Chapter 16 Flashcards
What modifications help in the movment of lymph?
- The squeezing action of skeletal muscles aids movement.
- The low pressure in the thoracic cavity created by breathing movements, moves lymph up from abdominal to thoracic region.
- one-way valves also help in the movement of lymph
What is inflammation?
- Is a tissue response to damage, injury or infection.
- Blood vessels dilate, increasing capillary permeability.
What are some characteristics of the IgD immunoglobulins?
- Occurs on the surface of most B-cells
- Involved in activation of B-cells.
Define Artificially acquired active immunity
A person who receives a vaccine containing a dead or weakened pathogen.
What is an allergic reaction?
Is an excessive inflamatory response against a non-harmful substance
Discuss the flow of lympg through the lymph nodes
- Lymph flow is in one direction.
- Lympatic capillaries
- Lymph enters the node through an afferent lymphatic vessel.
- Flows inward through sinuses
- Exits the node via an efferent lymphatic vessel at the hilum.
- Goes to the lymphatic trunk
- Collecting ducks
- Right and Left subclavian veins
What may cause autoimmune disorders?
- Previous viral infection.
- Faulty T-cell development.
- Reaction to a non-self antigen that is close in structure to a self-antigen.
- Persistent fetal cells, where fetal cells persist in the female’s circulation as an adult.
What are Natural Killer Cells?
- A group of lymphocytes that defend against viruses and cancer cells by secreting perforins.
- Perforins are compounds that lyse the cell membrane.
What is the thymus and its role in the lymphatic system?
- Thymocytes can be converted to T-lymphocytes and leave the thymus.
- Hassall’s corpuscles secrete thymosins which stimulate maturation of the T-lymphocytes after they leave the thymus.
What is adaptive resistance?
Protection against particular pathogens or to their toxins or metabolic by-products (specific target).
What are the 4 classes of immunity?
- Naturally acquired active immunity
- Artificially acquired active immunity
- Artificially acquired passive immunity
- Naturally acquired passive immunity
What is phagocytosis?
The process by which cells engulf and ingest foreign particles in order to destroy them.
Phagocytic cells are present at the spleen, liver, bone marrow and blood vessels.
What are some characteristics of the IgG immunoglobulins?
- IgG – occurs in plasma and tissue fluids.
- Most prevalent of the IGs.
- Defends against bacterial cells, viruses and toxins.
- Activates complement.
- ***Only antibody to cross placenta
What are autoimmune disorders?
When the the body produces antibodies against “self”-antigens, resulting in an attack on one’s tissues.
Define: Artificially acquired passive immunity
A person who receives an injection of gamma globulin that contains read-made antibodies.
Provides short-term production.
What are the six different mechanisms of nonspecific resistance?
- Species resistance
- Mechanical barriers
- Chemical barriers
- Fever
- Inflammation
- Phagocytosis
aWhat are the 5 major types of immunoglobuins?
- IgA
- IgD
- IgE
- IgG
- IgM
What are lymphatic nodules?
- Nodules are aggregated into a solitary, oval-shaped mass.
- Commonly found at the small intestine (Peyer’s patch and tonsils).
Define Immediate-reaction allergy
- Causes the production of an abnormally large amount of IgE.
- The response occurs within minutes of contact with the allergen.
What are some characteristics of the IgE immunoglobulins?
- Occurs in exocrine gland secretions.
- Promotes inflammation and allergic reactions due to the release of histamine from mast cells (basophils).
What is thymosin?
A substance that stimulates the maturation of the T-lymphocytes after they leave the thymus.
Define primary organs.
These are sites where cells are produced that carry out an immune response.
Define naturally acquired active immunity
when an individual encounters a live pathogen, which stimulates a primary IR, and suffers symptoms of a disease.
How are B-cells activated?
- B-cells become activated when they bind to an activated T-cell.
- Activated B-cells then proliferate, enlarging its clone.
- Activated B-cells develop into plasma cells that secrete antibodies.
The inflammatory response invovles what 4 things?
- Redness
- Swelling
- Heat
- Pain
What are the 5 types of allergic reactions?
- Delayed-reaction allergy
- Antibody-dependent cytotoxic allergic reactions
- Immune complex allergic reactions
- Immediate-reaction allergy
What are the 2 collecting ducts in the lymphatic system?
- Right lymphatic duct
- Thoracic (left lymphatic) duct
What are the three antigen presenting cells?
Macrophages
B-cells
Certain T-cells
What are some characteristics of the IgA immunoglobulins?
- Occurs in exocrine gland secretions (mammary glands, sweat glands).
- Defends against bacterial cells and viruses.
- Levels decrease during stress, lowering resistance to infection.
What are some characteristics of the IgM immunoglobulins?
- First antibodies to be secreted after initial exposure to an antigen.
- Occurs in plasma
- Produced in blood transfusions.
- Activates complement.
What are the functions of the lymphatic system?
- transport excess tissue (interstitial) fluid to the blood stream
- transport dietary fat,
- help defend the body against disease‑causing agents.
What is Edema?
The accumulation of excess interstitial fluid leading to swelling of tissues.
Any condition that blocks the flow of lymph will result in edema.
Discuss the structure of the lymph nodes, it’s function, and location.
- Node is enclosed in a dense CT capsule that extends into the node and subdivides it into nodules.
- Outer Region (Cortex) = contains nodules filled with areas of densely packed B-cells and macrophages.
- Inner region (Medulla) = contains T-cells and macrophages.
How are B-cells formed?
- B-cells are part of the Humoral/Antibody mediated response.
- B-cells proliferate into plasma cells which produce antibodies known an Immunoglobulins (IG)
Define species resistance
Each species is resistant to certain diseases that may affect a different species, but susceptible to diseases that other species may be able to resist.
What are the primary and secondary organs of the lymphatic system?
- The primary organs of the lymphatic system are the bone marrow and thymus gland.
- Secondary lymphatic organs include the lymph nodes and spleen.
Define chemical barriers
- Enzymes: enzymes present in gastric juice and tears degrade many pathogens.
- Acid- low pH in stomach prevents growth of some bacteria.
- Salts – high salt concentration in perspiration kills some bacteria.
- Interferon – a hormone-like peptide produced by healthy cells in response to the presence of pathogens.
IFNs interfere with the proliferation of viruses, stimulate phagocytosis, and enhance activity of cells that resist infection. - Defensins – peptides that destroy bacteria by destroying the cell wall/plasma membrane.
- Collectins – proteins that attach to pathogens increasing its susceptibility to phagocytosis.
- Complement – a series of reactions by a group of proteins that leads to inflammation, attract phagocytes, and increases phagocytosis.
What are the actions of antibodies?
- Attack antigens directly
- Activate complement
- Stimulate local tissue changes to prevent the spread of a pathogen.
What is diffuse lymphatic tissue?
- Diffuse tissue is not encapsulated (diffuse)
- Typically found in the submucosa of mucous lining.
Define mechanical barriers
- Comprised of the skin and mucous membranes.
- Represents the First Line of Defense.
- An intact mechanical barrier, prevents the entrance of many pathogens.
- Skin cells – carry away pathogens.
- Mucous membranes – trap and remove pathogens (respiratory tract)
- Tears/Saliva/Urine – remove organisms.
What is lymph, how is it formed, and what are it’s function?
- Lymph is tissue fluid that was forced into the lymphatic capillaries.
- Lymph has 3 functions:
- Returns small leaked plasma proteins back to the blood stream.
- Transports foreign particles to the lymph nodes.
- Transports lipids and lipid-soluble vitamins absorbed in GI tract to blood stream.
What is nonspecific resistance?
Protection against a wide range of pathogens
List the series of reactions leading to the activation of complement proteins
When certain antibodies are activated, they trigger a series of reactions leading to activation of complement proteins:
- Opsonization - process by which a pathogen is marked for phagocytosis.
- Chemotaxis
- Inflammation
- Lysis
- Agglutination
Discuss the spleen and its structure
The spleen largest lymph organ which is composed of 2 types of tissue:
- White pulp – lymphocytes arranged around central arteries.
- Red Pulp – blood filled sinuses
What is a primary immune response?
- The reaction caused by the first time a B-cell or T-cell encounters its specific antigen.
- During this response, antibodies are produced for several weeks. Some of these cells remain dormant (memory cells).
What is specific resistance?
Protection against particular pathogens or to their toxins or metabolic by-products (specific target).
Define delayed-reaction allergy
results from repeated exposure to antigenic substances.
Usually results in inflammation of the skin.
Define Naturally acquired passive immunity
- When antibodies pass through a placental membrane to the fetus.
- Provides short-term protection.
Define antibody-dependent cytotoxic allergic reactions
occurs when blood transfusions are mismatched
Define Immune complex allergic reactions
involves autoimmunity, which is an IR against self-antigens.
What causesa fever?
- Certain infections can cause lymphocytes to produce Interleukin 1 (IL-1), increasing body temperature.
- Increased body temperature decreases blood iron levels, which increases phagocytic activity.
What are the functions of their spleen?
- Removal and destruction of foreign particles and damaged red blood cells.
- Achieved by activity of macrophages. - Stores and releases blood during hemorrhage.
- Site of B-cell proliferation.
What are antigen and how are they formed?
Antigens are a substance (protein) that can elicit an immune response.
During development, body cells identify the proteins and other large molecules present in the body (“self”-proteins). After identifying all “self” proteins, lymphocytes develop receptors that allow them to determine a foreign protein from a “self” protein.
What is a pathogen?
Viruses and/or microorganisms that cause disease.
Define Secondary organs
- Sites where most of the immune responses occur.
- Lymph Nodes
- Spleen
- GALT (Gastro-Associated Lymphoid Tissue)
- MALT (Mucosal-Associated Lymphoid Tissue)
Define: Immediate-reaction allergy (anaphylactic shock):
Reaction that results from mast cells bursting and releasing allergy mediators, such as histamines, prostaglandins, and leukotrienes.
these mediators are responsible for the symptoms of the allergic reactions: decreased blood pressure and difficulty breathing.
Anaphylactic shock is treated with suppressor cells that inhibit the production of IgE.
What is a second response?
A strong, rapid reaction due to the presence of the same antigen at a later time.
What are Perforins?
Compounds that lyse a cell membrane (breakdown)
