A&p II Blood/Lymph & Immune Multiple Choice

Antibodies have the ability to neutralize an antigen, meaning they can render the antigen harmless by binding to it and preventing it from causing harm. They can also agglutinate or precipitate antigens, which involves clumping them together or causing them to form insoluble complexes. Antibodies can activate complement, a series of proteins that promote inflammation and destruction of pathogens. Additionally, antibodies can enhance phagocytosis, the process by which immune cells engulf and destroy pathogens. Therefore, the correct answer is "all of the above" because antibodies can perform all of these functions.

The blood performs several important functions in the body, including transportation of gases, nutrients, and wastes, regulation of body pH, protection against disease, and aid in maintaining fluid homeostasis in cells. However, the secretion of hormones is not a function of the blood. Hormones are typically produced and secreted by endocrine glands, such as the pituitary gland, thyroid gland, and adrenal glands. These hormones are then released into the bloodstream to be transported to target cells or organs where they exert their effects.

Eosinophils are a type of white blood cell that play a role in the immune response against parasites and in allergic reactions. They are responsible for releasing toxic substances that help to kill parasites and regulate inflammation. An increased number of eosinophils can be seen in allergic reactions, parasitic infections, and some autoimmune diseases as they are recruited to the site of inflammation to combat the foreign invaders or to modulate the immune response.

Antigen-presenting cells are responsible for presenting antigens to helper T cells and activating an immune response. Macrophages, B cells, and dendritic cells are all examples of antigen-presenting cells. They can present both antigens and costimulatory signals to helper T cells, which is crucial for the activation and differentiation of T cells. Therefore, the correct answer is "all of the above."

The spleen forms the single largest mass of lymphatic tissue in the body and is comprised of red and white pulp. The red pulp is responsible for filtering and removing old or damaged red blood cells, while the white pulp contains immune cells that help fight infections. The spleen also plays a role in storing and releasing red blood cells and platelets, as well as producing antibodies. Overall, the spleen is an important organ in the immune system and helps maintain overall health and well-being.

MHC proteins, also known as major histocompatibility complex proteins, are glycoproteins that are present on the surface of almost all body cells except for red blood cells. These proteins play a crucial role in the immune system by presenting antigens to T cells, which helps in distinguishing between self and non-self cells. By marking the body's own cells, MHC proteins aid in the recognition and elimination of foreign or infected cells by the immune system.

Biliverdin is a pigment that is derived from heme, a component of hemoglobin. It is released by the liver into bile, which is then excreted into the digestive system. This description accurately matches the molecule biliverdin.

The lymphatic system carries out immune responses by producing and transporting lymphocytes, which are white blood cells that help fight off infections and diseases. It also drains excess interstitial fluid, which is the fluid that surrounds the cells in our body, and helps maintain fluid balance. Additionally, the lymphatic system is responsible for transporting dietary lipids, such as fats and fat-soluble vitamins, from the digestive system to the bloodstream. Therefore, the correct answer is "carry out immune responses AND drain excess interstitial fluid AND transport dietary lipids."

The liver is responsible for synthesizing most of the plasma proteins. This organ plays a vital role in protein metabolism and is capable of producing a wide range of proteins, including albumin, globulins, and clotting factors. The liver's ability to synthesize these proteins is crucial for maintaining the balance of fluids in the body, transporting substances, and supporting the immune system. Other organs mentioned, such as the spleen, bone marrow, kidneys, and white blood cells, are not primarily involved in the synthesis of plasma proteins.

Class II MHC molecules are primarily found on antigen-presenting cells and activated T cells, while Class I MHC molecules are found on nucleated cells in the body. This distribution allows the immune system to recognize pathogens but ignore innocuous substances because most microbes infect body cells other than antigen-presenting cells. Requiring antigen-presenting cells and Class II MHC for presentation ensures that T cells only respond to properly presented exogenous antigens. Therefore, both options A and B are correct.

Macrophages and neutrophils are both actively phagocytic cells. Phagocytosis is the process by which cells engulf and digest foreign particles, such as bacteria and debris. Macrophages are large, specialized cells that are able to engulf and destroy pathogens. Neutrophils, on the other hand, are a type of white blood cell that are typically the first responders to sites of infection or inflammation. They are highly mobile and can quickly migrate to the site of infection, where they engulf and destroy pathogens. Therefore, both macrophages and neutrophils are actively involved in the process of phagocytosis.

The scenario describes a situation where the individual has developed a hepatitis A infection and is being treated with gamma globulin, which contains antibodies to hepatitis A. This treatment is an example of artificially acquired passive immunity because the individual is receiving pre-formed antibodies from an external source (gamma globulin) to fight against the infection. This type of immunity is temporary and does not involve the individual's own immune system producing the antibodies.

The bone marrow is considered a primary lymphoid organ because it is responsible for the production and maturation of lymphocytes, which are a type of white blood cell involved in the immune response. Lymph nodes and the spleen are considered secondary lymphoid organs, as they are involved in the activation and proliferation of lymphocytes, but they do not produce or mature lymphocytes like the bone marrow does.

Polycythemia is a condition characterized by an excessive increase in red blood cell production. In this condition, the body already has an excess of red blood cells, so there is no need for further stimulation of erythropoietin production. Erythropoietin is a hormone that stimulates the production of red blood cells in the bone marrow. Therefore, polycythemia would not cause an increase in erythropoietin levels as the body is already producing an excessive amount of red blood cells.

Swelling is not caused by decreased capillary permeability. Inflammation typically leads to increased capillary permeability, allowing fluid and immune cells to move from the blood vessels into the surrounding tissues, resulting in swelling.

Helper T cells are a type of immune cell that play a crucial role in coordinating the immune response. They recognize antigens displayed on the surface of other cells through their T cell receptors. MHC II proteins are responsible for presenting antigens to helper T cells. When a helper T cell encounters a cell displaying antigens bound to MHC II proteins, it can bind to it and initiate an immune response. Therefore, the presence of MHC II proteins is necessary for helper T cells to interact with other cells and carry out their functions.

The correct answer is "binding of antigen to TCR". This is because the T cell receptor (TCR) is responsible for recognizing specific antigens. When an antigen binds to the TCR, it triggers a signaling cascade that leads to T cell activation. This activation is the first step in the immune response, allowing the T cell to differentiate and carry out its effector functions. The other options mentioned, such as expression of TCR, binding of antigen to self-MHC, costimulation, and interaction with cytokines, are also important for T cell activation but are not the initial signal required.

Titanium is a metal and not a large complex organic molecule. The immune system typically responds to large complex organic molecules, such as proteins, that are associated with foreign substances. Since titanium is not part of any microbes and is not a large complex organic molecule, it is unlikely to trigger an immune response. Therefore, the correct answer is that there would be no immune response to titanium.

CD4 (helper) T cells acquire immunocompetence in the lymph nodes. The lymph nodes are small, bean-shaped organs found throughout the body that play a crucial role in the immune system. They contain specialized immune cells, including CD4 T cells, that help to coordinate immune responses. In the lymph nodes, CD4 T cells undergo a process called positive selection, where they interact with other immune cells and antigens to ensure they can recognize and respond to foreign invaders. This process is essential for the development of a functional immune system.