Microbiology Exam 4 (chapters 17-20)

How is the immune system able to recognize a limitless number of different antigens and epitopes?

While each lymphocyte carries receptors that recognize only one type of epitope, the immune system produces a wide variety of lymphocytes each of which carries unique receptors

Which tissues are the primary lymphoid tissues?

bone marrow and thalamus

Mast cells and basophils release which chemical moderator?

histamine

Which part of the brain controls body temperature?

hypothalamus

What are pathogen associated molecular patterns (PAMPs)? Think of some examples.

molecules commonly associated with microbes but not with human cells (peptidoglycan, dsRNA, LPS, β-glucan, profilin, etc.)

Which cell type is the most numerous white blood cell in circulation, is the first leukocyte recruited from the bloodstream to injured tissues, and releases potent antimicrobial peptides?

neutrophils

Toll-like receptors are examples of what?

Pattern recognition receptors (PRRs)

What portion of an antibody binds the epitope and be able to recognize it on a diagram.

paratope

What are antimicrobial peptides?

Proteins that destroy a wide spectrum of viruses, parasites, bacteria, and fungi

What are the main goals of inflammation?

Prevent initial establishment of infection or remove damaged tissue. Prevent the spread of infection or repair damaged tissue. Recruit effector cells if the immune cells of the innate immune system cannot control infection or repair damaged tissue

What are mechanical barriers?

rinse, flush, or trap pathogens to limit their spread into the body

What are the functions of antibodies?

- neutralization: antibodies prevent bacterial adhesion - opsonization: antibodies promote phagocytosis - complement activation: antibodies activate complement, which enhances opsonization, which results in lysis

What are the components of antibody molecules?

-2 heavy chains -2 light chains -Held together by covalent bonds

What are the branches of the adaptive immune response?

-Cellular response (T cell-mediated immunity) -Humoral response (antibody-mediated immunity) (B-cells)

What is chronic inflammation?

-May develop when an inflammatory response goes on too long or does not resolve -Not useful or protective -Exacerbates tissue injury -Promotes atherosclerosis, certain cancers, and progressive neurodegenerative disorders

What are the classes of PRRs?

-Toll like receptors (TLRs) -C-type lectin receptors (CLRs) -Retinoic acid-inducible gene (RIG) -I-like receptors (RLRs) NOD-like receptors (NLRs)

What is the term for the differentiation of stem cells into various blood cells?

Hematopoiesis

What is the function of secondary lymphoid tissues and where are they found?

Lymph Nodes: Serve as filtering and screening centers for lymph before returning it to the bloodstream Spleen: Filters blood rather than lymph Mucosa-associated lymphoid tissue (MALT): Diffuse system of lymphoid tissue

Which cell type is the largest agranular white blood cell? These cells mature as they leave the circulatory system into macrophages and dendritic cells and increase cell levels due to chronic infections and inflammation, autoimmune disorders, and certain cancers.

Monocytes

Which cell type is a subgroup of lymphocytes, abundant in the liver, has important roles in innate immune protection against microbes and even tumor cells, and releases perforin and granzymes?

Natural Killer (NK) cells

What is a cytokine?

Signaling proteins that allow cells to communicate with each other, initiating and coordinating immune actions

What is the difference between a granulocyte and an agranulocyte?

The granulocytes are present within the cytoplasm in the form of granules while agranulocytes exist without the granules

How is adaptive immunity different from innate immunity?

The innate immune response is activated by chemical properties of the antigen. Adaptive immunity refers to antigen-specific immune response. The adaptive immune response is more complex than the innate. The antigen first must be processed and recognized

What is pus?

accumulation of dead pathogens, neutrophils, tissue fluid, and other bystander cells that may have been killed by phagocytes at the site of an infection

What are the results of PRR activation?

activation of gene expression and synthesis of a broad range of molecules, including cytokines, chemokines, cell adhesion molecules, and immunoreceptors

What is a substance that may trigger an immune response, if presented in the right context?

antigen

Defensins target which process or structure of a microbial cell?

cell membrane

Which cytokine recruits leukocytes to sites of infections?

chemokine

What inflammatory response is triggered by a pyrogen?

febrile response (fever)

What is the best term to describe the process that occurs when an immune cell releases cytokines to nearby cells to trigger a response?

inflammation

Where are acute phase proteins produced?

liver

Which leukocytes are agranulocytes?

lymphocytes and monocytes

What are chemical barriers?

may directly attack invaders or establish environments that limit pathogen survival in or on a particular tissue

What are the cardinal signs of localized inflammation?

pain, heat, redness, swelling, loss of function

What are the results of complement activation?

robust and efficient proteolytic cascades, which terminate in opsonization and lysis of the pathogen as well as in the generation of the classical inflammatory response through the production of potent proinflammatory molecules

What is edema?

swelling due to accumulation of fluid and protein in tissue as a result of increased permeability of capillary walls during an inflammatory response; chronic edema can also result from blockage of lymphatic vessels, as in the case of elephantiasis

Where do T-cells mature?

thymus gland

What is the role of B cell receptors (BCRs) and T cell receptors (TCRs) in the immune response?

to recognize specific epitopes of an antigen