Lymphatic and Immune Systems

1. Chapter 21 Lymphatic and Immune Systems

2. Components Lymph Lymph vessels ___________, nodules, lymphatic organs, diffuse lymphatic tissue ________________

3. Immunity Filters fluids from capillary beds _____________________ _____________________ Lipid absorption ____________ in small intestine absorb lipids Fluid recovery/balance ______________________ ________________ (2 to 4 L/day) from tissues and returns it to CVS Functions of Lymphatic System

4. Lymph and Lymphatic Capillaries _________________ clear, colorless fluid, ________ __________________________ Lymphatic capillaries closed at one end tied to tissue by ___________ ____________________ endothelial cells loosely overlapped allow bacteria and cells to enter ____________________________ ____________________________ ____________________________

5. Lymphatic Vessels Large vessels composed of 3 layers ________________: endothelium and valves tunica media: ______________ ________________________ tunica externa: thin outer layer

6. Route of Lymph Flow Lymphatic capillaries Collecting vessels _________________: drain major portions of body

7. Collecting ducts : __________________ – R arm, R side of head and thorax; empties into R subclavian vein __________________ - larger & longer, begins at the cisterna chyli; gets lymph from below diaphragm, L arm, L side of head, neck and thorax; empties into L subclavian vein

8. Mechanisms of Lymph Flow __________________________________ Moves by contractions of vessels stretching of vessels stimulates contraction aided by skeletal muscle pump ______________________ aids flow from abdominal to thoracic cavity ______________________________ Rapidly flowing blood in subclavian veins, draws lymph into it Exercise _________________ lymphatic return

9. Lymphatic Cells __________________________ cells responsible for immune surveillance T lymphocytes _____________________________ B lymphocytes activation ? proliferation and differentiation into plasma cells ? antibodies __________________________ Cells _______________________________ _________________ (in epidermis, mucous membranes and lymphatic organs) ____________________ (also contribute to stroma of lymph organs)

10. Lymphatic Tissue ___________________________ tissue mucous membranes and CT of organs Mucosa-Associated Lymphatic Tissue (MALT): in passages open to exterior Lymphatic nodules dense oval masses of lymphocytes, __________________: at junction of small to large intestine

11. Lymphatic Organs _______________ lymphatic organs where T & B cells become immunocompetent __________________________ _________________ lymphatic organs immunocompetent cells live here __________________________________

12. Lymph Node Lymph nodes - filter lymph Fewer____________vessels, slows flow through node ____________________ divide node into compartments Formed from capsule containing stroma (reticular CT) and parenchyma (lymphocytes and APCs) divided into cortex (lymphatic nodules) and medulla ________________________________________________ lymphocytes respond to antigens

13. __________________ Collective term for lymph node diseases _____________________ swollen, painful node responding to foreign antigen Lymph nodes are common sites for metastatic cancer ______________________ ______________________

14. Tonsils ____________________ pair at posterior margin of oral cavity _____________________________ ____________________ pair at root of tongue ____________________ (adenoid) single tonsil on wall of pharynx Covered by epithelium Pathogens in tonsillar crypts and encounter lymphocytes

15. Thymus Trabeculae, divide parenchyma into lobules of cortex and medulla Reticular epithelial cells secretes hormones (______________________ _____________________________________) ______________________________________ ______________________________________ Very large in fetus;________________ after age 14 Elderly: fatty, fibrous tissue

16. Spleen Parenchyma _______________: sinuses filled with erythrocytes white pulp: _________________________________ Functions blood production in fetus ____________________________ ____________________________ ____________________________________________

17. Defenses Against Pathogens _________________________ - broadly effective, no prior exposure first line of defense ______________________ second line of defense ____________________________________________ ____________________________________________ ________________________ - results from prior exposure, ____________________________ _________________________________________ third line of defense ______________________________

18. External Barriers ____________________ toughness of keratin __________________________ ____________: peptides, from neutrophils attack microbes lactic acid (acid mantle) - sweat _________________________________ stickiness of mucus _______________: enzyme destroys bacterial cell walls Subepithelial areolar tissue tissue gel: ____________________________________ hyaluronidase: enzyme used by pathogens to spread

19. Leukocytes and Cutaneous Defenses Neutrophils Eosinophils Basophils Monocytes Lymphocytes

20. Neutrophils ________________________ Create a killing zone __________________________ lysosomes discharge into tissue fluid respiratory burst _____________________________ (O2.-, H2O2, HClO)

21. ___________________ ____________________________________ _____________________________ Promote action of basophils, mast cells Enzymes block excess inflammation, limit action of histamine

22. ___________________ Aid mobility and action of WBC’s by release of _________________________________ ? blood flow to infected tissue _________________________________ prevents immobilization of phagocytes

23. __________________ ___________________________________ Specialized macrophages found in specific localities ____________________________ epidermis, oral mucosa, esophagus, vagina, and lymphatic organs ___________________ (CNS) _____________________ (lungs) hepatic macrophages (liver)

24. _________________ Circulating blood contains 80% T cells 15% B cells 5% NK cells

25. Antimicrobial Proteins _______________________ Secreted by cells infected by viruses _____________________________ stimulate neighboring cells to produce antiviral proteins _______________________________________ destroy infected host cells ____________________________________________

26. Antimicrobial Proteins (cont.) __________________________ in blood activated by pathogens Mechanisms of action enhanced inflammation _____________________________ promoted by opsonization _____________________________ membrane attack complex forms on target cell immune clearance Ag-Ab complexes carried to liver and spleen

27. Immune Surveillance __________________ destroy bacteria, transplanted cells, cells infected by viruses, and cancer cells release _____________________ __________________________

28. ___________________ Response to tissue injury limits spread/destroys pathogens ____________________ initiates tissue repair ____________________ small proteins regulate inflammation and immunity ____________________________________ factor, and chemotactic factors

29. Inflammation ______________________________ redness (erythema) ______________________ ? capillary permeability and filtration heat caused by ____________________ _________________ ? inflammatory chemicals from damaged cells, pressure on nerves

30. Inflammation Three major processes _______________________________ containment and destruction of pathogens _______________________________

31. Mobilization of Defenses Leukocyte Deployment ________________ leukocytes adhere to blood vessel walls ___________________ (emigration) leukocytes squeeze between endothelial cells into tissues

32. Containment and Destruction of Pathogens ____________________ traps pathogens ____________________ prevents clotting pathogens are surrounded by clot ______________________ leukocytes are attracted to chemotactic chemicals ________________________________________ phagocytosis respiratory burst cytokines recruits macrophages and neutrophils macrophages and T cells secrete colony-stimulating factor to stimulate leukopoiesis

33. Tissue Cleanup Monocytes agents of cleanup arrive in 8 to 12 hours, ? macrophages ____________ ? venous flow, ? lymphatic flow that favors removal of bacteria and debris Formation of ____________ _______________________________________ _______________________________________ _______________________________________

34. ___________ Defense mechanism promotes _______________________ inreases metabolic rate and tissue repair inhibits pathogen reproduction ____________________________ _________________ resets body thermostat higher > 105?F may ?delirium, 111?F- 115?F, coma-death Stages of fever onset, stadium, _______________

35. Specific Immunity Specificity and memory _______________________: cell-mediated (T cells) ____________________________: _____________ mediated (B cells)

36. Passive and Active Immunity Active _________________________________ (produces memory cells) produce antibodies or T cells ___________________________ ____________________________________________________ Artificial active immunity (produces memory cells) ____________________________________________________ ___________________________ ______________________________ (_________________) temporary, fetus acquires antibodies from mother ______________________________________________ temporary, injection of immune serum (antibodies)

37. _________________ Trigger an immune response ___________________________ proteins, polysaccharides, glycoproteins, glycolipids _________________________________ stimulate immune responses Haptens _______________________________________ _______________________________________ _______________________________________

38. Life Cycle of T cells Specific immunity depends on lymphocytes _______________________________ _______________________________ maturing T cells to produce antigen receptors immunocompetent T cell has antigen receptors Deployment naïve T cells colonize lymphatic tissue and organs

39. B Lymphocytes (B cells) Sites of development fetal stem cells remain in bone marrow ________________________ B cells should not react to self antigens or suffer clonal deletion Self-tolerant B cells form B cell clones ________________________

40. Antigen-Presenting Cells (APCs) B cells and macrophages, display antigens to T cells

41. Cellular Immunity T cells attack foreign cells and diseased host cells; memory of Ag Three classes of T cells _______________________________________ Helper T cells: __________________________ _______________________________________ _______________________: provide immunity from future exposure

42. Attack Phase: Role of Helper T Cells ___________________ _________________ _________________ attract neutrophils, NK cells, macrophages _________________ _________________ stimulate T and B cell mitosis and maturation

43. Attack Phase: _________________ Only T cells directly attack enemy cells Killing mechanism __________________________________ interferons - decrease viral replication and activates macrophages _______________________________________

44. Memory ______________________ some T cells become long lived memory cells T cell recall response _______________________________________ _______________________________________

45. ____________ Immunity ____________________ B cell receptors bind antigen, take in and digest antigen then display epitopes TH cell divide, differentiate ? plasma cells? antibodies to that antigen Attack _______________________ _______________________ _______________________ ___________________ some B cells differentiate ? memory cells

46. Antibody Structure Protein _________________ Light chain __________________ __________________ Immune system capable of as many as 1 trillion different antibodies

47. Antibody Classes _______________________ Plasma, mucus, saliva, tears, milk, intestinal secretions _______________________ B cell membrane antigen receptor IgE: monomer on mast cells ______________________________ ______________________________ ______________________________ _____________________ 80% circulating, cross placenta to fetus, 2? immune response, complement fixation _____________________ 10% in plasma, 1? immune response, agglutination, complement fixation

48. Humoral Immunity - Attack ______________________ antibodies mask pathogenic region of antigen ________________________ antigen binds to IgM or IgG, antibody activates complement; primary defense against foreign cells, bacteria __________________________ antibody has 2-10 binding sites; binds to multiple enemy cells immobilizing them Precipitation _____________________________________________ _____________________________________________

49. Hypersensitivity (Allergy) Excessive immune reaction against antigens that most people tolerate - allergens Type I Antibody mediated (________), acute reaction ________________: anaphylactic shock ________________: pollen, dust cat dander asthma Type II Antibody mediated (___________), subacute _______________________________ 5-12 hours Graves disease, myasthenia gravis Type III Antibody mediated (__________), subacute Antibody complexes ppt, 3-8 hours ________________________________________________ Type IV Cell mediated, delayed (12-72 hours) __________________________________________ Poison ivy, TB test

50. Match Type 1 Type 2 Type 3 Type 4

51. Autoimmune Diseases Failure of self tolerance cross-reactivity __________________________________ changes in structure of self-antigens Production of ______________________

52. Immunodeficiency Diseases Severe Combined Immunodeficiency Disease hereditary lack of T and B cells __________________________ __________________________

53. AIDS HIV structure enters helper T cells, macrophages and dendritic cells by receptor mediated endocytosis _______________________________________ viral DNA inserted into host cell DNA, may be dormant for months to years Immunodeficiency Diseases

54. AIDS Signs and symptoms early symptoms: Flu-like chills and fever Later night sweats, fatigue, headache, extreme weight loss, lymphadenitis normal TH count is 600 to 1,200 cells/?L of blood in AIDS it is < 200 cells/?L opportunistic infections (Toxoplasma, Pneumocystitis, herpes simplex virus, CMV or TB) _______________: white patches on mucous membranes ____________________: cancer originates in endothelial cells of blood vessels causes purple lesions in skin

55. HIV Transmission ____________________________________ ____________________________________ Most common: sexual intercourse (vaginal, anal, oral) contaminated blood products contaminated needles ____________________________________ Latex condom is an effective barrier to HIV especially with spermicide nonoxynol-9

56. Treatment Strategies Prevent binding to CD4 proteins of TH cells Disrupt reverse transcriptase, inhibit assembly of new viruses or their release from host cells Medications none eliminate HIV, all have serious side-effects Resistance develops, meds used in combination AZT azidothymidine first anti-HIV drug, inhibits reverse transcriptase Protease inhibitors inhibit enzymes HIV needs to replicate now more than 16 anti-HIV drugs