Term
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Definition
| Disease-producing microbes such as bacteria and viruses |
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Term
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Definition
| The ability to ward off damage or disease through our defenses |
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Term
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Definition
| Vulnerability or lack of resistance |
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Term
| Innate (nonspecific) Immunity |
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Definition
| - Defenses that are present at birth. -- Does not involve specific recognition of a microbe and acts against all microbes in the same way |
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Term
| Adaptive (specific) immunity |
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Definition
| Defenses that involve specific recognition of a microbe once it has breached the innate immunity defenses |
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Term
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Definition
| - Consists of a fluid called lymph, vessels called lymphatic vessels that transport the lymph, a number of structures and organs containing lymphatic tissue (lymphocytes within a filtering tissue), and red bone marrow |
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Term
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Definition
| After interstitial fluid passes into lymphatic vessels, it is called lymph |
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Term
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Definition
- A specialized form of reticular connective tissue
- Contains large numbers of lymphocytes |
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Term
| Functions of the Lymphatic System |
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Definition
1. Drains excess interstitial fluid
2. Transports dietary lipids
3. Carries out immune responses |
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Term
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Definition
- Located in the spaces b/t cells
- Greater permeability than blood capillaries
- Can absorb large molecules such as proteins and lipids
- When pressure is greater in the interstitial fluid than in lymph, the cells separate slightly, like the open- ing of a oneway swinging door, and interstitial fluid enters the lymphatic capillary. |
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Term
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Definition
- Lymphatic capillaries unite to form
- Resemble small veins in structure but have thinner walls and more valves |
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Term
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Definition
- In small intestine
- Carry dietary lipids into lymphatic vessels and ultimately into the blood |
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Term
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Definition
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Term
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Definition
| As lymphatic vessels exit lymph nodes in a particular region of the body, they unite to form lymph trunks |
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Term
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Definition
| Receives lymph from the right and left lumbar trunks and from the intes- tinal trunk |
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Term
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Definition
- Receives lymph from right jugular, right subclavian, and right bronchomediastinal trunks
- Lymph from the upper right side of the body |
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Term
| Formation and Flow of Lymph |
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Definition
| Sequence of fluid flow is blood capillaries (blood) -> interstitial spaces (interstitial fluid) -> lymphatic capillaries (lymph) -> lymphatic vessels (lymph) -> lymphatic ducts (lymph) -> junction of the internal jugular and subclavian veins (blood) |
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Term
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Definition
| - The “milking action” of skeletal muscle contractions compresses lymphatic vessels (as well as veins) and forces lymph toward the junction of the internal jugular and subclavian veins |
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Term
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Definition
| Lymph flow is also maintained by pres- sure changes that occur during inhalation (breathing in) |
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Term
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Definition
Sites where stem cells divide and become immunocompetent
- Red bone marrow
- Thymus |
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Term
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Definition
- Derived from stems cells
- Capable of mounting an immune response |
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Term
| Secondary Lymphatic Organs and Tissues |
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Definition
- Sites where most immune responses occur
- Lymph nodes, the spleen, and lymphatic nodules (follicles)
- Thymus, lymph nodes, and spleen |
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Term
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Definition
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Term
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Definition
| Extensions of the capsule |
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Term
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Definition
| Composed of large numbers of T cells and scattered dendritic cells, epithelial cells, and macrophages |
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Term
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Definition
- Derived from monocytes
- Present antigens to T cells, causing their proliferation. T |
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Term
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Definition
| Help clear out the debris of dead and dying cells. |
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Term
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Definition
- Consists of widely scattered, more mature T cells, epithelial cells, dendritic cells, and macrophages
- Contains B cells, antibody-producing plasma cells that have migrated out of the cortex into the medulla, and macrophages.
- The various cells are embedded in a network of reticular fibers and reticular cells |
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Term
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Definition
- Scattered throughout body, both su- perficially and deep,
- Usually occur in groups |
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Term
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Definition
- Cover lymph nodes
- Dense connective tissue |
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Term
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Definition
- Capsular extensions
- Divide node into compartments, provide support, and provide a route for blood vessels into the interior of a node |
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Term
| Lymphatic Nodules (follicles) |
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Definition
- Egg-shaped aggregates of B cells called
- Sites of plasma cell and memory B cell formation. |
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Term
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Definition
- Does not contain lymphatic nodules
- Consists mainly of T cells and dendritic cells that enter a lymph node from other tissues |
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Term
| Afferent Lymphatic Vessels |
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Definition
| - Afferent vessels contain valves that open toward the center of the node, directing the lymph inward |
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Term
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Definition
- Within the node, lymph enters sinuses
- A series of irregular channels that contain branching reticular fibers, lymphocytes, and macrophages |
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Term
| Efferent Lymphatic Vessels |
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Definition
- Medullary sinuses drain into
- Contain valves that open away from center of the lymph node to convey lymph, antibodies secreted by plasma cells, and activated T cells out of the node. |
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Term
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Definition
| - A slight depression from which an efferent lymphatic vessels emerge from one side of the lymph node |
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Term
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Definition
- Lymphatic tissue, consisting mostly of lymphocytes and macrophages arranged around branches of the splenic artery
- B cells and T cells carry out immune functions, similar to lymph nodes, while spleen macrophages destroy blood-borne pathogens by phagocytosis |
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Term
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Definition
The spleen performs three functions related to blood cells:
(1) removal by macrophages of ruptured, worn out, or defective blood cells and platelets;
(2) storage of platelets, up to one-third of the body’s supply; and
(3) production of blood cells (hemopoiesis) during fetal life |
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Term
| Mucosa-associated Lymphatic Tissue (MALT) |
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Definition
| Lymphatic nodules (follicles |
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Term
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Definition
| Strategically positioned to participate in immune responses against inhaled or ingested foreign substances |
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Term
| Pharyngeal Tonsil & Adenoid |
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Definition
| Embedded in the posterior wall of the nasopharynx. |
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Term
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Definition
- Lie at posterior region of oral cavity, one on either side;
- Tonsils commonly removed in a tonsillectomy |
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Term
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Definition
| Located at the base of the tongue, may also require removal during a tonsillectomy |
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Term
| First Line of Defense: Skin and Mucous Membranes |
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Definition
- Provide both physical and chemical barriers that discourage pathogens and foreign substances from penetrating the body and causing disease
- Provides a formidable physical barrier to the entrance of microbes
- Epidermis
- Mucous Membranes
- Mucus |
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Term
| Second Line of Defense: Internal Defense |
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Definition
- Internal antimicrobial substances
- Phagocytesa
- Natural killer cells
- Inflammation
- Fever |
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Term
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Definition
| Discourage microbial growth: interferons, complement, iron-binding proteins, and antimicrobial proteins. |
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Term
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Definition
| Proteins produced be lymphocytes, macrophages, and fibroblasts infected with viruses |
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Term
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Definition
- Proteins “complement” or enhance certain immune reactions
- The complement system causes cytolysis (bursting) of microbes, promotes phagocytosis, and contributes to inflammation. |
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Term
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Definition
| Inhibit growth of certain bacteria by reducing the amount of available iron ex. transferrin |
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Term
| Antimicrobial Proteins (AMPs) |
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Definition
| Attract dendritic cells and mast cells, which participate in immune responses. |
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Term
| Natural Killer (NK) Cells |
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Definition
- Present in the spleen, lymph nodes, and red bone marrow
- Lack membrane molecules that identify B and T cells
- Have ability to kill wide variety of infected body cells and certain tumor cells |
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Term
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Definition
- Inserts into plasma membrane of the target cell and creates channels (perforations) in the membrane.
- Extracellular fluid flows into target cell and the cell bursts, a process called cytolysis |
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Term
| Five Phases of Phagocytosis |
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Definition
1. Chemotaxis
2. Sdherence
3. Ingestion
4. Digestion
5. Killing |
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Term
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Definition
- Chemically stimulated movement of phagocytes to a site of damage
- Chemicals that attract phagocytes might come from invading microbes, white blood cells, damaged tissue cells, or activated complement proteins. |
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Term
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Definition
- Attachment of the phagocyte to the microbe or other foreign material
- Binding of complement proteins to the invading pathogen enhances adherence |
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Term
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Definition
| - Plasma membrane of the phagocyte extends projections that engulf the microbe |
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Term
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Definition
- Phagosome enters the cytoplasm and merges with lysosomes
- lysosome contributes lysozyme, which breaks down microbial cell walls, and other digestive enzymes that degrade carbohydrates, proteins, lipids, and nucleic acids. |
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Term
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Definition
| - Chemical onslaught provided by lysozyme, digestive enzymes, and oxidants within a phagolysosome quickly kills many types of microbes |
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Term
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Definition
| Nonspecific, defensive response of the body to tissue damage |
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Term
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Definition
| Pathogens, abrasions, chemical irritations, distortion or disturbances of cells, and extreme temperatures. |
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Term
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Definition
- Mast cells in connective tis sue and basophils and platelets in blood release histamine.
- Neutrophils and macrophages attracted to the site of injury also stimulate the release of histamine, which causes vasodilation and increased permeability of blood vessels. |
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Term
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Definition
| - Induce vasodilation and increased permeability and serve as chemotactic agents for phagocytes |
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Term
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Definition
- Lipids, released by damaged cells and intensify the effects of histamine and kinins.
- PGs also may stimulate the emigration of phagocytes through capillary walls. |
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Term
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Definition
- Produced by basophils and mast cells
- Cause increased permeability; they also function in adherence of phagocytes to pathogens and as chemotactic agents that attract phagocytes |
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Term
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Definition
| Attract neutrophils by chemotaxis, and promote phagocytosis; some components can also destroy bacteria |
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Term
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Definition
| Neutrophils begin to squeeze through the wall of the blood vessel to reach the damaged area |
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Term
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Definition
| An increase in white blood cells in the blood |
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Term
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Definition
| Collection of dead cells and fluid |
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Term
| Adaptive (specific) Immunity. |
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Definition
| - Ability of body to defend itself against specific invading agents such as bacteria, toxins, viruses, and foreign tissues |
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Term
| Two properties distinguish adaptive immunity from innate immunity |
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Definition
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Term
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Definition
| Substances that are recognized as foreign and provoke immune responses |
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Term
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Definition
| Complete their development in red bone marrow, a process that continues throughout life |
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Term
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Definition
| Cells develop from pre-T cells that migrate from red bone marrow into the thymus, where they mature |
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Term
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Definition
- The ability to carry out adaptive immune responses
- Takes place before T cells leave the thymus or B cells leave red bone marrow |
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Term
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Definition
| Molecules capable of recognizing specific antigens |
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Term
| Two Major Types of Mature T Cells |
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Definition
- Exit thymus
- Helper T cells and cytotoxic T cells |
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Term
| Helper T cells (aka. CD4 T Cells) |
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Definition
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Term
| Cytotoxic T Cells (aka CD8 T Cells) |
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Definition
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Term
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Definition
| Cytotoxic T cells directly attack invading antigens |
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Term
| Antibody-mediated Immunity |
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Definition
| B cells transform into plasma cells, which synthesize and secrete specific proteins called antibodies (Abs) or immunoglobulins (Igs) |
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Term
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Definition
Particularly effective against
(1) Intracellular pathogens, which include any viruses, bacteria, or fungi that are inside cells;
(2) some cancer cells
(3) foreign tissue transplants |
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Term
| Antibody-mediated Immunity |
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Definition
| Works mainly against extracellular pathogens, which include any viruses, bacteria, or fungi that are in body fluids outside cells |
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Term
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Definition
- Integral transmembrane proteins
- Chemically similar to the antibodies that eventually are secreted by plasma cells |
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Term
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Definition
- Secrete antibodies
- A few days after exposure to an antigen, plasma cell secretes hundreds of millions of antibodies each day for about 4 or 5 days, until the plasma cell dies. |
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Term
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Definition
- Do not secrete antibodies
- Quickly proliferate and differentiate into more plasma cells and more memory B cells should the same antigen reappear at a future time. |
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Term
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Definition
- Combine specifically with the epitope on the antigen that triggered its production
- Structure matches its antigen much as a lock accepts a specific key |
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Term
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Definition
| Belong to a group of glycoproteins called globulins |
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Term
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Definition
- IgG
- Appear first
- Relatively short-lived
- Indicate a recent invasion |
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Term
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Definition
| Because the antibody “arms” can move somewhat as the hinge region bends, an antibody can assume either a T shape or a Y shape |
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Term
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Definition
- Most antibodies have two antigen-binding sites
- Variable region, which is different for each kind of antibody, is the part of the antibody that recognizes and attaches specifically to a particular antigen. |
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Term
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Definition
1. Neutralizing antigen
2. Immobilizing bacteria
3. Agglutinating and precipitating antigen.
4. Activating complement
5. Enhancing phagocytosis |
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Term
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Definition
| Reaction of antibody with antigen blocks or neutralizes some bacterial toxins and prevents attachment of some viruses to body cells. |
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Term
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Definition
| If antibodies form against antigens on the cilia or flagella of motile bacteria, the antigen–antibody reaction may cause the bacteria to lose their motility, which limits their spread into nearby tissues |
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Term
| Agglutinating and Precipitating Antigen |
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Definition
- Antibodies have two or more sites for binding to antigen
- Antigen– antibody reaction may cross-link pathogens to one another, causing agglutination (clumping together). Phagocytic cells ingest agglutinated microbes more readily.
- Likewise, soluble antigens may come out of solution and form a more easily phagocytized precipitate when cross-linked by antibodies. |
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Term
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Definition
| Antigen–antibody complexes initiate the classical pathway of the complement system |
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Term
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Definition
- Stem region of antibody acts as flag, attracts phagocytes once antigens have bound to the antibody’s variable region
- Enhance activity of phagocytes by causing agglutination and precipitation, by activating complement, and by coating microbes so that they are more susceptible to phagocytosis |
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Term
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Definition
| - Defensive system made up of over 30 proteins produced by the liver and found circulating in blood plasma and within tissues throughout the body |
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Term
| Role of the Complement System in Immunity |
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Definition
| - Complement proteins destroy microbes by causing phagocytosis, cytolysis, and inflammation; they also prevent excessive damage to body tissues |
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Term
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Definition
| - Due to presence of long-lasting antibodies and very long-lived lymphocytes that arise during clonal selection of antigen-stimulated B cells and T cells. |
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Term
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Definition
- After initial contact with antigen, no antibodies are present for a period of several days
- slow rise in antibody titer occurs, first IgM and then IgG, followed by gradual decline in antibody titer |
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Term
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Definition
| After subsequent encounters, antibody titer is far greater than during a primary response and consists mainly of IgG antibodies. |
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Term
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Definition
| T-cells must be able to recognize your own major histocompatibility com- plex (MHC) proteins, |
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Term
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Definition
| T-cells must lack reactivity to peptide fragments from your own proteins, a condition |
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Term
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Definition
- A contagious disease caused by the Epstein–Barr virus (EBV).
- Fatigue, headache, dizziness, sore throat, enlarged and tender lymph nodes, and fever. |
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Term
| Systemic Lupus Erythematosus |
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Definition
| - A chronic autoimmune, inflammatory disease that affects multiple body systems |
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