cells that recognize molecules associated with infecting viruses.

D) Innate lymphoid cells—a group of lymphocytes that have increased specificity in their mechanism of antigen recognition (example: natural killer (NK) cells). Natural killer cells, or NK cells, are a type of cytotoxic lymphocyte critical to the innate immune system. ... NK cells are known to differentiate and mature in the bone marrow, lymph nodes, spleen, tonsils, and thymus, where they then enter into the circulation. RIG-I-like receptors are a type of intracellular pattern recognition receptor involved in the recognition of viruses by the innate immune system.

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 E) Production of dsDNA

D) Production of dsRNA

How do some pathogens prevent complement activation or avoid the effects of activated complement? A) Some pathogens produce C5a peptidase that destroys complement C5a, a chemoattractant that recruits phagocytes to the area of infection. B) Some pathogens hijack the host's regulatory membrane proteins that inactivate C3b, preventing the triggering of the alternative activation pathway. C) Some pathogens produce C5a peptidase that causes destruction of phagoctyes recruited to the area of infection. D) Some pathogens hijack the host's regulatory membrane proteins that inactivate C3b, preventing the triggering of the alternative activation pathway AND some pathogens produce C5a peptidase that destroys complement C5a, a chemoattractant that recruits phagocytes to the area of infection. E) Some pathogens hijack the host's regulatory membrane proteins that inactivate C3b, preventing the triggering of the alternative activation pathway AND some pathogens produce C5a peptidase that causes destruction of phagoctyes recruited to the area of infection.

D) Some pathogens hijack the host's regulatory membrane proteins that inactivate C3b, preventing the triggering of the alternative activation pathway AND some pathogens produce C5a peptidase that destroys complement C5a, a chemoattractant that recruits phagocytes to the area of infection.

Syphilis, an STI, was once treated by intentionally infecting the patient with the parasite that causes malaria, a disease characterized by repeated boutsof fever, shaking,andchills. 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. 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. E) The bacteria that cause syphilis track down and destroy the protozoan that causes malaria. By doing this, the bacteria are "occupied" and do not cause damage to the human host.

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.

Toll-like receptors: A) are cytokines, are embedded in cellular membranes, AND are part of adaptive immunity. B) each recognize a specific "danger" molecule AND are cytokines. C) are embedded in cellular membranes AND are part of adaptive immunity. D) each recognize a specific "danger" molecule AND are embedded in cellular membranes. E) each recognize a specific "danger" molecule AND are part of adaptive immunity.

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

Which describes toll-like receptors? A) cytokines, embedded in cellular membranes, AND are part of adaptive immunity B) recognize a specific MAMP AND are cytokines C) embedded in cellular membranes AND are part of adaptive immunity D) each recognize a specific MAMP AND are embedded in cellular membranes E) each recognize a specific MAMP AND are part of adaptive immunity

D) each recognize a specific MAMP AND are embedded in cellular membranes

All blood cells originate from the: A) erythrocyte stem cell. B) leukocytic stem cell. C) eosinophilic stem cell. D) hematopoietic stem cell. E) osteocytes (bone cells).

D. hematopoietic stem cells - in the bone marrow

Your first patient of the day is complaining of pain in the area of his new tattoo. When you examine the tattoo, you note that the area around it is firm, red, and swollen. There is no evidence of pus, and your patient has a normal pulse, and no fever. You tell your patient that you have seen this type of response to a tattoo before, and that it is called a granulomatous reaction. You give him more information on the condition. Your patient questions why he has developed a granuloma. You explain to him that granulomas: A) are formed to recruit macrophages and neutrophils to an area of persistent inflammation such as that observed with a tattoo. B) result from activation of complement proteins; once complement C3 is activated, it causes a cascade of activation of C4 - C25. These activated proteins concentrate to form the granuloma. C) are immune cells that are normally synthesized to fight virus infections. In your patient's case, these cells were formed in response to ink particles. D) are proteins that recognize compounds unique to microbes or tissue damage; in your patient's case, these are made as a result to the tissue damage caused by the tattoo. E) are formed as an attempt by the body to wall off and contain persistent antigens - in his case, the red tattoo ink (red ink contains mercury compounds).

E

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

E - iron is one of the major components bacteria need for growth. Bind up the iron and stall the growth of invading microbes.

Which of the following is least likely to be detected by pattern recognition receptors? A) O antigen on Gram-negative bacteria B) Peptidoglycan in Gram-positive cells C) Flagellin and pilin D) Double-stranded viral RNA E) Enzymes involved in glycolysis

E) Enzymes involved in glycolysis

T/F - Antibody and antigen are held to one another by covalent bonds

False Antibodies bind antigens through weak chemical interactions, and bonding is essentially non-covalent. Electrostatic interactions, hydrogen bonds, van der Waals forces, and hydrophobic interactions are all known to be involved depending on the interaction sites. - the chains in antibodies are held together by disulfide bonds

T/F - Mast cells are only found in blood.

False - in tissues

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

Which of the following are lymphocytes? A) B cells B) T cells C) NK cells D) B cells AND T cells E) B cells, T cells, AND NK cells

E

How do cytokines function? A) They are produced by several cell types and bind directly to microbes to enhance their chance of being ingested, in a process called opsonization. B) They are secreted by lysozomes into the phagosomes of neutrophils to enhance the killing of ingested microbes within those organelles. C) They are secreted by one cell type, then work as a series of serum proteins to produce holes in the cytoplasmic membranes of microbes to directly lyse them. D) They are secreted by microbes that have been engulfed by phagocytes, causing those cells to produce destructive enzymes and undergo apoptosis. E) They are secreted by one cell type, 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.

E) They are secreted by one cell type, 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.

C3a and C5a are involved in: A) inflammation AND fever. B) interferon production AND attraction of phagocytes. C) properdin activation AND inflammation. D) attraction of phagocytes AND properdin activation. E) inflammation AND attraction of phagocytes.

E) inflammation AND attraction of phagocytes.

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

E) transferrin

T/F - Fever often enhances bacterial survival during an infection.

False

T/F - Gram-negative bacteria are less susceptible to complement lysis than Gram-positive bacteria.

False

T/F - Interferon directly interacts with and destroys viruses.

False

T/F - Neutrophils are the second phagocytic cell to respond to an infection.

False

T/F - Substances with a molecular weight of less than 10,000 Daltons make good antigens.

False

Which of the following would NOT trigger an inflammatory response? - Activation of complement proteins. - Binding of microbial products to PPRs. - Release of TNF by macrophages. - Tissue damage caused by microbial invasion. - Induction of antiviral protein synthesis by IFNs.

Induction of antiviral protein synthesis by IFNs.

Please identify the mismatched pair. - Alveolar macrophages—lungs - Peritoneal macrophages—meninges - Mesangial macrophages—kidneys - Microglial cells—brain - Kupffer cells—liver

Peritoneal macrophages—meninges

Which of the following is mismatched regarding protection of the body from pathogens? - Respiratory tract—mucociliary escalator - Stomach—acid conditions and normal microbiota - Saliva—lysozyme, peroxidase, and lactoferrin - Peroxidases—milk, saliva, mucus, and some phagocytes - Skin—salt, fatty acids, and normal microbiota

Stomach—acid conditions and normal microbiota

Your sister recently had her first child, a boy who she names Owen. Unfortunately, Owen seems to get sick really often, and after some investigation, he is diagnosed with an extremely rare genetic disorder called leukocyte adhesion deficiency (LAD). People with LAD suffer from repeated bacterial infections because their leukocytes have adhesion defects—they cannot adhere to the endothelium and as a result are unable to leave the blood vessels to move into tissues containing microbial invaders. Without this inflammatory response, the person experiences severe tissue infections and frequently has neutrophilia (high levels of neutrophils in the blood). You help your sister understand this disease, using your knowledge of the immune system. Which of the following is NOT true of neutrophils? - Their granules contain many enzymes and antimicrobial substances that help destroy engulfed materials. - They are the first leukocytes recruited to the site of an infection. - They are the most numerous and important granulocytes of the innate responses. - Their their numbers significantly decrease during most bacterial infections. - They are phagocytic and efficiently engulf and destroy bacteria and other material.

Their their numbers significantly decrease during most bacterial infections. - they significantly increase actually.

T/F - All pathways of complement activation follow the same sequence after C3.

True

T/F - Defensins are short antimicrobial peptides found within mucous membranes and phagocytes.

True

Your sister recently had her first child, a boy who she names Owen. Unfortunately, Owen seems to get sick really often, and after some investigation, he is diagnosed with an extremely rare genetic disorder called leukocyte adhesion deficiency (LAD). People with LAD suffer from repeated bacterial infections because their leukocytes have adhesion defects—they cannot adhere to the endothelium and as a result are unable to leave the blood vessels to move into tissues containing microbial invaders. Without this inflammatory response, the person experiences severe tissue infections and frequently has neutrophilia (high levels of neutrophils in the blood). You help your sister understand this disease, using your knowledge of the immune system. Given what you understand about inflammation, why do you think a person with LAD experiences neutrophilia (high numbers of neutrophils in the blood)? - When a person has an infection, their number of neutrophils increases. In a person with LAD, the neutrophils do not attach to endothelial cells, and thus cannot not leave the blood vessel to enter infected tissue. As a result, they accumulate in the blood. - When a person has an infection, their number of neutrophils always decreases significantly. In a person with LAD, there are so few neutrophils that these cells do not leave the blood vessel to enter infected tissue. As a result, they accumulate in the blood. - The inflammation response in a person with LAD is overactive. They produce an excess of phagocytic cells such as neutrophils and although some of these cells migrate into infected tissue, there are so many of these cells that the rest accumulate in the blood. - In a person with LAD, the neutrophils become "sticky" and adhere strongly to blood vessel walls. At the same time, endothelial cell junctions always tighten during inflammation, so the neutrophils cannot not leave the blood vessel and they accumulate in the blood. - None of these explains why a person with LAD suffers from neutrophilia.

When a person has an infection, their number of neutrophils increases. In a person with LAD, the neutrophils do not attach to endothelial cells, and thus cannot not leave the blood vessel to enter infected tissue. As a result, they accumulate in the blood.

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

chemotaxis

The leukocyte that contains histamine is the lymphocyte. monocyte. macrophage. basophil.

basophil - granules that stain purplish-blue with methylene blue. - involved in allergic rxns, like mast cells. - granulocyte - 2nd most numberous WBC

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

bone marrow - hematopoietic stem cells

Which of the following is a bacterial product? A) Lactoferrin B) Transferrin C) Colicin D) Defensin E) Mucus

colicin - A colicin is a type of bacteriocin produced by and toxic to some strains of Escherichia coli. Colicins are released into the environment to reduce competition from other bacterial strains.

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

complement

Which of the following are most susceptible to complement lysis? A) Gram-positive bacteria B) Gram-negative bacteria C) Bacteriophages D) Prions E) Acid-fast bacteria

gram negative bacteria