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84 Cards in this Set
- Front
- Back
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What are pathogens?
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Microscopic organisms that cause disease viruses, bacteria, fungi, & parasites
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What does the Lymphatic system protect us against?
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disease
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What are the lymphatic system cells called?
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lymphocytes
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What does lymphocytes respond to?
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environmental pathogens, toxins, & abnormal body cells, such as cancers
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What is Immunity?
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the ability to resist infection and disease
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What makes up the immune system?
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All body cells and tissues involved in production of immunity (not just the lymphatic system)
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Lymphocytes are Specific Defenses, what do Specific Defenses do?
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Identify, attack, and develop immunity to a specific pathogen
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What do Nonspecific Defenses do?
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Block or attack any potential infectious organism
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Why are they called Nonspecific Defenses?
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Because they cannot distinguish one attack from another
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What are the 4 parts of the Lymphatic System?
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Lymph,
Lymphatic vessels, Lymphoid tissues and organs, and Lymphocytes, phagocytes, and other immune system cells |
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What is Lymph?
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a fluid similar to plasma that does not have plasma proteins
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What are Lymphatic Vessels?
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networks that carry lymph from tissues to veins
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What is the function of the Lymphatic System?
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to produce, maintain, and distribute lymphocytes
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Where are lymphocytes produced?
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in lymphoid tissues,
lymphoid organs, and in red bone marrow |
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When lymphocytes detect problems, where do they travel?
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into the site of injury or infection
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Lymphatic vessels carry what?
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Lymph
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What are the smallest Lymphatic vessels?
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lymphatic capillaries
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In what 4 ways do lymphatic capillaries differ from blood capillaries?
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They:
1. start as pockets rather than tubes 2. have larger diameters 3. have thinner walls 4. flat or irregular in section |
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What are lymphatic capillaries?
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Endothelial cells loosely bound together
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What are lacteals?
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lymphatic capillaries in small intestine
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What do lacteals do?
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Transport lipids from digestive tract
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The lymphatic system is divided into:
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superficial lymphatics & deep lymphatics
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Where are the superficial lymphatics located?
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the skin, mucus membranes, and serous membranes lining body cavities
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What are the deep lymphatics?
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larger vessels that accompany deep arteries and veins
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What 2 things join together to make lymphatic trunks?
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superficial lymphatics & deep lymphatics
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The lymphatic trunks empty into 2 major collecting vessels called:
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the thoracic duct and the right lymphatic duct
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What is Lymphedema?
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Blockage of lymph drainage from a limb that causes swelling
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Lymphocytes make up what percent of leukocytes?
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20-30%
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Most lymphocytes are what instead of circulating?
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stored
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What are the 3 classes of circulating lymphocytes?
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T Cells, B Cells, and NK Cells
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T cells make up what percent of circulating lymphocytes?
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80%
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What are the 3 main types of T cells?
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1. Cytotoxic T cells
2. Helper T cells 3. and Suppressor T cells |
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Cytotoxic T cells attack cells infected by what?
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viruses
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Cytotoxic T cells produce what?
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cell-mediated immunity
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Helper T cells do what?
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Stimulate function of T cells and B cells
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Suppressor T cells do what?
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inhibit T cells and B cells
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Regulatory T cells are what kind of T cells?
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helper and suppressor
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What doe regulatory T cells control?
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sensitivity of immune response
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B cells make up what percent of circulating lymphocytes?
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10-15%
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B cells separate into:
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plasma cells
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Plasma cells produce and secrete what?
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antibodies (or Immunoglobin Proteins)
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What are antigens?
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targets that identify pathogens
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What is antibody-mediated immunity?
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A chain of events which destroys the target
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Natural Killer (NK) Cells make up what percent of circulating lymphocytes?
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5-10%
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NK cells are responsible for?
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immunological surveillance
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What do NK cells attack?
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foreign cells
virus-infected cells & cancer cells |
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Lymphopoiesis is what?
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lymphocyte production
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What does lymphopoiesis involve?
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bone marrow,
thymus, & peripheral lymphoid tissues |
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Hemocytoblasts in bone marrow divide into 2 types of what?
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lymphoid stem cells
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Group 1 of lymphoid stem cells is located where?
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in bone marrow
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What does Group 1 of lymphoid stem cells produce?
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B cells and NK cells
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Group 2 of lymphoid stem cells is where?
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thymus
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Group 2 of lymphoid stem cells produce what within a blood-thymus barrier?
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T cells
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Lymphoid tissues are what?
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connective tissues dominated by lymphocytes
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What is a Lymphoid Nodule?
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Areolar tissue with densely packed lymphocytes
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The Germinal center of the lymphoid nodule contains what?
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dividing lymphocytes
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Where are lymphoid nodules located?
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Lymph nodes,
Spleen, Respiratory tract (tonsils), & Along digestive and urinary tracts |
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Mucosa-Associated Lymphoid Tissue (MALT) are what?
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Lymphoid tissues associated with the digestive system
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Aggregated lymphoid nodules are clustered where?
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deep to intestinal epithelial lining
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What is an appendix?
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a mass of fused lymphoid nodules
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What are the 5 tonsils in the pharynx?
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the left and right palatine tonsils,
the pharyngeal tonsil (adenoid), and the 2 lingual tonsils |
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Name 3 Lymphoid Organs:
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1. Lymph nodes
2. Thymus 3. Spleen |
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Lymph Nodes have what size diameter?
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1–25 mm
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What are Trabeculae?
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bundles of collagen fibers that extend from capsule into interior of lymph node
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Afferent Lymphatic Vessels do what?
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Carry lymph from peripheral tissues to lymph node
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Efferent Lymphatic Vessels leave lymph node at the what?
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hilus
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Efferent Lymphatic Vessels carry lymph to where?
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venous circulation
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A Lymph Node acts as a filter and purifies lymph before it returns to venous circulation. What does it remove?
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debris,
pathogens, & 99% of antigens |
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What is the first step in immune response?
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Antigen Presentation
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What happens in Antigen Presentation?
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antigens are “presented” or attached to dendritic cells to stimulate lymphocytes
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Lymphoid tissues and lymph nodes are distributed to monitor what?
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peripheral infections
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When do Lymphoid tissues and lymph nodes respond?
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before infections reach vital organs of trunk
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Lymph glands are large lymph nodes located where?
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at groin and base of neck
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What do Lymph glands do in response to inflammation?
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swell
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Lymphadenopathy refers to what?
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enlargement of lymph nodes may indicate infections, endocrine disorders, or cancer
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The thymus deteriorates when?
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after puberty
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The thymus is divided into 2 what?
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thymic lobes
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What divides the thymic lobes into smaller lobules?
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septa
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What are the thymus hormones?
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thymosins
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What do thymosins do?
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Promote development of lymphocytes
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What are the 3 Functions of the Spleen?
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1. Removal of abnormal blood cells and other blood components by phagocytosis
2. Storage of iron recycled from red blood cells and 3. Initiation of immune responses by B cells and T cells |
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What are inside the fibrous capsule of the spleen?
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red and white pulp
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Phagocytes and other lymphocytes in spleen do what?
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identify and attack damaged and infected cells in circulating blood
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Body Defenses fight infection, illness, and disease. What are the 2 types of Defenses?
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nonspecific defenses and specific defenses
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