Patho Quiz Chapter 3

HIV is primarily transmitted through direct contact with certain body fluids, including blood, semen, and vaginal secretions, that come from an infected person. These fluids must enter the bloodstream of another person for transmission to occur. Kissing or coughing into another person's face, using toilet seats with infected secretions, or coming into contact with any contaminated surface or skin are not common modes of HIV transmission.

An autoimmune disease refers to a condition where the immune system mistakenly attacks and damages the body's own tissues and cells, as it fails to differentiate between self and nonself. This can lead to chronic inflammation and damage to various organs and systems in the body.

Anaphylaxis is considered a critical situation because bronchoconstriction and systematic vasodilation develop rapidly. These physiological responses can lead to severe respiratory distress and a drop in blood pressure, potentially causing organ damage or even death if not promptly treated. Additionally, the manifestations of anaphylaxis may not be obvious in the initial stages, making it crucial to recognize and treat the condition quickly to prevent further complications.

Anaphylaxis is a severe systemic allergic reaction that occurs when the immune system overreacts to an allergen. It is characterized by a rapid onset and can lead to life-threatening symptoms such as difficulty breathing, low blood pressure, and swelling of the throat. This reaction is triggered by the release of histamine and other chemicals in the body, causing widespread inflammation and affecting multiple organ systems. Immediate medical intervention, such as the administration of epinephrine, is crucial to treat anaphylaxis and prevent further complications.

The target cells for HIV are T helper lymphocytes because these cells express a receptor called CD4, which is necessary for the virus to enter and infect the cell. HIV primarily targets and destroys T helper lymphocytes, leading to a weakened immune system and the development of AIDS. B lymphocytes, natural killer cells, and macrophages can also be infected by HIV, but T helper lymphocytes are the main target.

Memory cells play a crucial role in supporting the immune response by recognizing certain antigens. These cells are formed after the initial exposure to an antigen and are responsible for "remembering" the specific antigen. When the body is exposed to the same antigen again, memory cells quickly recognize it and initiate a faster and more efficient immune response. By recognizing and responding to specific antigens, memory cells help in providing long-term immunity against pathogens.

HIV infection impairs both humoral and cell-mediated immunity. HIV primarily targets and destroys CD4+ T cells, which play a crucial role in coordinating both humoral and cell-mediated immune responses. With a decline in CD4+ T cell count, the body's ability to produce antibodies (humoral immunity) and activate cytotoxic T cells (cell-mediated immunity) is compromised. This impairment weakens the immune system, making individuals more susceptible to opportunistic infections and cancers.

Neutrophils are primarily phagocytic, meaning they have the ability to engulf and destroy foreign particles, such as bacteria and other pathogens. This function is essential for an effective immune response, as neutrophils play a crucial role in the body's defense against infections. Additionally, neutrophils are known to be the last cells to arrive in an inflamed area, indicating their importance in the later stages of the immune response. However, there is no mention of neutrophils being elevated during an allergic reaction in the given information.

A vaccination provides active artificial immunity. This means that the immune system is stimulated to produce its own antibodies in response to a weakened or inactive form of the pathogen present in the vaccine. This type of immunity is long-lasting and provides protection against future infections by the same pathogen.

Incompatible blood transfusions occur when the blood types of the donor and recipient do not match. This can lead to the destruction of red blood cells, known as hemolysis. When incompatible blood is transfused, the recipient's immune system recognizes the foreign blood cells as a threat and attacks them, causing the red blood cells to rupture and release their contents into the bloodstream. This can result in various complications, including organ damage and potentially life-threatening reactions. Therefore, the correct answer is "hemolysis of erythrocytes."

Type I hypersensitivity, also known as immediate hypersensitivity or allergic reaction, occurs when an allergen binds with IgE antibodies on mast cells. This binding triggers the release of chemical mediators, such as histamine, which cause an inflammatory response. This type of hypersensitivity is characterized by rapid onset and can result in symptoms ranging from mild itching and swelling to severe anaphylaxis.

Humoral immunity is mediated by B lymphocytes. B lymphocytes, also known as B cells, are a type of white blood cell that plays a crucial role in the immune response. When a B cell encounters an antigen, it produces antibodies that can specifically bind to that antigen. These antibodies then circulate in the blood and other body fluids, neutralizing pathogens and marking them for destruction by other immune cells. This process is known as humoral immunity and is essential for defending against bacterial and viral infections. Natural killer cells, T lymphocytes, and neutrophils are involved in other aspects of the immune response but not specifically in humoral immunity.

When a patient is HIV positive, the presence of antibodies in their blood indicates the presence of the virus. These antibodies are produced by the immune system in response to the HIV infection. Therefore, the presence of antibodies in the blood indicates that the virus is present in the body and there is a possibility of transmission to others. It is important for HIV-positive individuals to take appropriate precautions to prevent transmission to others.

Patients with AIDS have a weakened immune system, making them more susceptible to serious infections. Tuberculosis is a common infection in AIDS patients, as the bacteria can easily spread in individuals with compromised immune systems. Pneumocystis carinii pneumonia is also frequently seen in AIDS patients, as this fungal infection can cause severe respiratory symptoms. Influenza, although not specific to AIDS patients, can also cause serious complications in individuals with weakened immune systems. Tetanus, on the other hand, is not typically associated with AIDS or immune system compromise.

The distinguishing clinical feature of systemic lupus erythematosus is inflammation in multiple organs. This means that the disease can affect various parts of the body, including the joints, skin, kidneys, heart, lungs, and brain. Unlike some other diseases, there is no specific diagnostic blood test for lupus, making it challenging to diagnose. Additionally, lupus is characterized by a chronic and relapsing course, rather than an acute onset nonprogressive course. While a typical skin rash on the chest and back can be a symptom of lupus, it is not the defining feature that sets it apart from other diseases.

Macrophages are required to process and present antigens from foreign material as the initial step in the immune response. They are specialized immune cells that engulf and digest pathogens, such as bacteria or viruses, and then present small pieces of these pathogens, called antigens, on their cell surface. This presentation of antigens is crucial for activating other immune cells, such as T helper cells, which play a central role in coordinating the immune response. Therefore, macrophages are essential for initiating and regulating the immune response against foreign invaders.

A diagnosis of HIV positive means that the virus and its antibodies are present in the blood. This indicates that the individual has been infected with the human immunodeficiency virus (HIV), which attacks and weakens the immune system. The presence of the virus and its antibodies in the blood can be detected through various diagnostic tests, confirming the HIV infection. It does not necessarily mean that the individual has progressed to AIDS or that they have opportunistic infections, but it does indicate the presence of the virus in their body.

Contact dermatitis is a type of skin inflammation that occurs when the skin comes into direct contact with a substance that causes an allergic reaction. This allergic reaction is known as a type IV reaction, which involves the activation of T-cells in the immune system. Unlike IgE antibodies, which are involved in allergic reactions such as hives, contact dermatitis is not caused by the ingestion of foods. Instead, it specifically occurs in the area of direct contact with the causative substance.

CD4-positive helper T cells play a crucial role in the immune system by coordinating and regulating various immune responses. They help activate other immune cells, such as B cells and cytotoxic T cells, to mount an effective immune response against pathogens. Additionally, they assist in the production of antibodies by B cells, which are essential for targeting and neutralizing foreign invaders. Therefore, CD4-positive helper T cells facilitate all immune system activity by orchestrating and enhancing the overall immune response.

Polyarthritis is not commonly seen in AIDS patients. AIDS is caused by the human immunodeficiency virus (HIV) which primarily affects the immune system. Common conditions in AIDS patients include Kaposi sarcoma, a type of cancer that causes lesions on the skin and organs; wasting syndrome, which involves severe weight loss and muscle wasting; and lymphoma, a cancer that affects the lymphatic system. However, polyarthritis, which refers to inflammation in multiple joints, is not typically associated with AIDS.

Cytokines are signaling molecules that play a crucial role in the immune response. They are responsible for activating and stimulating the proliferation of B and T lymphocytes, which are important components of the immune system. By doing so, cytokines help to enhance the immune response and promote the production of antibodies and the killing of infected cells. This is important in fighting off infections and maintaining overall immune function.

Systematic lupus erythematosus is caused by the immune complex deposits of antinuclear antibodies. These antibodies mistakenly target the body's own cells and tissues, leading to inflammation and damage. The immune complexes formed by the antibodies deposit in various organs, causing a wide range of symptoms and complications associated with lupus. This autoimmune disease is not caused by a chronic allergic condition, development of an immune deficient state, or a deficiency of lymphocytes.

Host versus graft disease refers to transplant rejection by the recipient's immune system. This occurs when the recipient's immune system recognizes the transplanted tissue as foreign and mounts an immune response against it. The immune system attacks and destroys the transplanted tissue, leading to organ dysfunction or failure. This can happen immediately following the transplant or even years later. It is a major concern in transplantation and requires immunosuppressive therapy to prevent or manage it.

If a patient experienced an episode of influenza 6 months ago and is now exposed to a mutated form of the same virus, it would result in a primary immune response. This is because a primary immune response occurs when the immune system encounters a pathogen for the first time. It takes time for the immune system to recognize and respond to the specific antigens of the mutated virus, leading to the activation of immune cells and the production of antibodies. A secondary immune response, on the other hand, occurs when the immune system encounters a pathogen it has previously encountered, resulting in a faster and stronger immune response. Passive natural immunity and avoidance of any flu infection are not applicable in this scenario.

Seroconversion refers to the process in which antibodies specific to HIV are detected in the blood. This indicates that the individual has been exposed to the virus and their immune system has started producing antibodies against it. Seroconversion typically occurs a few weeks to a few months after HIV infection. It is an important milestone in HIV diagnosis as it confirms the presence of the virus in the body.

HIV-1 is a single-stranded RNA virus, so it does not contain 2 strands of DNA. However, it does tend to mutate frequently to form new strains, which is why it is difficult to develop a vaccine or cure for HIV. Additionally, HIV-1 is not inactivated by heat and many disinfectants, as it can survive outside the body for a short period of time. Therefore, the correct answer is 2 4.

HIV antibodies can be detected in the blood within 2 days of entry or exposure. Antibodies are produced by the immune system in response to the presence of a foreign substance, such as the HIV virus. Therefore, the presence of HIV antibodies in the blood indicates exposure to the virus. It is important to note that HIV antibodies may take some time to develop after infection, so a negative result within 2 days does not necessarily rule out HIV infection.

MHC proteins or molecules do not specifically alert the immune system to virus-infected cells. While MHC proteins do play a crucial role in the immune response by presenting antigens to T cells, their main function is to differentiate self from non-self and to facilitate successful tissue transplants. However, alerting the immune system to virus-infected cells is primarily carried out by other components of the immune system, such as pattern recognition receptors and interferons.