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BIOL 105
Lecture Outline Chapter 12 ʹ Lymphatic System & Immunity Read Chapter 14 in your textbook(pp. 402-‐439) Complete Review Questions (pp. 437-‐439) #͛ s: 3, 5-‐8, 12-‐16, 18-‐20, 22, 26-‐28, 30-‐ The Lymphatic System Functions to: ____________________ excess interstitial fluid Transports dietary ____________________ ( i.e. lacteals ) ____________________ the body against disease-‐causing agents ( immunity ) Consists of: Network of vessels that transport fluids Cells and chemicals that travel in the fluids Glands and organs that produce the cells/chemicals Lymphatic Pathways Lymphatic capillaries Æ Lymphatic vessels Æ Circulation (veins) Lymphatic Capillaries ____________________-‐ended tubes Composed of simple squamous ____________________ Extend into the ____________________ spaces Run parallel to the capillary networks of the cardiovascular system Fluid traveling through the lymphatic capillaries is termed ____________________ Lymphatic Vessels Structure is similar to ____________________ Walls composed of epithelium, smooth muscle, and connective tissue; thinner than veinwalls
Contain ____________________ to prevent backflow Large lymphatic vessels pass through ____________________________ and merge to formlymphatic trunks
Lymphatic Trunks & Collecting Ducts Drain lymph from the lymphatic ____________________ Join one of two collecting ducts:
- ____________________ duct Receives lymph from the lower limbs, abdominal organs, left upper limb, and left side of the thorax, head, and neck
- ______________________________ duct Receives lymph from the right side of the head and neck, right upper limb, and rightthorax
From the collecting ducts lymph drains into ________________________________________ Lymph moves into the R and L subclavian veins Lymphatic Pathway Lymphatic capillary Æ Collecting duct Æ Æ Subclavian vein Lymphatic vessel Æ Lymph node Æ Lymphatic vessel Æ Lymphatic trunk
Tissue Fluid & Lymph Tissue fluid becomes lymph when it enters a lymphatic capillary Tissue fluid formation: Tissue fluid originates from ________________________________ o Pressure at the ____________________ end of a capillary forces fluid out of the blood capillaries This becomes tissue fluid! Consistency is very similar to blood plasma (minus some plasma proteins) Lymph formation: ____________________ from the plasma typically exceeds ____________________ o Excess fluid drains into the lymphatic vessels, becoming lymph Important role of lymph: Returns lost ________________________________________ to the blood ____________________: excessive accumulation of tissue fluid in interstitial spaces
Bilobed organ; capsule of CT divides each lobe into lobules Maturation of the _____ cells occurs within the lobules ( thymosins ) Thymus shrinks significantly during the lifetime Larger in children; microscopic in the elderly Spleen ____________________ mass of lymphatic tissue in the body Located in the upper left portion of the ____________________________ cavity Consists of two different types of tissue:
- ____________________ pulp Lymphatic tissue ʹ consists of lymphocytes and macrophages
- ____________________ pulp Closely associated with the venous sinuses Blood flows into the spleen via the splenic artery Worn out or damaged RBCs and platelets are removed from circulation by macrophages Body Defenses Against Infection ____________________: a disease-‐causing agent Includes bacteria, viruses, fungi, and protozoans Defense against pathogens: ____________________ defense o o Respond rapidlyGuard against any pathogen
____________________ defense ( immunity ) o Slower to respond o Highly specific; carried out by lymphocytes Innate Defenses
Internal environment of one species fails to produce conditions required by pathogens of other species
ZĞƉƌĞƐĞŶƚƚŚĞďŽĚLJ͛ƐĨŝƌƐƚůŝŶĞŽĨĚĞĨĞŶƐĞ Unbroken skin and mucous membranes
________________________________
Enzymes in body fluids Interferons antiviral enzymes are released from virus-‐infected cells Æ induce neighboring cells to produce
________________________________ (NK cells) Secrete perforins ʹ lyse cell membranes
Tissue response to a pathogen characterized by redness, swelling, heat, ad pain o ____________________ of blood vessels -‐-‐ ____________________ in bloodvolume o ____________________ WBCs move into the area o _______________ is a mass of WBCs, bacterial cells, and damaged tissues Phagocytosis ____________________ and ____________________ are active phagocytes o Leave the bloodstream at areas of injury
Phagocytic cells are move active when the body temperature rises High temperatures interfere with conditions that allow bacteria to grow o Amount of iron in the blood is reduced Adaptive Defenses ( Immunity ) Resistance to ____________________ pathogens of their toxins Antigens Located on the ____________________ of a cell May be proteins, glycoproteins, glycolipids, or polysaccharides ĞĨŽƌĞďŝƌƚŚƚŚĞďŽĚLJůĞĂƌŶƐƚŽƌĞĐŽŐŶŝnjĞƚŚĞƐĞĂŶƚŝŐĞŶƐĂƐ͞ͺͺͺͺͺͺͺͺͺͺͺͺͺͺͺ͟ dŚĞůLJŵƉŚĂƚŝĐƐLJƐƚĞŵƌĞƐƉŽŶĚƐƚŽ͞ͺͺͺͺͺͺͺͺͺͺͺͺͺͺͺ͟;ĨŽƌĞŝŐŶͿĂŶƚŝŐĞŶƐ Lymphocyte origins Before birth the ________________________________________ releases lymphocytesinto circulation:
____________________ cells o Dormant; respond to future encounters with the antigens Antibodies Fives classes of antibodies
Most abundant ʹ 80% of all antibodies in the blood plasma Protects against bacteria and viruses Crosses the placental barrier from mother to fetus
Found in exocrine gland secretions Protects mucous membranes Levels decrease during stress ʹ lowers resistance to infection
First antibody to be produced following exposure to an antigen Causes agglutination (A and B blood groups) and lysis of microbes
B cell antigen receptors ʹ activates B cells
Located on mast cells and basophils Involved in allergic and hypersensitivity responses Actions of antibodies include: ____________________ antigen Blocks or neutralizes toxins ʹ prevents attachment of some viruses to body cells Immobilizing ____________________ Form against cilia/flagella of motile bacteria _________________________ and _________________________ Antibodies have multiple antigen binding sites ʹ microbes clump together Soluble antigens come out of solution when linked by antibodies Immune Responses First activation of B and T cells ʹ primary immune response Antibodies appear in the plasma _______________ days after exposure Production of antibodies continues for several ________________
Activation of B cells results in the formation of ____________________ cells Second exposure ʹ secondary immune response Produces additional antibodies within _______________ days Active vs. Passive Immunity ____________________ immunity Individual produces an immune response (including memory cells) to an antigen Long-‐lasting ____________________ immunity Individual receives antibodies from another individual Short-‐term o Individual does NOT produce an immune response o Susceptible upon exposure to the antigen at a later date Naturally vs. Artificially Acquired Active Immunity ____________________ acquired active immunity Exposure to live pathogens ____________________ acquired active immunity Exposure to a vaccine containing weakened or dead pathogens or their components Naturally vs. Artificially Acquired Passive Immunity ____________________ Acquired Passive Immunity Antibodies passed from mother to fetus during pregnancy ____________________ Acquired Passive Immunity Gamma globulin injection Allergic Reactions Immune response to a ______________________________ substance ( allergen ) May cause tissue damage ____________________-‐reaction allergy ( within 48 hours ) Repeated exposure to allergens causes inflammatory reactions in the skin ( dermatitis ) ____________________-‐reaction allergy ( within minutes ) Overproduction of _____ antibodies
