Module 2 - Chapter 20 Flashcards
(132 cards)
1
Q
What is the term for the set of diverse processes that protect the body from cellular injury and disease-causing cells?
A
Immunity
Immunity encompasses the functions of both the immune and lymphatic systems.
2
Q
What are the primary components of the immune system?
A
Cells and proteins in blood and tissues
The immune system consists of leukocytes (WBCs) and immune proteins located in plasma.
3
Q
What is the role of the lymphatic system?
A
Works with immune system and participates in fluid homeostasis
The lymphatic system consists of lymphatic vessels and lymphatic tissue and organs.
4
Q
What do lymphatic vessels do with excess fluid in the extracellular space?
A
Transport it back to the cardiovascular system
This process is essential to maintain blood volume and blood pressure.
5
Q
What is lymph?
A
Fluid that exits extracellular space and enters lymphatic vessels
Lymph and interstitial fluid are similar in composition.
6
Q
Fill in the blank: Lymphatic vessels pick up excess fluid in the extracellular space, transport it through the body, and deliver it back to the _______.
A
cardiovascular system
7
Q
What are the two main functions of the lymphatic system?
A
Regulation of interstitial fluid volume and absorption of dietary fats
The lymphatic system also plays an important role in immune functions.
8
Q
What are lymph trunks?
A
Larger vessels that drain lymph from specific body regions
There are nine lymph trunks in total.
9
Q
Which lymph trunk receives lymph from the lower limbs and pelvic area?
A
Lumbar trunks
10
Q
Which lymphatic duct drains lymph from the left side of the body?
A
Thoracic duct
The thoracic duct is the largest lymphatic duct.
11
Q
True or False: Lymphatic vessels operate under high pressure.
A
False
Lymphatic vessels make up a low-pressure circuit.
12
Q
What type of tissue is predominantly found in the lymphatic system?
A
Reticular tissue
Reticular tissue forms nets that trap disease-causing pathogens.
13
Q
What are the primary functions of macrophages in the lymphatic system?
A
Destroy old erythrocytes and filter pathogens
Macrophages are derived from mature monocytes.
14
Q
What is Mucosa-associated lymphatic tissue (MALT)?
A
Clusters of lymphoid tissue that protect mucous membranes
MALT is found in areas exposed to many pathogens, such as the gastrointestinal tract.
15
Q
List the three main types of tonsils.
A
- Pharyngeal tonsil (adenoid)
- Palatine tonsils
- Lingual tonsil
16
Q
What is the function of Peyer’s patches?
A
Defend against bacteria that escape from the large intestine
Peyer’s patches are located in the ileum.
17
Q
What is the function of lymph nodes?
A
Act as filters to trap pathogens
Lymph nodes limit the spread of pathogens through the body.
18
Q
What are the two main regions of a lymph node?
A
Cortex and medulla
19
Q
What is the primary function of the spleen?
A
Filter pathogens from blood and destroy old erythrocytes
The spleen is the largest lymphoid organ in the body.
20
Q
What is the primary function of the thymus?
A
Generate functional T cells
The thymus does not trap pathogens but secretes hormones for T cell maturation.
21
Q
What are the three lines of defense against pathogens in the immune system?
A
- Surface barriers (first line)
- Innate immunity (second line)
- Adaptive immunity (third line)
22
Q
What type of immunity responds quickly to all pathogens in the same way?
A
Innate (nonspecific) immunity
23
Q
What is the difference between innate and adaptive immunity?
A
Innate immunity responds quickly and nonspecifically, while adaptive immunity responds specifically and slowly
Adaptive immunity has immunological memory.
24
Q
Fill in the blank: The two arms of adaptive immunity are _______ immunity and antibody-mediated immunity.
A
cell-mediated
25
What is the role of B cells in the immune system?
Carried out antibody-mediated immunity
## Footnote
B cells produce immunoglobulins or antibodies.
26
True or False: Adaptive immunity provides immediate responses upon first exposure to an antigen.
False
## Footnote
Adaptive immunity takes 3-5 days to mount a response after exposure.
27
What is acquired immunity?
Immunity that takes 3–5 days to mount a response, becoming the dominant response after this period.
## Footnote
Acquired immunity involves specific lymphocytes and antibodies, allowing for a more rapid response upon subsequent exposures.
28
What is the capacity for immunological memory in adaptive immunity?
Adaptive immunity has the capacity to remember exposure to antigens, allowing for a more rapid and efficient response during subsequent exposures.
## Footnote
This memory is facilitated by specific lymphocytes and antibodies that 'remember' past encounters.
29
How does innate immunity differ from adaptive immunity in terms of memory?
Innate immunity lacks the capacity for immunological memory and responds the same way to repeated exposures to pathogens.
## Footnote
This means that innate immunity does not become more effective with repeated exposure.
30
Are adaptive immunity and innate immunity independently functioning?
No, adaptive and innate immunity rely on each other and involve a highly integrated series of events within both parts of the immune system.
## Footnote
This interdependence is crucial for an effective immune response.
31
What are surface barriers in the immune system?
The first line of defense includes coverings of body surfaces such as skin and mucous membranes, which secrete certain products.
## Footnote
These barriers provide a continuous physical barrier to block pathogen entry.
32
What role does sebum play in skin immunity?
Sebum, secreted by sebaceous glands, has a slightly acidic pH that deters the growth of most pathogenic organisms.
## Footnote
This property of sebum contributes to the skin's role as a barrier against pathogens.
33
What is the function of mucous membranes in the immune system?
Mucous membranes line all passageways that open to the outside, secreting mucus that traps pathogens and protects underlying cells.
## Footnote
Mucus serves as a physical barrier and a protective substance against pathogens.
34
What are the main cells of the immune system?
The main cells include different types of leukocytes such as agranulocytes and granulocytes.
## Footnote
Agranulocytes include B and T lymphocytes and monocytes, while granulocytes include neutrophils, eosinophils, and basophils.
35
What are phagocytes?
Phagocytes are cells that ingest foreign or damaged cells; includes macrophages, neutrophils, and eosinophils.
## Footnote
The process of ingestion by these cells is called phagocytosis.
36
What is the role of natural killer (NK) cells?
NK cells primarily function in innate immunity by recognizing and destroying cancerous and virus-infected cells.
## Footnote
They do not recognize specific antigens but are cytotoxic in nature.
37
What are antibodies?
Proteins produced by B lymphocytes that function in adaptive immunity.
## Footnote
Antibodies are critical for binding to specific antigens and facilitating their destruction.
38
What is the complement system?
A group of over 20 plasma proteins that play a critical role in both innate and adaptive immunity.
## Footnote
These proteins circulate in inactive forms and are activated through a cascade of enzymatic reactions.
39
What are the three pathways for activating the complement system?
1. Classical pathway
2. Lectin pathway
3. Alternative pathway
## Footnote
These pathways converge at the activation of C3 and lead to various immune responses.
40
What is opsonization?
The process by which C3b binds to pathogens, enhancing phagocytosis by making phagocytes bind more strongly.
## Footnote
Opsonization is crucial for the effective clearance of pathogens.
41
What are the cardinal signs of inflammation?
Redness, heat, swelling (edema), and pain.
## Footnote
These signs result from the inflammatory response to tissue damage.
42
What is the role of inflammatory mediators?
Inflammatory mediators are released by damaged cells and mast cells, causing local changes in damaged tissue and recruiting phagocytes.
## Footnote
Examples include histamine, cytokines, and prostaglandins.
43
What triggers vasodilation during inflammation?
Inflammatory mediators such as histamine and bradykinin.
## Footnote
Vasodilation increases blood flow to the area, resulting in redness and heat.
44
What is chemotaxis?
The process by which phagocytes migrate to damaged tissue in response to chemical signals.
## Footnote
This recruitment is essential for effective immune response and tissue repair.
45
What is the role of macrophages in inflammation?
Macrophages are the first responders to cellular injury, phagocytizing pathogens and damaged cells.
## Footnote
They also activate other immune cells and play a crucial role in the inflammatory response.
46
What initiates the inflammatory response?
Tissue damage that causes the release of inflammatory mediators from damaged cells and local mast cells.
## Footnote
This response helps to contain and repair damage.
47
What is the process by which neutrophils migrate to damaged tissue?
Chemotaxis
## Footnote
Neutrophils are attracted to damaged areas by inflammatory mediators and activated complement proteins.
48
What is margination in the context of neutrophil movement?
Adherence of neutrophils to the capillary wall
## Footnote
This occurs in the damaged area where the capillary endothelium becomes 'sticky'.
49
What increases capillary permeability during inflammation?
Inflammatory mediators
## Footnote
Increased permeability allows neutrophils to squeeze through into damaged tissue.
50
What is diapedesis?
The process of neutrophils squeezing through endothelial cells into damaged tissue
## Footnote
This process allows neutrophils to reach the site of infection.
51
What happens to neutrophil levels in the blood during inflammation?
Bone marrow releases stored neutrophils
## Footnote
This leads to a rapid rise in circulating neutrophils.
52
What do monocytes become when they migrate to tissue?
Macrophages
## Footnote
Macrophages phagocytize pathogens and cellular debris.
53
What is leukocytosis?
High white cell count
## Footnote
Caused by cytokines produced by activated phagocytes, leading to increased neutrophil and monocyte production.
54
What is pus?
A whitish mixture of dead leukocytes, dead tissue cells, and fluid
## Footnote
A wound filled with pus is termed purulent.
55
What is fever?
Body temperature above the normal range (36-38°C or 97-99°F)
## Footnote
An individual with fever is referred to as febrile.
56
What initiates a fever?
Release of pyrogens from damaged cells or certain bacteria
## Footnote
Pyrogens act on the hypothalamus to regulate body temperature.
57
What role does the hypothalamus play in fever?
It functions as the body's thermostat
## Footnote
It maintains body temperature through negative feedback loops.
58
What happens to the hypothalamic thermostat during fever?
It resets to a higher range
## Footnote
This causes the body to perceive normal temperature as low, triggering chills.
59
What are the mechanisms that lower body temperature after a fever breaks?
Sweating and dilation of blood vessels
## Footnote
These mechanisms make skin appear red or flushed.
60
What are the two main arms of the adaptive immune system?
Cell-mediated immunity and antibody-mediated immunity
## Footnote
Cell-mediated immunity involves T cells.
61
What types of T cells are involved in cell-mediated immunity?
Helper T (TH) cells and Cytotoxic T (TC) cells
## Footnote
These cells respond to infected cells and pathogens.
62
Where are T cells formed?
In the bone marrow
## Footnote
They migrate to the thymus to mature.
63
What is the purpose of thymus screening for T cells?
To ensure immunocompetence
## Footnote
It destroys clones that cannot recognize antigens.
64
What are self-reactive T cells?
T cells that recognize the body's own cells as foreign
## Footnote
They are destroyed to ensure self-tolerance.
65
What is an antigen?
A substance recognized by B or T cells
## Footnote
Antigens are usually peptides but can also include carbohydrates, lipids, and metals.
66
What are immunogens?
Antigens capable of generating an immune response
## Footnote
Self antigens are not immunogens in the body.
67
What are haptens?
Very small antigens that are immunogenic only when attached to a protein carrier
## Footnote
An example is urushiol from poison ivy.
68
What are major histocompatibility complex (MHC) molecules?
Glycoproteins that present antigens to T cells
## Footnote
They are crucial for tissue compatibility in transplants.
69
What are the two types of MHC molecules?
Class I and Class II MHC molecules
## Footnote
Class I MHC presents endogenous antigens; Class II presents exogenous antigens.
70
What is the role of dendritic cells in T cell activation?
They present antigens on both class I and class II MHC molecules
## Footnote
This allows them to activate both TH and TC cells.
71
What is clonal selection in T cell activation?
The process where a specific T cell clone is selected by an antigen
## Footnote
This leads to T cell activation and proliferation.
72
What are effector T cells?
T cells that cause immediate effects in the immune response
## Footnote
They differentiate from activated TH or TC cells.
73
What are memory T cells?
T cells responsible for immunological memory
## Footnote
They respond more rapidly to subsequent exposures to the same antigen.
74
What is the primary function of TH cells?
To secrete cytokines that activate and enhance the immune response
## Footnote
They do not have phagocytic or cytotoxic abilities.
75
What cytokine do TH cells secrete to stimulate macrophages?
Interleukin-3
## Footnote
This enhances macrophage phagocytic efficiency.
76
What stimulates macrophages to become more efficient phagocytes?
Interleukin-12
## Footnote
Interleukin-12 is a cytokine that enhances the ability of macrophages to engulf and destroy pathogens.
77
What is the role of T helper (T H) cells in the activation of T cytotoxic (T C) cells?
T H cells secrete interleukin-2 (IL-2)
## Footnote
IL-2 is essential for the activation of T C cells.
78
What happens to most T C cells in the absence of T H cells and IL-2?
They fail to activate and become unresponsive to antigen.
79
What is the primary function of cytotoxic T cells?
To kill other cells with foreign antigens bound to class I MHC molecules.
80
What is the mechanism by which activated T C cells destroy target cells?
They release perforin to form pores in the target cell's plasma membrane.
81
What happens to the target cell after T C cells release enzymes into it?
Degradation of target cell proteins and fragmentation of DNA lead to cell death.
82
What are the four basic kinds of tissue and organ transplants?
Autografts, Isografts, Allografts, Xenografts.
83
What is an autograft?
Tissue transplanted from one site to another in the same individual.
84
What triggers rejection of allografts and xenografts?
Antigens recognized as foreign by the recipient's immune system.
85
What is necrosis in the context of graft rejection?
Condition where rejected organ or tissue fails to function properly and its cells die.
86
What is the purpose of immunosuppressive therapy?
To suppress the immune response and prevent graft rejection.
87
What is antibody-mediated immunity?
Involves B cells and antibodies secreted by B cells.
88
What is a B cell clone?
A group of B cells that bind to a specific antigen.
89
What occurs during the first phase of the antibody immune response?
B cells develop and mature within bone marrow.
90
What happens to self-reactive B cells during maturation?
They are destroyed to prevent autoimmunity.
91
How do naïve B cells become activated?
By binding their specific antigen and interacting with T H cells.
92
What are the two types of cells resulting from the division of activated B cells?
Plasma cells and Memory B cells.
93
What is serology?
The study of antibodies.
94
What are the two types of regions in an antibody chain?
Constant (C) region and Variable (V) region.
95
What are the five basic classes of antibodies?
IgG, IgA, IgM, IgE, IgD.
96
What is the most prevalent antibody in the body?
IgG.
97
What type of antibody is IgM?
The largest antibody, a pentamer with five subunits.
98
What triggers the release of inflammatory mediators from mast cells?
IgE binding to antigens associated with allergens.
99
What is class switching in B cells?
The ability of a B cell clone to switch from producing one class of antibody to another.
100
What are the basic effects of secreted antibodies?
Agglutination, precipitation, opsonization, neutralization, and complement activation.
101
What is the difference between agglutination and precipitation?
Agglutination involves whole cells; precipitation involves soluble antigens.
102
What is the role of memory B cells?
To respond more efficiently upon re-encountering the same antigen.
103
What is the primary immune response characterized by?
A slow response with a lag phase of 4 to 5 days.
104
What is the primary immune response?
The response when plasma cells begin to secrete antibodies after encountering an antigen, typically slow with a 4- to 5-day lag phase.
105
What is the lag phase duration during the primary immune response?
4 to 5 days.
106
When do antibody levels peak after antigen exposure in the primary immune response?
7–14 days.
107
What is the secondary immune response?
The response activated by memory B cells upon re-exposure to the same antigen, lasting longer than the primary response.
108
What is the lag phase duration during the secondary immune response?
1 to 3 days.
109
How much larger are antibody levels during the secondary immune response compared to the primary response?
100–1000 times larger.
110
What is the major antibody involved in the secondary immune response?
IgG.
111
What is the major antibody involved in the primary immune response?
IgM.
112
What is vaccination also known as?
Immunization.
113
What do subunit vaccines require to develop immunity?
Only a portion of the pathogen that causes disease.
114
What are toxoids?
Vaccinations that contain inactivated toxins from bacteria, inducing the immune system to produce antibodies.
115
What are the two types of antibody-mediated immunity?
* Active immunity * Passive immunity
116
What characterizes active immunity?
Body’s cells actively respond to an antigen, resulting in memory cell production and long-lasting immunity.
117
What are the two types of immunodeficiency disorders?
* Primary immunodeficiencies * Secondary immunodeficiencies
118
What causes primary immunodeficiency disorders?
Genetic or developmental factors.
119
What is the most common cause of secondary immunodeficiency?
Viral disease, specifically AIDS caused by HIV-1.
120
What is the mechanism of HIV-1 infection?
HIV-1 is a retrovirus that inserts its RNA genome into host DNA via reverse transcriptase.
121
What is anaphylactic shock?
A severe, life-threatening reaction involving systemic release of histamine and inflammatory mediators.
122
What are the symptoms of type I hypersensitivity disorders?
* Allergies * Runny nose * Itchy eyes * Skin rashes * Asthma
123
What happens during the acute phase of HIV-1 infection?
Sharp decline in TH cells and sharp rise in HIV-1 virions, often with flu-like symptoms.
124
What is type II hypersensitivity?
Antibody-mediated hypersensitivity where antibodies bind to self antigens.
125
What is a common example of a type III hypersensitivity reaction?
Immune complex-mediated reactions that cause tissue damage.
126
What characterizes type IV hypersensitivity?
Delayed-type hypersensitivity mediated by T cells rather than antibodies.
127
What can trigger autoimmune disorders?
* Release of self antigens * Mimicry of self antigens by foreign antigens * Inappropriate expression of class II MHC molecules
128
What is the role of CD4 molecules in HIV-1 infection?
HIV-1 preferentially binds CD4 molecules to gain entry into host cells.
129
What are autoantibodies?
Antibodies that bind to self antigens.
130
What is the average duration of passive immunity?
About three months.
131
What therapeutic strategy is commonly used for HIV-1 treatment?
Combining multiple drugs to inhibit various aspects of the viral replication cycle.
132
True or False: The secondary immune response is quicker than the primary response.
True.
