Immunology Flashcards
(174 cards)
1
Q
Immune complex
A
Aka Antibody antigen complex. Each antibody molecule can bind to to antigen particles. This clumping of antigens which facilitates the recognition and destruction by the immune system.
2
Q
What is the cellular signaling pathway for degranulation of antibody tagged pathogens
A
Calcium channels open and calcium entry is a signal for exocytosis. This is similar to the release of vesicle contents in an endocrine cell.
3
Q
What is antibody-dependent cell-mediated cytotoxicity
A
When NK cells degranulate and destroy antibody tagged pathogens
4
Q
What are 5 key anti body functions
A
- Inactivate bacterial toxins
- Act as opsonins
- Trigger degranulation of immune cells
- Activate compliment proteins
- Activate B lymphocytes
5
Q
How does an antibody acting as a opsonin help destroy a pathogen
A
It tags the immune complex for destruction. When bacteria aren’t recognized by phagocytes the bacteria is coated with the antibody.The receptor binds to the stem of the antibody and phagocytosis is triggered for the entire immune complex.
6
Q
In regard to anti bodies, Adaptive immunity is subdivided in to what 2 categories
A
Passive immunity and active immunity
7
Q
What do activated T lymphocytes develop into
A
- Cytotoxic T cells (Tc)
- Helper T (Th)cells
- Regulatory T (Tregs) cells
8
Q
What kind of receptor do T lymphocytes have
A
T cell receptors. They can only bind to antigen that is displayed on MHC proteins on a target cell.
9
Q
What can B cell receptors bind to
A
Antigen that is free floating in the extracellular fluid
10
Q
What is humoral immunity
A
The soluble antibodies of the plasma
11
Q
What do regulatory T cells do
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They do not directly attack pathogens and infected cells. They bind to MHC 2 Complexes. Their activation suppresses immune cell function to help prevent excessive immune responses.
12
Q
What is the body’s integrated immune response
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The innate response starts 1st and it is reinforced by the more specific adaptive response
13
Q
Define immunity
A
The body’s ability to protect itself
14
Q
3 major functions of the immune system
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- Try to recognize and remove abnormal “self” cells created when normal cell growth and development go wrong
- Removes dead or damaged cells
- Protects the body from disease causing pathogens
15
Q
3 categories of immune pathologies
A
- Incorrect response
- Overactive response
- Lack of response
16
Q
Incorrect response pathology
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Mechanism for distinguishing self from non self fail and immune system attacks the body’s normal cells
17
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Over active response pathology
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Condition in which the immune system creates a response that is out of proportion to the threat posed by antigen, hypersensitivity reaction
18
Q
The lack of response pathology
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Immuno deficiency diseases, Some component of immune system fails to work. Inherited, acquired through virus infection, drug or radiation.
19
Q
2 types of infections common in the US
A
Bacterial or viral
20
Q
Pathogens common in other parts of the world
A
Parasites, prions, protists
21
Q
List structure, living conditions, reproduction, and susceptibility to drugs of bacteria
A
- True cells have, no organelles usually surrounded by cell wall, some have additional capsule
- Most can survive and exist outside host
- With the right nutrients temperature and ph they can survive and reproduce outside host
- Most can be killed by antibiotics. Plasmid are capable of transferring genetic information to become antibiotic resistant
22
Q
List structure, living conditions, reproduction, and susceptibility to drugs of virus
A
- Not cells, nucleic acid said core enclosed in protein capsid, some have external envelope
- Parasitic, must have a host cell to reproduce
- Must use intracellular machinery of host to replicate, spreads by rupturing and spreads to others
- Can only be treated with antivirals to target specific stages of viral replication
23
Q
What are the 2 categories of human immune response
A
Innate immunity and adaptive immunity
24
Q
What is innate immunity
A
Present from birth, Bodies in media immune response, Non specific to any pathogen, Begins within minutes to hours, The immune response to pathogen is not remembered and is triggered anew with each exposure
25
What is stop adaptive immunity
It is directed at particular invaders and his body's specific immune response, Can take days to weeks, With re exposure memory cells remember and react quicker. Consist of antibody mediated and cell mediated immunity
26
What is antibody mediated immunity
It is also known as humoral immunity. It uses antibody protein secreted by immune cells to carry out immune response. Immune cells find to foreign substances and make more visible or disable them.
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What is cell mediated immunity
It requires contact dependent signaling between immune cell and receptors on its target cell
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What are the lymphoid tissues of the body
Thymus gland, bone marrow, spleen, lymph nodes, tonsils, cells in skin, MALT, and GALT
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Which lymport tissue primary monitor the blood for pathogens
Spleen and lymph nodes
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What is MALT
Mucosa associated lymphoid tissues
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What is GALT
Gut associated lymphoid tissues
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What are granulocytes
Cells with prominent granules in cytoplasm. They release granule contents by exocytosis. They include basophils, eosinophils, and neutrophils
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What are phagocytes
They ingest materials from the antigen-presenting cells and from the ECF by phagocytosis. This is a receptor mediated event. They include neutrophils, macrophages and dendritic cells.
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Cytotoxic cells
Contact killers. They include T lymphocytes and eosinophils
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Antigen presenting cells (APCs)
They have the ability to display bits of antigen on their surface as a signal to the other immune cells. These include macrophages, dendritic cells, and B cells
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Basophils
1%-->Rare in circulation. Develop in bone marrow and mature in tissues. They are usually in the blood and mast cells in tissue. They migrate and accumulate to inflammation sites where they can leave blood vessels and enter tissue space. They release histamine, serotonin and and heparin. Increased affinity receptors for IgE. Part of innate immune response. Live for less than 2 weeks. Long lived mast cells.
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Eosinophils
1-4%, Few found in peripheral circulation. Most functioning found in digestive tract, lungs, urinary genital epithelial and connective tissue of skin. They attach to large antibody coated parasites and release substance from their granules damaging and killing them. Participate in allergic reactions really seem toxic enzymes and oxidate of substances. Live 8 to 18 hours in blood and 2 to 14 days in tissue.
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Neutrophils
50-70%, Most abundant. Imature cells are found in circulation and live 1 to 2 days. They are attracted to extravascular site of damage or inflection. They ingest bacteria in foreign particles and release said cytokines like pyrgens, inflammatory chemical mediators. Kill 5 to 20 bacteria in lifespan
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Macrophages and monocytes
Monocytes are the precursor cells of tissue macrophages. 2-8%. Spend 8 hours in transit from bone marrow to perminent tissue site. Is lost once and tissue they and large and to Fargo citic macrophages and scavenge tissues patrolling by amoebic motion or sedentary. They remove large particle such as red blood cells and dead neutrophil. Ingest 100 bacteria in Lifespan.
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How do macrophages participate as APCs
They are APC's. They are the 1st white blood cells to identify a bacterium as pathogen and ingest them via phagocytosis. They digest them and display bits of digested pathogen on their cell surface to attract cells in the adaptive immune response
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Lymphocytes
20 to 40% in circulation. The body contains a trillion lymphocytes at any one time. Most are found in circulation. They are the primary effector cell for antigens specific responses of adaptive immunity. The 3 subtypes are T cells, B cells, and natural killer cells.
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What are dendritic cells
They are relatives of macrophages with long thin processes that resemble dendrites of neurons. They are located in the skin, nose, lungs, stomach and intestines.
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What 3 things do dendritic cells do
1. At like amoebas and take bacteria to lymph system
2. Fact does messengers between innate and adaptive immune systems
3. They are an APC and they can stimulate naive T cells
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What are 3 examples of physical barriers against foreign invaders
Skin, Mucosa, Mucus
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Describe how the skin is a physical barrier against foreign invaders
It is the 1st line of defense. It is dry, salty, multi layer that sloughs off. It has tight junctions, fatty acids on skin, phagocytes called Langerhan cells
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How are mucous membrane 1st line of defense against foreign invaders
They trap bacteria and viruses from and entering their tight junctions and they have phagocytes called M cells in the membranes
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How does me this form a physical barrier against foreign invaders
They are sticky, have lysosomes, enzymes that breakdown bacteria
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What are PAMPs
Pathogen associated molecular patterns. They are part of the innate immune response. Some immune cells recognize classes of molecules that are unique to microorganisms. They bind to leukocyte PRRs
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What are PRRs
Pattern recognition receptor. PAMPs bind to leukocyte PRRs and activate responses that attempt to kill or ingest the invader
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What are chemotaxins
Chemical signal molecules that attract leucocytes to help fight infection. They're sent out at areas of invasion. They include bacterial toxins or cell well components that act as PAMPs
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What are 2 primary phagocytic immune cells responsible for defense
Tissue macrophages and neutrophils
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What is pus
Thick whitish to greenish substance with living and dead neutrophil and macrophages, tissue fluid, cell debris, and other remnants
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Opsonin
Molecules that coat foreign particles to make them visible like food for phagocytic leukocytes
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Examples of opsonins
Acute phase proteins, complement proteins, Creative proteins
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What feature allows some bacteria to hide from phagocytes
Some pathogens lack markers that react with pattern recognizing receptors. Bacteria have evolved a polysaccharide capsule that masks their surface markers from their host immune system. They are not recognized and grow unchecked.
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How does your immune system deal with bacteria that hide.
Once recognized they make antibodies against them
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How do natural killer cells recognize and destroy pathogens
They are programmed to recognize virus infected cells and induced them to commit suicide by apoptosis before they can replicate.
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Some viruses invade by blocking MHC protein synthesis on host cell. How do NK cells get rid of these pathogens
NK cells don't need MHC markers they look for low levels of MHC-1 and destroy those pathogens
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What are the effects of interferons
Interferons are cytokines that inhibit viral replication and modulate immune response. They change the chemistry of nearby cells to protect them and promote synthesis of antiviral proteins
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What are the primary phagocytes of innate immune response
Neutrophils and macrophages
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What are the primary APC's for adaptive immune response
Macrophages and dendritic cells
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What are the 3 roles inflammation has in fighting infection
Attracting immune cells and chemical mediators to the site, Producing a physical barrier to retard the spread of infection, Promoting tissue repair once infection is under control
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What cells initiate the inflammatory response
Mast cells and basophils degranulation releases histamines
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What chemical messengers or cytokines are involved in the inflammatory response
Histamines, bradykin, prostaglandins, leukotrines, integrins, C reactive protein , complement proteins, antiproteases
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What do basophils and mast cells release
Histamines
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What is the response created by histamine action
Attraction of leucocytes to the injury site to kill bacteria and remove cellular debris. This is done by the dilation of blood vessels which increases blood flow and by opening pores of capillaries. This makes capillaries more leaky and allows plasma proteins to escape into ISF, Pulling water with them and causing edema.
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What are the hallmarks of inflammation
Red, hot, and swelling around wound or infection site and pain
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Interleukins
Cytokines secreted by leukocytes to act primarily on other leukocytes.
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What is IL-1
Interleukin 1. It is secreted by macrophages and modulates and innate immune response. It brings about and an inflammatory response and induced fever. It causes the appearance of intergins on the surface of endothelial cells. They fish for neutrophils allowing cells to leave blood and enter tissues. This increases acute phase proteins, C reactive protein, antiproteases. It causes other cells to release cytokines and convert lignin to bradykinin and activates complement cascade.
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What are compliment proteins
Proteins that act as opsonins, cytolytic agents and mediators of inflammation. They can also insert themselves into pathogen membranes creating the complementary cascade.
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Where are compliment proteins found
In blood, body fluids, and cell surfaces
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What triggers complement cascade
They're secreted in inactive forms that are activated as the cascade proceeds. It is activated by binding to many bacterial surface molecules and promotes phagocytosis
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What is the membrane attack complex
It's the end of the compliment cascade.When a group of lipid soluble proteins that inserts themselves into a pathogen or virus infected cells and form giant pores. This allows water and ions to go into pathogen cell. The cells swell and lyse.
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How does acquired immunity differ from innate immunity
Acquired is antigens specific, You don't have it when you're born, It is mediated by lymphocytes, it improves over time with exposure to pathogens, Memory cells are created in case of re exposure
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Which immune cells primarily mediate the acquired response
Lymphocytes.
Each with a receptor specific to a different antigen
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What mediates the innate immune response
Interleukin 1
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What are the 3 types of lymphocytes
T lymphocytes
B lymphocytes
Natural killer cells
78
What are T lymphocytes
These are T cells. They attack and destroy virus infected cells and help regulate other immune cells. These include cytotoxic t cells, helper t cells, and regulating t cells
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What are be B lymphocytes
They develop into plasma cells. They secrete antibodies that work against antigens. They activate effector cells. These differentiate into memory cells or plasma cells.
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What our memory cells
They are long lived plasma cells that create immunologic memory
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What are natural killer cells
They attack and destroy virus infected cells as part of innate immune response
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Where is another name for antibodies
Immunoglobulins
83
What is the difference between active and passive immunity
Passive immunity are antibodies acquired by another organism. Active immunity is from exposure to pathogens and its own production of antibodies.
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Is passive or active immunity typically a life long immunity
Only active immunity is
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What are their 2 methods of acquiring immunity passively
From mother to fetus across placenta or by receiving injections containing gamma globulin
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What are the 2 methods of acquiring immunity actively
From pathogen invading body for artificially from vaccines
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How long does passive immunity usually last
It can last up to 3 months. Proteins degrade and are cleared from circulation after that.
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What are lymphocyte naive clones
These are a few lymphocytes with same receptor. These lymphocytes have not yet met a specific antigen and to have not been activated with 1st exposure
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What happens to a naive clone once it has been exposed to a specific antigen
After exposure it rapidly reproduces. This is called clonal expansion. During this time the cells differentiate into effector and memory cells
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How do memory cells differ from effector cells
Effector cells carry out immediate response and die within a few days. Memory cells are long lived and continue reproducing and are activated for re exposure.
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Where do B lymphocytes develop
They are made and develop in the bone marrow
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What purpose do surface anti bodies on B cells serve
There are as many as a 100,000 of them. The arms of receptors are available to find free floating extracellular antigens. When binding occurs lymphocytes are activated.
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What role do memory cells play
They wait for re exposure of the same antigen and trigger a secondary immune response which is faster and stronger
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What will do plasma cells play and humoral immunity
They synthesize and secrete and antibody molecules. These are soluble antibodies of the plasma. The short lived antibodies die and the long live remain in the bone marrow, secreting low levels for continual immunity.
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Why do immunizations help fight against infection
A vaccine contains an altered pathogen that triggers creation of memory cells specific to that particular pathogen. If they are infected by the pathogen at a later time, the memory B cells produce a stronger and more rapid secondary immune response.
96
What gives different lymphocyte specificity for particular ligands
Each lymphocyte that is generated has a unique arrangement of receptor amino acids. MRNA splicing creates millions of unique receptors. Alternative splicing is used to create a receptor that is unique and specific enough to bind to a specific ligand called an antigen.
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What is MCH
It is a major histocompatibility marker. Its primary function is antigen presentation.
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How is MCH1 classified if it is absent different or attached to something
It is categorized as a foreigner. Cytotoxic T cells and N K cells will attack it
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What happens if MCH2 is attached to something
It is a presentation and helper T cells will be activated.
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Do all cells of the body have MHC proteins on its membrane
Yes.
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What is the general function of MHCs
MHC proteins combine with peptide fragments of antigens there have been digested within the cell. The MHC antigen complex is inserted into a cell membrane and is visible on extracellular surface.
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When does contact dependent signaling occur of in regards to MHC
When they interact with T cell receptors
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Can free antigen in ECF bind with free MHC receptors
No
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What is the function of MHC class 1 molecules when cell becomes infected
When infected with a virus they can process virus proteins synthesized in their cytoplasma into peptides. In ER they combine those with MCH1. The complex is transported to plasma membrane. Here it can be presented to T cell receptor of cytotoxic t cell.
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What is the function of MHC class 2 molecules
They can be found on APC's including macrophages and dendritic cells. They present pathogen antigens to helper T cells.
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What is the main difference between MHC1 and MHC 2 in terms of the kind of cells that bear them
MHC 1 are on all nucleated cells. MHC 2are primarily on antigen presenting cells.
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Why do I MHC proteins vary from person to person
Because of the huge number of potential variants people can inherit from their parents. It is unlikely that any to people other than identical twins inherit exactly the same set
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Are T cell receptors antibodies?
No. They are antigen specific membrane proteins on T lymphocyte.
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T cell receptors can bind only to
MHC antigen complexes on the surface of an APC, meaning T cells cannot bind to free floating antigens like B cells do.
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Describe the action of helper T cells
They bind to immune cells displaying foreign antigen in MHC 2 complexes, activating T helper cells. They secrete cytokines to influence other immune cells.
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Describe how cytotoxic T cells recognize the infected cells and how they killed targeted cells
They recognize infected cells that this play MHC 1 antigen complexes. They release cytotoxic pore forming molecules called perforin with granzymes. This causes apoptosis. They can also instruct to apoptosis by activating Fas "death receptor"
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What is considered cell mediated immunity
The manner in which cytotoxic T cells recognize infected cells and kill them
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What cell type is the main line of defense after viral entry into a host
Cytotoxic T lymphocytes and NK cells
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Why might antibodies from one viral infection not be effective against subsequent viral infections
Because many viruses mutate constantly so the protein coat forming the primary antigen may change significantly over time and that antibody may no longer recognize it
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Define self tolerance
The lack of immune response by lymphocytes to cells of the body.
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When does self tolerance begin
During embryonic development
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What happens of self tolerance fails
The body makes antibodies against its own components through T cell activated B lymphocytes. The body attacks its own cells.
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What is auto immune disease
When the body attacks its own cells. This is because the body produces antibodies that are specific against a particular antigen and are usually restricted to a particular organ or tissue type.
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Describe the 3 known links between immune, nervous, and endocrine systems
1. The 3 systems share common signal molecules and common receptor is for those molecules
2. Hormones and neuropeptides can alter the function of immune cells
3. Cytokines from the immune system can affect neuroendocrine function
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What type of antibody class activates an allergic response
IgE
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What type of antibody activates degranulation and histamine release
Mast cells+IgEs+antigen
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IgD antibody class
Anti body proteins appear as receptors on the surface of B lymphocytes and help activate the B cells. Unclear physiological role
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This antibody classe is found an external secretions and disables pathogens before body entry
IgA
124
This antibody class is produced secondary immune responses, 75% of adult saram antibodies, Can cross placenta and provide passive immunity for infant
IgG
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This antibody class are associated with primary immune responses, reacts to blood group antigens and activates complement proteins
IgM. It has 10 binding sites.
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Where are most antibodies found
In the blood, Where they make up to 20% of the plasma proteins and healthy individuals
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Humoral antibodies are most effective against
Bacteria
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Humoral immunity can be transferred to another person
True
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Where do T lymphocytes develop
They're made in the bone marrow and grown in the thymus
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What is the main role of T lymphocytes
They are part of the adaptive community. They attack and destroy virus infected cells and help regulate other immune cells
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Cat dander, Hook worm parasite, Athlete's foot fungus, Chicken pox virus, Meningitis. Which of these is not a pathogen
Cat dander
132
Antibodies are drugs that destroy or inhibit the growth of
Bacteria
133
Viruses are
Parasitic and must reproduce inside host cells
134
Lymphoid tissues include
Thymus, Bone marrow, Lymph nodes, Spleen
135
Neutrophils recognize molecules that are unique to pathogens called
Pathogen associated molecular patterns
136
Chemotaxins function in
Attracting additional mune cells
137
Is substance that induces fever is known as
Pyrogen
138
Acute phase proteins are produced by the
Liver
139
A first line of defense against pathogens is
The skin
140
An inflammatory response is triggered when
Mast cells release granules containing histamine
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2 cells that are actively involved in immune surveillance are
Cytotoxic T cells and NK cells
142
The specificity of an antibody is determined by the
Variable region
143
For a cytotoxic T lymphocyte to identify an infected cell that antigen must
Be bound to MHC1
144
MHC class 2 molecules are found
On dendritic cells, macrophages, and lymphocytes
145
Estimated to reach populations of one trillion in normal adults most of these cells are found in lymphoid tissues. The cells look similar to one another under the microscope but function differently
Lymphocytes
146
A patient has increased neutrophils and macrophages with normal levels of Basophils, eosinophils and lymphocytes. Which is the most likely cause of this test result?
An acute viral infection
147
Substances that trigger is specific immune response are known as
Antigens
148
Cytokines that inhibit the replication of viruses
Interferons
149
The HIV virus that causes the disease known as AIDs selectively infects
Helper T cells
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Millie has just received a kidney transplant in is taking cyclosporin. This drug prevents rejection. What does this medication do
Inhibits cytotoxic T cells
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In a routine examination some blood is taken and analyzed. The results show a high IGM level for the mumps antigen. This would indicate the
The person is immune to mumps
152
What are the 4 basic steps of the immune response
1. Detection and identification of the pathogen
2. Communication with other immune cells
3. Recruitment of assistance and coordination of the response among all participants
4. Destruction or suppression of the pathogen
153
Humoral immunity is also known as
Antibody mediated immunity
154
Immediately following a break in the skin, Phagocytes engulf bacteria within the wound. This is an example of___________immune response which is_________ against a pathogen
Innate, nonspecific
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What is responsible for the production of antibodies against free pathogens and soluble products from pathogens
B cells
156
What destroys pathogen and virally infected cells and abnormal cells
Cytotoxic t cells
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If a be so clone began to produce antibody with altered binding strain and the specificity for antigen, You would expect the mutation of the antibody gene to involve
The variable regions of the light or heavy chains
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EBV infects endothelial cells and B cells. About half of us are infected by the virus while very young and do not suffer disease. Around half of individuals avoid the virus while young and are infected in their teenage years and develop a disease called mono. Which lymphocytes are produced to eliminate this virus producing cell?
Cytotoxic t cells to destroy virus containing cells
159
The theory of antibody diversity says
B cell precursors randomly rearrange varible coding parts of antibody genes. Afterwards, Antigen binds to a clone with specific membrane antibody, Resulting and differentiation to anti body secreting plasma cells.
160
MHC complex
1. Identify self to the immune system
2. Serves to present fragments of antigens to T cells and B cells
3. Can trigger helper T cells to increase the activity of antibody producing B cells
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Lack of immune response to self is called
Tolerance
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Non specific immune responses consist of
```
Compliment killing
Phagocytosis and antigen presentation
Natural killer cells
Inflammation
Interferon release
```
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Barriers to infection
Physical, mechanical, and chemical
164
Different names for adaptive immunity
Specific immune response, acquired immune response
165
Innate immune response includes
Cells: Macrophages, neutrophils, NK cells, dendritic cells, eosinophils, and basophils. And chemicals.
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Adaptive immune response includes
Cell mediated: lymphocytes. And antibody mediated response with chemicals such as antibodies
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Opsonin facilitate
Phagocytosis
168
Complement proteins can be activated by
Antibodies
169
Macrophages act like
Antigen cells
170
Location of eosinophils
Esophagus, intestines, heart, lung, skin, stomach
171
Where are basophils located
Many tissues
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Where are monocytes located
In the spleen and in circulation.
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Where are lymphocytes located
Lymphoid tissue
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Where are neutrophils located
Mostly in bone martow, circulate and migrated to tissues where they die within a few hours
