Exam Review for Chapter 14: Lymphatic system and Immunity

Describe how B cells are activated. How does the antibody response protect against diverse infections? Which immunoglobulins are most abundant?

B-cells are activated by the binding of antigen to receptors on its cell surface which causes the cell to divide and proliferate. Some stimulated B-cells become plasma cells, which secrete antibodies. Others become long-lived memory B-cells which can be stimulated at a later time to differentiate into plasma cells.

Describe the difference between an antigen and a hapten.

Both antigens and haptens (small molecules) can act as antigenic agents when faced with an active immune response in progress. But only antigens themselves can cause an immune response to begin; they are both antigenic and immunogenic. ... This is the difference between something that is immunogenic and antigenic.

List the general functions of the lymphatic system.

The lymphatic system has multiple interrelated functions: It is responsible for the removal of interstitial fluid from tissues. It absorbs and transports fatty acids and fats as chyle from the digestive system. It transports white blood cells to and from the lymph nodes into the bones.

Describe how T cells are activated, the type of T cells and how cytotoxic T cells destroy cells bearing foreign antigens.

how T cells are activated: Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, which are expressed on the surface of antigen-presenting cells (APCs). Once activated, they divide rapidly and secrete small proteins called cytokines that regulate or assist in the active immune response. Cytotoxic or "killer" T cells directly attack and destroy cells bearing antigenic material.

Describe an infection and describe the seven innate defense mechanisms.

infection: the process of infecting or the state of being infected the seven innate defense mechanisms: 1. physical barriers 2. chemical barriers 3. cellular defenses 4. inflammation 5. fever 6. molecular defenses

Describe immunity.

the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells

Distinguish between active and passive immunity.

Active immunity involves your bodies direct response to an unknown pathogen. ... However, the response lasts for a long period of time and in some cases, where antibodies remain in the body as memory cells, immunity to the specific pathogen may be life long.

Distinguish between allergic reactions and immune reactions.

Allergy symptoms can range from mild to a serious, life-threatening allergic reaction (anaphylaxis). ... When a harmless substance like dust, mold or pollen is encountered by a person who is allergic to that substance, the immune system may overreact by producing antibodies that attack the allergen.

Describe how antibodies function. Describe how complement is activated and how it functions.

Antibodies contribute to immunity in three ways: They prevent pathogens from entering or damaging cells by binding to them; they stimulate removal of pathogens by macrophages and other cells by coating the pathogen; and they trigger destruction of pathogens by stimulating other immune responses such as the complement

Describe the consequences of lymphatic obstruction.

Lymphatic obstruction. Lymphatic obstruction is a blockage of the lymph vessels that drain fluid from tissues throughout the body and allow immune cells to travel where they are needed. Lymphatic obstruction may cause lymphedema, which means swelling due to a blockage of the lymph passages.

Describe how tissue rejection involves an immune response.

Transplant rejection occurs when transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue. Transplant rejection can be lessened by determining the molecular similitude between donor and recipient and by use of immunosuppressant drugs after transplant.

Distinguish between primary and secondary immune response.

Differences between Primary and Secondary Immune Response. The primary immune response occurs when an antigen comes in contact to the immune system for the first time. ... The secondary immune response occurs when the second time (3rd, 4th, etc.) the person is exposed to the same antigen.

Describe the functions of the thymus and spleen and why they are considered organs of the lymphatic system.

It functions to produce T-lymphocytes that help in the immune response. It also secretes thymosin, which is thought to stimulate the maturation of T-lymphocytes after they leave the thymus. The spleen is the largest lymphatic organ. It resembles a large lymph node and is subdivided into chambers or lobules. they are part of the lymphatic system because they have T lymphocytes or stimulating hormones for T cells

Describe the factors that promote lymph flow.

It is influenced primarily by the rate of lymph formation. For example, if blood capillary pressure is increased by arterial vasodilation or venous constriction, the flow rate of lymph increases. ... Valves in the lymph vessels prevent retrograde flow similar to those in veins.

Describe the lymphatic pathway.

Lymph flows from lymphatic vessels into lymphatic trunks , and finally into collecting ducts where the lymph is disposed into the subclavian veins. Run parallel to blood capillaries in all body tissues. ... Allows diffusion of tissue fluid from interstitial spaces into the lymphatic pathway.

Describe the major function of a lymph node.

Lymph nodes serve two major functions in the body. They filter lymph and assist the immune system in building an immune response. Lymph is a clear fluid that comes from blood plasma that exits blood vessels at capillary beds. This fluid becomes the interstitial fluid that surrounds cells.

Describe how T cells and B cells originate.

Lymphocytes - T cells and B cells. White blood cells called lymphocytes originate in the bone marrow but migrate to parts of the lymphatic system such as the lymph nodes, spleen, and thymus. ... On the surface of each lymphatic cell are receptors that enable them to recognize foreign substances.

Describe the major functions of lymph.

The lymphatic system is a network of tissues and organs that help rid the body of toxins, waste and other unwanted materials. The primary function of the lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body.

Distinguish between a lymph node and lymph nodule.

The nodule differs from a lymph node in that it is much smaller and does not have a well-defined connective-tissue capsule as a boundary. It also does not function as a filter, because it is not located along a lymphatic vessel. ... In the small intestine, collections of lymph nodules are called Peyer's patches.

Describe the difference between thoracic duct and right lymphatic duct.

The right lymphatic duct drains lymph from the right upper limb, right side of thorax and right halves of head and neck. The thoracic duct drains lymph into the circulatory system at the left brachiocephalic vein between the left subclavian and left internal jugular veins.