Term
| Host defenses involving anatomical barriers, sensor systems that recognize patterns associated with microbes or tissue damage, phagocytic cells, and the inflammatory response. |
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Definition
|
|
Term
| What is a substance that causes an immune response called? |
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Definition
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Term
| Y-shaped proteins that bind to antigens and are an important part of adaptive immune response. |
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Definition
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Term
| What is the specialized defense system that vertabrates have evolved? |
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Definition
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Term
| What are the initial obstacles that microbes must overcome to invade tissues? (They include skin, mucous membranes and can be bathed in secretions that have antimicrobial properties.) |
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Definition
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Term
| How does the body recognize when first-line defenses have been breached? |
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Definition
| Certain cells (called sentinel cells) have pattern recognition receptors (PRRs) on their surface and within their endosomes and phagosomes. |
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Term
| What are the series of proteins always present in the blood and tissue fluids collectively called? |
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Definition
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Term
| How does the complement system work? |
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Definition
| it acts in combination with the adaptive immune defenses as a sensor and communicates with other cells. |
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Term
| During this response, cells that line local blood vessels undergo changes that allow complement system components and other proteins to leak out into the tissue. Phagocytes also accumulate in the tissues. |
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Definition
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Term
| What cells specialize in engulfing and digesting microbes and cell debris? |
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Definition
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Term
| What are two roles phagocytes can play? |
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Definition
1. destroying invaders
2. communicate with cells of the adaptive immune system. |
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Term
| Many cells have _____ _______ _______ in their cytoplasm, allowing them to recognize when they have been invaded by a microbe. |
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Definition
| PRRs (Pattern recognition receptors) |
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Term
| ciliated cells in the respiratory tract that beat in an upwards motion, moving materials away from the lings to the throat where they can be swallowed. |
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Definition
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Term
| contraction of the intestinal tract that helps remove microbes |
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Definition
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Term
| What are some of the antimicrobial substances found on the body? |
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Definition
1. saltiness of evaporated sweat
2. lysomzyme (in tears, saliva and mucous, and also phagocytic cells, blood and fluid that bathes tissues)
3. peroxidase enzymes (saliva and milk)
4. Lactoferrin
5. transferrin
6. defensins |
|
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Term
| What are short antimicrobial peptides produced by neutrophils and epithelial cells that insert into bacteria membranes that form pores and damage cells? |
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Definition
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Term
| An iron-binding protein in saliva, mucous , and milk (and some types of phagocytes) |
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Definition
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Term
| Why does iron-binding help defend against microbes? |
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Definition
| Because iron is one of the major elements and withholding it prevents microbial growth. |
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Term
| What iron-binding mechanism is found in the blood and tissues? |
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Definition
|
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Term
| How does the normal microbiota provide prtoection from pathogens? |
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Definition
1. by covering binding sites where pathogens may otherwise use for attachment
2. producing compounds toxic to other bacteria |
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Term
| The formation and development of blood cells is called what? |
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Definition
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Term
| All blood cells, including those important to the body's defense originate from what cell type? |
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Definition
| the hematopoietic stem cell |
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Term
| What induces hematopoietic stem cells to develop into various types of blood cells? |
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Definition
| A group of proteins called colony-stimulating factors (CSFs) |
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Term
| Erythrocytes are what type of blood cell? |
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Definition
| Red blood cells that carry oxygen |
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Term
| White blood cells are also called what? |
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Definition
|
|
Term
| What are the four groups of leukocytes? |
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Definition
1. granulocytes
2. mononuclear phagocytes
3. dendritic cells
4. lymphocytes |
|
|
Term
| What are the three types of granulocytes? |
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Definition
1. neutrophils
2. basophils
3. eosinophils |
|
|
Term
| How do you distinguish between the three types of granulocytes? |
|
Definition
| The staining properties of their granules |
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Term
| These efficiently engulf and destroy bacteria and other material. Their granules stain poorly. They normally make up more than half of the circulation white blood cells |
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Definition
|
|
Term
| What are other name of neutrophils? |
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Definition
| PMNs polymorphonuclear neutrophilic leukocytes |
|
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Term
| These are a type of granulocytes involved in allergic reactions and inflammation. Their granules stain dark purple-ish blue contain histamine and other chemicals that increase capillary permeability during inflammation. |
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Definition
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|
Term
| These are similar in appearance and function to basophils, but are found in tissues rather than blood. |
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Definition
| Mast Cells (responsible for many allergic reactions) |
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Term
| These are granulocytes that are thought to be primarily involved in ridding the body of parasitic worms. |
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Definition
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|
Term
| mononuclear phagocytes that circulate in the blood |
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Definition
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|
Term
| sentinel cells that function as "scouts". they engulf material in tissues and bring them in to the cells of the adaptive immune system for "inspection" |
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Definition
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|
Term
| These are responsible for adaptive immunity. |
|
Definition
|
|
Term
| What are the two major groups of lymphocytes? |
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Definition
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|
Term
| These cells are responsible for adaptive immunity and are highly specific in their recognition of antigen. |
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Definition
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Term
| These cells are part of adaptive immunity that are not specific in their anitgen recognition. |
|
Definition
| Natural Killer cells (NK) |
|
|
Term
| Where do lymphocytes usually reside? |
|
Definition
| lymph nodes and lymphatic tissues |
|
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Term
| Differentiated forms of monocytes, meaning that they have gained specialized properties |
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Definition
|
|
Term
| How are macrophages related to monocytes? |
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Definition
| Monocytes circulate in the blood, but enter different areas of the body and become different forms of monocytes called macrophages, that have specialized properties. They are called different things depending on where thwy end up in the body. |
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Term
| The eyes and ears of a cell that are usually proteins that span the plasma membrane connecting the outside of the cell to the inside and allow the cell to sense and respond to external signals. |
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Definition
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|
Term
| The voices of the cell. a _____ produced by one cell diffuses to another and binds to the appropriate ______ _______. |
|
Definition
Cytokine
cytokine receptor |
|
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Term
| Binding of a cytokine to its receptor causes what? |
|
Definition
Changes in the cell such as
1.growth
2.differentiation
3.movement
4.cell death |
|
|
Term
| cytokines important in chemotaxis of immune cells. |
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Definition
|
|
Term
| These are important in the multiplication and differentiation of leukocytes. (type of cytokine) |
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Definition
| Colony-stimulating Factors (CSFs) |
|
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Term
| These are important in the control of viral infections. They are antiviral, and help regulate function of cells in inflammatory response. They adjust certain roles in adaptive immunity. |
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Definition
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Term
| These are cytokines produced by leukocytes and have diverse, often over-lapping functions. They are important in innate and adaptive immunity. |
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Definition
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|
Term
| These are cytokines that have multiple roles. They help initiate the inflammatory response that triggers cell death.(apoptosis) |
|
Definition
| Tumor Necrosis Factor (TNF) |
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|
Term
| One example of a group of cytokines that act together to generate a specific response are ___-__________ ________. ( |
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Definition
| Pro-inflammatory cytokines (TNF, IL-1, IL-6, and others) |
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Term
| These, on the surface of cells, allow those cells to "grab" other cells.(They are produced by the cells) Ex: they are used by the endothelial cells that line the blood vessels to bind to passing phagocytic cells allowing them to leave the blood stream. |
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Definition
|
|
Term
| What is the function of a CSF? (colony-stimulating factor) |
|
Definition
| To multiply and differentiate leukocytes into what they need to be and where they need to be by adaptive immunity. |
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Term
|
Definition
| A molecule that binds to a specific receptor |
|
|
Term
| generic microbe-associated patterns that are recognized by PRRs (Pattern Recognition receptors) They are common in all microbes, not just pathogens. |
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Definition
| Pathogen-associated molecular patterns (PAMPs) or microbe-associated molecular patterns (MAMPs) |
|
|
Term
| WHat are some examples of PAMPs? |
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Definition
| various cell wall components(lipopolysacharride, peptidoglycan, lipoteichoic acid, and lipotproteins), flagellen subunits, and RNA molecules that characterize viruses. |
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Term
| Molecules that indicate host cell damage |
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Definition
| Danger-associated molecular patterns (DAMPs) |
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Term
| This type of PRRs are anchored in membranes of sentinel cells such as macrophages, dendritic cells, and cells that line sterile body sites. |
|
Definition
| Toll-like receptors(TLRs) |
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Term
| There are at least 10 different types of these in humans, and they each recognize a distinct compound or group of compounds in microbes. |
|
Definition
| Toll-like receptors(TLRs) |
|
|
Term
| When this type of PRR detects a compound, a signal is transmitted to the cells' nucleus, causing certain genes to be expressed. Its response can be tailored to the situation and category of pathogen. |
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Definition
| A toll-like receptor(TLRs) |
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|
Term
| Thess type of PRRs are cytoplasmic proteins that detect bacterial components, allowing the cell to recognize when its' own borders have been breached. |
|
Definition
| NOD-like receptors (NLRs) |
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|
Term
| At least 23 of these have been described in the human body. |
|
Definition
| NLRs (NOD-like receptors) |
|
|
Term
| When an NLR detects PAMPs or DAMPs what happens? |
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Definition
| They unleash a series of events to protect the cell, sometimes at the expense of the cell itself. |
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|
Term
| In macrophages, some NLRs can join with other proteins in the cytoplasm to form what? |
|
Definition
|
|
Term
|
Definition
| A complex that activates a potent pro-inflammatory cytokine, thus initiating an inflammatory response. |
|
|
Term
| an enclosed compartment full of extracellular material, brought into the cell during phagocytosis |
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Definition
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|
Term
| A membrane bound compartment formed during pinocytosis which then fuses with the digestive organelles called lysosomes. |
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Definition
|
|
Term
| These type of PRRs are cytoplasmic proteins that detect viral RNA. Allows the cell to detect that it has been invaded. |
|
Definition
| Rig-like receptors (RLRs) |
|
|
Term
| What are the two types of PRRs that are cytoplasmic proteins? |
|
Definition
| NLRs and RLRs (NOD-like receptors and Rig-like receptors) |
|
|
Term
| What type of PRR is anchored in the membranes of sentinel cells? |
|
Definition
| Toll-like receptors (TLRs) |
|
|
Term
| How do RLRs detect viral RNA from the cells own RNA? |
|
Definition
There are two differences btwn viral RNA and the cells own RNA.
1.Viral RNA often has 3 phosphates at the 5' end. Capping of cellular RNA hides its' phosphates
2. Viral RNA is often double stranded |
|
|
Term
| What occurs when the cells' RLRs detect viral RNA? |
|
Definition
| Interferons are synthesized and secreted by the cell. These proteins attach to specific receptors on the the infected cell and the neighboring cells, causing the cells to express inactive "suicide" enzymes that ultimately can be activated to degrade mRNA and stop protein synthesis, leading to apoptosis. |
|
|
Term
|
Definition
| inactive antiviral proteins (interferons) |
|
|
Term
|
Definition
| antiviral proteins(interferons) |
|
|
Term
| When are iAVPs activated? |
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Definition
| When the cell recognizes via the RLRs that it has been breached by viral RNA. |
|
|
Term
| If a cell produces antiviral proteins, what happens to that cell when those proteins encounter long dsRNA? |
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Definition
| IAVPs are activated by dsRNA. Thus, when cells bind interferon, only the infected cells are sacrificed. |
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Term
| This is a series of proteins that circulate the blood and the fluid that bathes the tissues. |
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Definition
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|
Term
| These "complement" the function of antibodies. |
|
Definition
|
|
Term
| What are the three pathways that lead to the complement system activation? |
|
Definition
1.Alternative pathway
2.Lectin pathway
3.Classical pathway |
|
|
Term
| what are the three outcomes of the activation of the complement system? |
|
Definition
1.The inflammatory response
2.Lysis of foreign cells
3.Opsonization |
|
|
Term
| When is the alternative pathway triggered? |
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Definition
| When C3b binds to foreign cell surfaces |
|
|
Term
| What are the nine major proteins of the complement system named? |
|
Definition
|
|
Term
| When do the three pathways of the complement system converge? |
|
Definition
| When a complex called C3 convertase is formed. |
|
|
Term
| When C3 convertase splits C3, what ocurrs? |
|
Definition
| additional steps of the activation cascade. |
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|
Term
| How can C3b be both a product of complement activation and an activator of the complement system? |
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Definition
| Because C3 is somewhat unstable, and spontaneously splits to C3a and C3b at a low rate even when the complement system has not been activated. |
|
|
Term
| What happens to C3a and C3b formed by C3's spontaneous splitting? |
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Definition
| It is rapidly inactivated by regulatory proteins, but some C3b is always present to trigger the alternative pathway when it is needed. |
|
|
Term
| What triggers the lectin pathway of the complement system? |
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Definition
| The binding of pattern recognition molecules called Mannose-binding lectins (MBLs) to certain arrangements of multiple mannose molecules that characterize microbial cells. |
|
|
Term
| What does C3 convertase do? |
|
Definition
| It splits C3 into C3a and C3b so that it can be used in the 3 different outcomes of the complement system. |
|
|
Term
| How is the classical pathway activated? |
|
Definition
| When antibodies bind to an antigen forming an immune complex. (Antibodies bind to microbial invaders) |
|
|
Term
| What are the three major protective outcomes of the complement system? |
|
Definition
1.Opsonization
2.inflammatory response
3.lysis of foreign cells |
|
|
Term
| What are the two effects when C3b concentration increases substantially when the complement system is activated? |
|
Definition
1.Continued complement activation via the alternative pathway
2.opsonization |
|
|
Term
| What does opsonization mean? (Think of it as coating a microbe with one layer of velcro, with phagocytes having the opposing layer on their surface.) |
|
Definition
| It has been "prepared for eating", and it is easier for phagocytes to bind to and engulf because phagocyted have receptors that attach specifically to opsonin. (C3b) |
|
|
Term
| This is a complement component that is a potent chemoattractant, drawing phagocytes to the area where the complement system has been activated. |
|
Definition
|
|
Term
| What do C3a and C5a do in the inflammatory response? |
|
Definition
| they induce changes in the endothelial cells that line blood vessels, contributing to vascular permeablility associated with inflammation. |
|
|
Term
| complexes of complement system proteins that assemble in cell membranes, creating pores in the membrane and disrupt the integrity of the cell. |
|
Definition
| Membrane Attack complexes (MACs) |
|
|
Term
| Do MACs have much effect on gram-positive bacteria? |
|
Definition
| No, because the peptidoglycan layer of these cells prevents CSCs (complement sytem components)from reaching their cytoplasmic membranes. |
|
|
Term
|
Definition
| secreted proteins that tag particles for phagocytosis |
|
|
Term
| A phagosome fused with a lysosome |
|
Definition
|
|
Term
| a phenomenon called respiratory burst enables what? (when oxygen consumption increases in a phagolysosome) |
|
Definition
| it allows an enzyme to produce reactive oxygen species (ROS)which are toxic. |
|
|
Term
| Describe the digestion process of a lysosome in phagocytosis. |
|
Definition
1.O2 consumption increases, creating ROS
2.another enzyme make nitirc oxide which reacts with ROS to produce more toxic cmpds
3.special pumps pump protons into the phagolysosome, lowering the pH
4.The degradation of the peptidoglycan layer occurs.
5.defensins damage membranes of invader
6.transferrins tie up iron |
|
|
Term
| concentrated groups of macrophages, giant cells and T cells that wall off and retain organisms or other material that cannot be destroyed. |
|
Definition
|
|
Term
| when pahocytes fuse together, they form what? |
|
Definition
|
|
Term
| When are giant cells and granulomas formed? |
|
Definition
| When activated macrophages fail to destroy microbes |
|
|
Term
| What is the problem with granulomas? |
|
Definition
| although they protect from the spread of microbes to other cells, they also harm the host because they interfere with normal tissue function. |
|
|
Term
| scavengers and sentries that are routinely phagocytizing dead cells and debris, but ready to destroy invaders and call in reinforcment when needed. |
|
Definition
|
|
Term
| The rapid response team quick to move into the area of trouble and ready to eliminate the invaders. |
|
Definition
|
|
Term
| How long can macrophages live? |
|
Definition
| a few weeks to a few months |
|
|
Term
| How long to neutrophils usually live? |
|
Definition
|
|
Term
| What is the benefit and weakness of neutrophils? |
|
Definition
| They have more killing power that macrophages, but they have a limited lifespan |
|
|
Term
| In what ways do nuetrophils kill microbes? |
|
Definition
1.phagocytosis
2.They also release their granules along with DNA to form neutrophil extracellular traps (NETs) |
|
|
Term
| How do the NETs of neutrophils kill microbes? |
|
Definition
| The DNA strands in the NET ensnare microbes, allowing the granule contents (enzymes and peptides) to destroy them. |
|
|
Term
| This type of programmed self-destruction triggers an inflammatory response |
|
Definition
|
|
Term
| What are the two major events that can initiate inflammation? |
|
Definition
1.Microbes
2.Tissue damage |
|
|
Term
| cytokines and other fever inducing substances |
|
Definition
|
|
Term
| What are fever-inducing cytokines made by the body? |
|
Definition
|
|
Term
| What are fever-inducing pyrogens that are introduced from external sources such as bacteria? |
|
Definition
|
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