Which of the following is not one of the bodys first lines of defense against invading microorganisms quizlet?

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Your body has a two-line defence system against pathogens (germs) that make you sick. Pathogens include bacteria, viruses, toxins, parasites and fungi.

The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, ‘friendly’ bacteria and white blood cells called neutrophils.

Pathogenic (disease-causing) microorganisms must make it past this first line of defence. If this defence is broken, the second line of defence within your body is activated.

Skin
The skin is the largest organ of your body. It acts as a barrier between invaders (pathogens) and your body. Skin forms a waterproof mechanical barrier. Microorganisms that live all over your skin can’t get through your skin unless it’s broken.

Tears, mucus and saliva
Your nose, mouth and eyes are obvious entry points for pathogens. However, tears, mucus and saliva contain an enzyme that breaks down the cell wall of many bacteria. Those that are not killed immediately are trapped in mucus and swallowed. Special cells line and protect the nose, throat and other passages within your body. The inner lining of your gut and lungs also produces mucus to trap invading pathogens.

Cilia
Very fine hairs (cilia) lining your windpipe move mucus and trapped particles away from your lungs. Particles can be bacteria or material such as dust or smoke.

Stomach acid
Stomach acid kills bacteria and parasites that have been swallowed.

Urine flow
Your urine flow flushes out pathogens from the bladder area.

‘Friendly’ (beneficial) bacteria
You have beneficial bacteria growing on your skin, in your bowel and other places in the body (such as the mouth and the gut) that stop other harmful bacteria from taking over.

Neutrophils
These are white blood cells that can find, kill and ingest pathogens seeking an entrance into the body.

You may now like to read this article The body's second line of defence.

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Terms in this set (92)

Which of the following is NOT considered part of the body's nonspecific lines of defense against disease?
A) antibodies
B) mucous membranes
C) intact skin
D) bloodborne chemicals
E) phagocytic cells

A) antibodies

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

D) dendritic cells

Chemotaxis is the
A) movement of cells toward or away from a chemical stimulus.
B) transport of substances across the cytoplasmic membrane.
C) squeezing of cells between the cells lining capillaries in order to attack invading microbes.
D) attachment of phagocytes to a microorganism by binding to complementary proteins.
E) extension of pseudopodia to surround a microbe

A) movement of cells toward or away from a chemical stimulus

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

D) eosinophils

Which of the following is NOT one of the signs of inflammation?
A) redness (rubor)
B) heat (calor)
C) swelling (tumor)
D) pain (dolor)
E) odor

E) odor

Protection from infection known as species resistance is a result of

A) the lack of suitable environment in the body.
B) the absence of receptors required for microbial attachment.
C) the presence of phagocytes in the tissues.
D) the salty, acidic condition of normal skin.
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

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

C) It has goblet cells

Which of the following contributes to protecting the eyes from microbial invasion?

A) Tears contain lysozyme and salt.
B) A mucus layer traps and removes microbes.
C) Tears mechanically flush particles from the eyes.
D) Tears contain lysozyme and salt and mechanically flush particles from the eyes.
E) Tears and mucus combine to trap microbes and remove them.

D) Tears contains lysosome and salt and mechanically flush particles from the eyes.

Microbial antagonism refers to

A) the presence of pathogens on the surface of the skin, which will invade the body through abrasions.
B) 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.
C) the presence of normal microbiota that can become pathogens under certain conditions.
D) the ability of microbiota to mutate into pathogens.
E) the presence of resident bacteria on the surface of the body and in cavities that connect to the surface

B) 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.

Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense against microbial invaders?

A) The mucus secreted by the mucous membrane physically traps microbes.
B) The mucus contains a variety of antimicrobial chemicals and molecules.
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.

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

E) chemokines and peptides from complement

Which of the following statements about natural killer lymphocytes is FALSE?

A) They accomplish extracellular killing.
B) They secrete toxins onto virally infected cells.
C) 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.
E) They identify and spare normal cells.

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

MACs are
A) the initial trigger for the classical complement system.
B) the initial trigger for the alternative complement system.
C) the initial trigger for the lectin complement system.
D) the end result of both the classical and alternative complement systems.
E) the end result of only the alternative complement system.

D) the end result of both the classical and alternative complement systems.

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

E) triggering inflammation and attracting phagocytes to sites of infection

Which of the following statements concerning the alternative complement system is true?

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

C) Its activation is independent of antibodies.

Which of the following is the key difference in the roles of the classical and alternative pathways of the complement system?

A) the formation of MACs
B) the range of microbes that can be targeted
C) triggering inflammation
D) production of chemotactic factors
E) the effectiveness in killing Gram-negative bacteria

B) the range of microbes that can be targeted

Which of the following cells can use nonphagocytic means to kill bacteria?

A) eosinophils
B) macrophages
C) neutrophils
D) natural killer cells
E) eosinophils and neutrophils

E) eosinophils and neutrophils

Which of the following pairs is MISMATCHED?

A) alveolar macrophage — lungs
B) microglial cells — brain
C) microglial cells — spleen
D) dendritic cells — epidermis
E) macrophages — lymph nodes

C) microglial cells — spleen

Which of the following is a correct pairing of activator and leukocyte?
A) C3b — natural killer lymphocyte
B) lectin — neutrophil
C) gamma interferon — eosinophil
D) alpha interferon — natural killer lymphocyte
E) NOD protein — neutrophil

D) alpha interferon — natural killer lymphocyte

Which of the following leukocytes have granules in their cytoplasm that stain blue with methylene blue?

A) eosinophils
B) monocytes
C) lymphocytes
D) neutrophils
E) basophils

E) basophils

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

A) monocyte

Which of the following is NOT involved in phagocytosis?
A) activation
B) chemotaxis
C) adherence
D) ingestion
E) killing

A) activation

The M protein on the surface of Streptococcus pyogenes
A) is part of the capsule and prevents adherence of phagocytes to its surface.
B) acts as a toxin to human cells.
C) is a pyrogen that elevates the body temperature.
D) is an iron-binding protein.
E) is a chemotatic substance that attracts neutrophils

A) is part of the capsule and prevents adherence of phagocytes to its surface.

Which of the following is(are) activities of neutrophils?

A) formation of neutrophil extracellular traps
B) phagocytosis
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 does NOT bind iron?

A) M protein
B) lactoferrin
C) ferritin
D) transferrin
E) siderophores

E) siderophores

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

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

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

C) are produced by infected fibroblasts and macrophages.

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

A) gamma interferons

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

Which of the following cells does NOT have the ability to release histamine?
A) mast cells
B) basophils
C) platelets
D) damaged body cells
E) macrophages

E) macrophages

Which of the following substances is responsible for the edema associated with inflammation?

A) leukotrienes
B) histamine
C) interferon
D) defensin
E) both leukotrienes and histamine

E) both leukotrienes and histamine

Which of the following is NOT an example of a walled-off site of infection that contains a fluid made of dead tissue cells and dead leukocytes?
A) a boil
B) an abscess
C) a pimple
D) a pustule
E) a tumor

E) a tumor

How does aspirin act to decrease the symptoms of inflammation?

A) It acts as an antiprostaglandin.
B) It is an antitoxoid for most microbial toxins.
C) It prevents complement activation.
D) It interferes with the action of interferons.
E) It blocks the release of histamine

A) It acts as an antiprostaglandin.

The residual body is
A) the remains of a phagosome after digestion.
B) the union of a phagosome with lysosomes.
C) a dead phagocyte.
D) the attachment of a phagosome to the surface of a pathogen.
E) a type of granule in a granulocyte

A) the remains of a phagosome after digestion.

Which of the following characteristics is shared by the skin and mucous membranes?

A) They are both constantly shedding and replacing cells.
B) They both have cilia.
C) The outer layers are composed of dead cells.
D) Sebum may be present.
E) Lysozymes are always present

A) They are both constantly shedding and replacing cells.

The phenomenon known as chemotaxis is defined as

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

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

Opsonization is

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

A) the coating of a pathogen by complement.

Diapedesis is the process in which
A) phagocyte receptors detect PAMPs.
B) leukocytes increase during allergies and helminth infection.
C) a cell moves toward or away from a chemical stimulus.
D) monocytes stick to the wall of the blood vessels at the site of infection.
E) cells squeeze through the lining of capillaries to attack invading microbes.

E) cells squeeze through the lining of capillaries to attack invading microbes.

Margination is defined as
A) the process in which nonspecific leukocytes secrete toxins onto the surface of virally infected cells.
B) the process in which monocytes stick to the wall of the blood vessels at the site of infection.
C) intact skin, sebum, tears, etc.
D) the coating of a pathogen by complement.
E) the release prostaglandins and leukotrienes in response to microbes.

B) the process in which monocytes stick to the wall of the blood vessels at the site of infection.

Which of the following statements is true of eosinophils?
A) They are in intact skin, sebum, tears, etc.
B) They produce the coating of a pathogen by complement.
C) They are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.
D) They increase in allergies and helminth infection.
E) They release prostaglandins and leukotrienes in response to microbes.

D) They increase in allergies and helminth infection.

Which of the following statements regarding macrophages is correct?
A) They cause damage resulting in cell lysis.
B) They are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.
C) They release prostaglandins and leukotrienes in response to microbes.
D) They produce the coating of a pathogen by complement.
E) They kill cells by causing cell lysis.

C) They release prostaglandins and leukotrienes in response to microbes.

TLRs are

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

A) phagocyte receptors that detect PAMPs.

The leukocytes called natural killer lymphocytes

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

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

First line of defense may be described as

A) the release of prostaglandins and leukotrienes in response to microbes.
B) intact skin, sebum, tears, etc.
C) damage resulting in cell lysis.
D) the coating of a pathogen by complement.
E) nonspecific leukocytes that secrete toxins onto the surface of virally infected cells

B) intact skin, sebum, tears, etc.

The complement cascade results in
A) the sticking of monocytes to the wall of the blood vessels at the site of infection.
B) the squeezing of cells through the lining of capillaries to attack invading microbes.
C) the release of interferons.
D) movement of a cell toward or away from a chemical stimulus.
E) damage resulting in cell lysis.

E) damage resulting in cell lysis.

Interferons work against viruses.

true

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

false

sweta contains lysozymse

true

Defensins are small peptides that work specifically against certain pathogens

false

Some Toll-like receptors (TLRs) are found on the surface of hist cells and recognize specific microbial molecules

true

The alternative pathway for complement activation is more effective than the classical pathway

false

Histamine and proataglandins are involved inflammatory reations

true

Pyrogens affect the hypothalamus, causing elevation of the internal body temperature

True

Neutrophils can kill bacteria by nonphagocytic mechanisms.

true

Inflammation is an important part of the body's first line of defense, and it involves migration of phagocytes to the area.

false

Antimicrobial peptides secreted by sweat glands are called __________.

dermcidins

The absence of necessary receptors is the basis of the defense against microbial invasion known as __________ resistance

species

Sweat glands produce __________, which destroys the cell wall of bacteria by cleaving the bonds between the sugar subunits present in the wall.

lysozyme

The __________ cells in the tracheal mucous membrane produce mucus

goblet

The oily substance that lowers the pH of the skin's surface to about pH 5 and is inhibitory to many bacteria is __________.

sebum

The normal microbiota compete with pathogens in a variety of ways to protect the body, creating a situation known as microbial __________.

antagonism

In a process called __________, blood stem cells located in the bone marrow produce the three types of formed elements found in the blood.

hematopoiesis

The process known as __________ allows neutrophils and eosinophils to squeeze between the cells lining the capillaries to attack invading microbes.

diapedesis

9) Neutrophils use their own __________ in the formation of NETs to trap bacteria. (Be sure to use all capitals in your answer.)

DNA

The proportion of __________, as determined by a differential white blood cell count, can serve as a sign of disease.

leukocytes

In the case of phagocytes, positive chemotaxis involves the use of __________ to move toward the microorganism

pseudopodia

The redness and heat of acute inflammation are caused in part by the production of __________ during the formation of blood clots.

bradykinin

Phagocytes kill a pathogen once it has been ingested, whereas eosinophils and __________ lymphocytes can accomplish extracellular killing by secreting toxins

NK

A chemical reaction in which the product of each reaction becomes the enzyme that catalyzes the next reaction is known as a(n) __________ reaction.

cascade

Phagocytes release __________, which result in the production of fever

pyrogens

The first and second lines of defense against microbial invasion are part of

Innate immunity

Response to specific pathogens that can improve with subsequent exposure is

the third line of defense

Which of the following areas of the body have mucous membranes?

mouth, nasal cavity, and urinary system

Which of the following statements about eosinophil function is true?

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

Mucus and sweat contain ________ which damage and kill bacteria

antimicrobial peptides

Receptors known as NOD proteins detect molecules associated with microbes

in the cytoplasm

The components of the second line of defense against microbes may be characterized as

responders to invasion

Which of the following proteins are part of the first line of defense against microbial invasion?

defensins

Which of the following iron-binding proteins is NOT part of the body's iron storage and transport system?

siderophores

Fever is beneficial during viral infection because the higher temperature

increases the effectiveness of interferons

Which of the following leukocyte functions do macrophages carry out?

phagocytosis of pathogens and secretion of alpha interferons and leukotrienes

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

first

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

inflammation

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

nonspecific

The growth of some microbes is inhibited by elevated body temperature

true

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

false

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

true

Lectins specific for mannose can lead to attack on fungi by

complement

Structures and products of pathogens that immune cells detect and respond to are called

PAMPs

Which of the following statements is true of eosinophils?

They secrete toxins onto the surface of helminth parasites

The ________ play a role in preventing neoplastic cells from progressing to cancer.

NK cells

Wandering macrophages recognize microorganisms by means of

both TLRs and NOD proteins

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