Chapter 15 - Innate Immunity

Basophils have large granules that release histamine to initiate inflammation. T/F

True

During phagocycotic migration when the phagocytic cells reach the site of injury, they begin to stick to the inner surface of the blood vessels. T/F

True

Histamine and prostaglandins are involved in inflammatory reactions. T/F

True

Inteferon are a class of antiviral proteins that are produced by virally infected host cells. T/F

True

Interferons alpha and beta are effective against viruses. T/F

True

Neutrophils can kill bacteria by nonphagocytic mechanisms. T/F

True

Some toll-like receptors (TLRs) are found on the surface of host cells and recognize specific microbial molecules. T/F

True

Sweat can cause damage to bacteria because it contains salt and lysozyme. T/F

True

The growth of some microbes is inhibited by elevated body temperature. T/F

True

The normal microbiota compete with pathogens in a variety of ways to protect the body, creating a situation known as microbial (antagonism/competition/resistance).

antagonism

The redness and heat of acute inflammation are caused in part by the production of (bradykinin/platelets/fibrinogen) during the formation of blood clots.

bradykinin

The two mechanisms for activation of complement system are _______ and _______.

classical pathway; alternative pathway

A nonspecific type of defensive system that consists of serum proteins that participate in the lysis of foreign cells, inflammation, and phagocytosis, is known as _______.

complement system

Intact skin layers are part of the body's (first/second/third) line of defense against pathogens.

first

The (epithelial/goblet/mucous) cells in the tracheal mucous membrane produce mucus.

goblet

Leukocytes are divided into two main categories based upon their appearance under the microscope. They are _______ and _______.

granulocytes; agranulocytes

In a process called (cytokinesis/hematopoiesis/hematocrit), blood stem cells located in the bone marrow produce the three types of formed elements found in the blood.

hematopoiesis

The process known as (complement/inflammation/phagocytosis) brings a variety of physical, chemical and cellular factors together to fight invading microorganisms.

inflammation

The proportion of (plasma/leukocytes/RBCs), as determined by a differential white blood cell count, can serve as a sign of disease.

leukocytes

Sweat glands produce (lysozyme/dermcidin/acid), which destroys the cell wall of bacteria by cleaving the bonds between the sugar subunits present in the wall.

lysozyme

Monocytes leave the blood and enter body tissues and mature into _______.

macrophages

During phagocytosis, the pagocytes begin to stick to the inner surface of the endothelium of blood vessels. This sticking process is called _______.

margination

The first and second lines of defense respond to invading microbes by (specific/nonspecific) mechanisms.

nonspecific

The process of ingestion of microorganisms or any other particle and their destruction is called _______.

phagocytosis

During phagocytosis, the phagosome and lysosome fuse together to form a single large structure called _______.

phagolysosome

The fluid part of the cell is called _______.

plasma

In the case of phagocytes, positive chemotaxis involves the use of (cilia/flagella/pseudopodia) to move toward the microorganism.

pseudopodia

Some pathogens produce toxins which function as (histamines/prostaglandins/pyrogens) to cause fever.

pyrogens

The oily substance that lowers the pH of the skin's surface to about pH 5 and is inhibitory to many bacteria is (sebum/sweat/serum).

sebum

The absence of necessary receptors is the basis of the defense against microbial invasion known as (natural/innate/species) resistance.

species

What are 3 ways normal microbiota play a role in immunity?

1) Microbial antagonism 2) Stimulate 2nd line of defense 3) Provide vitamins (clotting)

During cytolysis, the membrane attach complex is formed by initiation of a reaction involving proteins C______ through C______.

5; 9

What is a phagolysosome? A) A protein that covers the surface of an invading microbe, making it easier for the phagocyte to ingest. B) The structure that results from the fusion of a phagosome and a lysosome. C) A vesicle containing only an engulfed invading microorganism. D) A vesicle containing only digestive enzymes and other antimicrobial compounds.

A) A protein that covers the surface of an invading microbe, making it easier for the phagocyte to ingest.

Which of the following is a type of serum protein involved in the non-specific type of defense of the body? A) Complement B) Interferon C) Fibrinogen D) Prostaglandins E) Histamine

A) Complement

Which of the following phagocytic processes occurs last in the sequence? A) Exocytosis B) Formation of the phagolysosome C) Chemotaxis of the phagocyte to the site of infection D) Adherence

A) Exocytosis

Why is vasodilation important to tissue repair? A) It allows for an increased delivery of oxygen, nutrients, and phagocytes 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 more nutrients to be delivered to the site of damage.

A) It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage.

Which of the following exhibit maximum phagocytic activities? A) Neutrophils B) Erythrocytes C) Basophils D) Eosinphils E) Lymphocytes

A) Neutrophils

How is phagocytosis in the immune system different from protozoan phagocytosis? A) Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection. B) Protozoan phagocytosis is used to fight infection; phagocytosis by immune cells is used to feed the cells. C) There is no difference between the two.

A) Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection.

Which of the following contributes to protecting the eyes from microbial invasion? A) Tears contain lysozyme and salt and mechanically flush particles from the eyes. B) Tears mechanically flush particles from the eyes. C) A mucus layer traps and removes microbes. D) Tears and mucus combine to trap microbes and remove them. E) Tears contain lysozyme and salt.

A) Tears contain lysozyme and salt and mechanically flush particles from the eyes.

Adherence refers to A) The attachment of phagocytes to microbes B) The chemotactic response of phagocytes C) Adherence of phagocytes to the lining of blood vessels D) Dilation of blood vessels E) The movement of phagocytes through walls of blood vessels

A) The attachment of phagocytes to microbes

Which of the complement pathways was discovered first? A) The classical pathway B) The lectin pathway C) The alternative pathway

A) The classical pathway

What direct effect do histamines and leukotrienes have on capillaries? A) They allow capillary walls to open and become leaky. B) They decrease the diameter of capillaries. C) They prevent phagocytes from sticking to the walls of capillaries.

A) They allow capillary walls to open and become leaky.

What is the role of opsonins? A) They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader. B) They attract phagocytes to the location of infection. C) They are present on the surface of phagocytes. D) They aid in the formation of the phagolysosome.

A) They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.

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) a phagocyte. B) an antibody-producing cell. C) a cytotoxic T cell.

A) 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) a tumor B) a boil C) a pustule D) an abscess E) a pimple

A) a tumor

Which of the following are phagocytic cells found in the epidermis? A) dendritic cells B) natural killer lymphocytes C) wandering macrophages D) microglia E) neutrophils

A) dendritic cells

Which of the following pairs is MISMATCHED? A) microglial cells; spleen B) alveolar macrophage; lungs C) dendritic cells; epidermis D) macrophages; lymph nodes E) microglial cells; brain

A) microglial cells; spleen

Which cell becomes a macrophage when leaving the bloodstream? A) monocyte B) eosinophil C) basophil D) neutrophil E) lymphocyte

A) monocyte

Which of the following areas of the body have mucous membranes? A) mouth, nasal cavity, and urinary system B) mouth C) urinary system D) mouth and nasal cavity E) nasal cavity

A) mouth, nasal cavity, and urinary system

Antibodies from cellular immune responses are used in A) the classical pathway. B) the lectin pathway. C) the alternative pathway. D) both the classical and alternative pathways.

A) the classical pathway.

Which of the following is the key difference in the roles of the classical and alternative pathways of the complement system? A) the range of microbe types that can be targeted B) triggering inflammation C) the effectiveness in killing Gram-negative bacteria D) production of chemotactic factors E) the formation of MACs

A) the range of microbe types that can be targeted

Which of the complement pathways employs properdin? A) Classical pathway B) Alternative pathway C) Lectin pathway D) Alternative and lectin pathways all employ properdin. E) Classical, alternative, and lectin pathways all employ properdin.

B) Alternative pathway

Which of the following statements concerning the alternative complement system is true? A) It works best on Gram-positive bacteria. B) Its activation is independent of antibodies. C) It plays a very significant role in the elimination of parasitic helminths. D) It is not useful in the early stages of fungal infection. E) It is more efficient than the classical pathway.

B) Its activation is independent of antibodies.

The ________ play a role in preventing neoplastic cells from progressing to cancer. A) eosinophils B) NK cells C) mast cells D) basophils E) neutrophils

B) NK cells

Which of the following are functions of lectins? A) They produce factor P (properdin). 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 antibodies. D) They attach to carbohydrates on some bacterial and viral surfaces. E) They can activate C2 and C4.

B) They act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4.

Which of the following statements is true of eosinophils? A) They release prostaglandins and leukotrienes in response to microbes. B) They secrete toxins onto the surface of helminth parasites. C) They are in intact skin, sebum, tears, etc. D) They produce the coating of a pathogen by complement. E) They decline during allergic reaction.

B) They secrete toxins onto the surface of helminth parasites.

Mucus and sweat contain ________ which damage and kill bacteria. A) NOD proteins B) antimicrobial peptides C) complement fragments D) salts E) antibodies

B) antimicrobial peptides

The leukocytes called natural killer lymphocytes A) increase in allergies and helminth infection. B) are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells. C) release prostaglandins and leukotrienes in response to microbes. D) respond to the coating of a pathogen by complement. E) are specialists in killing bacteria.

B) are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.

Which of the following leukocytes have granules in their cytoplasm that stain blue with methylene blue? A) eosinophils B) basophils C) lymphocytes D) monocytes E) neutrophils

B) basophils

Which of the following are chemotactic factors for phagocytes? A) interferons B) chemokines and peptide fragments from complement C) interferons and chemokines D) chemokines E) peptide fragments from complement

B) chemokines and peptide fragments from complement

Pus is comprised of A) unused histamines and leukotrienes. B) dead phagocytes. C) collected cells from damaged tissue. D) excess fluid from leaky blood vessels.

B) dead phagocytes.

The first and second lines of defense against microbial invasion are part of A) species resistance. B) innate immunity. C) microbial antagonism. D) adaptive immunity. E) both species resistance and adaptive immunity.

B) innate immunity.

TLRs are A) nonspecific leukocytes that secrete toxins onto the surface of virally infected cells. B) phagocyte receptors that detect PAMPs. C) present in intact skin, sebum, tears, etc. D) the coatings of pathogens by complement. E) molecules that damage cells, resulting in cell lysis.

B) phagocyte receptors that detect PAMPs.

Diapedesis is A) the production and release of chemicals during inflammation. B) the migration of phagocytes through blood vessels to the site of tissue damage. C) the attachment of phagocytes to the walls of capillaries. D) the increase in the diameter of blood vessels.

B) the migration of phagocytes through blood vessels to the site of tissue damage.

Which complement protein is the key to activating the alternative pathway of complement activation? A) C1 B) C2 C) C3 D) C4 E) C5

C) C3

What does the plasma membrane of a phagocyte attach to on a microorganism? A) Lysosomes B) Pseudopods C) Glycoproteins D) Phagosomes

C) Glycoproteins

What cellular macromolecules make up the complement pathway? A) Nucleic acids B) Carbohydrates C) Proteins D) Lipids

C) Proteins

Which of the following characteristics is shared by the skin and mucous membranes? A) Lysozymes are always present. B) Sebum may be present. C) They are both constantly shedding and replacing cells. D) They both have cilia. E) The outer layers are composed of dead cells.

C) They are both constantly shedding and replacing cells.

Lectins specific for mannose can lead to attack on fungi by A) macrophages. B) neutrophils. C) complement. D) basophils. E) NK cells.

C) complement.

Which of the following cells increase in number during a helminth infection? A) lymphocytes B) neutrophils C) eosinophils D) basophils E) macrophages

C) eosinophils

Receptors known as NOD proteins detect molecules associated with microbes A) in the extracellular fluid. B) in the phagolysosome. C) in the cytoplasm. D) in the cytoplasmic membrane. E) on the surface of cells.

C) in the cytoplasm.

Phagocytosis is defined as A) the feeding of protozoans. B) the uptake of liquid material by a eukaryotic cell. C) the ingestion of solid material by a eukaryotic cell. D) cells of the immune system that ingest pathogens.

C) the ingestion of solid material by a eukaryotic cell.

Which of the following is the best definition of "microbial antagonism"? A) the presence of normal microbiota that can become pathogens under certain conditions B) the ability of microbiota to mutate into pathogens C) the presence of normal microbiota that protect the body by competing with pathogens in a variety of ways to prevent pathogens from invading the body D) the presence of resident bacteria on the surface of the body and in cavities that connect to the surface E) the presence of pathogens on the surface of the skin, which will invade the body through abrasions

C) the presence of normal microbiota that protect the body by competing with pathogens in a variety of ways to prevent pathogens from invading the body

Which of the following can release histamines? A) Invading bacterial cells B) Cells from damaged tissues C) Wood from a splinter D) Cells from damaged tissues and the complement pathway E) The complement system

D) Cells from damaged tissues and the complement pathway

Which of the following is not a mechanical factor to protect the skin and mucous membrane from infection? A) Skin B) Keratin C) Lacrimal apparatus D) Gastric juice E) Epiglottis

D) Gastric juice

How does aspirin act to decrease the symptoms of inflammation? A) It prevents complement activation. B) It blocks the release of histamine. C) It is an antitoxoid for most microbial toxins. D) It acts as an antiprostaglandin. E) It interferes with the action of interferons.

D) It acts as an antiprostaglandin.

Structures and products of pathogens that immune cells detect and respond to are called A) prostaglandins. B) NODs. C) leukotrienes. D) PAMPs. E) TLRs.

D) PAMPs.

Which of the following substances resets the body's thermostat to a higher temperature following infection? A) Complement B) Interferon C) Histamine D) Prostaglandins

D) Prostaglandins

Which of the following statements about eosinophil function is true? A) They identify and spare normal cells. B) They produce defensins. C) They secrete toxins onto virally infected cells. D) They attach to the surface of parasitic helminths and produce toxins that kill the parasite. E) They are involved in the removal of neoplastic cells.

D) They attach to the surface of parasitic helminths and produce toxins that kill the parasite.

Alpha and beta interferons A) produce active antiviral proteins (AVPs) that coat the surface of healthy cells and prevent the attachment of pathogenic viruses. B) produce no adverse effects in the body. C) help protect virus-infected cells from the effects of the pathogen. D) are produced by infected fibroblasts and macrophages. E) protect the cells that secrete them from being invaded by a virus.

D) are produced by infected fibroblasts and macrophages.

Which of the following proteins are part of the first line of defense against microbial invasion? A) TLRs B) C3 and C5 C) interferons D) defensins E) NOD proteins

D) defensins

First line of defense may be described as A) nonspecific leukocytes that secrete toxins onto the surface of virally infected cells. B) the release of prostaglandins and leukotrienes in response to microbes. C) damage resulting in cell lysis. D) intact skin, mucous membranes, sebum, tears, and so forth. E) the coating of a pathogen by complement.

D) intact skin, mucous membranes, sebum, tears, and so forth.

The components of the second line of defense against microbes may be characterized as A) detecting the unique features of specific pathogens. B) passive barriers. C) mechanisms to strengthen the first line of defense. D) responders to invasion. E) both passive barriers and detecting specific pathogen features.

D) responders to invasion.

Opsonization is A) the sticking of monocytes to the wall of the blood vessels at the site of infection. B) nonspecific leukocyte secretion of toxins onto the surface of virally infected cells. C) damage resulting in cell lysis. D) the coating of a pathogen by complement to facilitate phagocytosis. E) phagocyte receptors detecting PAMPs.

D) the coating of a pathogen by complement to facilitate phagocytosis.

Both the innate and adaptive defenses of the immune system work to prevent A) colonization by pathogens. B) disease. C) penetration by invading pathogens. D) the penetration and colonization by pathogens, and the diseases they cause.

D) the penetration and colonization by pathogens, and the diseases they cause.

Neutrophils use their own (DNA/RNA/TLR) in the formation of NETs to trap bacteria.

DNA

Which of the following are is involved in the destruction of large eukaryotic microorganisms? A) Neutrophils B) Basophils C) Monocytes D) Lymphocytes E) Eosinophils

E) Eosinophils

Which of the following statements regarding the surface of the skin is false? A) It is salty. B) It is acidic. C) It has sebum as a coating. D) It has normal microbiota. E) It has goblet cells.

E) It has goblet cells.

Which of the following statements regarding phagocyte recognition of pathogens is true? A) Lectins on the surface of microbes are bound by chemokine receptors. B) NOD proteins on the surface of microbes are detected by TLRs. C) MACs on the surface of microbes are detected by NOD proteins. D) TLRs on the surface of microbes trigger the accumulation of opsonins. E) TLRs in the phagocyte cytoplasmic membrane bind surface structures of microbes.

E) TLRs in the phagocyte cytoplasmic membrane bind surface structures of microbes.

Where are the complement proteins found in the body? A) The spleen B) The thymus C) The liver D) In every cell E) The blood serum

E) The blood serum

Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense against microbial invaders? A) The mucus contains a variety of antimicrobial chemicals and molecules. B) The mucus secreted by the mucous membrane physically traps microbes. C) Both the mucus and the outer layer of cells are shed frequently. D) The mucus is a physical trap that contains a variety of antimicrobial chemicals. E) The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.

E) The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.

Wandering macrophages recognize microorganisms by means of A) TLRs. B) NOD proteins. C) lectins and C3 protein. D) lectins. E) both TLRs and NOD proteins.

E) both TLRs and NOD proteins.

Which of the following cells can use nonphagocytic means to kill bacteria? A) eosinophils B) neutrophils C) natural killer cells D) macrophages E) both eosinophils and neutrophils

E) both eosinophils and neutrophils

Which of the following substances is responsible for the edema associated with inflammation? A) leukotrienes B) interferon C) histamine D) defensin E) both leukotrienes and histamine

E) both leukotrienes and histamine

Protection from infection known as species resistance is a result of A) the presence of phagocytes in the tissues. B) the absence of receptors required for microbial attachment. C) the salty, acidic condition of normal skin. D) the lack of suitable environment in the body. E) both the absence of necessary receptors and lack of suitable environment in the body.

E) both the absence of necessary receptors and lack of suitable environment in the body.

The complement cascade and its by-products contribute to A) attracting phagocytes to sites of infection. B) triggering inflammation. C) triggering inflammation and release of interferons. D) triggering release of interferons. E) both triggering inflammation and attracting phagocytes to sites of infection.

E) both triggering inflammation and attracting phagocytes to sites of infection.

Which of the following are among the activities of neutrophils? A) phagocytosis B) formation of neutrophil extracellular traps C) enzyme production that leads to the formation of nitric oxide D) formation of neutrophil extracellular traps and phagocytosis E) formation of neutrophil extracellular traps, phagocytosis, and production of nitric oxide

E) formation of neutrophil extracellular traps, phagocytosis, and production of nitric oxide

Which of the following substances stimulates the phagocytic activity of phagocytes? A) antiviral proteins B) beta interferons C) alpha interferons D) leukotrienes E) gamma interferons

E) gamma interferons

Fever is beneficial during viral infection because the higher temperature A) prevents viral infection of fibroblasts. B) denatures viral proteins. C) increases vasodilation, bringing more leukocytes to the site of infection. D) results in virus being shed in sweat. E) increases the effectiveness of interferons.

E) increases the effectiveness of interferons.

Which of the following leukocyte functions do macrophages carry out? A) secretion of leukotrienes B) phagocytosis of pathogens and debris C) release of alpha interferon D) phagocytosis of pathogens and production of NETs E) phagocytosis of pathogens and secretion of alpha interferons and leukotrienes

E) phagocytosis of pathogens and secretion of alpha interferons and leukotrienes

Which of the following iron-binding proteins is NOT part of the body's iron storage and transport system? A) gastroferritin B) transferrin C) ferritin D) lactoferrin E) siderophores

E) siderophores

The phenomenon known as chemotaxis is defined as A) the coating of a pathogen by complement. B) the release of prostaglandins and leukotrienes in response to microbes. C) the squeezing of cells through the lining of capillaries. D) an increase in allergies and helminth infection. E) the movement of a cell toward or away from a chemical stimulus.

E) the movement of a cell toward or away from a chemical stimulus.

Response to specific pathogens that can improve with subsequent exposure is A) innate immunity. B) the first line of defense. C) the second line of defense. D) microbial antagonism. E) the third line of defense.

E) the third line of defense.

Plasma is mostly water but also contains _______.

Electrolytes, dissolved gases, nutrients, and proteins

What are the two layers of a mucous membrane?

Epithelium and connective tissue layer

What are the three types of cells in blood?

Erythrocytes, platelets, and leukocytes

By doing a differential blood count of a blood sample one cannot determine the frequency of each type of white blood cell in a sample of 100 blood cells. T/F

False

Inflammation is an important part of the body's first line of defense, and it involves migration of phagocytes to the area. T/F

False

Inflammation produce by the complement system is mainly due to the direct action of the serum proteins C3 and C5. T/F

False

The alternative pathway for complement activation is more effective than the classical pathway. T/F

False

The resident microbiota have no role in defense against pathogen invasion. T/F

False

The various phagocytic cells of the second line of defense target specific microbes by their unique structures. T/F

False

Phagocytes kill a pathogen once it has been ingested, whereas eosinophils and (MAC/NK/NOD) lymphocytes can accomplish extracellular killing by secreting toxins. (Be sure to use capital letters in your answer.)

NK

Following tissue damage, blood vessels dilate in the area of damage and their permeability increases. This is called _______.

vasodilation