Lymphatic & Immune System

Which cells are responsible for antibody - mediated immunity?

B Cells

Which cells produce antibodies?

B cells

Which T cells contain CD8 markers? CD4 markers?

CD8 markers are found on cytotoxic T cells, memory T cells, and regulatory T cells; CD4 markers are found on all helper T cells

Explain the function of cytokines secreted by helper T cells

Cytokines secreted by helper T cells stimulate both cell-mediated and antibody-mediated immunity.

Which cells can be activated by direct contact with virus infected cells ?

Cytotoxic T cells and NK cells

Describe the structure of an antibody.

An antibody molecule consists of two parallel pairs of polypeptide chains: one pair of heavy chains and one pair of light chains. Each chain contains both constant segments and variable segments.

Identify the types of phagocytes in the body, and differentiate between fixed macrophages and free macrophages.

The body's phagocytes are neutrophils, eosinophils, and macrophages. Fixed macrophages are scattered among connective tissues and do not move; free macrophages are mobile and reach injury sites by migrating through adjacent tissues or traveling in the bloodstream.

Briefly explain the role of complement proteins.

The complement proteins of the complement system interact with each other in chain reactions that ultimately produce activated forms that target bacterial cell walls and plasma membranes, stimulate inflammation, attract phagocytes, or enhance phagocytosis

Provide a plausible explanation for the increased incidence of cancer in the elderly.

The increased incidence of cancer in elderly people may result from a decline in immune surveillance, which results in reduced elimination of tumor cells as they arise.

How does the integumentary system protect the body?

The integumentary system provides a physical barrier that is the first line of defense in preventing pathogens and toxins from entering body tissues. Skin secretions flush the surface, hair protects against physical abrasion, and the multiple layers of the skin's epithelium create an interlocking barrier.

Which would be more affected by a lack of memory B cells and memory T cells: the primary response or the secondary response ?

The secondary response would be more affected by a lack of memory cells, which are produced in response to an initial exposure to an antigen during the primary response.

How do NK cells detect cancer cells?

They recognize unusual proteins, celled tumor-specific antigens, on the plasma membranes of cancer cells. When these antigens are detected, the NK cells destroy the abnormal cells

Which chemicals do mast cells and basophils release when stimulated in an allergic reaction?

histamines, leukotrienes, and other chemicals that cause inflammation

List the components of the lymphatic system.

lymphocytes, lymph, lymphatic vessels, primary lymphoid tissues and organs, and secondary lymphoid tissues and organs.

Define chemotaxis

movement of a motile cell or organism, or part of one, in a direction corresponding to a gradient of increasing or decreasing concentration of a particular substance.

Define opsonization.

the coating of pathogen with antibodies that facilitates phagocytosis - allows phagocytes to bind more easily

Define immune surveillance

the constant monitoring of normal tissues by NK cells sensitive to abnormal antigens on the surfaces of cells.

Define antigenic determinant site.

the part of an antigen molecule to which an antibody molecule binds

What tissues are involved in lymphopoiesis?

thymus, bone marrow, and peripheral lymphoid tissues

A rise in the level of interferons in the body suggests what kind of infection?

viral infection

What is anaphylaxis?

A systemic hypersensitivity reaction - circulating allergen affects mast cells throughout the body

Beginning at the trabecular arteries, trace the path of blood through the spleen.

Beginning with the trabecular arteries, blood then flows to the central arteries ---> capillaries ---> reticular tissue of red pulp---> sinusoids-----> trabecular veins.

Which two cells coordinate adaptive immunity?

T cells and B cells

If NK cells are engaged in immune surveillance, how do cancer cells spread?

During Immunological escape, the NK cells aren't perfect and the cancer cells can spread and create secondary tumors.

Describe hypersensitivities.

Excessive immune response to antigens - sudden increase in cellular activity and antibody titers (neutrophils or cytotoxic T cells may destroy normal cells in addition to antigen)

What is the effect of histamine release?

Histamine release by mast cells and basophils in tissues increases local inflammation, thereby accelerating blood flow to the region.

Describe inflammation.

Inflammation is a localized response to injury characterized by redness, swelling, heat, and pain.

A child falls off her bike and skins her knee. Which form of immunity will be activated immediately?

Innate (nonspecific) immunity will be activated immediately in the child with a skinned knee.

Distinguish between innate immunity and adaptive immunity.

Innate immunity is nonspecific and does not distinguish one type of threat from another. Adaptive immunity is specific and protects against particular threats.

How does innate immunity protect us from disease?

Innate immunity protects us using physical barriers such as skin, phagocytes that engulf pathogens, immune surveillance of abnormal cells, interferons to defend from viruses, complement to assist antibodies, inflammation to limit the spread of infection, and fever.

What is the difference between a lymphocyte and lymph?

Lymphocytes are cells of the lymphatic system and lymph is interstitial fluid that has entered a lymphatic vessel

Define autoimmune disorders.

Malfunction in the body's self recognition system - activated B cells make antibodies against self antigens or body cell tissues (autoantibodies)

List the ways that antigen-antibody complexes can destroy target antigens.

Neutralization, prevention of pathogen adhesion, activation of complement, opsonization, attraction of phagocytes, stimulation of inflammation, and precipitation and agglutination

Identify three main classes of lymphocytes

T cells, B cells, and natural killer cells

If you observed a higher than normal number of plasma cells in a sample of lymph, would you expect antibody levels in the blood to be higher or lower than normal?

Plasma cells produce and secrete antibodies, so observing an elevated number of plasma cells in the lymph would lead you to expect higher-than-normal antibody levels in the blood.

Define sensitization

Preparation for activation (threat detected)

What effect do pyrogens have in the body?

Pyrogens increase body temperature (produce a fever), which can mobilize defenses, accelerate repairs, and inhibit pathogens.

Describe red pulp and white pulp found in the spleen.

Red pulp contains large numbers of red blood cells; white pulp resembles lymphoid nodules and contains lymphocytes.

Describe immunodeficiency diseases.

Result from problems with lymphoid and tissue development - an infection w virus that depresses immune function

What are the functions of the spleen?

Site of lymphocyte proliferation, immune surveillance and response, cleanses the blood. Stores breakdown products of RBC's for later reuse. Stores blood platelets. Site of fetal erythrocyte production.

Define interferons

Small proteins released by activated lymphocytes macrophages and virus-infected tissues - trigger production of antiviral proteins in cytoplasm of nearby cells

Which type of immunity develops when a child is given the polio vaccine?

artificially acquired active immunity

Which cells are involved in inflammation?

basophils and mast cells