Immune System

What is the primary function of Bone Marrow in the immune system?

All leukocyte production.

What organ is responsible for blood storage and B Cell activation?

Spleen.

What’s difference innate immunity?

defenses that are always active but non-specific (cellular and non cellular)

What is adaptive immunity?

defenses that are specific and take longer to activate (humoral and cell mediated)

What is humoral immunity?

B cells producing antibodies to target specific pathogens (adaptive)

What is cell mediated adaptive immunity?

T cells

Vaccines trigger what type of immunity

Active immunity

Where does T cell maturation occur?

Thymus.

What is the main role of Lymph Nodes in the immune system?

Immune communication and B cell activation.

What type of lymphoid tissue is found in the gut?

Gut-associated lymphoid tissue (GALT).

What are defensins?

Antibacterial enzymes found in the skin.

What do interferons produced by virally infected cells do?

Decrease cell/viral protein production of nearby cells and increase MHC Class 1 presentation.

What are the two types of MHC Class Presentation?

MHC Class 1 (endogenous pathway) and MHC Class 2 (exogenous pathway).

MHC 1 class molecules are present on what type of cells?

All nucleated cells

MHC Class 2 molecules display their antigens to what cell?

CD4+ T helper cells

What are interferons?

given off by virally infected cells and interfere with viral replication/dispersion

What is the role of macrophages in the immune response?

Phagocytize pathogens, present antigens on MHC molecules, and release cytokines for recruitment and inflammation.

What is the function of Natural Killer Cells?

Recognize downregulation of MHC class molecules and induce apoptosis of infected cells. (ALSO DIRECTLY KILLS CANCER CELLS)

What is clonal selection in B cells?

The process that allows only B cells with the highest affinity for an antigen to proliferate.

Where are B cells made?

bone marrow

What are the two types of active immunity?

Natural and artificial.

What role do lymph nodes play in the lymphatic system?

Contain germinal centers for B cell proliferation and maturation, and help in pathogen exposure.

What are eosinophils primarily involved in?

Allergic and parasitic reactions.

What are basophils involved in?

allergic reactions

Macrophages have what type of MHC Class?

MHC Class II

What type of cells release histamine during allergic reactions?

Basophils , eosinophils and mast cells.

What is passive immunity?

Acquiring antibodies from another individual.

What does isotype switching allow B cells to do?

Change the type of antibody they produce in response to specific cytokines.

What is the complement system?

A group of proteins that enhances the ability of antibodies and phagocytic cells to clear pathogens from an organism.

What are the main outcomes of the complement system activation?

Opsonization of pathogens, formation of the membrane attack complex (MAC), and inflammation.

What is opsonization in the context of the complement system?

The process by which complement proteins coat pathogens to enhance their recognition and uptake by phagocytes.

What is the membrane attack complex (MAC)?

A structure formed by the complement proteins that creates pores in the membrane of pathogens, leading to cell lysis.

How does the complement system contribute to inflammation?

Through the recruitment of immune cells and the release of chemical mediators that increase vascular permeability.

What is agglutination?

Pathogens clumped together by antibodies for phagocytosis

What is the function of IgG antibodies?

most abundant type in blood and extracellular fluid (made by plasma cells), providing the majority of antibody-based immunity against invading pathogens.

What is the function of IgA antibodies?

protecting mucous membranes lining the respiratory and gastrointestinal tracts.

What is the function of IgM antibodies?

first antibodies produced in response to an infection and are effective in forming complexes with pathogens for their removal.

What is the function of IgE antibodies?

allergic reactions and defend against parasitic infections.

What is the function of IgD antibodies?

activation and regulation of B cells.

What is the main difference between CD4 and CD8 T cells in terms of function?

CD4 T cells (Helper T cells) assist in activating B cells and other immune cells, while CD8 T cells (Cytotoxic T cells) are primarily responsible for killing infected or cancerous cells.

How do CD4 T cells contribute to the immune response?

CD4 T cells help orchestrate the immune response by secreting cytokines and enhancing the action of other immune cells.

What is the primary target of CD8 T cells?

CD8 T cells primarily target and kill virus-infected cells and tumor cells.

What is positive selection in T cell maturation?

Positive selection occurs in the thymus, where T cells that can adequately respond to MHC molecules are allowed to mature.

What is negative selection in T cell maturation?

Negative selection eliminates T cells that strongly react to self-antigens, preventing autoimmune responses.

Which cell adhesion molecules aids neutrophils in tethering to epithelial surfaces during inflammatory response?

selectins