1.
Increased vascular permeability in inflammation will allow large protein molecules to leave the vascular space. These include:
Correct Answer
B. Fibrinogen
Explanation
Increased vascular permeability in inflammation allows large protein molecules to leave the vascular space. Fibrinogen is one of these large protein molecules that can exit the blood vessels. Fibrinogen is a soluble protein that plays a crucial role in blood clotting. When there is inflammation, the increased permeability of blood vessels allows fibrinogen to leak out and contribute to the formation of fibrin, which is essential for clot formation and wound healing. Therefore, fibrinogen is a protein that can be found outside the vascular space during inflammation.
2.
Neutrophils leave capillaries in inflammation by the process of:
Correct Answer
A. Diapedesis
Explanation
Neutrophils leave capillaries in inflammation by the process of diapedesis, which refers to the migration of these white blood cells from the blood vessels to the site of inflammation. During diapedesis, neutrophils squeeze through the gaps between endothelial cells lining the capillaries, allowing them to enter the surrounding tissue and initiate an immune response. This process is crucial for the recruitment of neutrophils to the site of infection or tissue damage, where they can effectively combat pathogens and promote tissue repair.
3.
Neutrophil diapedesis is assisted by:
Correct Answer
A. Enlarged endothelial pores
Explanation
Neutrophil diapedesis refers to the process by which neutrophils, a type of white blood cell, squeeze through the walls of blood vessels to reach the site of infection or inflammation. Enlarged endothelial pores facilitate this process by creating larger openings in the endothelial lining of blood vessels, allowing neutrophils to pass through more easily. This is in contrast to the other options, such as digestive enzymes or increased phagocytic ability, which are not directly involved in assisting neutrophil diapedesis.
4.
Inflammatory cell movement into an area of acute inflammation is a passive process.
Correct Answer
B. False
Explanation
Inflammatory cell movement into an area of acute inflammation is an active process. Inflammation is a response to tissue injury or infection, and it involves the recruitment of inflammatory cells to the site of injury or infection. These cells actively migrate towards the site of inflammation in response to chemical signals and cytokines released by the damaged tissues. This movement is not a passive process but rather an active and regulated response by the immune system to combat the underlying cause of inflammation.
5.
Which of the following statements about fibrin is false?
Correct Answer
B. It is one of the constituents of scar tissue
Explanation
Fibrin is not one of the constituents of scar tissue. Scar tissue is primarily composed of collagen, which is a different protein. Fibrin is an insoluble polymer that is formed from fibrinogen through the action of thrombin.
6.
A primary function of neutrophils is:
Correct Answer
A. pHagocytosis of microorganisms
Explanation
Neutrophils are a type of white blood cell that play a crucial role in the immune system's defense against infections. One of their primary functions is phagocytosis, which involves engulfing and destroying microorganisms such as bacteria and fungi. This process helps to eliminate the pathogens and prevent further spread of infection. Neutrophils have specialized receptors that recognize and bind to the microorganisms, allowing them to internalize and kill the pathogens through the release of antimicrobial substances. Therefore, the correct answer is "phagocytosis of microorganisms."
7.
The marked active dilation of vessels in acute inflammation is due to:
Correct Answer
C. Release of chemical mediators by damaged cells
Explanation
The marked active dilation of vessels in acute inflammation is due to the release of chemical mediators by damaged cells. When tissue is damaged, cells release chemical mediators such as histamine, prostaglandins, and leukotrienes. These chemical mediators cause vasodilation, which increases blood flow to the damaged area. This increased blood flow helps to deliver immune cells and nutrients to the site of injury, promoting the inflammatory response and facilitating tissue repair. Reflex neural mechanisms and the effects of kinins can also contribute to vasodilation in acute inflammation, but the primary cause is the release of chemical mediators by damaged cells.
8.
The mononuclear cell type with the greatest role in acute inflammation is the:
Correct Answer
C. MacropHage
Explanation
Macrophages play a crucial role in acute inflammation. They are derived from monocytes and are responsible for engulfing and destroying pathogens, dead cells, and debris. Macrophages also release various inflammatory mediators and cytokines that help recruit other immune cells to the site of inflammation. Their ability to phagocytose and present antigens makes them essential in initiating and coordinating the immune response during acute inflammation. Therefore, macrophages have the greatest role in acute inflammation compared to other mononuclear cell types like monocytes and plasma cells.
9.
The synthesis of arachidonic acid metabolites is increased at inflammatory sites.
Correct Answer
A. True
Explanation
The synthesis of arachidonic acid metabolites refers to the production of various compounds derived from arachidonic acid, such as prostaglandins and leukotrienes. These metabolites play a crucial role in inflammation, as they are involved in the regulation of immune responses and the promotion of inflammation. Therefore, it is true that the synthesis of arachidonic acid metabolites is increased at inflammatory sites.
10.
The process by which inflammatory cells are attracted to an area of injury by directional migration along a chemical concentration gradient is termed:
Correct Answer
C. Chemotaxis
Explanation
Chemotaxis refers to the process in which inflammatory cells are attracted to an area of injury by directional migration along a chemical concentration gradient. In this process, the cells move towards higher concentrations of certain chemicals, such as cytokines or chemokines, which are released at the site of injury. This directional migration allows the inflammatory cells to reach and accumulate at the site of injury, where they can initiate the immune response and aid in tissue repair.
11.
Transudates are basically an ultrafiltrate of plasma.
Correct Answer
A. True
Explanation
Transudates are indeed an ultrafiltrate of plasma. This means that they are formed when fluid from the blood plasma passes through a membrane, such as the capillary walls, due to a pressure gradient. Transudates typically have a low protein content and are usually clear in appearance.
12.
Plasma cells secrete:
Correct Answer
C. Antibody
Explanation
Plasma cells are a type of white blood cell that are responsible for producing and secreting antibodies. Antibodies are proteins that are produced in response to the presence of foreign substances, such as bacteria or viruses, in the body. These antibodies help to neutralize and eliminate these foreign substances, thus playing a crucial role in the immune response. Therefore, the correct answer is antibody.
13.
Vaccination is used to produce immunity against infectious organisms, by inducing:
Correct Answer
C. The primary immune response
Explanation
Vaccination is a method used to stimulate the primary immune response. When a vaccine is administered, it triggers the production of specific antibodies and memory cells in the body. These memory cells remember the infectious organism and allow for a faster and stronger immune response if the person is exposed to the actual pathogen in the future. This is known as the primary immune response, and it is the main mechanism by which vaccination provides immunity against infectious organisms.
14.
The lack of response to our own antigens is termed:
Correct Answer
B. Self tolerance
Explanation
Self tolerance refers to the lack of response by the immune system to its own antigens. This is an important mechanism to prevent the immune system from attacking the body's own cells and tissues. Anergy refers to a state of unresponsiveness or lack of immune response. Immunogenicity refers to the ability of an antigen to induce an immune response.
15.
Sites of lymphocyte priming are the:
Correct Answer
C. Thymus and bone marrow
Explanation
The thymus and bone marrow are the primary sites of lymphocyte priming. Lymphocytes, a type of white blood cell, undergo maturation and differentiation in these organs. The thymus is responsible for the development of T lymphocytes, while the bone marrow is involved in the production of B lymphocytes. These lymphocytes are then released into the bloodstream and travel to peripheral lymph nodes, spleen, and tonsils, where they become fully activated and initiate immune responses against foreign substances.
16.
Amplification or expansion of the immune response is characteristic of:
Correct Answer
C. Both of the above
Explanation
Both the B cell response and the T cell response to antigen involve amplification or expansion of the immune response. B cells produce antibodies that can bind to antigens and neutralize them, while T cells can directly kill infected cells or help in the activation of other immune cells. In both cases, the immune response is enhanced and amplified to effectively eliminate the antigen and protect the body from infection.
17.
Complete the following statement correctly:
Macrophages:
Correct Answer
B. Secrete cytokines which can influence both T and B cell function
Explanation
Macrophages are a type of white blood cell that are found in various tissues throughout the body. They play a crucial role in the immune response by secreting cytokines, which are proteins that can influence the function of both T and B cells. This communication between macrophages and T and B cells is essential for coordinating the immune response and effectively fighting off infections and diseases. Macrophages do not express immunoglobulins on their surfaces, unlike B cells, which are responsible for antibody production.
18.
Lymph nodes which are enlarged because of response to an antigenic stimulus are termed:
Correct Answer
A. Reactive
Explanation
Enlarged lymph nodes that are a result of the body's response to an antigenic stimulus are referred to as "reactive." This term indicates that the lymph nodes are reacting to the presence of an antigen, such as an infection or inflammation, and are undergoing changes in size and activity as a result. The term "reactive" distinguishes these lymph nodes from other types of enlargement, such as those caused by edema or hypertrophy.
19.
The profound immunosuppression associated with AIDS is primarily associated with defective:
Correct Answer
B. Cell-mediated immunity
Explanation
The profound immunosuppression associated with AIDS is primarily associated with defective cell-mediated immunity. This means that the immune system is unable to mount an effective response against intracellular pathogens, such as viruses, leading to a weakened immune system. This is a hallmark of AIDS and is one of the reasons why individuals with AIDS are more susceptible to opportunistic infections and certain types of cancers.
20.
The term serology refers to the study of:
Correct Answer
C. Antigen-antibody reactions in a laboratory setting
Explanation
Serology is the study of antigen-antibody reactions in a laboratory setting. This field of study involves the detection and measurement of antibodies in serum, which is the clear liquid portion of blood after the cells have been removed. By studying these reactions, scientists can determine if a person has been exposed to a particular infectious disease and if they have developed immunity to it. Serology plays a crucial role in diagnosing and monitoring infectious diseases, as well as in the development and evaluation of vaccines.
21.
Molecules which evoke an immune response when introduced into a host are termed:
Correct Answer
A. Antigens
Explanation
Molecules that elicit an immune response when introduced into a host are called antigens. Antigens can be proteins, carbohydrates, or other substances that are recognized by the immune system as foreign. Upon recognition, the immune system produces antibodies or activates immune cells to eliminate the antigen. Haptens, on the other hand, are small molecules that can bind to larger proteins but do not typically elicit an immune response on their own. Pathogens are disease-causing microorganisms that can contain antigens and trigger an immune response.
22.
In Type II (antibody-dependent) hypersensitivity, antibody is:
Correct Answer
B. Directed against specific antigens on cell surfaces
Explanation
In Type II (antibody-dependent) hypersensitivity, the antibody is directed against specific antigens on cell surfaces. This means that the antibody specifically targets and binds to antigens present on the surfaces of cells. This binding triggers an immune response, leading to the destruction of the cells by various mechanisms such as complement activation or antibody-dependent cell-mediated cytotoxicity. This type of hypersensitivity reaction is commonly seen in autoimmune diseases and certain drug reactions.
23.
Theories on the development of auto-immunity describe:
Correct Answer
C. Reaction against slightly altered tissue components
Explanation
The correct answer is reaction against slightly altered tissue components. Theories on the development of auto-immunity suggest that the immune system can mistakenly identify slightly altered tissue components as foreign and mount an immune response against them. This can lead to the destruction of healthy tissues and the development of autoimmune diseases. Excessive lymphocyte clonal deletion during embryonic development and excessive suppressor T-cell activity are not described as theories on the development of auto-immunity.
24.
A primary characteristic of the immune response is its:
Correct Answer
B. Specificity
Explanation
The primary characteristic of the immune response is its specificity. This means that the immune system is able to recognize and target specific pathogens or foreign substances, while leaving the body's own cells unharmed. This specificity is achieved through the presence of specialized cells and molecules that can identify and bind to specific antigens. By being specific, the immune response can effectively eliminate the particular pathogens or foreign substances that have invaded the body, thus protecting against infectious diseases.
25.
Macrophages and monocytes act as important reservoirs and producers of HIV.
Correct Answer
A. True
Explanation
Macrophages and monocytes are immune cells that play a crucial role in the HIV infection. They act as reservoirs, meaning that they can harbor the virus for extended periods of time without being eliminated by the immune system. Additionally, these cells can also produce new copies of the virus, contributing to its replication and spread throughout the body. Therefore, it is true that macrophages and monocytes act as important reservoirs and producers of HIV.
26.
In the secondary immune response:
Correct Answer
A. Specific antibody production occurs more rapidly
Explanation
In the secondary immune response, specific antibody production occurs more rapidly compared to the primary immune response. This is because during the secondary response, memory B cells are already present and can quickly recognize the antigen, leading to a faster production of specific antibodies. This rapid response helps to eliminate the pathogen more efficiently and effectively.
27.
The systemic reactions of anaphylaxis are caused by:
Correct Answer
A. Mast cell degranulation and mediator release
Explanation
Anaphylaxis is a severe allergic reaction that can cause systemic reactions throughout the body. Mast cells, which are immune cells, play a crucial role in anaphylaxis. When an allergen triggers an allergic reaction, mast cells release mediators such as histamine, prostaglandins, and leukotrienes. These mediators cause various symptoms of anaphylaxis, including smooth muscle contraction, vasoconstriction, and inflammation. Therefore, mast cell degranulation and mediator release are responsible for the systemic reactions observed in anaphylaxis.
28.
The similarity between donor and recipient with regard to histocompatibility antigens is a major determinant of the success of tissue and organ transplants.
Correct Answer
A. True
Explanation
The success of tissue and organ transplants is greatly influenced by the similarity between the donor and recipient in terms of histocompatibility antigens. These antigens play a crucial role in determining whether the recipient's immune system will accept or reject the transplanted tissue or organ. If the histocompatibility antigens of the donor closely match those of the recipient, the chances of a successful transplant increase significantly. Therefore, it can be concluded that the statement "The similarity between donor and recipient with regard to histocompatibility antigens is a major determinant of the success of tissue and organ transplants" is true.
29.
Immune complex formation may cause:
Correct Answer
C. Complement activation
Explanation
Immune complex formation can lead to complement activation. Immune complexes are formed when antibodies bind to antigens, and these complexes can activate the complement system. The complement system is a group of proteins that work together to enhance the immune response. Activation of the complement system can lead to inflammation, cell lysis, and recruitment of immune cells to the site of immune complex formation. Therefore, complement activation is a possible consequence of immune complex formation.
30.
In acute inflammation, leucocytes tend to 'stick' more to endothelial cells of the microvasculature.
Correct Answer
A. True
Explanation
In acute inflammation, leucocytes tend to 'stick' more to endothelial cells of the microvasculature. This is because during inflammation, the endothelial cells of the blood vessels become activated and express adhesion molecules on their surface. These adhesion molecules allow the leucocytes to adhere to the endothelial cells and subsequently migrate out of the blood vessels and into the inflamed tissue. This sticking of leucocytes to endothelial cells is an important step in the inflammatory response, as it allows for the recruitment of immune cells to the site of inflammation to help fight off any pathogens or repair any damaged tissue.
31.
Septicemia refers to:
Correct Answer
B. Spread of bacteria and their toxins via the bloodstream
Explanation
Septicemia refers to the spread of bacteria and their toxins via the bloodstream. This condition occurs when bacteria enter the bloodstream and cause an infection throughout the body. The bacteria and their toxins can travel to various organs and tissues, leading to severe illness and potentially life-threatening complications. Prompt diagnosis and treatment are crucial to prevent further spread of the infection and to manage the associated symptoms.
32.
The inflammatory mediators having the greatest role in the early phase of the acute inflammatory response are:
Correct Answer
B. Vasoactive amines (histamine and serotonin)
Explanation
During the early phase of the acute inflammatory response, vasoactive amines such as histamine and serotonin play a significant role. These mediators are released by mast cells and platelets, causing vasodilation and increased vascular permeability. This results in the characteristic signs of inflammation, including redness, swelling, and heat. Histamine and serotonin also attract immune cells to the site of inflammation and promote the release of other inflammatory mediators, amplifying the inflammatory response. Arachidonic acid metabolites and cytokines also contribute to inflammation, but they have a lesser role compared to vasoactive amines in the early phase.
33.
Many of the chemical mediators of inflammation also act as chemotactic signals to inflammatory cells.
Correct Answer
A. True
Explanation
Chemical mediators of inflammation are substances released by cells during an inflammatory response. These mediators not only initiate and regulate the inflammatory process but also attract inflammatory cells to the site of inflammation. This chemotactic effect helps recruit immune cells such as neutrophils and macrophages to the site of injury or infection, enhancing the immune response. Therefore, it is true that many chemical mediators of inflammation also act as chemotactic signals to inflammatory cells.
34.
Leucocytes have specific receptors for opsonins (such as antibody, complement factors, and collectins), which causes phagocytosis to be
Correct Answer
A. Enhanced
Explanation
Leucocytes have specific receptors for opsonins, such as antibodies, complement factors, and collectins. These opsonins bind to pathogens and mark them for phagocytosis by the leucocytes. This enhances the process of phagocytosis, making it more efficient and effective in eliminating the pathogens. Therefore, the correct answer is "enhanced".
35.
The process by which certain inflammatory cells ingest and destroy particulate matter is termed:
Correct Answer
B. pHagocytosis
Explanation
Phagocytosis is the process by which certain inflammatory cells ingest and destroy particulate matter. During phagocytosis, the cells surround and engulf the foreign particles, forming a vesicle called a phagosome. The phagosome then fuses with lysosomes, which contain enzymes that break down the ingested material. This process is important for the immune system to eliminate pathogens and other harmful substances from the body. Opsonization, on the other hand, refers to the coating of particles with molecules that enhance their recognition and uptake by phagocytic cells. Exocytosis is the reverse process, where vesicles release their contents outside the cell.
36.
The increased blood flow into inflamed tissues is termed:
Correct Answer
A. Hyperemia
Explanation
Hyperemia refers to the increased blood flow into inflamed tissues. Inflammation is a response to tissue injury or infection, and it is characterized by redness, swelling, heat, and pain. Increased blood flow to the affected area brings in more immune cells and nutrients, helping to facilitate the healing process. This increased blood flow also contributes to the redness and warmth associated with inflammation. Therefore, hyperemia is the correct term to describe the increased blood flow into inflamed tissues.
37.
During the lag period of the primary immune response, B cells with receptors for the specific antigen:
Correct Answer
B. Undergo clonal expansion to produce a large number of plasma cells
Explanation
During the lag period of the primary immune response, B cells with receptors for the specific antigen undergo clonal expansion to produce a large number of plasma cells. This is because clonal expansion allows for the proliferation of B cells that recognize the specific antigen, leading to the generation of a large population of plasma cells. These plasma cells then begin secreting antibodies that are specific to the antigen, helping to eliminate the pathogen or foreign substance.
38.
Major sites of HIV infection and persistence are:
Correct Answer
C. CD4+ cells, macropHages and dendritic cells in lympH nodes
Explanation
HIV primarily infects and persists in CD4+ cells, macrophages, and dendritic cells in lymph nodes. CD4+ cells are a type of T cell that play a crucial role in the immune response. Macrophages are a type of white blood cell that engulfs and destroys pathogens, while dendritic cells are antigen-presenting cells that activate the immune response. Lymph nodes are important sites for immune cell activation and interaction. Therefore, HIV infection and persistence in these cells and tissues contribute to the progression of the disease.
39.
The specificity of T cells is determined by:
Correct Answer
B. The T cell receptor
Explanation
The specificity of T cells is determined by the T cell receptor. The T cell receptor is a protein located on the surface of T cells that recognizes and binds to specific antigens. This receptor allows T cells to distinguish between different types of antigens and initiate an immune response against them. Antibodies on the T cell surface and macrophage presentation of the antigen are not responsible for determining the specificity of T cells.
40.
Specificity and memory are characteristics of the:
Correct Answer
B. Immune response
Explanation
The immune response is characterized by specificity and memory. Specificity means that the immune system can recognize and target specific pathogens or foreign substances. Memory refers to the ability of the immune system to remember previous encounters with pathogens, allowing for a faster and more efficient response upon subsequent exposure. These characteristics are not typically associated with the inflammatory response or innate defense mechanisms.
41.
Plasma cells are derived from:
Correct Answer
B. B Cells
Explanation
Plasma cells are derived from B cells. B cells are a type of white blood cell that play a crucial role in the immune response. When B cells encounter an antigen, they differentiate into plasma cells, which are responsible for producing and secreting large amounts of antibodies. These antibodies help to neutralize or eliminate the antigen, thereby protecting the body against infections. Therefore, B cells are the correct answer as they give rise to plasma cells.
42.
When antigens react with their specific antibodies, they form:
Correct Answer
C. Immune complexes
Explanation
When antigens react with their specific antibodies, they form immune complexes. Immune complexes are formed when antibodies bind to antigens, creating a complex that can be recognized and eliminated by the immune system. These complexes play a crucial role in immune responses, as they help to neutralize pathogens and facilitate their removal from the body.
43.
Complete the following statement correctly: Immune suppression can:
Correct Answer
B. Result from therapy with corticosteroids
Explanation
Immune suppression can result from therapy with corticosteroids. Corticosteroids are medications that are commonly used to treat inflammation and suppress the immune system. They work by reducing the activity of immune cells, such as T cells and B cells, which can lead to a decrease in the body's ability to fight off infections and other diseases. Therefore, therapy with corticosteroids can result in immune suppression. This can make individuals more susceptible to infections and increase the risk of complications.
44.
Cells which play a key role in the early stages of the immune response are the:
Correct Answer
A. MacropHages
Explanation
Macrophages are a type of white blood cell that are responsible for engulfing and destroying foreign substances, such as bacteria and viruses, in the body. They play a crucial role in the early stages of the immune response by recognizing and phagocytosing pathogens. Macrophages also help to activate other immune cells, such as T cells, and release signaling molecules that coordinate the immune response. Therefore, macrophages are essential in initiating and coordinating the immune response during the early stages of an infection.
45.
The end result of immune-complex mediated hypersensitivity is:
Correct Answer
A. Fibrinoid necrosis of small vessels (necrotizing vasculitis)
Explanation
The end result of immune-complex mediated hypersensitivity is fibrinoid necrosis of small vessels (necrotizing vasculitis). This occurs due to the deposition of immune complexes in the vessel walls, leading to complement activation and subsequent inflammation. The inflammation causes damage to the vessel walls, resulting in necrosis and fibrinoid deposits. This can lead to impaired blood flow and tissue damage in the affected organs.
46.
A classic example of delayed type hypersensitivity is:
Correct Answer
B. The tuberculin reaction
Explanation
The tuberculin reaction is a classic example of delayed type hypersensitivity. Delayed type hypersensitivity is an immune response that occurs several hours to days after exposure to an antigen. In the tuberculin reaction, a small amount of purified protein derivative (PPD) from Mycobacterium tuberculosis is injected into the skin. If the person has been previously exposed to the bacteria, they will have memory T cells that recognize the PPD antigen. This leads to the recruitment of immune cells to the site of injection, resulting in inflammation and the formation of a raised, red bump.
47.
The type of inflammatory cell with the greatest role in inflammation is the:
Correct Answer
A. NeutropHil
Explanation
Neutrophils are the most abundant type of white blood cells and play a crucial role in the inflammatory response. They are the first cells to arrive at the site of infection or tissue damage and release various substances, such as enzymes and reactive oxygen species, to destroy pathogens and damaged cells. Neutrophils also help recruit other immune cells to the site of inflammation and promote tissue repair. Therefore, they have the greatest role in inflammation compared to lymphocytes and macrophages.
48.
Relative to transudates, exudates are characterized by:
Correct Answer
C. Greater numbers of cells
Explanation
Exudates are characterized by greater numbers of cells compared to transudates. This means that exudates have a higher concentration of cells, which can include inflammatory cells such as neutrophils, lymphocytes, and macrophages. In contrast, transudates have a lower cell count. This difference in cellular composition helps to distinguish between the two types of fluids.
49.
Exudation refers to
Correct Answer
B. increased movement of fluid and proteins out of vessels due to increased permeability
Explanation
Exudation refers to the increased movement of fluid and proteins out of vessels due to increased permeability. This process occurs when there is inflammation or injury to the blood vessels, causing them to become more permeable. As a result, fluid and proteins leak out of the vessels and into the surrounding tissues, leading to swelling and the formation of exudate. Exudation is an important part of the immune response and helps to deliver immune cells and substances to the site of injury or infection.
50.
Neutrophils contain:
Correct Answer
C. Enzymes which can degrade biologic material
Explanation
Neutrophils are a type of white blood cell that play a key role in the immune response. They contain enzymes, such as proteases and lysozymes, which are capable of breaking down and degrading biologic materials, including bacteria, viruses, and other foreign substances. These enzymes help neutrophils to destroy and eliminate pathogens and other harmful substances from the body. Therefore, the correct answer is that neutrophils contain enzymes which can degrade biologic material.