Lymphatic System (Practice Mode) - Www.Rnpedia.Com

IgE is the most responsible for promoting allergic reactions. IgE antibodies are produced in response to allergens and bind to mast cells and basophils. When the allergen is encountered again, it binds to the IgE antibodies, causing the release of histamine and other inflammatory mediators, leading to the symptoms of an allergic reaction.

The tibial is not considered a central location of lymph nodes. The other options, cervical, axillary, and inguinal, are all well-known central locations where lymph nodes are commonly found. The tibial is a bone located in the lower leg and does not typically have a significant concentration of lymph nodes.

The thymus is a gland that is located in the mediastinum, which is the central region of the chest between the lungs. It is responsible for the development and maturation of T-cells, which are a type of white blood cell that plays a crucial role in the immune system. The other options, peristinum, epistinum, and endostinum, are not anatomical locations and do not relate to the thymus.

Lymphocytes that reach the thymus undergo a process of maturation and differentiation, resulting in the development of T-cells. T-cells play a crucial role in the immune system by recognizing and attacking infected cells or foreign substances. They are responsible for cell-mediated immunity and are involved in various immune responses, including the activation of other immune cells. B-cells, on the other hand, mature in the bone marrow and are responsible for the production of antibodies. Plasma cells are a type of B-cell that secretes antibodies. Beta cells, found in the pancreas, are responsible for producing insulin.

Antinuclear antibodies are autoantibodies that target components of the cell nucleus, including DNA, RNA, and proteins. In systemic lupus erythematosus (SLE), the immune system mistakenly produces these antibodies, leading to inflammation and damage to various organs and tissues. Antinuclear antibodies are a hallmark feature of SLE and are commonly used in diagnostic testing for the disease. They are detected through tests such as the antinuclear antibody (ANA) test, which helps in confirming the diagnosis of systemic lupus.

The thymus is responsible for secreting thymosin from epithelial cells. Thymosin is a hormone that plays a crucial role in the development and maturation of T cells, which are important for the immune system. It helps in the differentiation and proliferation of T cells, as well as their migration to other lymphoid organs. Thymosin also aids in the production of antibodies and the regulation of immune responses.

IgG is the correct answer because it is the only immunoglobulin that binds complement. Complement is a group of proteins that play a role in the immune response by promoting inflammation, attracting immune cells, and destroying pathogens. IgG antibodies can activate the complement system by binding to antigens on pathogens, leading to the recruitment of complement proteins and the formation of a membrane attack complex, which can lyse the pathogen. IgA, IgD, and IgE do not have the ability to bind complement.

The TB skin test is an example of delayed hypersensitivity. This type of immune response occurs when the immune system reacts to an antigen after a delay of several hours or days. In the case of the TB skin test, a small amount of the TB antigen is injected into the skin, and if a person has been exposed to TB in the past, their immune system will mount a delayed hypersensitivity reaction at the injection site. This reaction is measured to determine if a person has been exposed to TB.

Alzheimer's disease is not an autoimmune disease. It is a neurodegenerative disorder characterized by memory loss and cognitive decline. Autoimmune diseases occur when the immune system mistakenly attacks healthy cells and tissues in the body. Graves disease, myasthenia gravis, and insulin-dependent diabetes mellitus are all examples of autoimmune diseases where the immune system targets specific organs or tissues.

Lymphocytes that do not reach the thymus become B-cells. The thymus is an organ in the immune system where T-cells develop and mature. B-cells, on the other hand, mature in the bone marrow. Therefore, lymphocytes that do not reach the thymus undergo maturation in the bone marrow and become B-cells.

The lymphatic pathway is a network of vessels that transport lymph, a clear fluid containing white blood cells, throughout the body. Lymphatic trunks and collecting ducts are directly associated with this pathway as they are major vessels that carry lymph. The subclavian vein is also directly associated as it receives lymph from the lymphatic system and returns it to the bloodstream. However, carotid arteries are not directly associated with the lymphatic pathway. Carotid arteries are major blood vessels that supply oxygenated blood to the head and neck, and they do not carry lymph.

The spleen is not limited in terms of blood supply within the lobules. In fact, the spleen is highly vascularized and contains a large amount of blood. It acts as a blood filter, removing old or damaged red blood cells and storing platelets. The spleen also plays a role in immune response by containing macrophages, which help in the removal of bacteria and other foreign particles from the bloodstream. Additionally, the spleen is similar to a large lymph node in terms of its function in filtering blood and producing lymphocytes. Therefore, the statement "Limited blood within the lobules" is false.

Bruton's agammaglobulinemia is associated with a B cell deficiency. This condition is characterized by the absence or low levels of B cells in the body, leading to a deficiency in antibody production. As a result, individuals with Bruton's agammaglobulinemia are more susceptible to recurrent infections, particularly of the respiratory and gastrointestinal tracts. Other symptoms may include poor growth, chronic diarrhea, and an increased risk of autoimmune disorders. Treatment typically involves regular infusions of immunoglobulins to help replace the missing antibodies.

IgA is the correct answer because it does not cross the barrier between mother and infant in the womb. IgA is primarily found in mucosal secretions and is passed on to the infant through breast milk after birth, providing protection against infections in the gastrointestinal and respiratory tracts. However, it does not pass through the placenta during pregnancy. IgM, IgD, and IgE can all cross the placenta and provide temporary immunity to the infant before their own immune system develops.

CD8 is a key component of cytotoxic T cells. Cytotoxic T cells, also known as CD8+ T cells, are a type of white blood cell that play a crucial role in the immune response against infected or cancerous cells. CD8 acts as a co-receptor on the surface of cytotoxic T cells and helps in the recognition and binding of antigens presented on infected cells. This interaction triggers the activation of cytotoxic T cells, leading to the release of toxic substances that destroy the target cells. CD2, CD4, and CD10 are not directly involved in the function of cytotoxic T cells.

Interleukin-4 is responsible for the growth and maturation of B cells. Cytokines are small proteins that play a crucial role in cell signaling and immune response regulation. Interleukin-4 specifically stimulates the proliferation and differentiation of B cells, leading to their maturation into antibody-producing plasma cells. It also promotes the class-switching of B cells, allowing them to produce different types of antibodies with varying functions. Therefore, Interleukin-4 is the correct answer for this question.

T cells are a type of white blood cell that play a crucial role in the immune response. They are primarily responsible for recognizing and eliminating infected cells and foreign invaders, such as viruses, fungi, and TB bacteria. However, toxins are not living organisms and do not infect cells. Therefore, T cells do not specifically target toxins.

IgD is located on the surface of most B-lymphocytes.

Macrophages are immune cells that play a crucial role in the immune response. They are known to secrete a variety of cytokines, which are small proteins that regulate immune responses. IL-1, also known as interleukin-1, is one of the cytokines secreted by macrophages. It is involved in inflammation and immune responses, helping to activate other immune cells and promoting the production of more cytokines. IL-1 plays a role in both innate and adaptive immunity, making it an important cytokine in the immune system.

T-cell activation requires an accessory cell. Accessory cells, also known as antigen-presenting cells (APCs), play a crucial role in the activation of T-cells. They capture, process, and present antigens to T-cells, which triggers their activation. This interaction between accessory cells and T-cells is essential for the immune response and the proper functioning of the immune system.