CH 20 and 21 Lymphatic System AND Immune System Objectives PDF

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Objectives were used to further understanding of chapters and material, a guideline for quizes...

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ANATOMY AND PHYSIOLOGY II CHAPTER OBJECTIVES Chapter 20: THE LYMPHATIC SYSTEM Chapter 21: THE IMMUNE SYSTEM After attending this series of lectures and studying the text and lecture presentations and notes the student should be able to: PART 1: Chapter 20 – The Lymphatics System 1.

Define the following: lymphatics, lymphoid organs, and lymph. State the source of the fluid that makes lymph. Lymphatics- transport fluids that have escaped from blood back to the blood Lymphoid organs-house phagocytic cells and lymphocytes which defend body Lymph- once interstitial fluid enters lymphatics

2.

Provide a general description of the distribution and structure of the lymphatic vessels. Include a functional description of lymph capillaries, minivalves, anchoring collagen, lymph node, collecting vessels, trunks, and ducts. In microscopic lymph capillaries—almost everywhere blood capillaries are. Lymph travels through lymphatic vessels One way flows toward heart Lymph capillaries- progress to collecting vesselstrunksducts Minivavles- endothelial cells of lymphatic capillary wall overlap form minivalve Anchoring collagen- little hair filaments Lymph node-cleans lymph of debris ‘examined’ by immune cells Collecting vesselsTrunks-largest collecting vessels join to form lymphatic trunks, empty into ducts

Ducts-empties lymph into venous circulation Right lymphatic ductDrains lymph from right upper arm, right side of head and thorax Thoracic DuctDrains lymph from rest of body

Cisterna Chyli- collects lymph from 2 lumbar trunks and from intestinal trunk 3.

List the major trunks of the lymphoid system. Name the duct the drains lymph from the right upper arm, right side of head, and thorax. Name the duct that drains lymph from the rest of the body. Provide a functional definition of the cisterna chili. Trunks-empty into ducts Paired lumbar Paired bronchomediastinal Paired subclavian Paired jugular Single intestinal Right lymphatic ductDrains lymph from right upper arm, right side of head and thorax Thoracic DuctDrains lymph from rest of body Cisterna Chyli- collects lymph from 2 lumbar trunks and from intestinal trunk

4.

Describe how lymph is transported since there is very little pressure gradient. Rely on milking action by active skeletal muscles Pressure changes within thorax during breathing Valves prevent backflow Smooth muscle in trunk walls contracts rhythmically

5.

Briefly describe the functional role of each of the cell types (lymphocytes, macrophages, dendritic cells, and reticular cells) found in the lymphatics. LymphocytesActivated T cells, manage the immune response, some directly attack and destroy foreign cells B-Cells Produce plasma cells(secrete antibodies) Macrophages- Phagocytize foreign substances, activate T cells

Dendritic cells- Phagocytize foreign substances, activate T cells Reticular cells- Produce reticular stroma (supporting network) 6.

Describe the general architecture of lymphoid tissue. Include in your description the lymphoid follicle, Peyer’s patches, and germinal centers. Lymphoid tissue- composed of reticular connective tissue, macrophages live on fibers, Lymphoid follicles-nodles found in lymph nodesPeyer’s patches- Also occur in intestinal wall and in appendix. Germinal centers- lighter staining centers, follicular dendritic & B cell

7.

List where clusters of lymph nodes are found. Describe the structure and function of a lymph node. Cervical-neck Axillary - underarm Inguinal nodes- groin Lymph node structural function is to filter pathogen and debris from interstitial fluid. More Afferent vessels than efferent allows for lingering filtering. Swollen lymph nodes when large number of bacteria and viruses present.

8.

Describe the structure of the spleen and how the spleen works as a lymphoid organ. Curves around L. of stomach Lymphocyte proliferation Immune surveillance Immune response Blood cleansing Stores/releases breakdown products of RBCs Erythrocyte production in fetus Stores platelets White pulp: Lymphocytes on reticular fiber

Surround central arteries Immune functions Red Pulp: Splenic cords Reticular fibers rich in macrophages Disposes of worn-out RBCs and blood bourne pathogens w/o spleen liver and bone marrow take over 9.

Describe how the thymus functions as a lymphoid organ. List the hormones secreted by the thymus. Active: newborn-childhood Prepares T lymphocytes to do battle Outer coretex, inner medulla Blood-thymus barrier Secretes: thymosin& thymopoietin

10.

Locate the palatine, lingual, pharyngeal, and tubal tonsils. State the functional and structural relationships of tonsils. Tonsils form ring around pharynx. Gather and remove pathogens entering the pharynx via air/food, crypts trap bacteria and particulate matter.

11.

Define MALT and state its function. Mucosa Associated Lymphatic Tissue Protects digetive and respiratory tracts from foreign matter(bacteria)

PART II: Chapter 21 – The Immune System

12.

List the 3 general lines of defense in the immune system. Categorize defense elements (i.e. skin, membranes, phagocytes, NK cells, inflammation, B cells, and T cells) into their respective general line of defense.

1 2 3

13.

Describe how the intact skin and mucosa act as surface barriers that confer primary innate (nonspecific) immune defenses. Skin has acidity secretion of pH 3-5, inhibiting bacterial growth Vaginal secretions are also acidic Stomach mucosa- HCL acid, protein digesting enzymes, killing microorganisms Salivia(and lacrimal fluid) contains lysozyme- destroys bacteria Sticky mucus traps microorganisms entering digestive and respiratory passageways.

14.

List the phagocytic cells and describe how they along with natural killer (NK) cells confer primary innate (nonspecific) immune defenses. Describe phagocytosis. Macrophages “big eaters” Natural Killer – less picky than lymphocytes, not phagocytic, attack virus infected/tumor cells, looks for “banners” of “self”

NeutrophilsEosinophils-weakly phagocytic PhagocytosisRecognizing microbes sugar coat Engulf Phagocytic vesicle (phagosome) fuses with a lysosome  phagolysosome Microbe in fused vesicle killed and digested Residual material removed by exocytosis 15.

Describe how inflammation confers a secondary innate (nonspecific) immune defense. List the cardinal signs of inflammation and what causes each of them (Figure 21.3). Define edema and state how it aides in the secondary innate (nonspecific) immune defense. Inflamation is a secondary innate immune defense by: Prevents spread of damaging agents to nearby tissue Disposes of cell debris and pathogens Sets stage for repair process

Cardinal signs: Redness-rubor- arterioles dilate, local hyperemia Swelling-tumor- arterioles dilate, local hyperemia Heat-calor- increased capillary permeability, capillaries leak fluid, protein fluid in tissue spaces Pain-dolor-increased capillary permeability, capillaries leak fluid, protein fluid in tissue spaces

Edema—protein rich fluid surge into tissue spaces Helps dilute harmful substances Brings in large quantities of oxygen & nutrients Allows entry of clotting proteins

16.

Define each of the 4 elements in phagocyte mobilization: leukocytosis, margination, diapedesis, and chemotaxis. Define selectins. Leukocytosis- neutrophils enter blood from bone marrow Margination- neutrophils cling to capillary walls Diapedesis- neutrophils flatten and squeeze out of capillaries Chemotaxis- neutrophils follow chemical trail Selectins- cell adhesion molecules

17.

Describe how antimicrobial/viral proteins like interferon and complement confer secondary innate (nonspecific) immune defenses. Describe the role of fever in the process. Interferon: Antiviral Activates macrophages and mobilizes NK cells Family of a,B, & Y interferons.

Fever: Widespread body response to invading microorganisms Pyrogens secreted by leukocytes, macrophages High fever denatures proteins Liver & spleen sequester Iron and Zinc- not available for microbes

Complement: Enhances effectiveness of both nonspecific and specific defenses Two pathways of C3 18.

Describe how the adaptive defenses are specific. Briefly describe the roles of each of the 2 parts of the adaptive immune system.

Specific: Antigen- specific Systemic- not just infection site “memory” 2 adaptive parts of Immune systemHumoralAntibodies Cell mediatedlymphocytes act against targets directly by lysing indirectly by releasing chemical mediators- enhance inflammatory response 19.

Compare and contrast an antigen and a hapten. Define antigenic determinants. Antigen-small molecules, peptides, nucleotides, hormones, NOT immunogenic, link with self proteins combination is considered foreign, reactive but not immunogenic Hapten- ARE immunogenic, target immune response, complex molecules, Antigenic determinantsPart of entire AG Immunogenic Free Abs/activated lymphocytes bind Single antigen may be recognized by many antibodies Large proteins have hundreds

20.

Define immunocompetent. State where B-cells and T-cells become immunocompetent. Immunocompetent- able to recognize a specific antigen by binding to it. B-cells- become immunocompetent in the bone marrow T-Cells- become immunocompatent thymus.

21.

Describe the process of T-cell selection. Describe B-cell maturation.

T-Cell selectionthymic cortex- positive selection of self tolerant, but immunocompetent tcells. Thymic medulla- negative selection of strongly anti-self T cells. B-cell maturation- self-reactive b-cells inactivated and killed, B and Tcell receptors determined genetically before antigen exposure. 22.

List the major types of antigen presenting cells and state their role in the adaptive immune response. Process and present antigen to T-cells Engulf foreign particles and present its antigens on their surface for recognition. Dendritic cellsActivated B LmphocytesMacrophages-

23.

Define antigen challenge and state where this may occur and what likely response the challenge may evoke. Antigen challenge- first encounter between naïve immunocompetent lymphocyte and antigen. Occurs in Spleen/Lymph Node/other lymphoid tissue If B cell involved, humoral immune response initiated—b cell produces antibodies to antigen.

24.

Describe the primary and secondary responses. State how the secondary response is different than the primary response and what is responsible for this difference. Primary – initial encounter with antigen. Memory B cells provide immunological memory. Secondary immune response faster, more prolonged, more effective. Difference b/c second is faster since it can quickly recognize

25.

Compare and contrast the following: active and passive humoral immunity; naturally acquired and artificially acquired active immunity; naturally acquired and artificially acquired passive immunity. Active humoral immunity – Bcells challenged, memory occurs. Ie Naturally acquired: infection contact with patogen. Artificially acquired: Vaccine: Dad or attenuated pathogens.

Passive humoral immunity- memory does not occur Naturally acquired- antibodies passed from mother to fetus via placentra; or infant in breast milk Artificially acquired—injection of exogenous antibodies 26.

Describe an immunoglobulin. Include in your description the functional definitions of the heavy and light chains and the variable and constant regions. Antibodies aka immunoglobuins- four polypeptide chains(2 heavy, 2 light): Heavy= longer ,identical to eachother, have ‘hinge’ Lighter=shorter, identical to eachother, Variable regions are antigen binding sites Constant (effector) regions determine antibody class

27.

Compare and contrast the structures and functions of the five classes of immunoglobulins. IgM,IgA,IgD,IgD,IgG,IgE IgM- occurs as a pentamer First antibody released to the blood by plasma cells Fixes complement IgA- Occurs as a monomer or dimmer Dimmer called secretory IgA In mucus and secretions that bathe body surface IgD- always bound to B cell surface, acts as a B cell receptor IgGMost aboundent antibody in plasma Mother to fetus across placenta Fixes complement IgE- Associated with allergies

28.

Describe the “PLAN” of attack of antibodies. Describe complement fixation. PLAN: P-precipitation L-lysis A-aggultination N-neutralization Complement fixation- antibody ammunition against cellular antigens such as bacteria, mismatched blood cells. Complement-binding sites on constant regions of antibody. Binding of antibody to cellular antigen surface triggers complement fixation.

29.

State the types of T-cells and their respective functions. State what T-cells cannot “see”. CD4- primary helper T cells (Th) CD8- Cytotoxic T cells (Tc), destroy any body cell containing foreign material T suppressor (Ts) Memory T cells T dh(delayed hypersensitivity T cells)

T-Cells can’t see free antigens- have to respond to processed fragments of protein antigens. 30.

State the cells that display and the immune function of MHC class I and MHC class II proteins. MHC Class I- Displayed by all cells but RBCs. Always recognized by CD8 T cells(cytotoxic) Self proteins Endogenous Ags- derived from viral proteins/mutated cancerous self proteins. MHC class II- mature B cells, some T cells, APCs Display peptide fragments of foreign(exogenous) antigens, recognized by CD4 cells(helper) Nonself-antigen Self- MHC protein of a body cell

31.

Describe the steps in T-cell activation. Define costimulation, cytokines, and anergy. Step 1:T cell activation, antigen binding T cell antigen receptor bind to antigen- MHC complex on surface of body cell MHC restriction CD4(Th) --bind only antigens linked to class II MHC proteins usually on APC surface CD8 (Tc) --bind to antigen fragments complexed with class I MHC proteins don’t need APCs for binding Require stimultaneous recognition of self and nonself Antigen bindng for CD4 shown

Step 2: T cell activation Once activated proliferate into clones Primary response takes 1 week then death Those not used are memory T cells Costimulation- binding to other surfaces on an APC Cytokines- released by macrophages or T cells, act as costimulators of T cells, secreted by T cells amplify immune response, can enhance killing power of macrophages Anergy- if T cell binds to antigen, but doesn’t receive costimulation becomes unresponsive. 32.

Describe why helper T cells are required for the adaptive immune response. Required for adaptive immune response Primed by APC presentation of antigen Chemically or directly stimulate proliferation of other antigen bound T and B cells

33.

Describe the role of cytotoxic T cells.

Directly attack and kill other cells: Virus infected, bacterial infected, parasite infected, cancer, foreign from blood transfusion, organ transplant. 34.

Define immunodeficiency and describe some causes of this condition. Describe autoimmune diseases and list some common ones. Define hypersensitivity. Immunodeficencies: compromised immune system CongenitalSevere combined immunodeficiency syndrome (SCID) Genetif defects produce marked deficit of both B and T cells -bubble boy -bone marrow transplants AcquireAIDS-inferers with CD4(helper T) --HIV virus transmitted in blood, semen, vaginal secretions --opportunistic infections --reverse transcriptase inhibitors Autoimmune diseaseFriendly fire from autoantibodies Most common Multiple sclerosis Myasthenia gravis Type I diabetes mellitus Rheumatoid arthritis Hypersensitivities: Immune system causes tissue damage fights off pollen of dander(allergens)...