Mastering Ch 16 Homework
Think through the steps of phagocytosis, and select strategies from the list provided that might enable a microbe to avoid or escape phagocytosis or phagocytic killing. Select each of the items from the list that would enable a microbe to evade phagocytosis or avoid phagocytic killing. - A capsule surrounds the microbe. - Microbe produces leukocidin. - Microbe prevents fusion of phagosome with lysosome to form phagolysosome. - Microbial cell wall contains an outer membrane of lipopolysaccharide. - Microbial cell wall contains peptidoglycan. - Microbe speeds up acidification of phagosome. - Microbe escapes from phagosome prior to fusion with lysosome.
- A capsule surrounds the microbe. - Microbe produces leukocidin. - Microbe prevents fusion of phagosome with lysosome to form phagolysosome. - Microbe escapes from phagosome prior to fusion with lysosome. You have identified a variety of mechanisms by which a microbe may evade phagocytes and/or avoid destruction within a phagocyte. Some microbes employ more than one of these mechanisms, ensuring their survival within the host. For those organisms that escape phagocytosis, other host defenses will have to become activated, specifically components of the third line of defense: the adaptive immune response. The generation of antibodies and T cells and cytokines of the cell-mediated immune response will be necessary to combat such microbes.
Part C - Chemotaxis - Cells on the Move What might interfere specifically with chemotaxis of a phagocyte? Think about the process of chemotaxis and what might compromise this process. Select each of the items that might specifically interfere with chemotaxis. Weak or inadequate flagellar movement Defective antibody production Lysosomal defects Defective microfilament function Absence of cytokine and complement receptors on phagocyte surfaces
- Defective microfilament function - Absence of cytokine and complement receptors on phagocyte surfaces Chemotaxis is brought about by the binding of various chemoattractant substances (microbial components, complement components, cytokines) to receptors on the surface of phagocytes. This triggers cell movement toward higher concentrations of the attractant. The interaction of actin microfilaments and myosin (cytoskeletal elements) within the phagocyte makes this movement possible.
Another Pic for Part B - Cascade Order of Complement Activation in the Classical Pathway Once activated, the complement cascade is an ordered process. Each reaction leads to another reaction. This activity asks you to place the cascade reactions in the correct order as they occur, starting with C1. Drag the text below into boxes to indicate the correct order of events when complement is activated via the classical pathway.
This is just the photo that shows up when you get it right.
Microbiology Animation: Inflammation: Overview Part C What is the function of inflammation in response to a burn from a hot iron? To destroy the agent causing injury, to limit the effects of the agent on the rest of the body, and to repair the damaged tissue To limit the effects of the agent on the rest of the body To repair the damaged tissue To destroy the agent causing injury
To repair the damaged tissue
Part B - Cascade Order of Complement Activation in the Classical Pathway Once activated, the complement cascade is an ordered process. Each reaction leads to another reaction. This activity asks you to place the cascade reactions in the correct order as they occur, starting with C1. Drag the text below into boxes to indicate the correct order of events when complement is activated via the classical pathway.
Watch this video: http://highered.mheducation.com/sites/0072507470/student_view0/chapter22/animation__activation_of_complement.html
Part D If a new bacterial pathogen entered a human body through an accidental needle stick, the first cell that would try to kill the pathogen would likely be a cytotoxic T cell. an antibody-producing cell. a phagocyte.
a phagocyte.
Multiple Choice Question 16.37 Part A All of the following pertain to fever EXCEPT that it is caused by interleukin-1 and TNF-alpha coming into contact with the hypothalamus. accelerates microbial growth by increasing iron absorption from the digestive tract. stimulates T lymphocyte activity. intensifies the effect of antiviral interferons. can be initiated by specific types of pathogens.
accelerates microbial growth by increasing iron absorption from the digestive tract.
Multiple Choice Question 16.10 Part A Margination refers to: the chemotactic response of phagocytes. the movement of phagocytes through walls of blood vessels. the adherence of phagocytes to microorganisms. adherence of phagocytes to the lining of blood vessels. dilation of blood vessels.
adherence of phagocytes to the lining of blood vessels.
Chapter 16 - Reading Questions - Question 1 Part A Activation of C3 results in __________. release of histamine and other pro-inflammatory chemicals enhancement of phagocytosis via opsonization formation of a membrane attack complex (MAC), which causes cytolysis of bacteria all of these
all of these
Multiple Choice Question 16.41 Part A All of the following are components of the inflammatory process EXCEPT release of histamines and prostaglandins. chemotaxis. antibody synthesis. dilation of blood vessels. diapedesis.
antibody synthesis.
Multiple Choice Question 16.28 Part A The classical pathway for complement activation is initiated by lipid-carbohydrate complexes and C3. C5-C9. antigen-antibody reactions. factors released from damaged tissues. factors released from phagocytes.
antigen-antibody reactions.
Chapter 16 - Reading Questions - Question 4 Part A Which of the following are best described as short chains of amino acids that are very stable and can have a variety of different antimicrobial activities, such as forming pores in bacterial plasma membranes and inhibiting cell wall synthesis? antimicrobial peptides mannose-binding lectin antiviral proteins siderophores
antimicrobial peptides
Multiple Choice Question 16.23 Part A A chill is a sign that body temperature is falling. the metabolic rate is decreasing. body temperature is not changing. body temperature is rising. blood vessels are dilating.
body temperature is rising.
Multiple Choice Question 16.44 Part A Lysozyme and the antibiotic penicillin have similar mechanisms of action in that they both cause damage to the bacterial capsule. cell membrane. DNA. ribosomes. cell wall.
cell wall.
Multiple Choice Question 16.25 Part A Which of the following is mismatched? abcess a cavity created by tissue damage and filled with pus pus tissue debris and dead phagocytes in a white or yellow fluid scab dried blood clot over injured tissue diapedesis movement of leukocytes between capillary walls cells out of blood and into tissue chemotaxis chemical degradation inside a phagolysosome
chemotaxis chemical degradation inside a phagolysosome
Microbiology Animation: Phagocytosis: Mechanism Part B The process by which a phagocyte moves toward a chemical signal at the site of an infection is called exocytosis. chemotaxis. digestion. elimination. adherence.
chemotaxis.
Multiple Choice Question 16.12 Part A Which of the following is found normally in serum? complement TLRs histamine leukocytosis-promoting factor interferon
complement
Multiple Choice Question 16.32 Part A After ingesting a pathogen, lysosomal enzymes produce all of the following EXCEPT complement. H2O2. O2-. OH•. HOCl.
complement.
Multiple Choice Question 16.42 Part A Several inherited deficiencies in the complement system occur in humans. Which of the following would be the MOST severe? deficiency of C3 deficiency of C5 deficiency of C6 deficiency of C7 deficiency of C8
deficiency of C3
Concept Map: Phagocytosis Part C In macrophages and dendritic cells (so-called antigen-presenting cells) some small parts of the phagocytosed particle are presented to other cells of the immune system. If you were to draw an arrow leading to "antigen presentation" as described above, from which word would it extend? exocytosis digestion ingestion adherence
digestion
Chapter 16 - Reading Questions - Question 9 Part A You note that the body temperature of one of your patients is starting to increase. As a result, you can infer that all of the following may be occurring in this patient EXCEPT __________. constriction of blood vessels increased metabolic rate dilation of blood vessels shivering
dilation of blood vessels
Multiple Choice Question 16.35 Part A Which of the following is involved in resistance to parasitic helminths? eosinophils lymphocytes basophils neutrophils monocytes
eosinophils
Multiple Choice Question 16.21 Part A All of the following are effects of histamine EXCEPT: redness. vasodilation. pain. fever. swelling.
fever.
Multiple Choice Question 16.16 Part A Each of the following provides protection from phagocytic digestion EXCEPT leukocidins. formation of phagolysosomes. capsules. M protein. biofilms.
formation of phagolysosomes.
Multiple Choice Question 16.18 Part A The swelling associated with inflammation decreases when the fluid returns to the blood. is transported into macrophages. goes into lymph capillaries. is excreted in urine. is lost as perspiration.
goes into lymph capillaries.
Microbiology Animation: Host Defenses: The Big Picture Part B According to the animation, B cells interact directly with helper T cells. inflammation. phagocytes. the complement system.
helper T cells.
Multiple Choice Question 16.14 Part A Which of the following is an effect of opsonization? increased margination of phagocytes inflammation increased diapedesis of phagocytes increased adherence of phagocytes to microorganisms cytolysis
increased adherence of phagocytes to microorganisms
Multiple Choice Question 16.17 Part A The antimicrobial effects of AMPs include all of the following EXCEPT lysis of bacterial cells. destruction of nucleic acids. pore formation in bacterial membranes. inhibition of phagocytosis. inhibition of cell wall synthesis.
inhibition of phagocytosis.
Microbiology Animation: Host Defenses: The Big Picture Part A Mucous membranes are a part of cell-mediated immunity. innate defense. humoral immunity. adaptive defense. the complement system.
innate defense.
Multiple Choice Question 16.13 Part A Each of the following is an effect of complement activation EXCEPT increased phagocytic activity. bacterial cell lysis. increased blood vessel permeability. interference with viral replication. opsonization.
interference with viral replication.
Multiple Choice Question 16.1 Part A Innate immunity: involves T cells and B cells. is slower than adaptive immunity in responding to pathogens. involves a memory component. provides increased susceptibility to disease. is nonspecific and present at birth.
is nonspecific and present at birth.
Multiple Choice Question 16.27 Part A The alternative pathway for complement activation is initiated by antigen-antibody reactions. factors released from phagocytes. lipid-carbohydrate complexes and C3. C5-C9. factors released from damaged tissues.
lipid-carbohydrate complexes and C3.
It's a compliment to have complement! Part C Because C5 is absent in their sera, which of the protective effects of complement activation does not occur in response to infection with Neisseria meningitidis? binding of properdin to invading bacteria promoting attachment of phagocytes to infecting microbes activation of C3 lysis of infecting microbes
lysis of infecting microbes Correct Anchored in a microbial membrane, C5b serves as the binding site for the complement proteins that form the membrane-attack complex.
Multiple Choice Question 16.33 Part A Activation of C5-C9 results in: phagocytosis. inflammation. lysis of microbial cells. activation of C3. fixation of complement.
lysis of microbial cells.
Concept Map: Phagocytosis Part B In which intracellular compartment would you expect most of the digestive enzymes involved in pathogen destruction to be found? phagocytosis macrophage lysosome phagosome
lysosome
Multiple Choice Question 16.20 Part A Phagocytes utilize all of the following to optimize interaction with microorganisms EXCEPT lysozyme. opsonization. chemotaxis. trapping a bacterium against a rough surface. complement.
lysozyme.
Multiple Choice Question 16.8 Part A All of the following increase blood vessel permeability EXCEPT histamine. kinins. lysozymes. leukotrienes. prostaglandins.
lysozymes.
Multiple Choice Question 16.4 Part A Which of the following exhibits the highest phagocytic activity? macrophages eosinophils neutrophils basophils erythrocytes
macrophages
Multiple Choice Question 16.40 Part A The lectin pathway for complement action is initiated by gram-positive cell walls. mannose on the surface of microbes. mannose on host membranes. lectins of the microbe. gram-negative cell walls.
mannose on the surface of microbes.
Multiple Choice Question 16.36 Part A Macrophages arise from which of the following? monocytes eosinophils basophils neutrophils lymphocytes
monocytes
Multiple Choice Question 16.45 Part A Which non-specific defense mechanism is mismatched with its associated body structure or body fluid? very acidic pH stomach lysozyme tears and saliva keratin and tightly packed cells skin cerumen and sebum ear mucociliary escalator intestines
mucociliary escalator intestines
It's a compliment to have complement! Concerned because his brother Charlie has not shown up at a family lunch and has not answered several phone calls, Pete drives to Charlie's apartment to check on him. Charlie, a 25-year old architect, had left Pete's bachelor party early last night because he felt exhausted and complained of aching muscles. Pete finds Charlie in bed, who says he has a pounding headache, feels dizzy, and has a stiff neck. Alarmed because Charlie had similar symptoms seven years ago, Pete drives his brother to the emergency room. The triage nurse finds that Charlie has a temperature of 102.8 and a racing pulse. She quickly calls for Dr. Molitor. The physician suspects meningococcal meningitis and starts Charlie on an i.v. with the antibiotic ceftriaxone. Dr. Molitor also removes a sample of cerebrospinal fluid (CSF) with a lumbar puncture and sends it to the lab for a stat Gram stain. Part A Below is a view at 1000X magnification of a Gram stain of the cerebrospinal fluid. What type of white blood cell predominates in Charlie's CSF? lymphocyte eosinophil neutrophil monocyte
neutrophil Correct The multilobed nucleus is characteristic of the neutrophil. The granules are not stained. Dr. Molitor learns from the family that Charlie had been diagnosed with meningococcal meningitis at the end of his high school senior year. Charlie's 18-year-old sister Rachelle also had the same infection last year. Based on this family medical history, Dr. Molitor speculates that Charlie and Rachelle have an inherited deficiency of a complement component. A CH50 test reveals that their sera lack the ability to lyse sheep red blood cells that have antibodies bound to them. Another test finds that both of them are missing the complement component C5 in their blood.
Multiple Choice Question 16.9 Part A A child falls and suffers a deep cut on her leg. The cut went through her skin and she is bleeding. Which of the following defense mechanisms will participate in eliminating contaminating microbes? normal skin flora mucociliary escalator lysozyme acidic skin secretions phagocytosis in the inflammatory response
phagocytosis in the inflammatory response
Concept Map: Phagocytosis Part A Mycobacterium tuberculosis is an intracellular pathogen of humans. After being ingested by a macrophage, it prevents formation of the ___________ by preventing fusion of the phagosome with the ___________________. lysosome, phagolysosome opsonins, lysosome phagolysosome, lysosome lysosome, opsonins
phagolysosome, lysosome
Multiple Choice Question 16.30 Part A Neutrophils with defective lysosomes are unable to: engulf microorganisms and other foreign material. undergo chemotaxis. migrate. attach to microorganisms and other foreign material. produce toxic oxygen products.
produce toxic oxygen products.
Multiple Choice Question 16.31 Part A Innate immunity includes all of the following EXCEPT inflammation. activation of complement. production of interferon. production of antibody. phagocytosis.
production of antibody.
Multiple Choice Question 16.38 Part A All of the following are iron-binding proteins found in humans EXCEPT hemoglobin. ferritin. transferrin. lactoferrin. siderophorin.
siderophorin.
Part E - Disorders of Phagocytosis Impaired phagocytosis can lead to several disorders. This activity asks you to think specifically about the process through which phagocytes kill and digest microbes and to identify steps of the process that might be compromised and interfere with this killing activity. Select each of the items that would be likely to interfere with the killing of microbes once phagocytes have ingested them. Assume that chemotaxis, attachment, and ingestion occurred normally. Lack of chemotactic receptors on phagocytes Defective microtubule function Myeloperoxidase deficiency Ineffective opsonization Defective oxidative burst An increase in the number of leukocytes
- Defective oxidative burst - Defective microtubule function - Myeloperoxidase deficiency Correct Once a phagocyte has ingested its target microbe, several processes ensue that bring about the destruction of the microbe. First, the phagosome must fuse with the lysosome. This process is enabled by microtubules, which facilitate the movement of organelles within cells. Defective microtubule function would likely prevent the formation of phagolysosomes. Chediak-Higashi is a human disease characterized by defective microtubule function and impaired phagocytosis. Individuals with this disease suffer from repeated infections. Once phagolysosomes are formed, the next step in phagocytosis is the generation of toxic oxygen products that are lethal to the ingested microbe. A defect in this process can compromise phagocytosis. Chronic granulomatous disease is an inherited disorder in which the oxidative burst process is defective and phagocytic cells are unable to effectively kill the microbes they phagocytize. As might be expected, this disease is characterized by repeated serious infections. A third disorder of phagocyte function is myeloperoxidase deficiency. Phagocytic cells may show an oxidative burst but be unable to produce hypochlorous acid; as a result, the phagocytes' ability to kill the microbes is compromised.
The Phases of Phagocytosis - Foundation Figure 16.7 Part A - What Types of Cells Are Phagocytes? Most phagocytes are types of white blood cells, but not all white blood cells participate in this process. Select the cell types that are actively phagocytic. Neutrophil Eosinophil Dendritic cell Basophil Erythrocyte B lymphocyte Macrophage T lymphocyte
- Dendritic cell - Eosinophil - Macrophage - Neutrophil The actively phagocytic cells include neutrophils, eosinophils, macrophages, and dendritic cells. Although monocytes leave circulation and mature into phagocytic cells, including both macrophages and dendritic cells, the monocytes that are circulating are themselves not activity phagocytic. Now that you have identified the cell types most often associated with phagocytosis, we will explore the process of how phagocytosis occurs.
MicroFlix Quiz: Immunology Part F Place the following steps of phagocytosis in the order that they occur: 1.Endosome fuses with lysozome 2.Dendritic cell engulfs Rhinovirus 3.Epitopes are attached to MHC-II 4.Digestion of the Rhinovirus 5.MHC-II plus the attached epitope move to the outside of the dendritic cell 2,4,1,3,5 2,1,3,4,5 1,2,4,3,5 2,1,4,3,5
2,1,4,3,5 2.Dendritic cell engulfs Rhinovirus 1.Endosome fuses with lysozome 4.Digestion of the Rhinovirus 3.Epitopes are attached to MHC-II 5.MHC-II plus the attached epitope move to the outside of the dendritic cell
MicroFlix Quiz: Immunology Part D Correctly order the steps involved cellular immunity: 1.The Tc recognizes the infected host cell 2 The Tc interacts with epitope presented by MHC-I on the dendritic cell 3.The Tc secretes perforin and granzyme, causing apoptosis 4.The helper T cell activates the Tc cell Correctly order the steps involved cellular immunity: 1,2,4,3 2,1,3,4 4,2,1,3 2,4,1,3
2,4,1,3 2 The Tc interacts with epitope presented by MHC-I on the dendritic cell 4.The helper T cell activates the Tc cell 1.The Tc recognizes the infected host cell 3.The Tc secretes perforin and granzyme, causing apoptosis Correct The cytotoxic T cell uses its CD8 glycoprotein to bind to the MHC-I of an infected host cell.
Part E - Outcomes of the Membrane Attack Complex You now know that once complement gets activated, all outcomes occur. With respect to the membrane attack complex (MAC), which of the following is most likely to occur once all of the C9 proteins insert into the bacterial membrane? You now know that once complement gets activated, all outcomes occur. With respect to the membrane attack complex (MAC), which of the following is most likely to occur once all of the C9 proteins insert into the bacterial membrane? The bacterium will repair the membrane and eventually recover. A hole will form in the bacterium, allowing water to rush into the cell, causing it to burst. A neutrophil will engulf the bacterium because C9 acts as an opsonin. More C1 becomes activated because C9 is an activator of C1 proteins.
A hole will form in the bacterium, allowing water to rush into the cell, causing it to burst. Correct You are correct! The MAC causes a very large hole in the membrane. Bacteria cannot withstand such a large amount of damage to the membrane and will be killed.
Based on the animation, which of the following is cleaved by C1? A. C2 and C4 B. C5 and C4 C. C5 D. C2 E. C4
A. C2 and C4
What complement result involves the use of phagocytes? A. Chemotaxis and opsonization B. Chemotaxis C. Cytolysis D. Opsonization A. Chemotaxis and opsonization
A. Chemotaxis and opsonization
How does cytolysis occur via the complement pathway? A. Formation of the MAC in invading cells, killing them B. Stimulation of the inflammatory response C. Triggering the release of histamine D. Disrupting cell wall of pathogens
A. Formation of the MAC in invading cells, killing them
If a person lacked the ability to form C5, what direct result of complement could still occur? A. Opsonization B. Chemotaxis C. Cytolysis
A. Opsonization
Pus is comprised of A. dead phagocytes. B. excess fluid from leaky blood vessels. C. collected cells from damaged tissue. D. unused histamines and leukotrienes.
A. dead phagocytes.
Diapedesis is A. the migration of phagocytes through blood vessels to the site of tissue damage. B. the attachment of phagocytes to the walls of capillaries. C. the increase in the diameter of blood vessels. D. the production and release of chemicals during inflammation.
A. the migration of phagocytes through blood vessels to the site of tissue damage.
Multiple Choice Question 16.5 Part A TLRs attach to all of the following EXCEPT AMPs. LPS. peptidoglycan. flagellin. PAMPs.
AMPs.
MicroFlix Quiz: Immunology Part H Which of the following is NOT a step that ultimately leads to antibody production? Differentiation of plasma cells Immature B cells conducting surveillance for foreign epitopes Activation of cytotoxic T cells by helper T cells Activation of helper T cells by dendritic cells
Activation of cytotoxic T cells by helper T cells Correct The activation of cytotoxic T cells leads down the path of cell-mediated immunity.
MicroFlix Quiz: Immunology Part J Which of the following statements is true? Memory B cells are typically established when the B cell binds to an antigen. Adaptive defenses include both humoral and cellular immunity. Adaptive defenses include humoral immunity only. Innate defenses are enough to keep a person healthly.
Adaptive defenses include both humoral and cellular immunity. Correct This answer is correct. Adaptive defenses are operating optimally when both humoral and cellular immunity are working together in response to a pathogen.
Outcomes of Complement Activation - Foundation Figure 16.9 Part A - Outcomes of the Classical Pathway When complement is activated via the classical pathway, which of the following outcomes is likely to occur? Membrane attack complex will form. Inflammation will be stimulated. Pathogens will become opsonized. All of the above will occur.
All of the above will occur Correct Yes. In ANY of the three pathways, all of these outcomes will occur. In all of the pathways, C3 eventually becomes cleaved. Once C3 becomes cleaved, the cascade commences until the pathogen is destroyed.
MicroFlix Quiz: Immunology Part B What is meant by the clonal expansion of a B cell? An activated B cell will kill infected host cells. An activated B cell divides into cells that give rise to memory B cells and plasma cells. An activated B cell will immediately begin to produce antibodies. An activated B cell will engulf and digest anything foreign.
An activated B cell divides into cells that give rise to memory B cells and plasma cells. Correct This answer is correct. The activated B cell divides until there are many clones. Some differentiate into memory cells, other become plasma cells that produce and secrete antibodies.
Part A A response that is uniquely directed against pathogenic Bordetella pertussis would involve what component? Skin barrier Inflammation The complement system Antibodies
Antibodies
Which of the following are functions of lectins? A. They attach to carbohydrates on some bacterial and viral surfaces. B. They act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4. C. They produce factor P (properdin). D. They produce antibodies. E. They can activate C2 and C4. F. They act as opsonins for phagocytosis.
B. They act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4.
MicroFlix Quiz: Immunology Part G Which pair of molecules do NOT directly interact with one another? CD4 and MHC-II BCR and TCR CD8 and MHC-I BCR and epitope
BCR and TCR Correct Both of these molecules interact with epitopes. BCRs interact with epitopes on the whole pathogen. TRCs interact with processed epitopes when presented on MHC-II.
Chapter 16 - Reading Questions - Question 7 Part A Which of the following statements concerning phagocytosis is true? Phagocytes cannot ingest microorganisms unless they are coated with antibodies. Adherence always requires opsonization. Phagocytes ingest microorganisms by using protein transporters that are specific for the bacteria. Bacteria are digested when the phagosome fuses with a lysosome.
Bacteria are digested when the phagosome fuses with a lysosome.
If a person could not form C2, which result of complement would be affected? A. Opsonization B. Cytolysis C. Cytolysis, chemotaxis, inflammation, and opsonization D. Chemotaxis and inflammation
C. Cytolysis, chemotaxis, inflammation, and opsonization
Which of the complement pathways was discovered first? A. The lectin pathway B. The alternative pathway C. The classical pathway
C. The classical pathway
Antibodies from cellular immune responses are used in A. the lectin pathway. B. the alternative pathway. C. the classical pathway. D. both the classical and alternative pathways.
C. the classical pathway.
Multiple Choice Question 16.7 Part A The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway beginning with the activation of: C1. C2. C3. C5. C6.
C3
Multiple Choice Question 16.43 Part A Which of the following statements about the classical pathway of complement activation is FALSE? The C1 protein complex is initiated by antigen-antibody complexes. C1 is the first protein activated in the classical pathway. Cleaved fragments of some of the proteins act to increase inflammation. C3b causes opsonization. C3 is not involved in the classical pathway.
C3 is not involved in the classical pathway.
Based on the animation, which of the complement proteins can directly bind to the surface of a bacterial cell? C5b C3b C2b C2a C4a
C3b
Which complement protein is used as an opsonin? C3a C3b C2a C7 C5b C4a
C3b
It's a compliment to have complement! Part B The absence of C5 means that the molecule is not present to be activated. What happens in normal serum when C5 is "activated"? C3b is a part of enzyme that splits C5 into two fragments, C5a and C5b. C5 is bound to the membrane-attack complex. C5 becomes a protein-digesting enzyme that splits C3 into two fragments, C3a and C3b. C5 binds to Factor B.
C3b is a part of enzyme that splits C5 into two fragments, C5a and C5b. Correct This happens in the three complement activation pathways. C3b is a part of an enzyme that digests C5.
It's a compliment to have complement! Part D Fragment C5b initiates the binding of the terminal complement proteins that form the membrane-attack complex (MAC). Which of these proteins associates with the MAC? Mannose-binding lectin C1 Factor D C7
C7 The sequence of assembly is C6, C7, and C8. C8 then recruits multiple C9 proteins that assemble into a pore in the membrane.
MicroFlix Quiz: Immunology Part I A person who has AIDS contracts rare and often life-threatening infections because their helper T cell count is so low. Which of the following components of the immune response still respond to antigen despite the low helper T cell count? Clonal expansion and antibody production Clonal selection of B cells Activation of cytotoxic T cells Apoptosis of infected host cells
Clonal selection of B cells Correct B cells can still bind to antigen, which is the process of clonal selection. However, without a helper T cell, clonal expansion and antibody production will not occur.
Microbiology Animation: Phagocytosis: Overview Part A Phagocytosis is defined as the feeding of protozoans. the uptake of liquid material by a eukaryotic cell. cells of the immune system that ingest pathogens. the ingestion of solid material by a eukaryotic cell.
the ingestion of solid material by a eukaryotic cell.
Multiple Choice Question 16.6 Part A A differential cell count is used to determine each of the following EXCEPT the numbers of each type of white blood cell. the number of red blood cells. leukopenia. the total number of white blood cells. leukocytosis.
the number of red blood cells.
Part C Both the innate and adaptive defenses of the immune system work to prevent: disease. penetration by invading pathogens. colonization by pathogens. the penetration and colonization by pathogens, and the diseases they cause.
the penetration and colonization by pathogens, and the diseases they cause.
Microbiology Animation: Phagocytosis: Microbes that Evade it Part B Which microorganism requires the low pH inside a phagolysosome in order to reproduce? Streptococcus pyogenes Streptococcus pneumoniae Haemophilus influenzae Coxiella burnetii
Coxiella burnetii
Microbiology Animation: Host Defenses: The Big Picture Part E Which cells directly attack abnormal cells in the body? Phagocytes Cytotoxic T cells B cells Helper T cells
Cytotoxic T cells
Based on the animation, which of the following is responsible for cleaving C3? A. C1 B. C4aC2b C. C5bC6C7 D. C2aC4b
D. C2aC4b
Which of the following can release histamines? A. The complement system B. Invading bacterial cells C. Wood from a splinter D. Cells from damaged tissues and the complement pathway E. Cells from damaged tissues
D. Cells from damaged tissues and the complement pathway
Why is vasodilation important to tissue repair? A. It allows more nutrients to be delivered to the site of damage. B. It allows more phagocytes to travel to the site of damage. C. It allows for an increase in oxygen to the site of damage. D. It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage.
D. It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage.
In the classical pathway, which of the following directly activates cellular responses? A. C3a and C5a B. C5bC6C7 C. C2aC4b D. C3b E. C3a, C5a, and C5bC6C7 F. C4aC2bC3b
E. C3a, C5a, and C5bC6C7
Where are the complement proteins found in the body? A. The liver B. In every cell C. The spleen D. The thymus E. The blood serum
E. The blood serum
Enhances phagocytosis: -Complement peptides deposited on microbe surface -Antibody molecules attaching to microbe surface Interferes with phagocytosis: -Microbial capsules -Deposition of host-derived fibrin on microbe surface -M protein of Streptococcus pyogenes
Enhances phagocytosis: -Complement peptides deposited on microbe surface -Antibody molecules attaching to microbe surface Interferes with phagocytosis: -Microbial capsules -Deposition of host-derived fibrin on microbe surface -M protein of Streptococcus pyogenes
Microbiology Animation: Phagocytosis: Mechanism Part C Which of the following phagocytic processes occurs last in the sequence? Adherence Chemotaxis of the phagocyte to the site of infection Exocytosis Formation of the phagolysosome
Exocytosis
Multiple Choice Question 16.11 Part A Which of the following statements is TRUE? Beta interferon attacks invading viruses. Alpha interferon promotes phagocytosis. All three types of interferons have the same effect on the body. Gamma interferon causes bactericidal activity by macrophages. Alpha interferon acts against specific viruses.
Gamma interferon causes bactericidal activity by macrophages.
Microbiology Animation: Phagocytosis: Mechanism Part A What does the plasma membrane of a phagocyte attach to on a microorganism? Lysosomes Pseudopods Glycoproteins Phagosomes
Glycoproteins
Multiple Choice Question 16.2 Part A All of the following protect the skin and mucous membranes from infection EXCEPT saliva. multiple layers of cells. HCl. tears. the "ciliary escalator."
HCl.
MicroFlix Quiz: Immunology Part A What is the role of helper T cells in the adaptive immune response? Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells. Helper T cells directly kill infected host cells. Helper T cells produce and secrete antibodies. Helper T cells phagocytize bacteria and viruses.
Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells. Correct Helper T cells activate B cells that are displaying antigen, causing clonal expansion. Helper T cells also activate cytotoxic T cells, which will search for and destroy infected host cells.
Chapter 16 - Reading Questions - Question 5 Part A Which of the following statements about innate immunity is true? Innate immunity is present at birth. Innate immunity involves specific recognition of microorganisms via a memory response. The innate immune response does not have a mechanism for detecting invading microorganisms. It is activated only in response to tissue damage or a signal from an infected cell. It involves the activity of B and T cells.
Innate immunity is present at birth.
Chapter 16 - Reading Questions - Question 6 Part A Which of the following statements about beta interferon is true? It is produced only in response to infection with the hepatitis B virus. It is a protein that specifically degrades viral RNA. It acts as a signal that induces uninfected cells to produce antiviral proteins. It induces neutrophils and macrophages to kill bacteria.
It acts as a signal that induces uninfected cells to produce antiviral proteins.
Microbiology Animation: Inflammation: Overview Part A An inflammatory response would result from which of the following? Jellyfish sting A headache Vomiting
Jellyfish sting
Chapter 16 - Reading Questions - Question 8 Part A ________________ is/are always present in an individual's blood. However, in the absence of infection, it is in an inactive form. Cytokines Kinins Histamine Prostaglandins
Kinins
Chapter 16 - Reading Questions - Question 10 Part A Which statement regarding the lymphatic system is true? Lymph nodes are sites of activation of neutrophils, which destroy microbes. Lymphatic capillaries possess one-way valves. These valves permit the uptake of fluid from the body but do not allow the fluid to flow back out of the capillaries into the intracellular spaces. The pancreas contains lymphocytes and macrophages that monitor the blood for microbes. The thymus serves as the site for activation of B cells.
Lymphatic capillaries possess one-way valves. These valves permit the uptake of fluid from the body but do not allow the fluid to flow back out of the capillaries into the intracellular spaces.
MicroFlix Quiz: Immunology Part C The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. What component of the immune system will protect her from getting the same cold again? Memory B cells Plasma cells Antibodies that are "left over" from the last infection Dendritic cells
Memory B cells Correct Memory cells to that specific virus are stored in the lymph nodes for many years. When the student comes into contact with this specific Rhinovirus, these memory cells quickly divide and differentiate into antibody-producing plasma cells. The antibodies will prevent the virus from reaching an infectious titer (number that causes infection).
Multiple Choice Question 16.26 Part A All of the following are part of the mechanism of action of alpha and beta interferons EXCEPT they disrupt stages of viral multiplication. they bind to the surface of uninfected cells. they are effective for long periods. they initiate transcription. they initiate manufacture of antiviral proteins.
they are effective for long periods.
Multiple Choice Question 16.34 Part A All of the following are true regarding NK cells EXCEPT they are found in tissues of the lymphatic system. they are a type of lymphocyte. they destroy infected body cells by phagocytosis. they release toxic substances that cause cell lysis or apoptosis. they have the ability to kill infected body cells and some tumor cells.
they destroy infected body cells by phagocytosis.
Multiple Choice Question 16.15 Part A Normal microbiota provide protection from infection in each of the following ways EXCEPT: they produce antibacterial chemicals. they produce lysozyme. they compete with pathogens for nutrients. they make the chemical environment unsuitable for nonresident bacteria. they change the pH of the environment.
they produce lysozyme.
Multiple Choice Question 16.3 Part A The function of the "ciliary escalator" is to remove microorganisms from the gastrointestinal tract. remove microorganisms from the upper respiratory tract. remove microorganisms from the lower respiratory tract. propel inhaled dust and microorganisms toward the throat. trap inhaled dust and microorganisms in mucous and propel it away from the lower respiratory tract.
trap inhaled dust and microorganisms in mucous and propel it away from the lower respiratory tract.
It's a compliment to have complement! Part E Suppose that Charlie and Rachelle have a C3 deficiency rather than a C5 deficiency. What would be one consequence for innate immunity to microbes if these siblings lack C3 in their blood? Targeted bacteria would be lysed. Bone marrow cells do not receive the signal required for differentiating into mast cells. Without mast cells, inflammatory responses to invading microbes are greatly diminished. Mast cells release histamine and tumor necrosis factor when bacteria invade tissues. Phagocytes could not attach as easily to invading microbes. Phagocytes would be attracted to tissue sites where early complement proteins have been activated.
Phagocytes could not attach as easily to invading microbes. Correct C3b is an important opsonin.
Microbiology Animation: Host Defenses: The Big Picture Part D According to the animation, antibodies interact with which innate defenses? The complement system Phagocytosis and the complement system First-line defenses Phagocytosis Phagocytosis, inflammation, and the complement system Inflammation
Phagocytosis and the complement system
Multiple Choice Question 16.39 Part A All of the following occur during inflammation. What is the first step? margination phagocyte migration diapedesis vasodilation repair
vasodilation
What cellular macromolecules make up the complement pathway? Lipids Proteins Carbohydrates Nucleic acids
Proteins
Microbiology Animation: Phagocytosis: Overview Part B How is phagocytosis in the immune system different from protozoan phagocytosis? Protozoan phagocytosis is used to fight infection; phagocytosis by immune cells is used to feed the cells. Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection. There is no difference between the two.
Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection.
MicroFlix Quiz: Immunology Part E Which of the following is NOT a step used by cytotoxic T cells to kill infected host cells? Recognition of infected host cell using its TCR Secretion of perforin Secretion of granzyme Recognition of infected host cell using its CD4 glycoprotein
Recognition of infected host cell using its CD4 glycoprotein
Steps of Phagocytosis: 1. Chemotaxis of phagocyte to microbe occurs. 2.Phagocyte adheres or attaches to microbe. 3. Pseudopods of the phagocyte engulf and internalize the microbe, forming a phagosome. 4. Lysosome fuses with the phagosome, forming phagolysosome. 5. Digestion of microbe occurs within phagolysosome. 6. Indegistible material is discharged.
Steps of Phagocytosis: 1. Chemotaxis of phagocyte to microbe occurs. 2.Phagocyte adheres or attaches to microbe. 3. Pseudopods of the phagocyte engulf and internalize the microbe, forming a phagosome. 4. Lysosome fuses with the phagosome, forming phagolysosome. 5. Digestion of microbe occurs within phagolysosome. 6. Indegistible material is discharged. Chemotaxis refers to the movement of a cell in response to a chemical stimulus. It is the process by which phagocytes locate and approach microbes that have entered the body. Chemotaxis is described as positive if the cell moves toward an attractant, and negative if the cell moves away from a stimulus. Phagocytes exhibit positive chemotaxis as they move toward chemical stimuli provided by invading microbes, components of white blood cells, damaged tissue, complement components, and cytokines released by white blood cells. The movement of phagocytes is described as ameboid motion because it resembles the movement of amebae (which are protozoans). This movement involves elements of the cytoskeleton of the phagocyte, specifically the microfilaments. Microfilaments are composed of the protein actin. Polymerization of actin can lengthen the microfilament, whereas depolymerization will shorten the microfilament. The lengthening or shortening of the microfilaments is what enables pseudopods to extend and retract.
Microbiology Animation: Phagocytosis: Microbes that Evade it Part C Which of the following microorganisms use M protein to avoid destruction of a phagocyte? Haemophilus influenzae Streptococcus pyogenes Streptococcus pneumoniae Coxiella burnetii
Streptococcus pyogenes
Microbiology Animation: Host Defenses: The Big Picture Part C Which of the following defense systems would be involved in eliminating virally-infected cells? Humoral immunity Phagocytosis Complement system T lymphocytes
T lymphocytes
Microbiology Animation: Inflammation: Overview Part B If a person turns their ankle, how would one determine if damage to the tissue in the ankle has occurred? The ankle is very warm to the touch. The ankle swells. The ankle is red, swollen, and warm to the touch. The ankle is red.
The ankle is red, swollen, and warm to the touch.
Microbiology Animation: Phagocytosis: Mechanism Part E What is a phagolysosome? The structure that results from the fusion of a phagosome and a lysosome. A vesicle containing only digestive enzymes and other antimicrobial compounds. A vesicle containing only an engulfed invading microorganism. A protein that covers the surface of an invading microbe, making it easier for the phagocyte to ingest.
The structure that results from the fusion of a phagosome and a lysosome.
Part F - Why Stimulate Inflammation? One of the outcomes of complement activation is the stimulation of inflammation. Inflammation may result in redness, heat, swelling, and pain. Of the following, which is NOT a way that inflammation helps the body clear infection? One of the outcomes of complement activation is the stimulation of inflammation. Inflammation may result in redness, heat, swelling, and pain. Of the following, which is NOT a way that inflammation helps the body clear infection? Inflammation allows for more macrophages to come to the area of infection. The swelling of the infected area destroys pathogens by squishing them. Inflammation causes diapedesis, which allows more neutrophils to the area of infection. Inflammation causes more blood to flow to the infected area, as evidenced by redness.
The swelling of the infected area destroys pathogens by squishing them. Correct You are correct! Swelling due to inflammation is caused by the increase of blood to the area of infection. This extra blood contains lots of immune cells as well as red blood cells. Swelling does not, however, put enough pressure on the pathogen to destroy it.
Multiple Choice Question 16.24 Part A Which of the following statements is TRUE? Complement activity is antigen-specific. Factors B, D, and P cause cytolysis. There are at least thirty complement proteins. Complement increases after immunization. All of the complement proteins are constantly active in serum.
There are at least thirty complement proteins.
What direct effect do histamines and leukotrienes have on capillaries? They prevent phagocytes from sticking to the walls of capillaries. They allow capillary walls to open and become leaky. They decrease the diameter of capillaries.
They allow capillary walls to open and become leaky.
Part B First line defenses have what aspect in common with each other? They involve the production of antibodies. They are physical barriers against invading pathogens. They involve unique cells that attack invading pathogens. They recognize specific pathogens.
They are physical barriers against invading pathogens.
Microbiology Animation: Phagocytosis: Mechanism Part D What is the role of opsonins? They attract phagocytes to the location of infection. They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader. They are present on the surface of phagocytes. They aid in the formation of the phagolysosome.
They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.
Multiple Choice Question 16.19 Part A Which of the following statements about fixed macrophages is FALSE? They gather at sites of infection. They are mature monocytes. They are cells of the mononuclear phagocytic system. They are found in certain tissues and organs. They develop from neutrophils.
They develop from neutrophils.
