Immune System: Exam 2

The redness and heat of an inflamed area are due to a local hyperemia caused by vasodilation. Inflammation is the body's response to injury or infection, and it involves the release of chemical mediators that cause blood vessels to dilate, allowing increased blood flow to the affected area. This increased blood flow brings more immune cells and nutrients to the site of inflammation, resulting in redness and heat. Vasodilation helps to facilitate the immune response and promote healing.

Antigenic is not a type of T cell. T cells are a type of white blood cell that play a key role in the immune response. The different types of T cells include helper T cells, regulatory T cells, and cytotoxic T cells. Helper T cells assist in coordinating the immune response, regulatory T cells help maintain immune tolerance, and cytotoxic T cells are responsible for killing infected cells. However, antigenic is not a recognized type of T cell.

Cytotoxic cells are a type of T cells that have the ability to directly attack and kill other cells. These cells play a crucial role in the immune response by identifying and destroying infected or abnormal cells in the body. Unlike regulatory cells, which help regulate the immune response, or helper cells, which assist in coordinating the immune response, cytotoxic cells have the specific function of eliminating harmful cells. Plasma cells, on the other hand, are a type of B cells that produce antibodies to fight against pathogens.

Natural killer cells are a type of immune cell that can recognize and kill cancer cells and virus-infected body cells before the activation of adaptive immunity. Unlike T lymphocytes and B lymphocytes, which are part of the adaptive immune response, natural killer cells are part of the innate immune system and do not require prior exposure to specific antigens. They can directly recognize and eliminate abnormal cells through a process called natural cytotoxicity, making them an important component of the early defense against cancer and viral infections. Pinocytosis, on the other hand, is a process of cellular uptake and does not directly kill cancer cells or virus-infected cells.

Chemotaxis is the process by which neutrophils and other white blood cells are attracted to an inflammatory site. During inflammation, certain molecules known as chemotactic factors are released from the site of injury or infection. These chemotactic factors act as chemical signals, guiding the white blood cells towards the site of inflammation. Once the white blood cells reach the inflammatory site, they can then carry out their immune functions, such as phagocytosis, to help eliminate pathogens and promote healing. Margination refers to the process of white blood cells sticking to the blood vessel walls, while phagocytosis is the engulfment and digestion of pathogens by white blood cells. Diapedesis is the process of white blood cells squeezing through blood vessel walls to enter the surrounding tissues.

The innate immune system defenses include phagocytosis, which is the process by which certain cells engulf and destroy foreign particles or pathogens. This is an important mechanism for the innate immune system to recognize and eliminate potential threats to the body. Phagocytosis involves specialized cells such as macrophages and neutrophils that engulf and digest the foreign substances, helping to protect the body from infection and disease. Plasma cells, T cells, and B cells are components of the adaptive immune system, which responds to specific pathogens and develops immunity over time.

Immunocompetence refers to the ability of individual cells to recognize a specific antigen by binding to it. This means that the cells of the immune system are capable of identifying and interacting with specific foreign substances, such as pathogens or toxins, by binding to their antigens. This recognition is crucial for the immune response, as it allows the immune system to mount a targeted defense against the invader. Immunocompetence is acquired through the development and maturation of immune cells, as well as exposure to antigens.

Passive immunity refers to the transfer of pre-formed antibodies from one individual to another, providing immediate but temporary protection against a specific pathogen. In this case, the passage of IgG antibodies from a pregnant mother to her fetus is associated with passive immunity. These antibodies are transferred through the placenta and provide the newborn with temporary protection against various infections until their own immune system develops fully. This process is crucial for the health and well-being of the newborn during the early stages of life.

Antigens can come from various sources, including proteins, nucleic acids, lipoproteins, glycoproteins, and certain large polysaccharides. They exhibit immunogenicity and reactivity, meaning they can stimulate an immune response and react with specific antibodies. The parts of antigen molecules that initiate immune responses are called epitopes or antigenic determinants. Therefore, the statement that antigens only come from microbes is incorrect. Antigens can come from both microbial and non-microbial sources.

Antigens are substances that can induce an immune response in the body, leading to the production of antibodies. Antigens can have different regions called antigenic determinants, which are recognized by specific antibodies. Therefore, one antigen can have multiple antigenic determinants, and as a result, it can stimulate the production of more than one antibody. This allows the immune system to target different parts of the antigen and enhance its ability to fight against various pathogens.

Antibodies are composed of heavy and light polypeptide chains. This means that they are made up of two different types of protein chains, which are the heavy chains and the light chains. These chains come together to form the structure of the antibody. The heavy chains are larger and provide stability, while the light chains are smaller and help with antigen recognition. This composition allows antibodies to have specific binding sites that can recognize and bind to antigens, which is important for their role in the immune response.

Cytokines are released by activated T cells and macrophages to mobilize immune cells and attract other leukocytes into the area. Cytokines act as chemical messengers, coordinating the immune response by stimulating the production and activation of various immune cells. They play a crucial role in inflammation and immune system regulation.

Cytotoxic T cells are a specific type of T cells that have the ability to directly attack and kill other cells. Unlike other T cells that mainly function to stimulate the proliferation of other T cell populations or self-destruct once the antigen has been neutralized, cytotoxic T cells have the unique capability to directly eliminate infected or abnormal cells. They recognize and bind to specific antigens presented on the surface of target cells, leading to the release of cytotoxic molecules that induce cell death. Therefore, cytotoxic T cells play a crucial role in immune responses against viruses, intracellular bacteria, and cancer cells.

Phagocytes are a part of the second line of defense against microorganisms. Phagocytes are a type of white blood cell that engulf and destroy foreign particles, such as bacteria and viruses, through a process called phagocytosis. They play a crucial role in the immune response by recognizing and eliminating harmful microorganisms in the body. Cilia are hair-like structures that help move mucus and trapped particles out of the respiratory tract, gastric juice is a part of the first line of defense in the stomach, and keratin is a protein that forms a protective layer on the skin and is not directly involved in the second line of defense against microorganisms.

Active and passive humoral immunity are both mechanisms of adaptive immunity that use antibodies. This means that both active and passive immunity involve the production and use of antibodies to fight against pathogens. Active immunity occurs when the body's immune system is stimulated to produce its own antibodies in response to an infection or vaccination. Passive immunity, on the other hand, occurs when pre-formed antibodies are transferred to an individual, providing immediate but temporary protection. Both types of immunity rely on the use of antibodies to target and neutralize pathogens.

The given statement that "NK cells are a type of neutrophil" is false or incorrect. NK cells, also known as natural killer cells, are a distinct type of lymphocyte and not a type of neutrophil. Neutrophils are a different type of white blood cell involved in the innate immune response.

Helper T cells play a crucial role in the activation of the adaptive immune system. They recognize antigens presented by antigen-presenting cells and help stimulate the production of antibodies by B cells and the cytotoxic response of T cells. By releasing cytokines and other signaling molecules, helper T cells enhance the immune response and promote the elimination of pathogens. Therefore, they function in the activation of the adaptive immune system.

Opsonization is the process by which complement proteins and antibodies coat a microorganism, providing binding sites for macrophages and neutrophils. This coating enhances the recognition and phagocytosis of the organism by the immune cells.

Acquired immune deficiency syndrome (AIDS) is caused by a virus that recognizes CD4 proteins. This virus is known as the human immunodeficiency virus (HIV). HIV attacks and destroys CD4 cells, which are a type of white blood cell that plays a crucial role in the immune system. As a result, the immune system becomes weakened, making individuals more susceptible to infections and diseases. AIDS is not hereditary but is acquired through exposure to the virus, typically through sexual contact, sharing needles, or from mother to child during childbirth or breastfeeding.

B lymphocytes, also known as B cells, are a type of white blood cell that plays a crucial role in the immune response. They are responsible for producing antibodies that help to neutralize pathogens. The development of immunocompetence refers to the process by which B lymphocytes acquire the ability to recognize specific antigens and mount an immune response against them. This process occurs in the bone marrow, where B cells undergo maturation and selection to ensure that they can effectively respond to a wide range of pathogens. Therefore, the correct answer is bone marrow.

Type II diabetes is not an autoimmune disease because it is primarily caused by a combination of genetic factors, lifestyle choices, and insulin resistance. Autoimmune diseases occur when the immune system mistakenly attacks healthy cells and tissues in the body, but in the case of type II diabetes, the immune system is not directly involved in the development of the disease.

Immediate hypersensitivities involve IgE antibodies and the release of histamine from mast cells and basophils. This means that when a person with immediate hypersensitivity is exposed to an allergen, their immune system produces IgE antibodies specific to that allergen. These antibodies then bind to mast cells and basophils, causing the release of histamine. Histamine is responsible for the symptoms of immediate hypersensitivity, such as itching, swelling, and difficulty breathing.

Haptens are small molecules that bind with self-proteins to produce antigenic substances. This means that when haptens bind with self-proteins, they create substances that can trigger an immune response in the body. Antibodies, on the other hand, are proteins produced by the immune system in response to antigens. Reagins and ions are not related to the process of binding with self-proteins to produce antigenic substances.

Interferon plays a crucial role in the defense against disease by protecting cells that have not yet been infected by viruses. It is a type of protein that is released by cells in response to viral infection. Interferon helps to prevent the spread of the virus to neighboring cells by signaling nearby cells to increase their antiviral defenses. This protective response helps to limit the replication and spread of the virus, thus reducing the severity and duration of the infection.

NK cells are a type of lymphocyte that can kill cancer cells before the immune system is fully activated. Unlike cytotoxic T cells, which are part of the adaptive immune system, NK cells do not require prior exposure to antigens to recognize and attack cancer cells. They are able to directly recognize and destroy cancer cells through various mechanisms, such as releasing toxic substances or inducing apoptosis. This early response by NK cells helps in the initial defense against cancer before the adaptive immune system mounts a specific immune response.

Phagocytosis is the process by which cells engulf and digest foreign particles or microorganisms. Chemotaxis refers to the movement of cells towards a chemical signal, in this case, towards the site of infection. Adherence is the attachment of the phagocyte to the foreign particle. Ingestion is the engulfment of the particle by the phagocyte. Digestion involves the breakdown of the ingested particle by enzymes within the phagocyte. Killing refers to the destruction of the ingested particle. Therefore, the correct sequence of events in phagocytosis is chemotaxis, adherence, ingestion, digestion, and killing.

The primary immune response has a lag period while B cells proliferate and differentiate into plasma cells. This means that when the body is exposed to a new pathogen for the first time, it takes some time for the immune system to mount a response. During this lag period, B cells, which are a type of white blood cell, undergo proliferation and differentiation into plasma cells. These plasma cells then produce antibodies to fight against the pathogen. This lag period is necessary for the immune system to recognize and respond to the specific pathogen, and it is a characteristic of the primary immune response.

TLRs are known to activate immune responses by recognizing pathogen-associated molecular patterns (PAMPs). Upon activation, TLRs stimulate the release of various signaling molecules, including cytokines. Cytokines are small proteins that play a crucial role in cell signaling and communication, particularly in the immune system. They act as chemical messengers, attracting white blood cells to the site of infection or inflammation. Therefore, the release of cytokines triggered by TLRs helps in recruiting white blood cells to the scene, aiding in the immune response against pathogens.

Delayed hypersensitivities include allergic contact dermatitis. This is a type IV hypersensitivity reaction that occurs when the immune system overreacts to a substance that comes into contact with the skin. It is characterized by redness, itching, and a rash at the site of contact. Unlike immediate hypersensitivity reactions, delayed hypersensitivities do not involve B cells and are instead mediated by T cells. Anaphylactic shock, on the other hand, is a type I hypersensitivity reaction that is mediated by IgE antibodies and involves a rapid and severe systemic allergic reaction.

The correct answer is disulfide. Disulfide bonds are covalent bonds formed between two sulfur atoms in the amino acid cysteine. These bonds play a crucial role in stabilizing the structure of antibody molecules by connecting different regions of the molecule. The disulfide bonds help maintain the integrity and shape of the antibody, allowing it to effectively recognize and bind to specific antigens.

Graft rejection occurs when the recipient's immune system recognizes the transplanted tissue as foreign and attacks it. Using a xenograft, which involves transplanting tissue or organs from a different species, can lead to graft rejection because the immune system recognizes the foreign tissue as non-self and mounts an immune response against it. This immune response can cause inflammation, tissue damage, and ultimately rejection of the xenograft.

B cells respond to the initial antigen challenge by producing progeny cells that include plasma cells and memory cells. This is because B cells are a type of white blood cell that plays a crucial role in the immune response. When B cells encounter an antigen, they undergo a process called clonal expansion, where they divide and differentiate into two types of cells: plasma cells and memory cells. Plasma cells are responsible for immediately producing large amounts of antigen-specific antibodies, while memory cells are long-lived cells that "remember" the antigen and provide a faster and more robust response upon subsequent exposure to the same antigen.

Allergic contact dermatitis is classified as a delayed hypersensitivity reaction because it occurs hours to days after exposure to an allergen. In this type of reaction, the immune system recognizes the allergen as foreign and triggers an immune response, leading to inflammation and skin irritation. This delayed response is different from immediate hypersensitivity reactions like anaphylaxis, which occur within minutes of exposure to an allergen. Cytotoxic hypersensitivity involves the destruction of cells by antibodies, while immune complex hypersensitivity involves the formation of immune complexes that can cause tissue damage.

In clonal selection of B cells, antigens are responsible for determining which cells will eventually become cloned. Antigens are molecules that can elicit an immune response and bind specifically to B cell receptors. When a B cell encounters an antigen that matches its receptor, it becomes activated and undergoes clonal expansion, producing identical copies of itself called clones. These clones are then able to produce antibodies that specifically recognize and neutralize the antigen, leading to an effective immune response. Therefore, antigens play a crucial role in determining which B cells will be selected for cloning.

The inflammatory response is a protective mechanism of the body that is triggered in response to injury or infection. It involves various processes such as vasodilation, increased vascular permeability, recruitment of immune cells, and release of inflammatory mediators. These processes aim to eliminate the injurious agent, prevent its spread to nearby tissues, dispose of cellular debris and pathogens, and set the stage for repair processes. However, the replacement of injured tissues with connective tissue is not a direct function of the inflammatory response. This process is more closely associated with the subsequent phase of tissue repair, which occurs after the inflammatory response has subsided.

Interferons are proteins that are produced by cells in response to viral infection. They play a crucial role in the body's immune response by interfering with viral replication within cells. This means that they inhibit the ability of viruses to reproduce and spread within the body. By doing so, interferons help to limit the spread of viral infections and promote the body's ability to fight off the infection.

Antibodies work by enhancing phagocytosis, neutralizing antigens, and agglutinating and precipitating antigens. However, activating cytokines is not a method by which antibodies work. Cytokines are small proteins that play a crucial role in cell signaling and immune responses, but they are not directly involved in the action of antibodies.

The adaptive immune system is not specific for a given organ. It is a systemic response that can target antigens throughout the body. This is because the adaptive immune system involves the activation of lymphocytes, such as T cells and B cells, which circulate in the blood and lymphatic system, allowing them to encounter and respond to antigens wherever they may be present in the body. This systemic nature of the adaptive immune system allows for a coordinated and widespread response to infections or other foreign substances.

IgM is a type of antibody that contains 10 binding sites. This means that IgM can bind to 10 different antigens simultaneously. IgG and IgA both contain 6 binding sites, while IgD contains 4 binding sites. The number of binding sites per functional antibody unit varies depending on the type of antibody.

Macrophages are immune cells that play a crucial role in chronic infections. They are known to predominate at the sites of such infections due to their ability to phagocytose pathogens and present antigens to other immune cells. Macrophages also release various cytokines that help regulate the immune response and promote tissue repair. Their presence at the sites of chronic infections indicates their importance in controlling and resolving these infections.

Our genes determine what specific foreign substances our adaptive immune system will be able to recognize and resist. This is because our genes encode the information needed to produce the receptors on immune cells that can recognize and bind to specific antigens. These receptors are known as antigen receptors and they are responsible for initiating the immune response against foreign substances. Therefore, our genes play a crucial role in determining the range of antigens that our immune system can effectively respond to.

Fever is a higher-than-normal body temperature that is a result of production being regulated by chemicals that reset the body's thermostat to a higher setting. This means that when the body detects the presence of an infection or illness, it releases certain chemicals that increase the body's temperature, which helps to fight off the infection. By raising the body's temperature, the immune system becomes more effective at killing off bacteria or viruses.

Reactivity with an antibody is characteristic of complete antigens. Antigens are substances that can trigger an immune response in the body, leading to the production of antibodies. Complete antigens have specific regions called epitopes that can bind to antibodies, initiating an immune response. This reactivity is essential for the antigen-antibody interaction, which plays a crucial role in the immune system's recognition and elimination of foreign substances. Antigens that do not react with antibodies are considered incomplete antigens or haptens.

The correct answer is mainly neutrophil and macrophage migration into inflamed areas. Phagocyte mobilization refers to the movement of phagocytes, which are cells that engulf and destroy pathogens, into areas of inflammation. Neutrophils and macrophages are the most active phagocytes in the immune system and they migrate to inflamed areas to eliminate pathogens and initiate the immune response. This process is crucial for the body's defense against infection and tissue damage.

A second exposure to an allergen is not a mechanism for the development of autoimmune disorders. Autoimmune disorders occur when the immune system mistakenly attacks the body's own tissues. This can happen due to various mechanisms such as mutation followed by the appearance of new membrane proteins, cross-reaction of antibodies formed against foreign antigens with self-antigens, and exposure of previously "hidden" self-antigens to the adaptive immune system. However, a second exposure to an allergen does not directly contribute to the development of autoimmune disorders. Allergies involve an overreaction of the immune system to harmless substances, but they are not classified as autoimmune disorders.

Clonal selection of B cells refers to the process by which B cells with specific receptors are selected and activated in response to antigens. This process leads to the proliferation and differentiation of these selected B cells into plasma cells, which are responsible for producing and secreting antibodies. Therefore, the correct answer is that clonal selection of B cells results in the formation of plasma cells.

Regulatory T cells have been extensively studied and are the most thoroughly understood type of T cells. They play a crucial role in preventing autoimmune reactions, which occur when the immune system mistakenly attacks healthy cells in the body. These cells release cytokines that enhance the activity of cytotoxic T cells and activated B cells, which are important in fighting off infections and eliminating abnormal cells. Additionally, regulatory T cells decrease their activity when the antigenic stimulus decreases, helping to maintain immune homeostasis.

Isografts refer to tissue grafts that are transferred between genetically identical individuals, such as identical twins. This means that the donor and recipient have the same genetic makeup, minimizing the risk of rejection or immune response. This type of graft has a higher chance of success compared to other types of grafts, such as xenografts (between individuals of the same species), autografts (between two genetically identical individuals), and allografts (between different species).

T cells are a type of white blood cell that play a crucial role in the immune response. Interleukins 1 and 2 are signaling molecules that help regulate the proliferation and activation of T cells. These interleukins enhance the proliferation of T cells, allowing them to multiply and increase in numbers. This increased proliferation is important for a robust immune response against pathogens. Therefore, the statement that "Their proliferation is enhanced by interleukins 1 and 2" is true about T cells.

Complement fixation is the main mechanism by which antibodies provide protection. Complement fixation refers to the activation of the complement system, a group of proteins that work together to enhance the immune response. When antibodies bind to antigens on the surface of pathogens, they can activate the complement system, leading to the formation of a membrane attack complex that destroys the pathogens. This mechanism is crucial for eliminating pathogens and providing protection against infections.