A&P ch. 22

functions of the lymphatic system

- draining excess interstitial fluid and plasma proteins from tissue spaces - transporting dietary lipids and vitamins from GI tract to the blood - facilitating immune responses - recognize microbes or abnormal cells and responding by killing them directly or secreting antibodies that cause their destruction

cytotoxic T cells: - receptor on CD8 cell binds to foreign antigen fragment part of MHC-1 - costimulation from __ t cell - proliferates and differentiates into population (clone) of Tc cells and memory Tc cells - occurs in __ such as lymph node helper t cells: - receptor on CD4 cell binds to foreign antigen fragment associated with MHC-II - costimulation with __ - proliferates and differentiates into population (clone) of Th cells and long-lived memory Th cells

- helper - secondary lymphatic organs - interleukin

lymphatic capillaries have a slightly __ diameter than blood capillaries and have __ endothelial cells which work as one-way valves for fluid to enter the lymphatic capillary __ attach endothelial cells to surround tissue a lymphatic capillary in the villus of the small intestine is the __. It functions to transport digested fats from the small intestine into blood

- larger - overlapping anchoring filaments lacteal

lymphatic vessels resemble veins with __ walls and __ valves fluid flows through lymph nodes towards large veins above the __ lymph is emptied into the __

- thin - more heart blood stream

vessels unite to form __ and __ right side head, arm, and chest empty into __ and rest of body empties into __ lymph is dumped directly into __

trunks, thoracic ducts right lymphatic duct, thoracic duct left and right subclavian artery

four basic types of hypersensitivity reactions __ - the most common and occur within a few minutes after a person sensitized to an allergen is reexposed to it. Anaphylaxis results from the interaction of allergens with IgE antibodies on the surface of mast cells and basophils. In anaphylactic shock, which may occur in a susceptible individual who has just received a triggereing drug or been stung by a wasp, wheezing and shortness of breath as airways constrict are usually accompanied by shock due to vasodilation and fluid loss from blood. This is a life threatening emergency __ - reactions are caused by antibodies (IgG or IgM) directed against a person's blood cells or tissue cells. The reaction of antibodies and antigens usually leads to activation of complement. Type II reaction, which may occur in incompatible blood transfusion reactions, damage cells by causing lysis. __ - reactions involve antigens (not part of a host tissue cell), antibodies (IgA or IgM), and complement. Some type II conditions include glomerulonephritis, systemic lupus erythematosus, and rheumatoid arthritis. __ - reactions or delayed hypersensitivity reactions usually appear 12-72 hours after exposure to an allergen and occur when allergens are taken up by antigen-presenting cells that migrate to lymph nodes and present

type I type II (cytotoxic) type III (immune complex) type IV (cell-mediated)

cell-mediated immunity begins with activation of a __ by a specific antigen result is T cell capable of an immune attack - elimination of the intruder by a direct attack in a cell-mediated immune response, an antigen is recognized (bound), a small number of specific T cells proliferate and differentiate into a clone of __ cells (a population of identical cells that can recognize the same antigen and carry out some aspect of the immune attack) and the antigen (intruder) is eliminated

T cell effector

__ - a condition in which a person experiences a telltale assortment of infections as a result of the progressive destruction of immune cells by the human immunodeficiency virus (HIV) although HIV has been isolated from several body fluids, the only documented transmissions are by way of blood, semen, vaginal secretions, and breast milk from an infected nursing mother. It does not appear that people become infected as a result of routine, nonsexual contacts the AIDS virus is generally thought to be quite fragile outside of the body and easily eliminated with standard disinfecting techniques prevent aids by blocking transmission of the virus, including abstinence, use of condoms, use of sterile hypodermic needles.

acquired immunodeficiency syndrome (AIDS)

flow in lymph nodes is in one direction __ vessels lead in __ lead to efferent vessels that exit at __ only __ filter lymph lymph nodes concentrated near __ , __ , and __ parenchyma is divided into two regions: lymphatic nodules with germinal centers containing dendritic cells - antigen-presenting cells and macrophages contains B cell and plasma cells in medullary cords __ is the capsule, trabeculae, and reticular fibers

afferent sinuses, hilus nodes mammary glands, axillae, groin cortex, medulla cortex medulla stroma

__ - a protein that can combine soecifically with the antigenic determinant on the antigen that triggered its production antibodies consist of heavy and light chains and variable and constant portions based on chemistry and structure, antibodies are grouped into 5 principle classes each with specific biological roles ( IgG, __ , IgM, __ , and IgE) glycoproteins called __ - __ polypeptide chains - __ heavy, and __ light chains - hinged midregion lets assume T or Y shape - tips are variable regions - rest are __ region - 5 different classes based on constant region - __ , IgA, __ , IgD, and __ - __ form antigen binding sites

antibody IgA, IgD immunoglobins 4, 2, 2 constant IgG, IgM, IgE tips

cells called __ process exogenous antigens (antigens formed outside the body) and present them together with MHC II molecules to T cells APCs include macrophages, B cells, and dendritic cells the presentation of exogenous antigens together with MHCII molecules on antigen presenting cells alerts __ cells that intruders are present foreign antigen in body fluid is phagocytized by __ antigen is digested and fragments are bound to MHC-II molecules stuck into antigen presenting cell membrane APC migrates to __ to find T cells

antigen presenting cells T APC lymphatic tissue

__ - molecules or bits of foreign material - entire microbes, parts of microbes, bacterial toxins, pollen, transplanted organs, incompatible blood cells required characteristics to be considered an antigen: __ - ability to provoke immune responses __ - ability to react to cells or antibodies it caused to be formed get past the bodies nonspecific defenses - enter the bloodstream to be deposited in the __ - penetrate the skin and end up in __ - penetrate mucous membrane and lodge in associated __

antigens - immunogenicity - reactivity - spleen - lymph nodes - lymphoid tissue

in an __ , the immune system fails to display self-intolerance and attacks the person's own tissue __ is a contagious disease primarily affecting lymphatic tissue throughout the body but also affecting the blood. It is caused by the Epstein-Barr virus which multiplies in B cells. There is no cure, and treatment consists of watching for and treating complications. Usually the disease runs its course in a few weeks. __ are cancers of the lymphatic organs especially the lymph nodes. The two main types are: Hodgkin disease and non-Hodgkin lymphoma. __ is a chronic autoimmune, inflammatory disease that affects multiple body systems.

autoimmune disease infectious mononucleosis lymphomas systemic lupus erythematosus

lymphatic capillaries are found throughout the body except in __ (cartilage, epidermis, and cornea) structure is designed to let tissue fluid in but not out - __ keep tube from collapsing under outside pressure - __ open when tissue pressure is high (one-way valve)

avascular tissue anchoring filaments overlapping endothelial cells

cancer cells travel via __ or __ cells establish new tumors where they lodge secondary tumor sites can be predicted by direction of lymphatic flow from primary site cancerous lymph nodes are __, __, and __ - infected lymph nodes are not firm and are very tender

blood, lymphatic system firm, enlarged, nontender

t- cells: __-mediated response - __ cells attack antigens - __ cells costimulate T and B cells effective against fungi, viruses, parasites, cancer, and tissue transplants b cells in bone marrow __-mediated response - plasma cells form __ effective against bacteria

cell - killer - helper antibody - antibodies

during activation of a B cell, an antigen binds to antigen receptors on the __ B cell antigen receptors are __ similar to the antibodies that will eventually be secreted by their progeny some antigen is taken into the B cell, broken down into __ fragments and combined with MHC-II self-antigen, and moved to the B cell surface __ recognize the antigen MHC-II combination and deliver the costimulation needed for B cell proliferation and differentiation some activated B cells become __ cells. Tthers become memory B cells

cell surface chemically peptide helper T cells antibody-secretion plasma

__ - refers to the destruction of antigens by T cells - particularly effective against __ , such as fungi, parasites, and viruses; some cancers cells; and foreign tissue transplants - CMI always involves cells attacking __ __ - refers to destruction of antigens by antibodies - works mainly against antigens dissolved in body fluids and extracellular pathogens, primarily bacteria, that multiply in body fluids but rarely enter body cells often a __ provokes both types of immune responses

cell-mediated immunity - intracellular pathogens - cells antibody-mediated (humoral) immunity pathogen

__ - attraction to chemicals from damaged tissues, complement proteins, or microbial products __ - attachment to plasma membrane of phagocyte __ - engulf by pseudopods to form phagosome __ - merge with lysosome containing digestive enzymes and form lethal oxidants - exocytosis residual body

chemotaxis adherence ingestion digestion and killing

neutralization of antigen by blocking effects of toxins or preventing its attachment to body cells immobilize bacteria by attacking __ agglutinate and precipitate antigens by __ them causing clumping and precipitation complement activation enhancing phagocytosis through precipitation, complement activation or __ (coating with special substance)

cilia/flagella cross-linking opsonization

a group of about 20 proteins present in blood plasma and on cell membranes comprises the __ system - when activated, these proteins "complement" or enhance certain immune, allergic, and inflammatory reactions

complement

t cell receptors recognize antigen fragments associated with MHC molecules on the surface of a body cell proliferation of T cells requires __ , by cytokines such as interleukin-1 and interleukin-2, or by pairs of plasma membrane molecules, one of the surface of the I cell and a second on the surface of an APC

costimulation

Small protein hormones involved in immune responses - secreted by __ and antigen presenting cells cytokine therapy uses cytokines (interferon) __ - used to treat Kaposi's sarcoma, genital herpes, hepatitis B and C, and some leukemias __ - used to treat multiple sclerosis __ - used to treat cancer (side effects)

cytokines - lymphocytes - alpha-interferon - beta-interferon -interleukin-2

display CD8 on surface known as t8 or Tc or killer t cells recognize antigen fragments associated with MHC-I molecules - cells infected with virus - tumor cells - tissue transplants costimulation required by cytokine from helper t cell

cytotoxic t cells

inflammation initiated by __ signs of inflammation loss of function may be a fifth symptom, depending on the site and extent of injury function is to trap microbes, toxins, or foreign material and begin tissue repair

damaged cells redness, heat, swelling, pain

__ - synthesized within the body and include viral proteins or proteins produced by cancer cells most of the cells of the body can process endogenous antigens fragments of endogenous antigen are associated with MHCI molecules inside the cell the antigen MHCI complex moves to the __ where it alerts T cells

endogenous antigens cell's surface

__ - small part of antigen that triggers the immune response - antigenic determinant __ is smaller substance that can not trigger an immune response unless attached to body protein - lipid of poison ivy

epitope hapten

B cells can bind to antigen in __ T cells can only recognize fragments of antigens that have been processed and presented to them as part of a MHC molecule - __ T cells "see" antigens if part of MHC-II molecules on surface of antigen presenting cell - __ T cells "see" antigens if part of MHC-I molecules on surface of body cells

extracellular fluid - helper - cytotoxic

abnormally high body temperature that occurs because the hypothalamic thermostat is reset occurs during infection and inflammation - bacterial toxins trigger release of fever-causing cytokines such as interleukin-1 benefits - intensifies effects of interferons, inhibits bacterial growth, speeds up tissue repair

fever

__ - after organ transplant, immune system has both cell-mediated and antibody-mediated immune responses close match of histocompatibility complex antigens has __ graft rejection response - immunosuppressive drugs (cyclosporine) - inhibits secretion of interleukin-2 by __ T Cells - little effect on __ cells so maintains some resistance

graft rejection weaker helper B

display CD4 on surface so also known as T4 cells or Th cells recognize antigen fragments associated with MHC-II molecules and activated by APCS function is to costimulate al other lymphocytes - secrete cytokines - autocrine function in that it costimulates itself to proliferate and secrete more interleukin (positive feedback effect causes formation of many more helper T cells)

helper t cells

antibodies against a particular antigen can be harvested from blood - different antibodies will exist for the different epitopes on that antigen growing a clone of plasma cells to produce identical antibodies is difficult fused B cells with tumor cells that will grow in culture producing a __ antibodies produced called __ antibodies used clinically

hybridoma monoclonal antibodies

__ - a person who is overly reactive to a substance that is tolerated by most others when an allergic reaction occurs, there is tissue injury. The antigens that induce an allergic reaction are called __

hypersensitive allergens

__ - the ability of the body to defend itself against specific invading agents - bacteria, toxins, viruses, cat dander differs from nonspecific defense mechanisms __ - recognize self and non-self __ - 2nd encounter produces even more vigorous response __ - substances recognized as foreign by the immune responses __ - the branch of science that deals with the responses of the body when challenged by antigens

immunity - specificity - memory antigens immunology

__ - due to the presence of long-lived antibodies and very long-lived lymphocytes that arise during proliferation and differentiation of antigen-stimulated B and T cell - immunization against certain microbes is possible because memory B cells and memory T cells remain after the __ response to an antigen - the __ response (immunological memory) provides protection should the same microbe enter the body again. There is rapid proliferation of memory cells, resulting in a far greater antibody titer (amount of antibody in serum) than during a primary response

immunological memory primary secondary

__ - carried out by cytotoxic T cells - they recognize tumor antigens and destroy the tumor cell - the immune system can recognize proteins in transplanted organs as foreign and mount a graft rejection success of a proposed organ or tissue transplant depends on __ . Tissue typing (histocompatibility testing) is done before any organ transplant organ transplant recipients also receive immunosuppresive drugs

immunological surveillance histocompatibility

the thymus gland is a large organ in __ (70 g) but atrophied as __ (3 g) the thymus gland is a __ lobed organ located in the __ __ and __ divide it into lobules each lobule has a __ and __ the __ contains tightly packed lymphocytes and macrophages the __ contains reticular epithelial cells produces thymic hormones - Hassall's corpuscles

infants, adult 2, mediastinum capsule, trabeculae cortex, medulla cortex medulla

cytotoxic t cells migrate to the site of __ or tumor formation recognize, attach and attack - secrete granules containing __ that punch holes in target cell - secrete __ that activates enzymes in the target cell causing its DNA to fragment - secrete __ to activate phagocytic cells

infection perforin lymphotoxin gamma-interferon

body cells infected with viruses produce proteins called __ once produced and released from virus-infected cells, IFN diffuses to uninfected neighboring cells and binds to __ , inducing uninfected cells to synthesize antiviral proteins that interfere with or inhibit viral replication INFs also enhance the activity of phagocytes and natural killer cells, inhibit cell growth, and suppress tumor formation; they may hold promise as clinical tools in AIDS and cancer treatment once they are more fully understood

interferons surface receptors

the second line of defense: - involves internal antimicrobial proteins, phagocytic and natural killer cells, inflammation, and fever __ discourage microbial growth - interferons - complement proteins - transferrins

internal defenses antimicrobial

mechanica protection: - skin is composed of closely packed, __ cells - shedding helps remove __ - mucous membrane secretes __ - __ and mucus trap and move microbes toward the throat - washing action of tears, urine, and saliva chemical protection - __ inhibits growth of bacteria and fungus - __ break down bacterial cells - __ pH of gastric juice and vaginal secretions destroy bacteria

keratinized microbes viscous mucous cilia sebum perspiration lysozymes acidic

with advancing age, the immune system functions __ effectively individuals become more susceptible to infections and malignancies response to vaccines is __ produce more antibodies reduced immune system function - t cells __ responsive to antigens - age related atrophy of thymus - decreased production of thymic hormones - B cells less responsive - production of antibodies is slowed

less decreased less

the principle lymph trunks, formed from the exiting vessels of lymph nodes, are the __, __, __, __, and __ trunks the __ begins as a dilation called the cisterna chyli and is the main collecting duct of the lymphatic system the thoracic duct receives lymph from the __ side of the head, neck, and chest, and the left upper extremity, and the entire body below the ribs it drains lymph into venous blood via the __

lumbar, intestinal, bronchomediastinal, subclavian, and jugular trunks thoracic duct left left subclavian arteries

the lymphatic system consists of a fluid called __ flowing within lymphatic vessels, several structures and organs that contain lymphatic tissue (specialized reticular tissue containing large numbers of lymphocytes) and bone marrow, which is the site of lymphocyte production major difference of interstitial fluid and lymph the __ functions to drain interstitial fluid, return leaked plasma proteins to the blood, transport dietary fats, and protect against invasion by nonspecific defenses and specific immune responses

lymph location lymphatic system

interstitial fluid drains into __ the passage of lymph is from arteries and blood capillaries (blood) to __ (interstitial fluid) to lymph capillaries (lymph) to __ to lymph trunks to the __ or right lymphatic duct to the __ (blood) lymph flows as a result of the milking action of __ muscle contractions and respiratory movements it is also aided by lymphatic vessel valves that prevent the backflow of lymph an excessive accumulation of interstitial fluid may be caused by __ fluid and proteins escaping from vascular capillaries is collected by __ and returned to the blood respiratory and muscular pumps promote flow of lymphatic fluid lymphatic vessels empty into __

lymph capillaries interstitial spaces, lymphatic vessels, thoracic duct, subclavian veins skeletal an obstruction to lymph flow lymphatic capillaries subclavian veins

lymphatic vessels begin as blind-ended ___ in tissue spaces between cells interstitial fluid drains into lymphatic capillaries, thus forming __ lymph capillaries merge to form larger vessels, called ___, which convey lymph into and out of structures called ___

lymph capillaries lymph - lymphatic vessels - lymph nodes

encapsulated oval structures located along lymphatic vessels - contain t cells, macrophages, follicular dendritic cells, and B cells lymph enters nodes through __ lymphatic vessels , is filtered to remove damaged cells and microorganisms, and exits though __ lymphatic vessels foreign substances filtered by the lymph nodes are trapped by __ macrophages then destroy some foreign substances by __ and lymphocytes bring about the destruction of others by __ __ are the site of proliferation of plasma cells and T cells knowledge of the location of the lymph nodes and the direction of lymph flow is important in the diagnosis and prognosis of the spread of cancer by metastasis; many cancer cells are spread by way of the __ , producing clusters of tumor cells where they lodge

lymph nodes afferent, efferent nodal reticular fibers phagocytosis, immune response lymph nodes lymphatic system

B cells sit still in the __ , spleen, or peyer's patches once activated, differentiate into __ cells that secrete antibodies antibodies circulate in __ and blood - combines with __ on antigen similarly to how a key fits a specific lock

lymph nodes plasma lymph epitopes

lymphatic vessels develop from __ , which develop from veins. Thus, they are derived from __ lymph nodes develop from lymph sacs that become invaded by __

lymph sacs, mesoderm mesenchymal cells

concentrations of lymphatic tissue not surrounded by a capsule scattered throughout connective tissue of mucous membranes - mucosa-associated lymphoid tissue (MALT) appendix payers patches are located in the __ of the small intestines __ form ring at the top of throat __ - pharyngeal tonsil __ - on each side of the wall __ - in the back of the tongue

lymphatic nodules ileum tonsils adenoids palatine tonsils lingual tonsil

cells with antitumor activity are injected into blood stream of cancer patient - culture patient's inactive cytotoxic t cells with interleukin-2 - called __ can cause tumor __ , but has severe complications

lymphokine-activated killer cells (LAK) regression

__ in the splenic cord removes worn-out defective RBCs, WBC, and platelets the spleen stores blood platelets in the __ the red pulp is involved in the production of blood cells during the second trimester of pregnancy

macrophages red pulp

t cells from a clone that did not turn into cytotoxic t cells during a cell-mediated response available for swift response if a 2nd exposure should occur

memory t cell

Natural killer cells kill a variety of __ and __ cells NK cells are found in __ , spleen, __ , and red marrow phagocytes ( neutrophils and macrophages) ingest __ or particulate matter macrophages developed from __ fixed macrophages stand guard in specific tissues - histiocytes in the skin, __ cells in the liver, alveolar macrophages in the lungs, __ in the brain, and macrophages in spleen, red marrow and lymph nodes wandering macrophages in most tissue

microbes, tumor cells blood, lymph nodes microbes monocytes kupffer, microglia

__ - important in measuring levels of a drug in a patient's blood diagnosis of pregnancy, allergies, and diseases such as hepatitis, rabies,, and some STDs they have also been used in early detection of cancer and assessment of extent of metastasis they may be useful in preparing vaccines to counteract transplant rejection, to treat autoimmune diseases, and perhaps to treat AIDS

monoclonal antibodies

t cells undergo both positive and negative selection to ensure that they can recognize self-MHC antigens (self-recognition) and that they do not react to other self-proteins (tolerance) __ - involves both deletion and anergy __ - develop tolerance much research has centered on __ , the study of ways to use the immune system for detecting, monitoring, and treating cancer

negative selection B cells cancer immunology

__ are cells specialized to perform phagocytosis and include __ and __ the four phases of phagocytosis include __ , adherence, __ , digestion and killing after phagocytosis has been accomplished, a __ is formed the __ in the phagolysosome, along with lethal oxidants produced by the phagocyte, quickly kills many types of microbes some of the reasons why a microbe may evade phagocytosis include: capsule formation. __ production, interference with lysozyme secretion, and the microbe's ability to counter __ produced by the phagocytes

phagocytes, neutrophils, macrophages chemotaxis, ingestion phagolysosome lysosome toxin, oxidants

the field of __ deals with common pathways that link the nervous, endocrine, and immune systems PNI has shown that thoughts, feelings, moods, and beliefs influence the level of health and the course of disease

psychoneuroimmunology (PNI)

__ is dead phagocytes, damaged tissue cells and fluid __ is an accumulation of pus in a confined space not open to the outside - pimples and boils ulcer is an __ sore people with poor circulation (diabetics with advanced atherosclerosis) - __ ulcers in tissues of legs due to poor oxygen and nutrient supply to tissues

pus abscess open stasis

organs involved in the lymphatic system site of lymphocyte production

red bone marrow, thymus, spleen, lymph nodes, diffuse lymphatic tissue - tonsils, adenoids, peyers patches bone marrow

The ability to ward of pathogens that produce disease lack of resistance __ resistance to disease includes defense mechanisms that provide general protection against invasion by a wide range of pathogens __ involves activation of specific lymphocytes that combat a particular pathogen or other foreign substances the body system that carries out immune responses is the ___

resistance susceptibility nonspecific immunity lymphatic system

the right lymphatic duct drains lymph from the upper __ side of the body it drains lymph into venous blood via the __

right right subclavian artery

the three basic stages of inflammation: vasodilation and increased permeability of vessels - caused by histamine from mast cells, kinins from precursors in the blood, prostaglandins from damaged cells, and leukotrienes from basophils and mast cells - occurs within minutes producing heat, redness, and edema - pain can result from injury, pressure from edema or irritation by toxic chemicals from organisms - blood-clotting factors leak into tissues trapping microbes phagocyte emigration - within an hour, neutrophils and then monocytes arrive and leave blood stream (emigration) tissue repair

1. vasodilation and increased permeability of vessels 2. phagocyte emigration 3. tissue repair

complement system is made up of over __ proteins many complement proteins are __ and must be activated activated complement acts in a cascade that causes - __ - dilation of arterioles, release of histamine, and increased permeability of capillaries - __ - protein binds to microbe making it easier to phagocytize - __ - a complex of several proteins can form holes in microbe membranes causing leakiness and cell rupture compliment may be activated by the __ pathway, alternative pathway, and the __ pathway

30 inactive - inflammation - opsonization/phagocytosis - cytolysis classical, lectin

developmental anatomy begins to develop by the __ week __ and __ form thoracic duct sacs develop into __ spleen develops into __ thymus is outgrowth of __

5th jugular sac, cisterna chyli lymph nodes gastric mesentery 3rd pharyngeal pouch

the first line of defense __ refers to a wide variety of body responses against a wide range of pathogens (disease producing organisms) and their toxins __ include that intact epidermis layer of the skin, mucous membranes, the lacrimal apparatus, saliva, mucus, cilia, the epiglottis, and the flow of urine. Defecation and vomiting also may be considered mechanical processes that expel microbes. __ is localized on the skin, in loose connective tissue, stomach, and vagina the skin produces __ , which has a low pH due to the presence of unsaturated fatty acids and lactic acid __ is an enzyme component of sweat that also has antimicrobial properties __ renders the stomach nearly sterile because its low pH kills many bacteria and destroys most of their toxins; vaginal secretions are also slightly acidic

skin and mucous membranes nonspecific resistance mechanical protection chemical protection sebum lysozyme gastric juice

Primary immune response - first exposure to antigen response is steady and __ - memory cells may remain for decades secondary immune response with 2nd exposure - 1000s of memory cells proliferate and differentiate into __ cells and cytotoxic t cells - antibody titer is measure of __ (amount serum antibody) - recognition and removal occurs so quickly not even sick

slow plasma memory

B cell receptors bind to antigen. The response is more intense if on __ helper T cell costimulates rapid cell division and differentiation occurs - long-lived memory cells - secrete only one kind of antibody antibody enters the circulation to attack antigen

APC

5 inch organ between stomach and diaphragm hilus contains __ and __ stroma consists of capsule, trabeculae, fibers, and fibroblasts parenchyma consists of __ and __ white pulp is lymphatic tissue (lymphocytes and macrophages) around branches of __ red pulp is __ filled with blood and splenic tissue (splenic cords)

spleen blood, lymphatic vessels white pulp, red pulp splenic artery venous sinuses

both T and B cels derive from __ in bone marrow B cells complete their development in __ t cells develop from pre-T cells that migrate to the __ before t cells leave the thymus or B cells leave bone marrow, they acquire several distinctive surface proteins; some function as __ , molecules capable of recognizing specific antigens

stem cells bone marrow thymus antigen receptors

cancerous cell displays unusual __ antigens (tumor antigens) surveillance - immune system finds, recognizes, and destroys cells with tumor antigens - done by cytotoxic t cells, __ , and natural killer cells - most effective in finding tumors caused by __ transplant patients taking immunosuppressive drugs suffer most from __ - induced cancers

surface macrophages viruses viral

Cytotoxic T cells fight foreign invaders by killing the __ cell (the cell that bears the same antigen that stimulated activation or proliferation of their progenitor cells) without damaging the cytotoxic T cell itself - when cytotoxic T cells encounter a cell displaying a microbial antigen, they can release granzymes which trigger __ . The microbe then destroyed the phagocytes - cytotoxic t cells can also bind to infected cells and release perforin and __ . Perforin causes __ while granulysin destroys the microbes. - cytotoxic t cells can also release __ which activates damaging enzymes within the target cell - when the cytotoxic t cell detaches from the target cell, it can destroy another cell

target apoptosis granulysin, cytolysis lymphotoxin

primary lymphatic organs provide an environment for stem cells to divide and mature into __ and __ lymphocytes red bone marrow gives rise to mature __ the __ is the site where pre-T cells from red bone marrow mature __ is the site where most immune responses occur

B, T B cells thymus secondary lymphatic organs and tissues - lymph nodes, spleen, and lymphatic nodules

classical pathway begins with activation of __ alternate pathway begins with activation of __ lead to inflammation, enhanced phagocytosis, or microbe bursting

C1 C3

T cells must learn to recognize self (its own MHC molecules) and lack reactivity to own proteins - self-recognition and immunological tolerance - t cells mature in __ those that cant recognize self or react to it are - destroyed by programmed cell death (apoptosis or deletion) - inactivated (anergy) - alive but unresponsive only 1 in 100 emerges immunocompetent T cell b cells similarly develop in __

thymus bone marrow

__ - a form of retrovirus with a protein coat wrapped by an envelope of glycoproteins HIV enters T cells where it sheds its __ the t cells are ultimately destroyed common signs and symptoms: fever, fatigue, rash, headache, joint pain, sore throat, swollen lymph nodes. Infected individual ultimately develops antibodies to HIV progression to AIDS occurs because of reduced numbers of T cells and resulting immunodeficiency. AIDS lowers body's immunity by decreasing number of helper T cells; the result is progressive collapse of immune system, making the person susceptible to opportunistic infection (invasion of normally harmless microorganisms that now proliferate wildly because of defective immune system) treatment of HIV with reverse transcriptase inhibitors and protease inhibitors has shown to delay the progression of HIV infection to AIDS

HIV protein coat

Major Histocompatibility complex antigens all our cells have unique surface markers (1000s molecules) - integral membrane proteins called __ MHC-1 molecules are built into cell membrane of all cells except __ - function: if cell is infected with virus MHC-I contain bits of virus marking cell so __ cells recognize there is a problem MHC-II markers seen only on membrane of __ presenting cells (macrophages, B cells, thymus cells) - function: if antigen presenting cells ingest foreign proteins, they will display as part of their MHC-II histocompatibility is a similarity of MHC antigens on body cells of different individuals - tissue typing must be done __ any organ transplant - can help identify biological parents

HLA antigens red blood cells - T antigen before

__ - display CD4 protein, recognize antigen fragments associated with MHC-II molecules, and secrete several cytokines, most important, interleukin-2, which acts as a costimulator for other helper t cells, cytotoxic t cells, and b cells __ - develop from t cells that display cd8 protein and recognize antigen fragments associated with MHC-1 molecules __ - programmed to recognize the original invading antigen, allowing initiation of a much swifter reaction should the pathogen invade the body at a later date

Helper t cells cytotoxic t cells memory t cells