Chapter 12 (module 4)

Question 1

a multilevel network of innate protections and adaptive protections that are commonly referred to as the first, second, and third lines of defense

Answer 1

host defenses

Question 2

includes any barrier that blocks invasion at the portal of entry; also limits access to the internal tissues of the body.

Answer 2

first line of defense (INNATE)

Question 3

also called innate immunity; is a more internal system of protective cells, fluids, and processes that includes inflammation and phagocytosis; acts rapidly at both the local and systemic levels once the first line of defense has been overcome

Answer 3

second line of defense (INNATE)

Question 4

acquired only as each foreign substance is encountered by WBCs called lymphocytes -> lymphocytes specifically adapt to each individual invader (adaptive immunity); provides long term immunity

Answer 4

third line of defense (ADAPTIVE)

Question 5

line of defense that includes fever, inflammation, phagocytosis, antimicrobial products

Answer 5

second line of defense

Question 6

a healthy functioning immune system is responsible for what three things?

Answer 6

1. Surveillance of the body
2. Recognition of foreign material
3. Destruction of entities deemed to be foreign

Question 7

cells display a unique mix of macromolecules on their surfaces that the immune system “senses” to determine if they are foreign or not, what are these called?

Answer 7

antigens

Question 8

natural markers of the body that are recognized by the immune system

Answer 8

self

Question 9

molecules recognized by the immune system as containing foreign markers, indicating a need for immune response

Answer 9

nonself

Question 10

many autoimmune disorders are a result of what

Answer 10

the immune system mistakenly attacking the body’s own tissues and organs

Question 11

any trait or factor of a cell, virus, or molecule that makes it distinct and recognizable; generally consist of sugars and proteins; ie. a genetic marker

-> another term for antigens

Answer 11

marker

Question 12

molecules on the surfaces of MANY types of microbes that are not present on host cells that mark the microbes as foreign

Answer 12

pathogen-associated molecular patters (PAMPs)

Question 13

used to recognize PAMPs; molecules on the surface of host defense cells that recognize pathogen-associated patterns on microbes

Answer 13

Pattern recognition receptors (PRRs)

Question 14

mandate of the immune system

Answer 14

Search, Recognize, Destroy

Question 15

a collection of monocytes and macrophages scattered throughout the extracellular spaces that function to engulf and degrade foreign material

Answer 15

Mononuclear Phagocyte System (MPS)

Question 16

a system of vessels and organs that serve as sites for development of immune cells and immune reactions. It includes the spleen, thymus, lymph nodes, and gut-associated lymphoid tissue (GALT)

Answer 16

lymphatic system

Question 17

what system does these major functions?

1. Provides a route for the return of extracellular fluid to the circulatory system proper
2. Acts as a “drain-off” system for the inflammatory response
3. Renders surveillance, recognition, and protection against foreign materials through a system of lymphocytes, phagocytes, and antibodies

Answer 17

lymphatic system

Question 18

the lymphatic system is present in the ___________ of the brain

Answer 18

meninges

Question 19

plasma-like liquid carried by the lymphatic circulation; it is formed when certain blood components move out of the blood vessels into the extracellular spaces and diffuse or migrate into the lymphatic capillaries

Answer 19

lymph

Question 20

what is the function of lymph?

Answer 20

transports numerous WBCs (especially lymphocytes) and miscellaneous materials such as fats, cellular debris, and infectious agents that have gained access to the tissue spaces

Question 21

lymph is never subjected to _________ _________

Answer 21

high pressure

Question 22

lymphatic vessels are more similar to ____-____ ____.

-> due to the fact that they are not exposed to high pressure

Answer 22

thin walled veins

Question 23

what parts of the body do lymphatic capillaries not extend into?

Answer 23

parts of the CNS, and certain organs like bone, placenta, and thymus

Question 24

where are there a lot of lymphatic vessels?

Answer 24

hands, feet, and areola of the breast

Question 25

what are two difference in the circulation of the lymphatic system vs blood stream?

Answer 25

1. lymph flows only in one direction ->from the extremities to the heart; and is then returned to the blood stream through the thoracic duct->right lymphatic duct->subclavian vein near the heart.
2. while blood is transported by means of the heart -> lymph is moved only through contraction of the skeletal muscles

Question 26

in the lymphatic system, sites of immune cell birth and the locations where they mature are considered what?

-> sites where B and T lymphocytes are generated and become mature (red bone marrow and thymus)

Answer 26

primary lymphoid organs

red bone marrow and thymus

Question 27

in the lymphatic system sites where immune cells become activated, reside, or carry out their functions are called what?

ie. lymph nodes, MALT, SALT, spleen

Answer 27

secondary lymphoid organs

Question 28

important intersection between circulatory, skeletal, and lymphatic systems; typically found in flat bones and at the ends of long bones and is the site of blood cell production

-> primary lymphoid organ

Answer 28

red bone marrow

Question 29

site of T-Cell maturation

Answer 29

thymus

Question 30

butterfly shaped organ near the tip of the sternum that is the site of T-Cell maturation

Answer 30

thymus

Question 31

lymphocytes that originate in the bone marrow as naive T lymphocytes migrate to the _______ to complete their maturation

Answer 31

thymus

Question 32

where the action of immunity takes place

Answer 32

secondary lymphoid organs -> spleen, lymph nodes

Question 33

where are the major aggregations of lymph nodes?

Answer 33

axilla (axillary nodes), groin (inguinal nodes), and neck (cervical nodes)

Question 34

function is to filter out materials in the lymph and provide appropriate cells for immune reactions

Answer 34

lymph nodes

Question 35

the outer rim of the lymph node is called the ______.

Answer 35

cortex

Question 36

in regard to lymph nodes:
There are T lymphocytes in the _______ area,
and there are B lymphocytes and macrophages in the ________ sinus.

Answer 36

1. paracortical (houses T cells)

2. medullary (houses B cells)

Question 37

what may lymph node enlargement indicate?

Answer 37

systemic illness
or enlargement of an individual one may indicate a local infection

-> reflects the replication of many lymphocyte clones during an adaptive immune response

Question 38

lymphoid organ in the upper left portion of the abdominal cavity; functions to filter out worn out blood cells AND to filter pathogens from the blood and to start phagocytosis by macrophages

Answer 38

spleen

Question 39

SALT

Answer 39

skin associated lymphoid tissue

Question 40

MALT

Answer 40

mucosa associated lymphoid tissue

Question 41

in the pharynx, the ______ provide an active source of lymphocytes

Answer 41

tonsils

Question 42

GALT

Answer 42

gut associated lymphoid tissue

Question 43

what are some examples of GALT?

Answer 43

appendix, lacteals, Peyer’ patches (compact aggregations of lymphocytes in the ileum of the small intestine)

Question 44

what does whole blood consist of?

Answer 44

blood cells and plasma

Question 45

_____ is essentially the same as plasma, except it is the clear fluid from clotted blood.

Answer 45

serum

Question 46

term for production of blood cells

Answer 46

hematopoiesis

Question 47

what is the primary precursor of new blood cells?

Answer 47

a pool of undifferentiated cells called pluripotential stem cells in the bone marrow.

Question 48

“Pluripotent” in regard to stem cells being precursors for blood cells

Answer 48

means that the cells are able to become any type of blood cell that is needed

Question 49

two lines of cells that arise from stem cells

Answer 49

1. those that differentiate from a common myeloid cell (RBC precursors (erythroblasts) and platelet precursors (megakaryoblasts))
2. those that differentiate from a common lymphoid precursor cell such as precursors of many WBCs (myeloblasts) and precursors of lymphocytes (lymphoblasts)

Question 50

two categories of leukocytes (WBCs, the primary infection-fighting blood cells)

Answer 50

granulocytes -> have dark staining granules (basophils, eosinophils, neutrophils, mast cells)

agranulocytes -> do not have granules and typically have large nuclei (monocytes (macrophages and dendritic cells) and lymphocytes (T, B, NK cells, NKT cells, Gamma-delta T cells))

Question 51

what can the granules in granulocytes do?

Answer 51

be released to kill foreign cells

Question 52

regulatory chemical released by cells of the immune system that serves as signals between different cells

Answer 52

cytokines

Question 53

Four categories of Cytokines

Answer 53

1. Pro-inflammatory (ENCOURAGE adaptive and innate immune responses)
   - > Interleukin-1 (IL-1)
2. Anti-inflammatory (DISCOURAGE adaptive and innate immune responses)
   - > Interleukin-10 (IL-10)
3. Vasodilators/Vasoconstrictors (can change diameter of blood vessels or vessel permeability)
   - > histamine, serotonin
4. Growth factor (regulate lymphocyte growth or activation)
   - > Interleukin-7 (IL-7), Erythropoietin

Question 54

where is the Mononuclear Phagocyte System (MPS) found?

Answer 54

in the thymus, where important WBCs mature; and in the lymph nodes, tonsils, spleen, and lymphoid tissue in the mucosa of the gut and resp. tract where most of the MPS “action” takes place

Question 55

where are some locations with greater phagocyte concentration?

Answer 55

head, chest/neck, ribs, inside of elbows, groin, wrists, knees, ankles

Question 56

another term for macrophage

Answer 56

histiocyte

Question 57

histiocyte cells in liver

Answer 57

Kupffer cells

Question 58

histiocyte cells in lungs

Answer 58

alveolar macrophages

Question 59

histiocyte cells in skin

Answer 59

Langerhans cells

Question 60

12.2
defenses that are the physical and chemical barriers that impede the entry of not only microbes but any foreign agent, whether living or not

ie. mucus, sebaceous glands, cilia

Answer 60

inborn defenses

Question 61

how does the stratum corneum skin layer block entry of pathogens through the skin?

Answer 61

it is a thick, compacted, cemented layer containing an insoluble protein called keratin

-> thick, tough layer that is highly impervious and waterproof

Question 62

to shed the cuticle in scaled; to peel off the outer layer of a surface
-> helps shed microbes from the skin

Answer 62

desquamate

Question 63

how do sebaceous glands help block microbial entry into the body?

Answer 63

flushing of the glands, and sweating helps remove microbes

Question 64

the mucous membranes of the digestive, urinary, and resp. tracts and of the eye are moist and permeable, and provide

Answer 64

barrier protection

Question 65

lacrimation and its function

Answer 65

tear production

-> flushes the eye’s surface with tears to rid of irritants

Question 66

function of saliva in blocking microbial infection

Answer 66

constant flow of saliva helps carry microbes into the harsh conditions of the stomach

Question 67

how do vomiting and defecation help rid of microbes

Answer 67

they evacuate noxious substances or microbes from the body

Question 68

resp tract functions of ridding microbes

Answer 68

nasal hair traps microbes, copious amounts of fluid and mucus that occur in colds/allergies flush microbes, ciliated epithelium in the trachea and bronchi move foreign particles entrapped in mucus toward the pharynx to be removed

sneezing expels a large volume of air at a high velocity

coughing ejects irritants

Question 69

protection by genitourinary tract

Answer 69

continuous trickle of urine though the ureters and from periodic bladder emptying that flushes the urethra

Question 70

vaginal secretions

Answer 70

provide cleansing of the lower reproductive tract in females

Question 71

the human microbiome forms a type of

Answer 71

structural barrier

Question 72

specialized glands of the eyelids lubricate the conjunctiva with

Answer 72

antimicrobial secretions

Question 73

additional defense in tears and saliva is

Answer 73

lysozyme

Question 74

lysozyme

Answer 74

an enzyme that hydrolyzes, or breaks down glycosidic bond between the neighboring sugars in the peptidoglycan layer of bacterial cells

Question 75

sweat and skin in inhibiting microbes

Answer 75

the high lactic acid and electrolyte concentrations of sweat and the skin’s acidic pH and fatty acid content are inihbitory

Question 76

HCl

Answer 76

hydrochloric acid in the stomach renders protection against many pathogens that are swallowed

Question 77

intestines

Answer 77

digestive juices and bile are potentially destructive to microbes

Question 78

penis and vagina

Answer 78

semen contains an antimicrobial chemical that inhibits bacteria

vagina during repro years has a protective acidic pH maintained by normal biota

Question 79

12.2 Outcome

identify three components of the first line of defense

Answer 79

Physical or anatomical barriers at the body’s surface

Non-specific chemical defenses

specific resistance acquired immunity

_________________________________________________________

skin, mucous membranes and their secretions, normal biota

Question 80

12.2 Outcome

identify four body systems that participate in the first line of defense

Answer 80

skin
respiratory system
gastrointestinal
urogenital

Question 81

12.2 Outcome

Describe two examples of how the normal microbiota contribute to the first line of defense

Answer 81

• normal microbiota help protect the body by competing with potential pathogens (microbial antagonism)
• consumption of nutrients makes them unavailable to pathogens and they create an environment unfavorable to other microorganisms by changing pH

Question 82

12.3 The Second Line of Defense

Four mechanisms with important roles in host defenses

Answer 82

1. Phagocytosis
2. Inflammation
3. Fever
4. Antimicrobial products

Question 83

1. Phagocytosis
2. Inflammation
3. Fever
4. Antimicrobial products

innate or adaptive?

Answer 83

considered innate in their effects, BUT also support and interact with the adaptive immune responses

Question 84

three main types of phagocytes

Answer 84

1. neutrophils
2. macrophages
3. dendritic cells

Question 85

1. survey tissue compartments and discover microbes, particulate matter (dust, carbon particles, antigen-antibody complexes) and injured or dead cells
2. ingest and eliminate these materials
3. read immunologic information (antigens) from foreign matter

Answer 85

general activities of a phagocyte

Question 86

innate

Answer 86

referring to the fact that line of defense does not require previous training of the human cells

Question 87

mature granulocyte, phagocyte with limited ability due to rapid death when exposed to their own toxic oxygen products that also kill engulfed bacteria; common sign of bacterial infection when this granulocyte is in high count in the blood; multilobular

-> most common leukocyte

Answer 87

neutrophil

Question 88

after emigrating out of the blood stream into the tissues, ________ are transformed by various inflammatory mediators into __________.

-> this process is marked by an increase in size and by enhanced development of lysosomes and other organelles

Answer 88

monocytes -> macrophages

Question 89

_________ live much longer than neutrophils and can consume a lot more material.

Answer 89

macrophages

Question 90

what events are included in phagocytosis?

Answer 90

chemotaxis, ingestion, phagolysosome formation, destruction, and secretion

Question 91

describe chemotaxis in phagocytosis

Answer 91

phagocytes migrate into a region of inflammation, attracted by a gradient of stimulant projects from the parasite and host tissue at the site of injury

Question 92

describe adhesion in phagocytosis

Answer 92

phagocytes use their PRRs to recognize PAMPs on foreign cells, this receptor interaction causes the two to stick together

Question 93

describe engulfment and PHAGOSOME FORMATION in phagocytosis

Answer 93

once the phagocyte makes contact with its prey, it extends PSEUDOPODS that enclose the cells or particle in a pocket and internalize them in a vacuole called a PHAGOSOME.
It also secretes cytokines to further amplify the innate response.

Question 94

describe the PHAGOLYSOSOME FORMATION and killing process of phagocytosis

Answer 94

lysosomes migrate to the scene of the phagosome and fuse with it to form a PHAGOLYSOSOME.
Granules containing antimicrobial chemicals are released into the phagolysosome, forming a toxic brew designed to poison and then dismantle the ingested material

Question 95

describe the destruction process of phagocytosis

Answer 95

oxygen-dependent system (oxidative burst) involves several substances such as Myeloperoxidase, hydrogen peroxide, lactic acid, lysozyme, nitric oxide (NO), cationic proteins that injure bacterial cytoplasmic membranes, and a number of other enzymes that can degrade DNA, RNA, and proteins

Question 96

describe the elimination process of phagocytosis

Answer 96

the small bits of undigestible debris are released from the macrophage by exocytosis

Question 97

molecules shared by many microorganisms but are not present in mammals, and therefore serve as “red flags”

Answer 97

Pathogen-associated molecular patterns (PAMPs)

Question 98

Peptidoglycan, lipopolysaccharide, double stranded RNA (viruses)

Answer 98

first two: bacterial PAMP

third: viral PAMP

Question 99

PRRs

Answer 99

pattern recognition receptors

Question 100

a large protein in phagocytic cells that contain PRRs to help these cells initiate the inflammatory response

Answer 100

inflammasome

Question 101

describe rubor, calor, tumor, and dolor in regards to inflammation

Answer 101

rubor - redness (caused by increased circulation and vasodilation in injured tissues)

calor - warmth (heat given off by the increased blood flow)

tumor - swelling (caused by increased fluid escaping into the tissues)

dolor - pain (caused by stimulation of nerve endings)

*loss of function has also been added to the characteristics of identifying inflammation)

Question 102

what can cardiovascular disease be caused by?

Answer 102

chronic inflammation

Question 103

inflammation can be at a local site, or it can affect

Answer 103

an entire system ie. lungs, joints, blood vessels, etc.

Question 104

1. To mobilize and attract immune components to the site of injury
2. To set in motion mechanisms to repair tissue damage and localize and clear away harmful substances
3. To destroy microbes and block their further invasion

Answer 104

the chief functions of inflammation

Question 105

the inflammation response is a powerful defensive reaction, but can also cause….

Answer 105

tissue injury, destruction, and disease

Question 106

stage one of inflammation

Answer 106

Injury/Immediate Reactions

• chemical mediators & cytokines are released by blood cells, tissues cells, and platelets in the injured area
• some mediators are vasoactive -> they dilate or constrict the vessels
• some mediators are chemotactic factors (chemokines) and stimulate the movement of WBCs

Question 107

stage two of inflammation

Answer 107

Vascular Reactions

• blood vessels dilate, then constrict, and then dilate again (flushes irritants away from the area, and brings helpful components to the site)
• exudate is formed (fluid that escapes in the extracellular spaces)

Question 108

stage three of inflammation

Answer 108

Edema and Pus Formation
-accumulation of fluid in the tissues (edema)
-fluid contains plasma proteins (globulins, albumin, fibrinogen, blood cells, cellular debris)
-fluid may be clear (serous) or may contain RBCs or pus
-pus is composed mainly of WBCs and debris from phago
-

Question 109

final and fourth stage of inflammation

Answer 109

Resolution/Scar Formation

• repair
• macrophages do diapedesis (migration of intact blood cells between endothelial cells of a blood vessel such as a venule)
• differentiated stem cells in the area begin to divide and repopulate the damages site with new cells to replace the damaged ones

Question 110

the migration of WBCs out of blood vessels and into the tissues

Answer 110

diapedesis

Question 111

WBCs are actively _____ and readily change _______, allowing for diapedesis to take place (the migration of WBCs out of the vessels, they squeeze between spaces, and into the tissues)

Answer 111

motile

shape

Question 112

the tendency of cells to migrate to in response to a specific chemical stimulus given off at a site of injury

Answer 112

chemotaxis

Question 113

benefits of edema and leaky vessels

Answer 113

• secretion of fluids helps dilute toxic substances (edema)
• fibrin clot can effectively trap microbes and prevent further spread
• neutrophils can aggregate in the inflamed site and are immediately involved in phagocytosing and destroying bacteria, dead tissues, and particulate matter

Question 114

in some types of inflammation, accumulated phagocytes contribute to ___, a white, gooey mass of cells, liquefied cellular debris, and bacteria.

Answer 114

pus

Question 115

pertains to pus formers

ie. such as: pneumococci, streptococci, staphylococci, and neisseriae

Answer 115

pyogenic

Question 116

where is body temp controlled in the brain?

Answer 116

hypothalamus region

Question 117

substance that causes rise in body temp

Answer 117

pyrogens

Question 118

low grade fever

Answer 118

37.7-38.3 C

100-101 F

Question 119

high grade fever

Answer 119

40-41 C

104-106 F

Question 120

pyrogens are described as __________ (coming from outside the body) or ________ (originating internally)

Answer 120

exogenous

endogenous

Question 121

_________ pyrogens are products of infectious agents such as viruses, bacteria, protozoa, and fungi

ie. endotoxin lipopolysaccharide

Answer 121

exogenous

Question 122

blood, blood products, vaccines, or injectable solutions can contain ______ pyrogens

Answer 122

exogenous

Question 123

_________ pyrogens are released by monocytes, neutrophils, and macrophages during phagocytosis and appear to be a part of normal immune response

Answer 123

endogenous

Question 124

Interleukin-1 (IL-1) and TNF (tumor necrosis factor)

Answer 124

two potent pyrogens released by macrophages (endogenous)

both are cytokines

Question 125

fevers above 104-105 should be

Answer 125

treated to prevent serious damage to host tissues

Question 126

benefits of fever

Answer 126

• fever inhibits multiplication of temp-sensitive microorganisms such as the poliovirus, cold viruses, herpes zoster virus, systemic and subQ fungal infections
• fever interferes with the nutrition of bacteria by reducing the availability of iron
• fever increases metabolism and stimulates immune reactions and naturally protective physiological processes
• speeds up hematopoiesis (blood cell formation), phagocytosis, adaptive immune reactions, and helps specific lymphocytes home in on sites of infection

Question 127

Hippocrates and fever

Answer 127

offered the idea that it was the body’s attempt to burn off a noxious agent

Question 128

side effects of fever

Answer 128

tachycardia, tachypnea, and in some a lowering of seizure threshold

Question 129

natural human chemical that inhibits viral replication; used therapeutically to combat viral infections and cancer

-> best known for targeting viruses, but can also target bacteria and tumor cells

Answer 129

interferon (IFN)

Question 130

serum protein components that act in a definite sequence when set in motion either by antigen-antibody complex or by factors of the alternative (properdin) pathway

-> targets membranes of pathogens and also pathogen-infected host cells

Answer 130

complement

Question 131

host cell molecules that inhibit viral replication

-> inhibit the multiplication of viruses in host cells

Answer 131

restriction factors

->restrict viral replication

Question 132

short protein molecules found in epithelial cells; have the ability to kill bacteria
-> can directly kill all manner or microbes

Answer 132

antimicrobial peptides

Question 133

small proteins produced naturally by certain WBCs and tissue cells

• three major types of it are alpha and beta (ie. lymphocytes, fibroblasts, macrophages), and interferon gamma (product of T cells)
• induce changes in genetic expression once bound to cell surfaces that inhibit viral multiplication
• can inhibit the expression of cancer genes and have tumor suppression effects
• not microbe specific

Answer 133

interferons

Question 134

• consists of over 30 different blood proteins that work together to primarily destroy bacteria, but can also affect viruses, nearby cells, or other parasites
• complement cascade:
  1. initiation (blood protein = hydrolyzed into two fragments)
  2. activation & cascade (C3b protein cleaves the protein C5 into C5a and C5b)
  3. polymerization (C5b fragment is now free to form a complex with C6, C7, C8) = this is the Membrane Attack Complex (MAC)
  4. membrane attack (MAC is positioned on offending cell’s membrane and forms pores in the membrane, structural integrity of mem is lost, and permeability is messed up= lysis
• classical complement pathway: initiated by specific antigen-antibody interaction
• alternative complement pathway: initiated by spontaneous breakdown of a blood protein called C3 in the presence of microbes

Answer 134

complement

Question 135

short proteins of between 12-50 amino acids
-have the capability of inserting themselves into bacterial membranes

• ex: defensin inserts into mem of bacteria causing the membrane to fold around it, once a few defensin peptide molecules gather in the area they can form a pore and can lyse the cell
• some are effective against eukaryotes or viruses

Answer 135

antimicrobial peptides

Question 136

molecules that can limit the ability of viruses to replicate once they are inside the host cell

-prevent synthesis of new virus parts, prevent assembly of a new virus, or prevent virus release from host cells

Answer 136

host restriction factors

Question 137

four main groups of antimicrobial products

Answer 137

interferon
complement
host restriction factors
antimicrobial peptides

Question 138

outline the steps of inflammation

Answer 138

1. injury/immediate reactions - these changes are controlled by nervous stimulation, chemical mediators, and cytokines released by blood cells, tissue cells, and platelets in the injured area.
2. vascular reactions - blood vessels dilate, the constrict, the dilate again. the wide-narrow-wide sequence is thought to be for the purpose of flushing irritants away from the area. The over all vasodilation is to increase the flow of blood to the area, which facilitates the influx of immune components and also causes redness and warmth
3. edema and pus formation - accumulation of this fluid in the tissue gives rise to local swelling and hardness called edema. The fluid contains varying amounts of plasma proteins such as globuins, albumin, the clotting protein fibrinogen, blood cells, and cellular debris. Pus is composed mainly of white blood cells and the debris generated by the phagocytosis.
4. resolution/scar formation - complete resolution to healthy tissue or the formation of scar tissue, depending on the tissue type and the extent of the damage.

Question 139

discuss the mechanisms of fever and how it helps defend the body

Answer 139

Inhibits multiplication of temperature-sensitive microorganisms

Impedes nutrition of bacteria by reducing the availability of iron

Increases metabolism and stimulates immune reactions and naturally protective physiological processes: speeds up hematopoiesis, phagocytosis, and specific immune reactions

Question 140

outline the steps of phagocytosis

Answer 140

1. chemotaxis - phagocytes migrate into region of inflammation with a deliberate sense of direction, attracted by a gradient of stimulant products from the parasite and host tissue at the site of injury
2. adhesion - phagocytes use their PRRs to recognize PAMPS on foreign cells. This receptor interaction causes these two to “stick” together
3. /4. engulfment and Phagosome formation - once the phagocyte has made contact with its prey. It extends pseudopods that enclose the cells or particles in a pocket and internalize them in a vacuole called a phagosome. It also secretes more cytokines to further amplify the innate response.
4. Phagolysosome Formation and Killing - lysosomes migrate to the scene of the phagosome and fuse with it to form a phagolysosome. Granules containing antimicrobial chemicals are released into the phagolysosome, forming a potent brew designed to poison and then dismantle the ingested material.
5. Destruction
6. chemotaxis - phagocytes migrate into region of inflammation with a deliberate sense of direction, attracted by a gradient of stimulant products from the parasite and host tissue at the site of injury
7. adhesion - phagocytes use their PRRs to recognize PAMPS on foreign cells. This receptor interaction causes these two to “stick” together7. Elimination - the small bits if indigestible debris are released from the macrophage by exocytosis

Question 141

overview of 12.1

Answer 141

the first line of defense consists of physical barriers, microbiota, and chemical barriers

the second line of defense consists of innate mechanisms

the third line of defense consists of adaptive responses to specific microorganisms

Question 142

12.2 overview

Answer 142

The first line of defense is made of physical, chemical, and microbiome barriers.

Mucous membranes and skin are physical barriers

Sweat, lysozyme, fatty acids, and pH levels are typical chemical barriers

Question 143

12.3 overview

“the second line of defense”

Answer 143

innate immune reactions are generalized responses to invasion, regardless of the source.

reactions include phagocytosis, inflammation, fever, and various antimicrobial products (interferons, complements, host restriction factors, antimicrobial peptides)

Question 144

a microorganism carries _______ markers, and a B cell carries ______ markers

Answer 144

nonself

self

Question 145

which of the following are lymphocytes

a. macrophages
b. neutrophils
c. RBCs
d. B cells

Answer 145

d

Question 146

cytokines are secreted by which cells?

a. macrophages
b. B cells
c. T cells
d. all of these

Answer 146

d

Question 147

the initial reaction to the presence of viruses in a human cell is the production of _____ by that cells.

a. complement
b. interferon
c. antiviral protein
d. fever

Answer 147

b

Question 148

endotoxin is an example of a _________ pyrogen

Answer 148

exogenous

Question 149

lymphatic fluid flows ______ the heart

Answer 149

toward