Chapter 12 (module 4) Flashcards
1
Q
a multilevel network of innate protections and adaptive protections that are commonly referred to as the first, second, and third lines of defense
A
host defenses
2
Q
includes any barrier that blocks invasion at the portal of entry; also limits access to the internal tissues of the body.
A
first line of defense (INNATE)
3
Q
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
A
second line of defense (INNATE)
4
Q
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
A
third line of defense (ADAPTIVE)
5
Q
line of defense that includes fever, inflammation, phagocytosis, antimicrobial products
A
second line of defense
6
Q
a healthy functioning immune system is responsible for what three things?
A
- Surveillance of the body
- Recognition of foreign material
- Destruction of entities deemed to be foreign
7
Q
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?
A
antigens
8
Q
natural markers of the body that are recognized by the immune system
A
self
9
Q
molecules recognized by the immune system as containing foreign markers, indicating a need for immune response
A
nonself
10
Q
many autoimmune disorders are a result of what
A
the immune system mistakenly attacking the body’s own tissues and organs
11
Q
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
A
marker
12
Q
molecules on the surfaces of MANY types of microbes that are not present on host cells that mark the microbes as foreign
A
pathogen-associated molecular patters (PAMPs)
13
Q
used to recognize PAMPs; molecules on the surface of host defense cells that recognize pathogen-associated patterns on microbes
A
Pattern recognition receptors (PRRs)
14
Q
mandate of the immune system
A
Search, Recognize, Destroy
15
Q
a collection of monocytes and macrophages scattered throughout the extracellular spaces that function to engulf and degrade foreign material
A
Mononuclear Phagocyte System (MPS)
16
Q
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)
A
lymphatic system
17
Q
what system does these major functions?
- Provides a route for the return of extracellular fluid to the circulatory system proper
- Acts as a “drain-off” system for the inflammatory response
- Renders surveillance, recognition, and protection against foreign materials through a system of lymphocytes, phagocytes, and antibodies
A
lymphatic system
18
Q
the lymphatic system is present in the ___________ of the brain
A
meninges
19
Q
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
A
lymph
20
Q
what is the function of lymph?
A
transports numerous WBCs (especially lymphocytes) and miscellaneous materials such as fats, cellular debris, and infectious agents that have gained access to the tissue spaces
21
Q
lymph is never subjected to _________ _________
A
high pressure
22
Q
lymphatic vessels are more similar to ____-____ ____.
-> due to the fact that they are not exposed to high pressure
A
thin walled veins
23
Q
what parts of the body do lymphatic capillaries not extend into?
A
parts of the CNS, and certain organs like bone, placenta, and thymus
24
Q
where are there a lot of lymphatic vessels?
A
hands, feet, and areola of the breast
25
what are two difference in the circulation of the lymphatic system vs blood stream?
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
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)
primary lymphoid organs
| red bone marrow and thymus
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
secondary lymphoid organs
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
red bone marrow
29
site of T-Cell maturation
thymus
30
butterfly shaped organ near the tip of the sternum that is the site of T-Cell maturation
thymus
31
lymphocytes that originate in the bone marrow as naive T lymphocytes migrate to the _______ to complete their maturation
thymus
32
where the action of immunity takes place
secondary lymphoid organs -> spleen, lymph nodes
33
where are the major aggregations of lymph nodes?
axilla (axillary nodes), groin (inguinal nodes), and neck (cervical nodes)
34
function is to filter out materials in the lymph and provide appropriate cells for immune reactions
lymph nodes
35
the outer rim of the lymph node is called the ______.
cortex
36
in regard to lymph nodes:
There are T lymphocytes in the _______ area,
and there are B lymphocytes and macrophages in the ________ sinus.
1. paracortical (houses T cells)
| 2. medullary (houses B cells)
37
what may lymph node enlargement indicate?
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
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
spleen
39
SALT
skin associated lymphoid tissue
40
MALT
mucosa associated lymphoid tissue
41
in the pharynx, the ______ provide an active source of lymphocytes
tonsils
42
GALT
gut associated lymphoid tissue
43
what are some examples of GALT?
appendix, lacteals, Peyer' patches (compact aggregations of lymphocytes in the ileum of the small intestine)
44
what does whole blood consist of?
blood cells and plasma
45
_____ is essentially the same as plasma, except it is the clear fluid from clotted blood.
serum
46
term for production of blood cells
hematopoiesis
47
what is the primary precursor of new blood cells?
a pool of undifferentiated cells called pluripotential stem cells in the bone marrow.
48
"Pluripotent" in regard to stem cells being precursors for blood cells
means that the cells are able to become any type of blood cell that is needed
49
two lines of cells that arise from stem cells
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)
50
two categories of leukocytes (WBCs, the primary infection-fighting blood cells)
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))
51
what can the granules in granulocytes do?
be released to kill foreign cells
52
regulatory chemical released by cells of the immune system that serves as signals between different cells
cytokines
53
Four categories of Cytokines
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
54
where is the Mononuclear Phagocyte System (MPS) found?
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
55
where are some locations with greater phagocyte concentration?
head, chest/neck, ribs, inside of elbows, groin, wrists, knees, ankles
56
another term for macrophage
histiocyte
57
histiocyte cells in liver
Kupffer cells
58
histiocyte cells in lungs
alveolar macrophages
59
histiocyte cells in skin
Langerhans cells
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
inborn defenses
61
how does the stratum corneum skin layer block entry of pathogens through the skin?
it is a thick, compacted, cemented layer containing an insoluble protein called keratin
-> thick, tough layer that is highly impervious and waterproof
62
to shed the cuticle in scaled; to peel off the outer layer of a surface
-> helps shed microbes from the skin
desquamate
63
how do sebaceous glands help block microbial entry into the body?
flushing of the glands, and sweating helps remove microbes
64
the mucous membranes of the digestive, urinary, and resp. tracts and of the eye are moist and permeable, and provide
barrier protection
65
lacrimation and its function
tear production
| -> flushes the eye's surface with tears to rid of irritants
66
function of saliva in blocking microbial infection
constant flow of saliva helps carry microbes into the harsh conditions of the stomach
67
how do vomiting and defecation help rid of microbes
they evacuate noxious substances or microbes from the body
68
resp tract functions of ridding microbes
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
69
protection by genitourinary tract
continuous trickle of urine though the ureters and from periodic bladder emptying that flushes the urethra
70
vaginal secretions
provide cleansing of the lower reproductive tract in females
71
the human microbiome forms a type of
structural barrier
72
specialized glands of the eyelids lubricate the conjunctiva with
antimicrobial secretions
73
additional defense in tears and saliva is
lysozyme
74
lysozyme
an enzyme that hydrolyzes, or breaks down glycosidic bond between the neighboring sugars in the peptidoglycan layer of bacterial cells
75
sweat and skin in inhibiting microbes
the high lactic acid and electrolyte concentrations of sweat and the skin's acidic pH and fatty acid content are inihbitory
76
HCl
hydrochloric acid in the stomach renders protection against many pathogens that are swallowed
77
intestines
digestive juices and bile are potentially destructive to microbes
78
penis and vagina
semen contains an antimicrobial chemical that inhibits bacteria
vagina during repro years has a protective acidic pH maintained by normal biota
79
12.2 Outcome
| identify three components of the first line of defense
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
80
12.2 Outcome
| identify four body systems that participate in the first line of defense
skin
respiratory system
gastrointestinal
urogenital
81
12.2 Outcome
| Describe two examples of how the normal microbiota contribute to the first line of defense
- 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
82
12.3 The Second Line of Defense
Four mechanisms with important roles in host defenses
1. Phagocytosis
2. Inflammation
3. Fever
4. Antimicrobial products
83
1. Phagocytosis
2. Inflammation
3. Fever
4. Antimicrobial products
innate or adaptive?
considered innate in their effects, BUT also support and interact with the adaptive immune responses
84
three main types of phagocytes
1. neutrophils
2. macrophages
3. dendritic cells
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
general activities of a phagocyte
86
innate
referring to the fact that line of defense does not require previous training of the human cells
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
neutrophil
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
monocytes -> macrophages
89
_________ live much longer than neutrophils and can consume a lot more material.
macrophages
90
what events are included in phagocytosis?
chemotaxis, ingestion, phagolysosome formation, destruction, and secretion
91
describe chemotaxis in phagocytosis
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
92
describe adhesion in phagocytosis
phagocytes use their PRRs to recognize PAMPs on foreign cells, this receptor interaction causes the two to stick together
93
describe engulfment and PHAGOSOME FORMATION in phagocytosis
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.
94
describe the PHAGOLYSOSOME FORMATION and killing process of phagocytosis
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
95
describe the destruction process of phagocytosis
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
96
describe the elimination process of phagocytosis
the small bits of undigestible debris are released from the macrophage by exocytosis
97
molecules shared by many microorganisms but are not present in mammals, and therefore serve as "red flags"
Pathogen-associated molecular patterns (PAMPs)
98
Peptidoglycan, lipopolysaccharide, double stranded RNA (viruses)
first two: bacterial PAMP
| third: viral PAMP
99
PRRs
pattern recognition receptors
100
a large protein in phagocytic cells that contain PRRs to help these cells initiate the inflammatory response
inflammasome
101
describe rubor, calor, tumor, and dolor in regards to inflammation
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)
102
what can cardiovascular disease be caused by?
chronic inflammation
103
inflammation can be at a local site, or it can affect
an entire system ie. lungs, joints, blood vessels, etc.
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
the chief functions of inflammation
105
the inflammation response is a powerful defensive reaction, but can also cause....
tissue injury, destruction, and disease
106
stage one of inflammation
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
107
stage two of inflammation
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)
108
stage three of inflammation
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
-
109
final and fourth stage of inflammation
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
110
the migration of WBCs out of blood vessels and into the tissues
diapedesis
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)
motile
| shape
112
the tendency of cells to migrate to in response to a specific chemical stimulus given off at a site of injury
chemotaxis
113
benefits of edema and leaky vessels
- 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
114
in some types of inflammation, accumulated phagocytes contribute to ___, a white, gooey mass of cells, liquefied cellular debris, and bacteria.
pus
115
pertains to pus formers
ie. such as: pneumococci, streptococci, staphylococci, and neisseriae
pyogenic
116
where is body temp controlled in the brain?
hypothalamus region
117
substance that causes rise in body temp
pyrogens
118
low grade fever
37.7-38.3 C
| 100-101 F
119
high grade fever
40-41 C
| 104-106 F
120
pyrogens are described as __________ (coming from outside the body) or ________ (originating internally)
exogenous
| endogenous
121
_________ pyrogens are products of infectious agents such as viruses, bacteria, protozoa, and fungi
ie. endotoxin lipopolysaccharide
exogenous
122
blood, blood products, vaccines, or injectable solutions can contain ______ pyrogens
exogenous
123
_________ pyrogens are released by monocytes, neutrophils, and macrophages during phagocytosis and appear to be a part of normal immune response
endogenous
124
Interleukin-1 (IL-1) and TNF (tumor necrosis factor)
two potent pyrogens released by macrophages (endogenous)
| both are cytokines
125
fevers above 104-105 should be
treated to prevent serious damage to host tissues
126
benefits of fever
- 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
127
Hippocrates and fever
offered the idea that it was the body's attempt to burn off a noxious agent
128
side effects of fever
tachycardia, tachypnea, and in some a lowering of seizure threshold
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
interferon (IFN)
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
complement
131
host cell molecules that inhibit viral replication
-> inhibit the multiplication of viruses in host cells
restriction factors
| ->restrict viral replication
132
short protein molecules found in epithelial cells; have the ability to kill bacteria
-> can directly kill all manner or microbes
antimicrobial peptides
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
interferons
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
complement
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
antimicrobial peptides
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
host restriction factors
137
four main groups of antimicrobial products
interferon
complement
host restriction factors
antimicrobial peptides
138
outline the steps of inflammation
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.
139
discuss the mechanisms of fever and how it helps defend the body
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
140
outline the steps of phagocytosis
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.
5. 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.
6. Destruction
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" together7. Elimination - the small bits if indigestible debris are released from the macrophage by exocytosis
141
overview of 12.1
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
142
12.2 overview
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
143
12.3 overview
| "the second line of defense"
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)
144
a microorganism carries _______ markers, and a B cell carries ______ markers
nonself
| self
145
which of the following are lymphocytes
a. macrophages
b. neutrophils
c. RBCs
d. B cells
d
146
cytokines are secreted by which cells?
a. macrophages
b. B cells
c. T cells
d. all of these
d
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
b
148
endotoxin is an example of a _________ pyrogen
exogenous
149
lymphatic fluid flows ______ the heart
toward
