Week 6- The Immune System (pt 1) Flashcards
A combining form meaning “making, formation”
-poeisis
The immune system is comprised of a number of cells in ____ groups
3
Monocytes, neutrophils, eosinophils, basophils, mast cells, natural killer cells
Innate immune system
B and T cells or lymphocytes
Adaptive immune system
Macrophages and dendritic cells
Innate and adapative systems
Poly-morpho-nuclear cells (PMNs) due to their segmented nucleus (3-5 lobes)
Neutrophils
True or false: Neutrophils are only classified as phagocytes
False
(phagocytes and granulocytes)
Neutrophils are the ________ cells to arrive at sites
First
Neutrophils constitute a major line of defense against ___________
Pus-forming bacteria
True or false: During acute inflammation or infection, neutrophils increase dramatically in number
True
These cells are large, long-lived cells with a bi-lobed nucleus that originate in bone marrow
Monocytes
In response to infection and inflammation, monocytes migrate into tissues and mature into ____________
Macrophages
True or false: Macrophages take over the neutrophils’ job by filtering the debris produced by the neutrophils and kill any damaged, but not dead, bacteria or bacteria that are too large for neutrophils to eliminate
True
Macrophages can remove other cells such as aged _____ or dead ______
RBCs
Neutrophils
These cells are involved in allergic responses and parasitic infections
Eosinophils
True or false: Eosinophils surround the pathogens if they are too small for neutrophils and macrophages to eliminate
False
(too large)
Eosinophils release granules that contain…
Histamine (vasodilator)
Heparin (anticoagulant)
Cytokines (inflammatory reactions)
The granulocytes that involve in allergic reactions
Basophils
Involved in allergic responses, anaphylaxis, wound healing and against invading pathogens
Mast cells
True or false: Mast cells posses granules containing histamine and other molecules that dilate blood vessels
True
Basophils and mast cells both increase the ___________ by recruiting more __________ to the site of infection
Blood supply
Phagocytes
Movement and removal of antigens, antibodies, and portions of the complement system
Erythrocytes (RBCs) and thrombocytes (platelets)
Platelets are the primary cells for _________ and __________
Thrombosis
Hemostasis
These lymphocytes mature in the bone marrow and produce antibodies to neutralize invading pathogens
B lymphocytes
These lymphocytes are produced in the bone marrow and mature in the thymus
T lymphocytes
Two types of T lymphocytes
Helper T cells
Cytotoxic T cells
Mature natural killer cells are in __________ and __________
Blood
Spleen
These cells kill cells infected with viruses, other intracellular microbe-infected cells, and tumor cells
Natural killer cells
How NK cells kill other cells
-Localized to infected tissues in response to inflammatory cytokines
-Release cytotoxic granules –> create pores–> activate a programmed death cascade
-Release more cytokines to recruit macrophages and initiate adaptive immunity
These cells readily ingest pathogens and kill them to protect against infections
Phagocytes
Two principle families of phagocytes
Neutrophils
Monocytes
Granulocytes that are short lived for 2-3 days
Neutrophils
Non-granulocytes that persist for months or years
Monocytes
True or false: Eosinophils and basophils are broadly referred to as non-professional phagocytes
True
A decreased number of phagocytic leukocytes can make an individual more susceptible to ___________
Infection
Three major types of cells that place a peptide (antigen) on their MHC class II complex and present to T helper cells (CD4+)
Macrophages
Dendritic cells
B cells
Can be recognized by cytotoxic T cells (CD8+)
Class I
Can be recognized by helper T cells (CD4+)
Class II
_____________ prevent initial microbial colonization
Physical mechanisms
If the invading microbe breaches the first line of defense, ____________ immune mechanisms function to eliminate the pathogen
Nonspecific innate
When innate immunity fails to prevent the spread of infection, ____________ serves as a specific and comprehensive third line of defense
Adaptive immunity
The __________ response takes time to develop and is mediated by _________ and their products
Adaptive immune
Lymphocytes
True or false: The kinetics of various human defense mechanisms may differ, depending on the type of infection
True
This type of immunity is capable of resolving most threats and compromised of early host defense mechanisms
Innate immunity
Physical, chemical, and mechanical barriers that provide protection against invaders
External defenses
Skin, mucus, peristalsis, coughing, sneezing, stomach acid, cerumen, tears, and saliva are examples of this defense
External defense
Soluble factors (complement system, cytokines, chemokines, acute phase proteins) are part of this defense
Internal defense
Cellular components (neutrophils, monocytes/macrophages, natural killer cells) are included in this defense
Internal defense
____________ occurs to increase blood flow and decrease blood velocity
Vasodilation
Increased permeability leads to _______ migrating across the vessels walls
WBC
Term used to describe the process of WBC migrating across the vessel walls
Diapedesis
Cellular debris and fluid eventually drains through the __________ system
Lymphatic
_____ and _____ cells receive training in adaptive immunity
B cells
T cells
Plasma Protein Systems
Complement system
Clotting system
Kinin system
Type of acquired immunity that is based on natural contact and infection with the antigen (environmental exposure)
Active natural
The length of resistance for active natural immunity is…
Usually permanent but may be temporary
Type of acquired immunity that is based on inoculation of the antigen (vaccination)
Active artificial
The length of active artificial immunity is…
Usually permanent but may be temporary (occasional exceptions)
Type of acquired immunity that is based on natural contact with antibody (mother to fetus) or through colostrum and breast milk
Passive natural
The length of resistance for natural passive immunity is…
Temporary
Type of acquired immunity that is based on inoculation of antibody or antitoxin; immune serum globulin
Passive artificial
The length of resistance for passive artificial immunity is…
Temporary
Immunologically active site on an antigen that binds to a T-cell receptor or to an antibody
Epitope
True or false: The humoral and cell-mediated aspects of adaptive immunity have nonspecific interactions with different antigens
False
(specific)
This part of adaptive immunity is mediated by antibodies (produced by plasma cells– differentiated form of B lymphocytes) presented as serum globulins
Humoral
True or false: Humoral adaptive immunity has a primary and secondary (memory) T-cell response
False
(antibody response)
This part of adaptive immunity is mediated by T lymphocytes. It secretes cytokines and produces, helper T cells, cytotoxic T cells, and regulatory/suppressor T cells
Cell-mediated
True or false: Cell-mediated adaptive immunity has a primary and secondary (memory) T-cell response
True
__________ are produced by B cells
Antibodies
Globulins with antibody activity
Immunoglobulins
The _________ determines the type of the antibody (immunoglobin) encoded by a gene segment
Heavy chain
There are ____ categories of gene segments that encode the immunoglobulin heavy chain
5
-Produced by and expressed on the surface of a B cell
-The first secreted antibody and is predominant in a primary or initial immune response
IgM
-The major antibacterial and antiviral antibody in the blood
-Synthesized during a secondary immune response (after IgM)
IgG
-In serum and secretions (ex: saliva, breast milk, urine, tears, nasal fluids, etc.)
-Defends external body surfaces (ex: mucous membrane)
IgA
-Low levels in the blood
-Predominantly found bound to high affinity receptors on mast cells and basophils
-Function during allergic reactions
IgE
-Low levels in the blood
-Serve as an antigen receptor on mature naive B cells
IgD
Major functions of immunoglobulins
-Directly attack antigens, destroying/neutralizing them through the process of agglutination, precipitating the toxins out of solution, neutralizing antigenic substances, lysing the organism’s cell wall
-Activate the complement system
-Activate anaphylaxis by releasing histamine in tissue and blood
-Stimulate antibody mediated hypersensitivity
The generation of a diverse T-cell repertoire depends upon rearrangement of _____ that comprise the variable region of the T-cell receptor
Genes
Through __________ processes, the genes that encode the B cell receptors undergo permanent changes in DNA sequence during B-cell development to create millions of unique antigen receptors
Gene rearrangement
These immunities are part of the adaptive immune responses
B-cell and T-cell immunity
The principle function of this immunity is the destruction of microbes that are able to survive in the cytoplasm or phagocytic vesicles of infected cells
Cell-mediated immunity
Cell-mediated immunity is responsible for the rejection of ___________ and certain _________
Transplanted tissue
Autoimmune diseases
Bone marrow –> thymus gland –> secondary lymphoid organs (lymph nodes and spleen)
T-cell development
The basis for vaccination
Immunologic memory
________ rapidly differentiate into effectors that can respond more rapidly and with heightened immune responses, resulting in pathogen clearance
Memory T cells
CD4 + T lymphocytes
Helper T cells
HIV infection results in the gradual decline of __________
CD4 + T cells
-The effector cells
-Primarily CD8 + T lymphocytes and thus MHC class I restricted
-Controlling viral infections by directly killing virally infected cells and producing cytokines (e.g., IFNγ) that inhibit viral replication
Cytotoxic T lymphocytes (CTLs)
-Prevent inappropriate responses against “self” antigens of the host or commensal microorganisms
Regulatory T lymphocyte
__________ (produced by B lymphocytes) present in different body fluids or secretions, such as saliva, blood, or vaginal secretions
Antibodies
True or false: Antibodies are not very effective against organisms that are free floating in the body
False
(they are very effective)
Bone marrow –> secondary lymphoid organs (spleen and lymph nodes) –> sample antigens –> immature B cells express IgD on the cell surface and become mature B cells –> second signal (come from helper T cells or innate immune components such as complement proteins) for proliferation –> plasma cells (IgM) and memory B cells
B-cell development
Primary function of immune system
Eliminate infections agents without attacking the body’s own tissues
Phases of the immune response
-Recognition phase
-Amplification phase
-Effector phase
-Termination phase
-Memory
Factors affecting immunity
-Aging
-Nutrition
-Environmental pollution and exposure to chemicals
-Trauma or illnesses
-Many more (New research is discovering the sensory functions of the intestine and how neural, hormonal, and immune signals interact)
__________ can regulate the ability of the immune system to initiate a response against pathogens
Exercise
The immune system is __________ or __________ during exercise, depending on intensity
Enhanced
Suppressed
True or false: Regular and moderate exercise can be beneficial for the immune system
True
True or false: Strenuous, intense or long-duration exercise do not impair the immune system
False
(they do impair)
Exercise triggers a rise in blood levels of _________ and stimulates the phagocytic activity of __________ and __________
Neutrophils (PMNs)
Neutrophils
Macrophages
If the exercise goes beyond _____ minutes, a second, or delayed, rise in PMNs occurs over next ______ hours
30
2-4
The delayed rise in PMNs (Poly-morpho-nuclear cells) is probably the result of _________
Cortisol
The number and the function of ________ increase during and immediately after exercise of various types, duration, and intensity
NK (Natural Killer) cells
The NK enhancement (promoting cytotoxicity) is __________ and seems to result from a surge in __________ levels
Temporary
Epinephrine
After intense exercise of long duration, the concentration of NK cells and NK cytolytic activity ________ _________ preexercise values
Declines below
True or false: Brisk exercise increases WBC count
True
True or false: Lymphocytes decrease during exercise but increase below normal levels for several hours after intense exercise
False
(increase, decrease)
True or false: Strenuous or high-intensity exercise >80% of VO2max, can suppress immune function and damage enough tissue to evoke the acute-phase response in human beings
True
True or false: Regular exercise, anti-inflammatory effects of an acute bout of exercise will not protect against chronic systemic low-grade inflammation
False
(will protect)
True or false: Exercise regulates immune system and delaying the onset of immunosenescence (decline function due to aging)
True
Regular exercise is associated with…
-Enhanced responses to vaccinations
-Lower numbers of exhausted/senescent T cells, circulatory levels of inflammatory cytokines, and inflammatory response to bacterial challenge
-Increased T-cell proliferative capacity, neutrophil phagocytic activity, and NK cell cytotoxic activity
-Longer leukocyte telomere lengths in aging humans
-Delay apoptosis
Factors to determine overtraining
Current level of fitness, recovery (short and long term), presence of pathogens, and nutrition
The immune cells most altered by overtraining were _________
Neutrophils
True or false: Intense exercise causes suppression of immune parameters in young subjects, but no detrimental effect on immune function or rate of infections in older adults
True
True or false: Relatively intense exercise programs may be prescribed without impairing immune function in strong, young people
False
(Frail, elderly)
True or false: During an infectious episode, intense exercise should be avoided
True
If you want to determine if one should exercise in the presence of acute viral or bacterial infection, a _______ should be conducted
Neck check
True or false: If the symptoms of an acute viral or bacterial infection are located above the neck, exercise should be performed cautiously through the scheduled workout at half speed
True
True or false: If a fever or symptoms below the neck are evident, exercise should be initiated
False
(should not be initiated)
Phase in which innate immune receptors bind to common molecular motifs on pathogens or antibodies that are bound to the invader
Recognition
Phase that involves complement cascades, production of soluble factors, and recruitment of an army of cells in the case of innate immunity
Amplification
Phase that results in removal of antigens by a number of different mechanisms (ex: neutralization, lysis, phagocytosis, direct killing by cytotoxic T cells)
Effector
Phase that dampens the immune system after the antigen has been cleared. It is critical for the prevention of excessive responses that may harm the host.
Termination
Phase that involves the generation of long-lived T and B lymphocytes
Memory
