A&P 2, Unit 2, Chapter 22 Homework
Place the events of lymphocyte maturation in the correct sequence.
- Primary lymphatic structures produce lymphocytes - pre T-lymphocytes - lymphocytes mature in primary lymphatic structures - naive immunocompetent t-lymphocytes - lymphocytes migrate and are housed in secondary lymphatic structures - lymphocytes proliferate and are activated - T-lymphocytes carry out effector functions - foreign antigens are eliminated
Indicate whether each statement is true or false.
1. Specificity and memory are characteristics of adaptive and innate immunity. FALSE 2. Specificity involves the immune system's ability to recognize a particular substance. TRUE 3. Memory involves the immune system's ability to "remember" previous substances. TRUE 4. Memory and specificity speed up and lengthen the immune system's reaction time. TRUE
Place a single word into each sentence to make it correct. Not all terms will be used.
A __fever__ is an abnormal elevation of the body temperature. A low to moderate fever, when allowed to run its course, can be __beneficial__. Fever can __promote__ interferon activity. Fever can also __accelerate__ tissue repair. Lastly, fever will inhibit the __reproduction__ of bacteria and viruses.
Fill in the blanks with the terms provided.
Activated and MEMORY helper T-lymphocytes leave secondary lymphatic structures after several DAYS of exposure to antigens. They migrate to the site of infection, where they continue to release CYTOKINES to regulate OTHER IMMUNE cells. They activate CYTOTOXIC T-lymphocytes through the release of these molecules. They also ENHANCE the formation and activity of cells of the INNATE immune system, including MACROPHAGES and NK cells.
Complete the sentences with the terms provided. Not all terms will be used.
Activating complement triggers __lysis__ of the infected cell. Precipitation and __agglutination__ result from antigen-antibody complexes that make substances aggregate. During __neutralization__, bacterial surfaces are covered to prevent effective movement and release of toxins. Production of antibodies is referred to as the __humoral__ immune response. Each antibody recognizes a specific __antigen__ unique to its target. An antibody is a __protein__ used by the immune system to identify and otherwise block or kill foreign objects such as bacteria and viruses. When antibodies are bound to __target__ cells they function as an __opsonin__, which enhances phagocytosis.
Fill in the blanks with the terms provided. Not all terms will be used.
After a __pathogen__ enters the body it must be destroyed. One type of response by the body's __second__ line of defense is phagocytosis. Macrophages are the biggest __phagocyte__. They float in the bloodstream as monocytes, enter tissue, and turn into macrophages. For example, __alveolar__ macrophages live in the lungs and keep the lungs clean and disease free. Lastly dendritic cells, also called __Langerhans__ cells, live in the skin.
Fill in the blanks with the terms provided.
An EXOGENOUS antigen, through the process of ENDOCYTOSIS, is brought into the cell. A PHAGOSOME is formed. This contains foreign antigens and merges with a LYSOSOME to form a PHAGOLYSOSOME, where the substance is digested into PEPTIDE fragments. The vesicle containing these fragments then merges with vesicles containing newly synthesized MHC CLASS II molecules. The peptide fragments are then "loaded" into these molecules. These vesicles in turn then merge with the plasma membrane of the APC.
Fill in the blanks with the terms provided. Not all terms will be used.
Antibodies are the effectors of HUMORAL immunity. Antibodies are formed by PLASMA CELLS, typically within the lymph NODES. Antibodies circulate throughout the body in the lymph and BLOOD, ultimately coming in contact with antigen at the site of infection. Plasma cells, over their life span of about 5 DAYS, produce hundreds of millions of antibodies against the specific antigen. The circulating blood concentration of antibody against a specific antigen is referred to as the antibody TITER.
Drag each label into the appropriate position to identify what type of immunity is classified by each label.
Antibody-Mediated Immunity: Humoral immunity B-lymphocytes Agglutination Cell-Mediated Immunity: Cytotoxic T-lymphocytes CD8 cells Perforins and granzymes Both: Helper T-lymphocytes Plasma cells MHC-II
Fill in the blanks with the terms provided. Not all terms will be used.
Antigen challenge causes the formation of MEMORY CELLS in response to the activation of T-LYMPHOCYTES and B-lymphocytes. These long-lived lymphocytes represent an "army" of thousands against specific antigens and are responsible for IMMUNOLOGIC memory. On subsequent exposures to an antigen, these vast numbers of memory cells make contact with the antigen more RAPIDLY and produce a MORE POWERFUL response, which is referred to as the secondary response, memory response, or ANAMNESTIC response. On each subsequent exposure to a specific pathogen, the pathogen is typically eliminated even before disease symptoms develop.
Fill in the blanks with the terms provided. Not all terms will be used.
B-lymphocyte activation begins when antigens bind to several __receptors__ on the B-lymphocyte. The antigen is taken into the cell by receptor-mediated __endocytosis__. The B-lymphocyte then processes the antigen, links some of the __epitopes__ to its MHC-II proteins, and then displays it on the cell surface. A helper T-lymphocyte binds to the Ag-MHC complex and secretes interleukins that activate the B-lymphocyte and trigger __clonal__ selection. Most cells of the clone differentiate into __plasma__ cells and begin producing __antibodies.__
Select the correct word from the list to complete each sentence. Not all terms will be used.
B-lymphocytes produce __antibodies__ against specific antigens. When B-lymphocytes are exposed to an appropriate antigen, they proliferate into plasma cells and __memory cells__. Each antibody consists of __four__ polypeptide chains. Antigens bind to the __variable__ regions of the polypeptide chains.
Select all that are infectious agents
Bacteria Fungi Viruses Parasites
Fill in the blanks with the terms provided. Not all terms will be used.
Basophils and __mast cells__ are both proinflammatory chemical secreting cells. Recall that __basophils__ circulate in the blood, and __mast cells__ reside in connective tissue of the skin, mucosal linings, and various internal organs. These cells release granules during the inflammatory response. These cellular granules contain various substances including __histamine__, which increases both vasodilation and capillary permeability, and __heparin__, an anticoagulant. They also release __eicosanoids__ from their plasma membrane which increase(s) inflammation.
Place the events of the lifetime of a lymphocyte in the correct sequence.
Beginning of lymphocyte lifecycle - formation and maturation in red bone marrow and thymus - become able to recognize only one specific foreign antigen - migration to spleen, tonsils, lymph nodes, and MALT - have first exposure to antigen in which they bind - replicate to make identical cells - effector functions carried out to eliminate pathogens End of lymphocyte lifecycle
Classify each description as associated with either cell-mediated or humoral immunity.
Cell-mediated - utilizes perforin - induces apoptosis - utilizes granzymes - lymphocytes kill infected cells directly Humoral - pathogens are tagged for destruction - antibodies bind infected cells - plasma cells are involved
Read each description regarding cellular and humoral immunity. Then click and drag each into the appropriate category based on the form of immunity to which it applies.
Cellular Immunity: Utilizes cytotoxic T-lymphocytes MHC-I Humoral Immunity: Produces antibodies Attacks extracellular viruses Both: Utilizes help T-lymphocytes MHC-II Attacks bacteria Has a secondary response Phagocytosis
Fill in the blanks with the terms provided. Not all terms will be used.
Cytokines are small, soluble __proteins__ produced by cells of both the innate and adaptive immune system to regulate and facilitate immune system activity. A cytokine is released from one cell and binds to a specific __receptor__ of a target cell, where its action is similar to that of a hormone. Cytokines can act on the cell that released it __(autocrine)__, local neighboring cells __(paracrine)__, or circulate in the blood to cause systemic effects __(endocrine)__.
Match the T-lymphocyte type with its function.
Cytotoxic T-lymphocytes: Cause cell lysis Memory T-lymphocytes: Provide a secondary response and long-lasting immunity
Classify the body locations with the leukocytes found there.
Dendritic Cells: Epidermis T-lymphocytes: Lymph nodes Spleen Tonsils Microglia: Brain Mast Cells: Connective tissues
Place the events that occur during the effector response of cytotoxic T-lymphocytes in the correct sequence.
Exposure to unhealthy or foreign cell - antigen is presented to t-lymphocytes in secondary lymphatic structures - cytotoxic t-lymphocytes migrate to the site of infection - activated cytotoxic t-lymphocyte contacts an infected cell at site of infection - cytotoxic t-lymphocyte releases perforin and granzymes - apoptosis of infected cell
Classify each item as a first, second, or third line of defense.
First Line of Defense: - Skin - Mucosal membranes Second Line of Defense: - Eosinophils - Inflammation - Fever Third Line of Defense: - Cell-mediated immunity - Lymphocytes - Antibodies
Classify esch description as associated with either the first or second signal to helper T-lymphocytes during their activation.
First Signal: APC presents antigen with MHC class II. CD4 of helper T-lymphocyte binds MHC molecule. Occurs in secondary lymphatic structure. Second Signal: Helper T-lymphocyte secretes interleukin 2. Memory helper T-lymphocytes produced. Activated helper T-lymphocytes produced.
Order the events of formation and display of MHC class I molecules in an infected cell.
Formation - proteasome digests viral proteins - MHC class I molecules bind viral antigens in RER - vesicles carry MHC class I molecules to the golgi apparatus - secretory vesicles carry MHC class I molecules to plasma membrane Display
Drag each label into the appropriate position to identify what type of immunity is classified by each label. Not all terms will be used.
Four cardinal signs of __inflammation__ are recognized. Erythrocytes arriving at the site and perfusing the dermis are visible through the skin which produces __redness__. The increase in blood flow to an area of injury or infection brings __heat__ from the axial regions of the body. With increased blood flow and leakiness of capillaries, fluids are delivered to the tissue faster than they are removed resulting in __swelling (edema)__. Swelling increases the pressure of fluids and mechanical structures on adjacent structures and thus activating receptors for __pain.__
Fill in the blanks with the terms provided. Not all terms will be used.
Generally, two categories of cells present antigen to T-lymphocytes: all nucleated cells of the body and a category of cells called ANTIGEN-PRESENTING cells. The latter includes any immune cell that functions specifically to communicate the presence of ANTIGEN to both helper T- lymphocytes and cytotoxic T-LYMPHOCYTES. Dendritic cells, macrophages, and B-LYMPHOCYTES function as APCs.
Which of the following properties distinguishes specific immunity from nonspecific defense? Check all that apply.
Immunity is directed against a particular pathogen. The body reacts quickly to a pathogen to which it was previously exposed. When reexposed to a pathogen, there are usually no noticeable signs or symptoms of disease from that pathogen.
Complete each sentence with the correct word. Not all terms will be used.
In the first step of local inflammation, antigens on the surface of bacteria bind with __antibodies__. Exposure to __antigens__ cause(s) mast cells to release histamine. Neutrophils and macrophages __phagocytize__ bacteria. The production of antibodies by B-cells is an example of __specific__ immunity. Activation of complement proteins is an example of __nonspecific__ immunity. Leukocytes are attracted to certain chemicals produced by bacteria and roll along the wall of the vessel toward them, a process called __chemotaxis__.
Complete each sentence by dragging the proper label into the appropriate position. Not all terms will be used.
Interestingly, __antibodies__ do not directly attack nor destroy any pathogens, rather they bind to pathogens and in doing so render them incapable of causing an immune response. Antibodies bind to antigen sites on pathogenic cells and in doing so open binding sites and promote __complement fixation__ resulting in a conversion of complement proteins to fight the pathogen. Antibodies that bind to more than one cell simultaneously can rapidly cause clumping or __agglutination__ to occur which prevents the pathogen from contacting and damaging human cells. Small pathogenic molecules that are soluble are clumped together by antibodies, making the molecule insoluble and less mobile. This is an example of __precipitation__.
Fill in the blanks with the terms provided. Not all terms will be used.
Interferons ( IFNs) are a class of CYTOKINES released from a variety of cells, including leukocytes and FIBROBLASTS. IFN serves as a NONSPECIFIC defense mechanism against the spread of any VIRAL infection.
Classify the given terms or examples with the appropriate category. Terms may be used more than once.
MHC Class I Molecules: Produced in RER Displays self-antigens Displayed by all nucleated cells Recognized by cytotoxic T-lymphocytes Displays nonself-antigens MHC Class II Molecules: Produced in RER Displayed by professional APCs Displays nonself-antigens Recongnized by helper T-lymphocytes
Which of the following statements is true about memory cells? Check all that apply.
Memory cells respond to antigens more rapidly than naive T cells. Upon reexposure to a pathogen, memory cells engage in the T cell recall response, destroying the pathogen quickly.
Classify each characteristic with the appropriate cell.
Neutrophils: Most abundant First to arrive Respiratory burst Basophils: Release granules of histamine Release granules of heparin Eosinophils: Attack parasites
Read each description below regarding nonspecific resistance and immunity. Then click and drag each into the appropriate category.
Nonspecific Resistance: - Skin - A fever as a result of a bacterial infection - Natural killer cells patrol the body on the lookout for diseased host cells - The inflammatory response. Immunity: - Producing an antibody against a cold virus - A tetanus vaccination stimulates the body to produce antibodies against the C. tetani bacteria. - Antibodies pass from the placenta into the fetus. - Receiving anti-venom after being bitten by a rattlesnake.
Small pieces of infectious proteins are called _________.
Prions
Classify the given terms or examples with the appropriate category.
Prokaryotic: Bacteria Prions Eukaryotic: Fungi Protozoans Multicellular parasites Acellular: Viruses Prions
Complete the sentences with the terms provided. Not all terms will be used.
Skin is an important part of the immune system. It acts as a __primary__ boundary between germs and your body. Skin is tough and generally impermeable to bacteria and viruses. The skin also secretes __antibacterial__ substances. Tears and mucus contain __lysozyme__ that breaks down the cell wall of many bacteria. Saliva is also antibacterial. Because the nasal passage and lungs are coated in __mucus__, many germs are trapped in this substance and soon __swallowed__ down the esophagus.
Fill in the blanks with the terms provided. Not all terms will be used.
Some substances are too SMALL to function as an ANTIGEN alone, but when attached to a carrier molecule in the host, become ANTIGENIC and trigger an immune response; these molecules are called HAPTENS. Such immune responses account for HYPERSENSITIVITY reactions to drugs, such as penicillin, and to chemicals in the environment.
Indicate whether the label identifies a specific or nonspecific form of defense.
Specific: B-lymphocytes Antibodies Cytotoxic T-lymphocytes Plasma cells Nonspecific: Skin Neutrophils Monocytes
Indicate whether each item identifies a specific or nonspecific form of defense.
Specific: Vaccines Memory Third line of defense Nonspecific: Acid mantle Lysozyme First line of defense Defensins Hyaluronic Acid Second line of defense
Match the chemical mediator with its description.
Surface chemicals: Lysozymes; prevent microbial growth or kill microorganisms. Histamines: Amine released from basophils, platelets, and mast cells; cause vasodilation. Kinins: Polypeptides derived from plasma proteins; cause vasodilation. Interferons: Proteins produced by cells; interfere with virus production. Prostaglandins: Polypeptides derived from plasma proteins; cause vasodilation Leukotrienes: Group of lipids: cause smooth muscle contraction.
Select the correct word from the list to complete each sentence. Not all terms will be used.
T-lymphocytes mature and differentiate in the __thymus__. Cytotoxic T-lymphocytes __do not__ secrete antibodies. Cytotoxic T-lymphocytes __need to be__ in direct contact with the cell in order to kill it. Cytotoxic T-lymphocytes secrete __perforins__, which cause a hole in the victim cell's plasma membrane.
Fill in the blanks with the terms provided.
T-lymphocytes originate in RED BONE MARROW and then migrate to the THYMUS to complete their maturation. They possess a unique TCR and initially both the CD4 and CD8 proteins. Each T-lymphocyte must have its TCR "tested" to determine not only whether it is able to bind to the MHC molecule with presented ANTIGEN, but also whether it binds only to antigens that are NONSELF. This testing results in T-LYMPHOCYTE selection.
Fill in the blanks with the terms provided. Not all terms will be used.
The __antigen-presenting cell__ encounters and processes the antigen. With the antigen, the antigen-presenting cell migrates to the nearest __lymph node__. The antigen-presenting cell displays the antigen to the __T-lymphocytes.__ If the antigens are viral proteins or abnormal antigens, the T-lymphocytes initiate the __immune response__ Infected or malignant cells are then __destroyed __before they can do further harm to the body.
Fill in the blanks with the terms provided. Not all terms will be used.
The binding of a PROTEIN to a portion of bacteria or other cell type that enhances its removal by PHAGOCYTOSIS is a process called OPSONIZATION. The binding protein is called an OPSONIN. The binding of COMPLEMENT makes it more likely that a substance is identified and engulfed by phagocytic cells.
An immune cell is observed to present antigen to naive helper and cytotoxic T-lymphocytes. Using this information, select all that apply.
The cell is an antigen-presenting cell. The cell may be a macrophage. The cell may be a dendritic cell. The cell may be a B-lymphocyte.
Fill in the blanks with the terms provided. Not all terms will be used.
The final step in T-lymphocyte selection is that each T-lymphocyte differentiates into either a HELPER T-lymphocyte (CD4⁺ cell) by the selective loss of the CD8 protein, or a CYTOTXIC T-lymphocyte (CD8⁺ cell) by the selective loss of CD4 protein. Consequently, two primary types of IMMUNOCOMPETENT T-lymphocytes leave the THYMUS. Each of these T-lymphocytes is also classified as a NAIVE T-lymphocyte because it has not yet been exposed to the specific foreign antigen it recognizes.
Fill in the blanks with the terms provided. Not all terms will be used.
When a person is exposed to an antigen for the first time the immune reaction is called the __primary__ response. The appearance of protective __antibodies__ is delayed for 3-6 days while naive B cells multiply and differentiate. As the plasma cells begin secreting antibody, the antibody __titer__ begins to rise. Eventually the primary response will make an immune __memory__ of the antigen.
Plasma cells release __________ in response to activation by antigen.
antibodies
A particular virus strain is highly effective in activating an immune response. In other words it has a high degree of ______________.
immunogenicity
