Assignement 10
Which of the following is a way that antimicrobial peptides are used in the second line of defense? They interrupt internal signaling in cells. They serve as chemotactic factors for leukocytes. They punch holes in the cytoplasmic membranes of pathogens. They are found on the skin and mucous membranes.
They serve as chemotactic factors for leukocytes. By serving as chemotactic factors for leukocytes, antimicrobial peptides can play a role in such processes as phagocytosis, a component of the second line of defense.
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
Which of the following is NOT an example of a walled-off site of infection that contains a fluid made of dead and dying tissue cells, leukocytes, and pathogens? a pustule a boil a pimple an abscess a tumor
a tumor
A differential white blood cell count that shows elevated levels of eosinophils probably indicates which of the following in the patient? viral infection bacterial infection cancer allergies
allergies Although their exact function in allergies is disputed, eosinophils are usually present in large numbers during allergic reactions.
The leukocytes called natural killer lymphocytes are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells. respond to the coating of a pathogen by complement. release prostaglandins and leukotrienes in response to microbes. increase in allergies and helminth infection. are specialists in killing bacteria.
are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells
Alpha and beta interferons produce no adverse effects in the body. are produced by infected fibroblasts and macrophages. produce active antiviral proteins (AVPs) that coat the surface of healthy cells and prevent the attachment of pathogenic viruses. protect the cells that secrete them from being invaded by a virus. help protect virus-infected cells from the effects of the pathogen.
are produced by infected fibroblasts and macrophages
Which of the following leukocytes have granules in their cytoplasm that stain blue with methylene blue? lymphocytes monocytes basophils neutrophils eosinophils
basophils
Wandering macrophages recognize microorganisms by means of lectins and C3 protein. NOD proteins. lectins. TLRs. both TLRs and NOD proteins.
both TLRs and NOD proteins
Which of the following cells can use nonphagocytic means to kill bacteria? natural killer cells neutrophils eosinophils macrophages both eosinophils and neutrophils
both eosinophils and neutrophils
The complement cascade and its by-products contribute to triggering inflammation. attracting phagocytes to sites of infection. triggering release of interferons. triggering inflammation and release of interferons. both triggering inflammation and attracting phagocytes to sites of infection.
both triggering inflammation and attracting phagocytes to sties of infection
The process of blood clotting leads to the formation of _____ a potent mediator of inflammation. bradykinin prostaglandin histamine leukotriene
bradykinin Bradykinin is formed as a byproduct of blood clotting.
Which of the following can release histamines? Cells from damaged tissues The complement system Cells from damaged tissues and the complement pathway Wood from a splinter Invading bacterial cells
cells from damaged tissues and the complement pathway
Which of the following are chemotactic factors for phagocytes? peptide fragments from complement interferons chemokines chemokines and peptide fragments from complement interferons and chemokines
chemokines and peptide fragments from complement
The process by which a phagocyte moves toward a chemical signal at the site of an infection is called exocytosis. adherence. chemotaxis. elimination. digestion.
chemotaxis
Lectins specific for mannose can lead to attack on fungi by NK cells. neutrophils. complement. macrophages. basophils.
complement
Pus is comprised of excess fluid from leaky blood vessels. dead phagocytes. collected cells from damaged tissue. unused histamines and leukotrienes.
dead phagocytes
Which of the following proteins are part of the first line of defense against microbial invasion? defensins C3 and C5 TLRs interferons NOD proteins
defensins
Acute and chronic inflammations differ in that acute inflammation _____. develops slowly, lasts a long time, and is potentially damaging involves the formation of pus always involves a fever develops quickly, ends quickly, and is typically beneficial
develops quickly, ends quickly, and is typically beneficial Acute inflammation has a quick onset and is quick to heal with a mostly beneficial purpose.
Leukocytes have the ability to cross the vessel wall out of the blood stream and into the tissues. This process is known as _____. phagocytosis diapedesis apoptosis phagocytosis
diapedesis Diapedesis means "across" and "foot," which explains how the leukocytes use a false foot to cross through gaps between the endothelial cells.
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 adherence digestion ingestion
digestion
Increased permeability of the vessels leads to _____ and pain. redness heat edema fever
edema The excess fluid collects in the tissues and leads to edema or swelling, which in turn exerts pressure on the nerves, causing the pain associated with inflammation.
Choose the statement that is the most likely outcome of enhanced margination. enhanced phagocytosis increased vessel permeability increased blood flow to the area of infection enhanced tissue repair
enhanced phagocytosis Tissue repair occurs as the inflammatory response subsides. Extra nutrients and oxygen will be delivered to the site of inflammation
Which of the following cells increase in number during a helminth infection? lymphocytes eosinophils neutrophils basophils macrophages
eosinophils
Which of the following phagocytic processes occurs last in the sequence? Exocytosis Chemotaxis of the phagocyte to the site of infection Formation of the phagolysosome Adherence
exocytosis
Which of the following substances stimulates the phagocytic activity of phagocytes? alpha interferons antiviral proteins beta interferons gamma interferons leukotrienes
gamma interferons
Fever is beneficial during viral infection because the higher temperature increases vasodilation, bringing more leukocytes to the site of infection. prevents viral infection of fibroblasts. increases the effectiveness of interferons. denatures viral proteins. results in virus being shed in sweat.
increases the effectiveness of interferons
The first and second lines of defense against microbial invasion are part of microbial antagonism. adaptive immunity. species resistance. innate immunity. both species resistance and adaptive immunity.
innate immunity
How does aspirin act to decrease the symptoms of inflammation? It prevents complement activation. It is an antitoxoid for most microbial toxins. It blocks the release of histamine. It interferes with the action of interferons. It acts as an antiprostaglandin.
it acts as an antiprostaglandin
Why is vasodilation important to tissue repair? It allows more phagocytes to travel to the site of damage. It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage. It allows more nutrients to be delivered to the site of damage. It allows for an increase in oxygen to the site of damage.
it allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage
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 activation of C3 lysis of infecting microbes promoting attachment of phagocytes to infecting microbes
lysis of infecting microbes Anchored in a microbial membrane, C5b serves as the binding site for the complement proteins that form the membrane-attack complex
In which intracellular compartment would you expect most of the digestive enzymes involved in pathogen destruction to be found? lysosome phagosome macrophage phagocytosis
lysosome
Which cell becomes a macrophage when leaving the bloodstream? lymphocyte neutrophil monocyte eosinophil basophil
monocyte
Which of the following factors in the first line of defense are affected by Tim's smoking? mucus production production of antimicrobial peptides and lysozyme migrating phagocytes mucus expulsion and normal microbiota
mucus expulsion and normal microbiota The poisons and tars in Tim's cigars damage the cilia and disrupt mucus expulsion. In addition, smoking can alter or affect normal microbiota. (Recall that Tim's sputum culture detected reduced numbers of normal microbiota).
Which statement about protective mechanisms employed by normal microbiota is false? Normal microbiota directly kill invading organisms. Normal microbiota consume nutrients. Normal microbiota alter the pH of their environment. Normal microbiota stimulate the second line of defense.
normal microbiota directly kill invading organisms
Which of the following leukocyte functions do macrophages carry out? release of alpha interferon secretion of leukotrienes phagocytosis of pathogens and debris phagocytosis of pathogens and production of NETs phagocytosis of pathogens and secretion of alpha interferons and leukotrienes
phagocytosis of pathogens and secretion of alpha interferons and leukotrienes
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 ___________________. phagolysosome, lysosome opsonins, lysosome lysosome, opsonins lysosome, phagolysosome
phagolysosome, lysosome
Tim was treated with azithromycin, a macrolide drug. This family of drug targets __________. mucus production cell wall synthesis the normal microbiota protein synthesis
protein synthesis Macrolides inhibit protein synthesis.
What cellular macromolecules make up the complement pathway? Lipids Proteins Nucleic acids Carbohydrates
proteins
Which of the following groupings contain things that are all true indicators of inflammation? redness, coolness, numbness, fever redness, heat, edema, pain, fever blueness, coolness, edema, pain redness, heat, edema, pain
redness, heat, edema, pain The redness and heat are due to the increased blood flow attributed to vasodilation, and the edema and pain are due to the increased permeability that allows fluids to leak into the surrounding tissues
The components of the second line of defense against microbes may be characterized as mechanisms to strengthen the first line of defense. responders to invasion. passive barriers. detecting the unique features of specific pathogens. both passive barriers and detecting specific pathogen features.
responders to invasion
Ideally, antibiotic therapy should target the pathogen and not the normal flora. Given the spectrum of activity for macrolides, azithromycin is most likely to have an effect on normal flora of the __________. skin gastrointestinal tract blood stream urinary tract
skin The skin harbors primarily gram-positive microbes
Which of the following contributes to protecting the eyes from microbial invasion? Tears and mucus combine to trap microbes and remove them. Tears contain lysozyme and salt and mechanically flush particles from the eyes. Tears contain lysozyme and salt. A mucus layer traps and removes microbes. Tears mechanically flush particles from the eyes.
tears contain lysozyme and salt and mechanically flush particles from the eyes
If a person turns their ankle, how would one determine if damage to the tissue in the ankle has occurred? The ankle is red. The ankle is very warm to the touch. The ankle is red, swollen, and warm to the touch. The ankle swells.
the ankle is red, swollen, and warm to the touch
Where are the complement proteins found in the body? The spleen The thymus The blood serum In every cell The liver
the blood serum
Which of the complement pathways employs properdin? Classical pathway Alternative pathway Lectin pathway Alternative and lectin pathways all employ properdin. Classical, alternative, and lectin pathways all employ properdin. The classical and alternative pathways both require properdin.
Alternative pathway
Antibodies from cellular immune responses are used in the alternative pathway. both the classical and alternative pathways. the lectin pathway. the classical pathway.
the classical pathway
Which of the complement pathways was discovered first? The classical pathway The lectin pathway The alternative pathway
the classical pathway
Opsonization is the coating of a pathogen by complement to facilitate phagocytosis. phagocyte receptors detecting PAMPs. nonspecific leukocyte secretion of toxins onto the surface of virally infected cells. damage resulting in cell lysis. the sticking of monocytes to the wall of the blood vessels at the site of infection
the coating of a pathogen by complement to facilitate phagocytosis
A response that is uniquely directed against pathogenic Bordetella pertussis would involve what component? Inflammation Antibodies Skin barrier The complement system
Antibodies
Based on the animation, which of the following is cleaved by C1? C2 and C4 C2 C5 C5 and C4 C4
C2 and C4
Based on the animation, which of the following is responsible for cleaving C3? C1 C4aC2b C5bC6C7 C2aC4b
C2aC4b
Which complement protein is the key to activating the alternative pathway of complement activation? C1 C2 C3 C4 C5
C3
The absence of C5 means that the molecule is not present to be activated. What happens in normal serum when C5 is "activated"? C5 is bound to the membrane-attack complex. C5 becomes a protein-digesting enzyme that splits C3 into two fragments, C3a and C3b. C3b is a part of enzyme that splits C5 into two fragments, C5a and C5b. C5 binds to Factor B.
C3B is a part of enzyme that splits C5 into two fragments, C5a and C5b. This happens in the three complement activation pathways. C3b is a part of an enzyme that digests C5
Histamines are released when mast cells are exposed to _____, which are fragments of complement proteins. C3 and C5 bradykinins C3a and C5a platelets
C3a and C5a The complement proteins C3a and C5a lead to the release of histamines, resulting in inflammation and chemotaxis.
In the classical pathway, which of the following directly activates cellular responses? C2aC4b C3a, C5a, and C5bC6C7 C5bC6C7 C3b C4aC2bC3b C3a and C5a
C3a, C5a, and C5bC6C7
Based on the animation, which of the complement proteins can directly bind to the surface of a bacterial cell? C2b C4a C3b C5b C2a
C3b
Which complement protein is used as an opsonin? C7 C3b C4a C3a C2a C5b
C3b
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? C1 Factor D C7 Mannose-binding lectin
C7 The sequence of assembly is C6, C7, and C8. C8 then recruits multiple C9 proteins that assemble into a pore in the membrane
What complement result involves the use of phagocytes? Chemotaxis and opsonization Opsonization Cytolysis Chemotaxis
Chemotaxis and opsonization
Phagocytosis is defined as the feeding of protozoans. cells of the immune system that ingest pathogens. the ingestion of solid material by a eukaryotic cell. the uptake of liquid material by a eukaryotic cell.
the ingestion of solid material by a eukaryotic cell
Diapedesis is the attachment of phagocytes to the walls of capillaries. the migration of phagocytes through blood vessels to the site of tissue damage. the increase in the diameter of blood vessels. the production and release of chemicals during inflammation.
the migration of phagocytes through blood vessels to the site of tissue damage
The phenomenon known as chemotaxis is defined as an increase in allergies and helminth infection. the coating of a pathogen by complement. the release of prostaglandins and leukotrienes in response to microbes. the squeezing of cells through the lining of capillaries. the movement of a cell toward or away from a chemical stimulus.
the movement of a cell toward or away from a chemical stimulus
Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense against microbial invaders? The mucus is a physical trap that contains a variety of antimicrobial chemicals. The mucus contains a variety of antimicrobial chemicals and molecules. The mucus secreted by the mucous membrane physically traps microbes. Both the mucus and the outer layer of cells are shed frequently. The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.
the mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells
Both the innate and adaptive defenses of the immune system work to prevent disease. colonization by pathogens. penetration by invading pathogens. the penetration and colonization by pathogens, and the diseases they cause.
the penetration and colonization by pathogens, and the diseases they cause
Which microorganism requires the low pH inside a phagolysosome in order to reproduce? Coxiella burnetii Streptococcus pneumoniae Streptococcus pyogenes Haemophilus influenzae
Coxiella burnetii
If a person could not form C2, which result of complement would be affected? Chemotaxis and inflammation Opsonization Cytolysis, chemotaxis, inflammation, and opsonization Cytolysis
Cytolysis, chemotaxis, inflammation, and opsonization
Which of the following is the key difference in the roles of the classical and alternative pathways of the complement system? production of chemotactic factors the formation of MACs the range of microbe types that can be targeted the effectiveness in killing Gram-negative bacteria triggering inflammation
the range of microbe types that can be targeted
The various phagocytic cells of the second line of defense target specific microbes by their unique structures. True False
False
How does cytolysis occur via the complement pathway? Stimulation of the inflammatory response Formation of the MAC in invading cells, killing them Disrupting cell wall of pathogens Triggering the release of histamine
Formation of the MAC in invading cells, killing them
What does the plasma membrane of a phagocyte attach to on a microorganism? Pseudopods Lysosomes Glycoproteins Phagosomes
Glycoproteins
What would be the likely outcome if a microbe could prevent the activation of C3 in the complement cascade? The microbe would be killed by the membrane attack complex. The microbe would be opsonized. The microbe would be unaffected by complement. Inflammation would be the only outcome of complement activation if C3 activation is blocked
Inflammation would be the only outcome of complement activation if C3 activation is blocked
An inflammatory response would result from which of the following? Jellyfish sting Vomiting A headache
Jellyfish stings
Response to specific pathogens that can improve with subsequent exposure is the third line of defense. the second line of defense. innate immunity. microbial antagonism. the first line of defense
the third line of defense
Basophils, platelets, and _____ are all capable of secreting histamines. mast cells complement neutrophils monocytes
Mast cells Mast cells are found in the tissues outside of the blood and release histamine in response to complement
Which of the following are functions of lectins? They produce antibodies. They act as opsonins for phagocytosis. They can activate C2 and C4. They produce factor P (properdin). They act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4. They attach to carbohydrates on some bacterial and viral surfaces.
they act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4.
The ________ play a role in preventing neoplastic cells from progressing to cancer. NK cells mast cells basophils eosinophils neutrophils
NK cells
Which of the following characteristics is shared by the skin and mucous membranes? They both have cilia. Sebum may be present. The outer layers are composed of dead cells. They are both constantly shedding and replacing cells. Lysozymes are always present.
they are both constantly shedding and replacing cells
What is the role of opsonins? They attract phagocytes to the location of infection. 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. They are present on the surface of phagocytes.
they create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader
Which of the following statements is true of eosinophils? They produce the coating of a pathogen by complement. They release prostaglandins and leukotrienes in response to microbes. They decline during allergic reaction. They are in intact skin, sebum, tears, etc. They secrete toxins onto the surface of helminth parasites.
they secrete toxins onto the surface of helminth parasites
Choose the statement that best describes why the lectin or alternative pathway would stimulate a more immediate response than the classical pathway. Neither pathway relies on antibodies. The lectin and alternate pathways don't stimulate a strong inflammatory response compared to the classical pathway. There are fewer events that lead to the activation of the alternative and lectin pathways. Both pathways lead to the formation of more membrane attack complexes compared to the classical pathway.
Neither pathway relies on antibodies The major advantage to targeting lectin or alternative pathways is that they do not require antibodies for their activation, allowing for an immediate response to infection. The classical pathway will not be activated until antibodies have been generated, which, upon first exposure to a pathogen can take several days. In addition, the lectin and alternative pathways are directly activated by microbial surfaces.
If a person lacked the ability to form C5, what direct result of complement could still occur? Chemotaxis Opsonization Cytolysis
Opsonization
Structures and products of pathogens that immune cells detect and respond to are called NODs. leukotrienes. TLRs. PAMPs. prostaglandins.
PAMPs
What is the function of inflammation in response to a burn from a hot iron? To limit the effects of the agent on the rest of the body To destroy the agent causing injury To repair the damaged tissue 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 repair the damaged tissue
Roger Brown, an African American cancer patient, received a chemotherapeutic agent as a treatment for his disease. The drug used to destroy the cancer also produced an undesirable condition known as bone marrow depression. The complete blood count (CBC) profile shown here indicates that this patient is in trouble. Review the lab values, 1. Platelet count is low. 2. White blood cell count and types of WBCs are abnormally low. 3. Red blood cell count, hemoglobin level, and hematocrit are all low. Red blood cell size and hemoglobin content are normal. Part A Why would bleeding time be increased in this patient? White blood cell numbers are decreased. Red blood cell numbers are decreased. Neutrophil numbers are decreased. Platelet count is decreased. Part B. What is the most expedient way to increase the blood cell and platelet counts of this patient right now? blood transfusion intravenous fluids intramuscular antibiotic injection intramuscular iron injections Part C. What aspect of this patient's immune function would be most directly impacted by this condition? interferon production mucus production bleeding gums phagocytosis Part D. What does anemia mean? decreased white blood cell numbers decreased red blood cell numbers decreased platelet numbers increased urine production
Part A. Platelet count is decreased Correct. Platelets are megakaryocyte fragments that contribute to sealing small holes in a blood vessel wall. Part B. blood transfusion Correct. This is not a cure, but an attempt to temporarily improve the patient's condition. Part C. phagocytosis Correct. The decrease in white blood cells includes neutrophils. Part D. decreased red blood cell numbers Correct. Red blood cells contain hemoglobin, a protein that carries oxygen.
Histamine and prostaglandins are involved in inflammatory reactions. True False
true
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? 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 would be attracted to tissue sites where early complement proteins have been activated. Phagocytes could not attach as easily to invading microbes. Targeted bacteria would be lysed.
Phagocytes could not attach as easily to invading microbes. C3b is an important opsonin.
Why are smokers more likely to have infections with respiratory pathogens? Poisons in tobacco smoke damage ciliated columnar cells. Smokers do not produce as much mucus as do nonsmokers. Respiratory pathogens produce substances that react with tobacco smoke. Smokers do not produce lysozyme in their mucus.
Poisons in tobacco smoke damage ciliated columnar cells. Tobacco smoke contains substances that damage ciliated cells in the respiratory tract. This makes it more difficult for smokers to clear their lungs of potential pathogens.
Inflammatory mediators such as bradykinin and histamine cause blood vessels to _____. lengthen vasoconstrict increase permeability vasodilate
vasodilate Vasodilation of the blood vessel causes the diameter to increase and allow the flow of more blood to the site of inflammation.
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
Consider the effect of Mycoplasma pneumoniae as it burrows between respiratory epithelial cells. Which element(s) of the second line of defense will be most effective in fighting this invader? interferons lysozyme wandering macrophages IgG antibodies
wandering macrophages Wandering macrophages are effective in fighting off this respiratory infection because they can travel throughout the body, including extracellular spaces.
Which of the following microorganisms use M protein to avoid destruction of a phagocyte? Streptococcus pneumoniae Haemophilus influenzae Coxiella burnetii Streptococcus pyogenes
Streptococcus pneumoniae
Which of the following statements regarding phagocyte recognition of pathogens is true? MACs on the surface of microbes are detected by NOD proteins. TLRs on the surface of microbes trigger the accumulation of opsonins. TLRs in the phagocyte cytoplasmic membrane bind surface structures of microbes. Lectins on the surface of microbes are bound by chemokine receptors. NOD proteins on the surface of microbes are detected by TLRs.
TLRs in the phagocyte cytoplasmic membrane bind surface structures of microbes
What will happen if an animal raised in an axenic environment is exposed to a pathogenic microbe later in life? The animal's second line of defense will respond normally, but the first line of defense will be compromised. The animal will exhibit a very poor immune response to the pathogen. The animal's immune system will respond normally to the pathogen. The animal's immune system will produce an excessive response to the pathogen
The animal will exhibit a very poor immune response to the pathogen Animals raised in axenic environments have immune systems that respond poorly, if at all, to microbial invaders because they have not been constantly stimulated by the presence of normal microbiota.
A microbiologist has isolated a bacterium from the skin and wishes to determine whether it might be a member of the normal microbiota. Which of the following would NOT be evidence for such a conclusion? The bacterium is extremely salt tolerant. The bacterium is an acidophile. The bacterium produces a number of virulence factors. The bacterium is resistant to lysozyme.
The bacterium produces a number of virulence factors. A member of the normal microbiota of the skin would be expected to be salt and acid tolerant, as well as resistant to the body's defensive chemicals such as lysozyme.
What is a phagolysosome? The structure that results from the fusion of a phagosome and a lysosome. 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. A vesicle containing only digestive enzymes and other antimicrobial compounds.
The structure that results from the fusion of a phagosome and a lysosome
How is Streptococcus pneumoniae able to avoid destruction by a phagocyte? They cause the lysosomes to empty their contents into the phagocyte, killing it. They prevent the fusion of the lysosome and phagosome. Their capsules make them "slippery" to phagocytes.
Their capsules make them "slippery" to phagocytes
What direct effect do histamines and leukotrienes have on capillaries? They decrease the diameter of capillaries. They prevent phagocytes from sticking to the walls of capillaries. They allow capillary walls to open and become leaky.
They allow capillary walls to open and become leaky
First line defenses have what aspect in common with each other? They recognize specific pathogens. They involve the production of antibodies. They involve unique cells that attack invading pathogens. They are physical barriers against invading pathogens.
They are physical barriers against invading pathogens
