Immune System Flashcards

Flashcards based on Immune System Lecture Notes

What is the immune system?

A complex network of organs, tissues, cells, and molecules that protects the body from harmful pathogens and foreign substances; recognizes and eliminates damaged or malignant cells.

What is the immune response?

A reaction to microbes and molecules recognized as foreign or abnormal.

What is immunology?

The study of immune responses.

What are the four key actions of the immune system?

Identify threats, mount an attack, eliminate pathogen, remember.

What are the two complementary arms of the immune system?

Innate and adaptive immune systems.

Name three roles of the immune system.

Defense against infections, defense against tumors, control of tissue regeneration and scarring.

List the leukocytes that are part of the immune system.

Mast cells, eosinophils, basophils, neutrophils, monocytes/macrophages, dendritic cells, B lymphocytes, T lymphocytes, natural killer (NK) cells.

What is hematopoiesis?

The production, development, differentiation, and maturation of blood cells from multipotent stem cells.

Where does hematopoiesis occur during embryogenesis and early fetal development?

The yolk sac.

Where does hematopoiesis shift to once organogenesis begins?

The liver and spleen, and finally, to the bone marrow.

What two progenitor cells can multipotent stem cells give rise to?

Common lymphoid progenitor cell or a common myeloid progenitor cell.

What cells arise from the common lymphoid progenitor cell?

B lymphocytes, T lymphocytes, and natural killer (NK) cells.

What cells arise from the common myeloid progenitor cell?

Erythrocytes, megakaryocytes/thrombocytes, mast cells, eosinophils, basophils, neutrophils, monocytes/macrophages, and dendritic cells.

Which cells perform non-specific, stereotypic responses in the innate immune branch?

Cells of the myeloid lineage, except erythrocytes and megakaryocytes.

Which cells perform focused, antigen-specific roles in immunity?

B lymphocytes and T lymphocytes of the lymphoid lineage.

Where do B lymphocytes complete their development?

Within the bone marrow.

Where do T lymphocytes undergo development?

Within the thymus.

What is the function of a natural killer (NK) cell?

Recognizes tumor and virally infected cells through non-specific binding.

Name the important players of the immune system

T Cell, B Cell, Antibodies, Macrophage, Dendritic Cell, Neutrophil, Complement, Natural Killer Cell, Basophil, Eosinophil, Mast Cell

What are cytokines?

Cell signaling proteins, often released by immune cells, that travel locally to stimulate inflammatory response.

What is the function of chemokines?

Cytokines which attract immune cells.

What is the function of interferons?

Interfere with viral replication.

List the components of innate immunity.

Neutrophils, macrophages, complement, dendritic cells, infected cells, natural killer cells, monocytes.

List the components of adaptive immunity.

Virgin Helper T cells, Virgin Killer T cells, Infected Cells, Killer T Cells, Helper T Cells, Eosinophil, Basophil, Mast Cell, Long Lived Plasma Cell, Plasma Cell, B Cell, Parasitic Worms, Antibodies, Memory Killer T Cells, Memory Helper T Cells, Virgin B Cell, Memory B Cell

What are the crucial characteristics of innate immune defenses?

They are present independently of a previous stimulation. They have limited specificity. They have limited diversity. Activity is not enhanced upon subsequent exposure, therefore no memory.

Define specificity in the context of the immune system.

How precisely it recognizes and responds to a specific target.

List three ways that the innate immune system handles pathogens.

Inflammation, interferons/NK cells, elimination of microbes.

List the three types of defensive barriers involved in innate immunity.

Anatomic and physical, physiologic, complement, cellular, and inflammation.

What is the role of the adaptive immune system?

Targets specific antigens and exhibit diversity.

What is an epitope?

The part of an antigen that is recognized by the immune system, specifically by antibodies, B cells, or T cells.

What are heterophile antigens?

A group of similar antigens found in unrelated animals.

What is the functional significance of specificity, in regard to Innate and Adaptive Immunity?

Ensures that the immune responses are precisely targeted to microbial pathogens.

What is the functional significance of diversity, in regard to Innate and Adaptive Immunity?

Enables the immune system to respond to a large variety of antigens.

What is the functional significance of memory, in regard to Innate and Adaptive Immunity?

Leads to enhanced responses to repeated exposures to the same antigens.

What is the functional significance of Clonal expansion, in regard to Innate and Adaptive Immunity?

Increases number of antigen-specific lymphocytes from a small number of naive lymphocytes.

What is the functional significance of Specialization, in regard to Innate and Adaptive Immunity?

Generates responses that are optimal for defense against different types of microbes.

What is the functional significance of Contraction and homeostasis, in regard to Innate and Adaptive Immunity?

Allows immune system to respond to newly encountered antigens.

What is the functional significance of Nonreactivity to self, in regard to Innate and Adaptive Immunity?

Prevents injury to the host during responses to foreign antigens.

Differentiate group specificity in Innate Immunity from Adaptive Immunity

Innate Immunity responds to molecules shared by groups of related microbes and molecules produced by damaged host cells; Adaptive Immunity responds to many different microbial and nonmicrobial antigens.

How long does it typically take after the primary infection for the adaptive immune response to begin clearance of the infection through the action of effector cells and antibodies?

It typically takes 1-2 weeks.

Define antigens.

A substance that can provoke the production of an antibody.

Define immunogen

A substance that can stimulate the immune system to produce an immune response.

For a molecule to be an immunogen, what three basic criteria must it fulfill?

It must be recognized as foreign. It must have a certain degree of chemical complexity. It must have a large molecular weight.

Define hapten

A low molecular weight substance which is incapable of inducing an immune response alone but when coupled with a carrier molecule (protein) it can act as an antigen.

What is the role of adjuvants?

Substances that can enhance the immune response to an immunogen.

Humoral immunity is mediated by what?

Antibodies, which are produced by the B-cell component of the immune response.