Anatomy and Physiology 2 Lymphatics and Immunity
reticuloendothelial system
(monocyte-macrophage) almost every tissue in the body shelters resident or visiting macrophages
IgD
.2% mainly found on B-cell antigen receports - aids activation monomers
List and describe the cells and chemicals the body uses as its second line of defense.
1. Phagocytes, such as neutrophils or macrophages, engulf foreign particles. These cells are in nearly every body organ and confront pathogens that make it through the surface membrane barriers. 2. Natural killer cells, found in blood and lymph, are lymphocytes. They can lyse and kill cancer cells and virus-infected body cells. 3. The inflammatory response is a nonspecific response that occurs when body tissues are injured.
long term secretion of glucocorticoids inhibits response of immune systems by
1. depressing the inflamm response via mast cell inhibition and decrease capillary permeability 2. inhibits activity of phagocytes 3. reduces activity of phagocytes 4. inhibiting interleukin secretion
purpose of inflammation
1. dispose of source of tissue insult 2. prevent spread of injury to other tissue 3. prepare injured area for repair - regeneration
activated macrophages
1. engulf and destroy target 2. bind to target and wait for assistance by other immune cells 3. release toxic chemicals (tumor necrosis factor, H202) to destroy target
interleukins
1. increase T-cell sensitivity to antigens exposed on macrophage membranes 2. increase B-cell activity 3. enhance non-specific defenses 4. suppress or shorten the immune response
steps in processing and presenting exogenous antigens by APCs
1. ingestion of antigen by APC 2. digest antigen into peptide fragments and synthesis of MHC-II molecules 3. fusion of vesicles w/ peptide fragment with vesicles w/ MHC-II molecules 4. binding of peptide fragment with MHC-II 5. insertion of peptide MHC-II complex into plasma membrane after exocytosis 6. APC migrates to lymphatic tissue to present antigen to T-cells - immune response triggered
the second response is immediate bc
1. memory b cells are activated at relatively low antigen conc. 2. antibodies they synthesize are more effective and destructive
IgA
10-15% of antibodies; found in secretions; monomers and dimers
complement system
11 plasma proteins in an ordered cascade of rxns that leads to inflammation, lysis of microbes and enhanced phagocytosis
primary response
1st encounter w/ antigen; slow rise in antibody titer (first IgM then IgG) - folowed by gradual decline; peaks 1-2 wks post initial exposure
phagocytic cells
2 general classes: microphages (neutrophils and eosinophils) and macrophages
antibody structure (glycoproteins called immunoglobulins - contain 4 polypeptide chains) antibody is in Y or T shape
2 heavy chains - have short carb chains attached to each heavy chain 2 light chains - disulfide bonds hold each light chain to a heavy chain hinge region - two disulfide bonds link the mid-region of the 2 heavy chains stem region - parts of the 2 heavy chains beond the hinge region
IgM
5-10% pentamers activates complement found in blood and lymph 1st antibody class to be secreted by plasma cells after initial exposure to antigen
IgG
80% of antibodies; found in blood, lymph, intestines; monomer; ONLY antibody that crosses placenta; triggers complement, enhances phagocytosis and neutralizes toxins; Anti-Rh antibodies
T-cells
80% of circulating WBCs - includes cytotoxic T-cells which attack foreign cells or virally infected cells; helper T-cells which stimulate the activation and function of T-cells and B-cells; suppressor T-cells - inhibit the activation and function of T-cells and B-cells originate within the red bone marrow, but complete their development within the thymus
Which one of the following is NOT an autoimmune disease: A) AIDS B) rheumatoid arthritis C) type I diabetes mellitus D) Gravesʹ disease E) multiple sclerosis
A) AIDS
The immune system cell type that is preferentially destroyed by the Epstein-Barr virus in mononucleosis is the A) B lymphocyte. B) cytotoxic T lymphocyte. C) helper T lymphocyte. D) macrophage.
A) B lymphocyte.
The relatively common autoimmune disease in which the thyroid gland produces excessive amounts of thyroxine is called: A) Gravesʹ disease B) myasthenia gravis C) multiple sclerosis D) systemic lupus erythematosis E) glomerulonephritis
A) Gravesʹ disease
With immediate hypersensitivy, the antibody class that binds to mast cells and basophils that trigger the release of histamine and other chemicals is: A) IgE B) IgD C) IgG D) IgM E) IgA
A) IgE
The specific antibody class that has the ability to cross the placental barrier and provide immunity to the fetus is: A) IgG B) IgM C) IgD D) IgE E) IgA
A) IgG
The lymph tissues found within the walls of the small intestine are called: A) Peyerʹs patches B) tonsils C) appendix D) thymus tissues E) intestinal nodes
A) Peyerʹs patches
By secreting hormones, the thymus causes which cells to become immunocompetent? A) T lymphocytes B) B lymphocytes C) macrophages D) monocytes
A) T lymphocytes
Lymph vessels drain lymph from all the lymphoid organs (simply because lymph vessels drain almost all organs of the body). However, lymph vessels enter (empty into) only one type of lymphoid organ. The only organ with such afferent lymph vessels is A) a lymph node. B) the spleen. C) the appendix. D) the thymus
A) a lymph node.
A bubo is A) an infected lymph node containing a large number of pathogens that are trapped in the node but not destroyed. B) a cancer-infiltrated lymph node. C) any enlarged lymph node. D) a structure that is unrelated to lymph nodes
A) an infected lymph node containing a large number of pathogens that are trapped in the node
Which one of the following is NOT one of the nonspecific body defenses: A) antibody production B) natural killer cells C) the inflammatory response D) intact skin E) fever
A) antibody production
The largest kind of lymphatic vessel is a lymphatic A) duct. B) trunk. C) sinus. D) capillary.
A) duct.
Regardless of whether it matures into a B cell or a T cell, a lymphocyte that is capable of res ponding to a specific antigen by binding to it is said to be: A) immunocompetent B) immune C) incompetent D) complemented E) clonal
A) immunocompetent
In lymph nodes, follicles are always located A) in the cortex. B) near the hilum. C) in the lymph sinuses. D) in the medullary cords.
A) in the cortex
The lymph trunk that contains chyle and is unpaired is the A) intestinal. B) subclavian. C) jugular. D) right lymph trunk.
A) intestinal
Which of the following is not classified as a lymphoid organ? A) liver B) spleen C) tonsils D) aggregated nodules in the intestine
A) liver
Lymphocytes attack antigens mostly in lymphoid organs (except the thymus) and in A) loose connective tissue. B) the bloodstream. C) cartilage. D) the thyroid.
A) loose connective tissue
The lymphatic capillaries are A) more permeable than blood capillaries. B) less permeable than blood capillaries. C) as permeable as blood capillaries. D) completely impermeable
A) more permeable than blood capillaries.
Lymphatic capillaries are present in A) skin. B) teeth. C) the central nervous system. D) bone marrow.
A) skin.
Vaccines are NOT for: A) snake bites B) polio C) measles D) pneumonia E) tetanus
A) snake bites
Lymph from the left arm would return to the heart through the: A) thoracic duct B) aorta C) left subclavian artery D) right lymphatic duct E) inferior vena cava
A) thoracic duct
T cells gain immunocompetence in this lymphoid organ. A) thymus B) tonsils C) spleen—red pulp D) lymph nodes E) spleen—white pulp
A) thymus
The lymphoid organ that atrophies with age. A) thymus B) tonsils C) aggregated lymphoid nodules D) lymph nodes E) spleen
A) thymus
Lymphoid organs located in the mucosal lining of the pharynx. A) tonsils B) salivary glands C) uvula D) pharygotympanic tube E) aggregated lymphoid nodules
A) tonsils
Lymph flows: A) toward the heart only B) in a circular pattern within the tissues C) away from the heart only D) both toward and away from the heart E) into the capillaries
A) toward the heart only
Immune sera are used for all of the following EXCEPT: A) tuberculosis B) botulism C) snake bites D) rabies E) tetanus
A) tuberculosis
Describe the four major types of transplant grafts.
Autografts are tissue grafts transplanted from one site to another within the same person. Isografts are tissue grafts harvested from a genetically identical person (identical twin). Allografts are tissue grafts harvested from an unrelated person. Xenografts are tissue grafts harvested from different animal species.
antibody mediated immune responses
B cells transform into plasma cells which produce and secrete immunoglobulins (antibodies)
Which of these statements regarding lymph capillaries is false? A) They begin as closed-ended tubes. B) They have precapillary sphincters that regulate drainage of lymph from tissues. C) They lack barriers to stop cancer cells from entering the lymphatic system. D) They unite with each other to form collecting vessels.
B) They have precapillary sphincters that regulate drainage of lymph from tissues.
Is it possible for lymphocytes to gain immunocompetence in the thymus of an 82-year-old person? A) Yes, but the thymus has shifted to the production of B lymphocytes. B) Yes, but fewer than in youth. C) No, because the thymus has completely degenerated. D) No, because all lymphocytes have turned into thymic corpuscles.
B) Yes, but fewer than in youth.
The distal region of the small intestine contains clumps of lymph follicles called A) pancreatic islets. B) aggregated lymphoid follicles. C) rugae. D) villi.
B) aggregated lymphoid follicles
An isograft is a tissue graft donated by: A) an unrelated person B) an identical twin C) a different animal species D) a parent E) the same person
B) an identical twin
B lymphocytes are to ________ as T lymphocytes are to ________. A) antibodies; antigens B) antibodies; programmed cell death C) antigens; antibodies D) programmed cell death; antibodies
B) antibodies; programmed cell death
B cells develop immunocompetence in the: A) spleen B) bone marrow C) lymph nodes D) thyroid gland E) thymus gland
B) bone marrow
Which one of the following is NOT a method by which antibodies inactivate antigens: A) agglutination B) chemotaxis C) precipitation D) neutralization E) complement fixation
B) chemotaxis
Which cell has the responsibility of presenting foreign antigens to lymphocytes? A) cytotoxic CD8+ T lymphocyte B) dendritic cell C) helper CD4+ T lymphocyte D) natural killer
B) dendritic cell
The process by which neutrophils are squeezed through the capillary walls during the inflammatory process is called: A) coagulation B) diapedesis C) agglutination D) chemotaxis E) antibody production
B) diapedesis
Lymph leaves a lymph node via A) afferent lymphatic vessels. B) efferent lymphatic vessels. C) the cortical lymph sinus. D) the subcapsular sinus.
B) efferent lymphatic vessels.
Which one of the following is NOT a type of immunosuppressive therapy given after surgery to prevent rejection of a graft: A) antiproliferative drugs B) gamma globulin C) immunosuppressive drugs D) radiation E) corticosteroids
B) gamma globulin
In a histological cross section through an artery, a vein, and a lymphatic vessel, one can recognize the lymphatic vessel because it A) has the fewest valves. B) has the thinnest walls. C) has the thickest tunica media. D) always lies closest to the artery, which has the thinnest walls
B) has the thinnest walls
Given that a germinal center arises from a single activated lymphocyte, how many different kinds of antibodies are secreted by a single germinal center (and by the plasma cells it produces)? A) none; T cells do not produce antibodies B) one C) several dozen D) thousands
B) one
The bulges that give lymph vessels a string-of-beads appearance are really A) lymph nodes. B) pockets for valves. C) weakenings in the wall of the vessels. D) temporary constrictions caused by bulging skeletal muscles that squeeze the lymph vessel
B) pockets for valves
The bodyʹs first line of defense against the invasion of disease-causing microorganisms is: A) phagocytes B) skin and mucous membranes C) natural killer cells D) fever E) inflammatory response
B) skin and mucous membranes
Compared to the nonspecific chemicals that cover body surfaces and mucous membranes, the specific body defense system is: A) sometimes faster and sometimes slower B) slower C) the same speed D) faster E) not comparable in speed
B) slower
Macrophages that destroy aged and defective blood cells from circulation are present in the ________ of the spleen. A) hilum B) splenic cords C) venous sinuses D) white pulp
B) splenic cords
The lymph organ that programs T cells and functions at peak levels only during youth is the: A) spleen B) thymus C) Peyerʹs patches D) appendix E) tonsils
B) thymus
Two-lobed lymphoid organ located posterior to the sternum. A) cisterna chyli B) thymus C) MALT D) lacteals E) crypts
B) thymus
Which lymphoid tissues trap and remove bacteria entering the throat: A) cervical lymph nodes B) tonsils C) axillary lymph nodes D) Peyerʹs patches E) thymus gland
B) tonsils
Musoca-associated lymphatic tissue (MALT) includes: A) spleen B) tonsils and Peyerʹs patches C) tonsils only D) thymus gland E) tonsils and spleen
B) tonsils and Peyerʹs patches
In the spleen, lymphoid tissue is confined to the A) red pulp. B) white pulp. C) trabeculae. D) hilus
B) white pulp.
self tolerance
B-cell or T-cell's lack of reactivity to peptide fragments from one's own proteins - neg. selection
primary nodule develops into secondary nodule when
B-cells in primary lymphatic nodule recognize an antigen
A person with many enlarged lymph nodes that do not feel tender or sore is most likely to have A) lymphangitis. B) mononucleosis. C) Hodgkin's lymphoma. D) buboes.
C) Hodgkin's lymphoma.
Which one of the following is NOT one of the antibody classes: A) IgG B) IgD C) IgB D) IgA E) IgE
C) IgB
Which of the following statements about the right lymph duct is false? A) Not all people have one. B) This duct and its tributaries drain the superior right quarter of the body. C) It empties into the thoracic duct. D) It forms from the union of a jugular, subclavian, and bronchomediastinal trunk.
C) It empties into the thoracic duct
Lymphoid tissue associated with the digestive, respiratory, urinary, and reproductive tracts. A) aggregated lymphoid nodules B) tonsils C) MALT D) lacteals E) crypts
C) MALT
The process by which antibodies bind to specific sites on bacterial exotoxins (toxic chemicals secreted by bacteria) to block their harmful effects is called: A) chemotaxis B) precipitation C) agglutination D) neutralization E) complement fixation
C) agglutination
The lymph trunk that drains the thoracic organs is called the A) posterior intercostal trunk. B) great cardiac trunk. C) bronchomediastinal trunk. D) azygos trunk
C) bronchomediastinal trunk
The sinuses within lymph nodes A) are separated from the bloodstream by a blood-node barrier. B) consist of star-shaped epithelial cells that secrete immune-boosting hormones. C) contain macrophages living along a reticular fiber network. D) surround clumps of lymphoid tissue called white pulp.
C) contain macrophages living along a reticular fiber network
Which cell secretes cytokines that will stimulate the proliferation of other types of immune cells? A) cytotoxic CD8+ T lymphocyte B) dendritic cell C) helper CD4+ T lymphocyte D) natural killer cell
C) helper CD4+ T lymphocyte
The immune system cell type that is preferentially destroyed by the AIDS virus is the A) B lymphocyte. B) cytotoxic T lymphocyte. C) helper T lymphocyte. D) helper B lymphocyte
C) helper T lymphocyte
The study of immunity is called: A) histology B) anatomy C) immunology D) pathology E) microbiology
C) immunology
Clusters of lymph nodes occur in all of the following sites except A) along the aorta. B) in the mediastinum. C) in bones and bone marrow. D) in the inguinal region
C) in bones and bone marrow
Lymphatic ducts deliver lymph to the cardiovascular system proximal to the A) external jugular veins. B) inferior vena cava just below the right atrium. C) internal jugular and subclavian veins. D) superior vena cava and azygos vein.
C) internal jugular and subclavian veins
The paired lymph trunks that carry lymph from the lower limbs are the A) cisterna chyli. B) iliac trunks. C) lumbar trunks. D) femoral trunks
C) lumbar trunks
Structures comprised of endothelial cells separated by flaplike minivalves that are opened as fluid accumulates in peripheral tissue describes A) blood capillaries. B) lymph nodes. C) lymph capillaries. D) cisterna chyli. E) thoracic duct.
C) lymph capillaries.
Masses of lymphoid tissue within a lymph node. A) trabeculae B) hilum C) lymphoid follicles D) white pulp E) subcapsular sinus
C) lymphoid follicles
The specific type of acquired immunity that a fetus obtains from maternal antibodies that cross the placenta is called: A) naturally acquired active immunity B) artificially acquired passive immunity C) naturally acquired passive immunity D) artificially acquired active immunity E) artificially acquired natural immunity
C) naturally acquired passive immunity
Because the appendix is a narrow tube, it traps microorganisms from the digestive tract, and these microorganisms enter its wall and activate memory lymphocytes for long-term immunity. Another immune organ that traps microorganisms is the A) thymus. B) bone marrow. C) palatine tonsil. D) the spleen.
C) palatine tonsil
Which of the following cells are the largest producers of antibodies? A) B lymphocytes B) T lymphocytes C) plasma cells D) macrophages
C) plasma cells
Which of the following is not a normal component of lymph? A) water B) plasma proteins C) red blood cells D) ions
C) red blood cells
Which lymphatic structure drains lymph from the right upper limb? A) lumbar trunk B) thoracic duct C) right subclavian duct D) cisterna chyli
C) right subclavian duct
Which one of the following CANNOT be said about the history of immunity: A) scientists of the 1800s demonstrated that immune serum could protect another animal from disease B) scientists of the mid-1900s discovered that injection of serum containing antibodies did NOT always protect a recipient from disease C) scientists of the mid-1900s discovered the viral origin of AIDS D) scientists of the 1800s discovered ʺfactorsʺ now called antibodies E) the ancient Greeks knew something existed within the body to protect it from infectious disease
C) scientists of the mid-1900s discovered the viral origin of AIDS
Which of the following lymphoid structures have a hilum? A) tonsils and appendix B) thymus and aggregated lymphoid nodules C) spleen and lymph nodes D) MALT
C) spleen and lymph nodes
Fever has the effect of doing all of the following EXCEPT: A) denaturing (scrambling) proteins B) stimulating the liver and spleen to gather up iron and zinc C) stimulating complement fixation D) speeding up repair processes E) increasing metabolic rate of tissue cells
C) stimulating complement fixation
In humans, T lymphocytes originate in A) the spleen. B) the thymus. C) the red bone marrow. D) the lymph nodes.
C) the red bone marrow
Which of the following lymphoid organs does not directly fight antigens? A) tonsil B) spleen C) the thymus D) aggregated lymphoid nodules
C) the thymus
Which one of the following is NOT true of macrophages: A) they are considered the ʺbig eatersʺ of the immune system B) they engulf foreign particles C) they circulate continuously throughout the body D) they secrete monokines E) they act as antigen presenters
C) they circulate continuously throughout the body
Begins at the cisterna chyli. A) thymic corpuscles B) aggregated lymphoid nodules C) thoracic duct D) MALT E) inguinal lymph nodes
C) thoracic duct
This organ has a superficial cortex filled with lymphocytes and an inner medulla with few lymphocytes and a sizable number of degenerating epithelial reticular cells. A) lymph node B) spleen C) thymus D) tonsil
C) thymus
All of the following mechanisms help move lymph through the lymphatic vessels except A) contractions of smooth muscle in the wall of the lymph vessels. B) body movements during exercise. C) tiny lymph hearts. D) contraction of skeletal muscles
C) tiny lymph hearts
The HIV that causes AIDS infects immune cells that have the surface protein called ________.
CD4
cell mediated immune responses
CD8+ cells DIRECTLY attack invading antigen
One location where lymphoid tissue is found is "in the frequently infected mucous membranes of the digestive, respiratory, urinary, and reproductive tracts." Specifically, this refers to A) intestinal and bronchomediastinal lymph trunks. B) the intestinal and tracheobronchial lymph nodes. C) the cisterna chyli and lacteals. D) MALT.
D) MALT.
Which of the following might explain why most people are sick more often as children than as adults in their 20s through 50s? A) The immune system does not appear until the preteen years. B) The thymus is so active in children that it fights bacteria so hard that it produces strong symptoms of disease. C) Because of their small size, children's bodies cannot contain as much lymphoid tissue as those of adults. D) We build up many varieties of memory lymphocytes during childhood, providing immunity to more and more antigens during adulthood.
D) We build up many varieties of memory lymphocytes during childhood, providing immunity to more and more antigens during adulthood
A lymphoid nodule is A) a small lymph node. B) a type of lymphoma. C) a bulge in a lymphatic collecting vessel. D) a cluster of densely packed lymphocytes.
D) a cluster of densely packed lymphocytes
Which one of the following is NOT a type of lymphoid organ: A) spleen B) thymus gland C) Peyerʹs patches D) appendix E) tonsils
D) appendix
What specific type of acquired immunity do vaccines provide: A) naturally acquired artificial immunity B) naturally acquired passive immunity C) artificially acquired passive immunity D) artificially acquired active immunity E) naturally acquired active immunity
D) artificially acquired active immunity
Lymphatic vessels perform all of the following functions except A) returning excess tissue fluid to the bloodstream. B) returning leaked blood proteins to the bloodstream. C) transporting digested fats. D) carrying blood.
D) carrying blood
The thymus is most active during A) fetal development. B) adolescence. C) old age. D) childhood.
D) childhood
Allergic contact dermatitis following skin contact with poison ivy would normally lead to: A) immediate hypersensitivity B) anaphylactic shock C) immunodeficiency D) delayed hypersensitivity E) acute hypersensitivity
D) delayed hypersensitivity
The specific foreign substances that an individualʹs immune system has the ability to recognize and resist is determined by: A) the total number of lymphocytes present at a given time B) individual exposure to the specific foreign substance C) the total number of macrophages at a given time D) individual genetic makeup E) the total number of self-antigens at a given time
D) individual genetic makeup
Set of lymphatic capillaries that collect fat-laden fluids from the intestinal tract. A) lumbar trunks B) subclavian trunks C) bronchomediastinal trunks D) lacteals E) intestinal trunk
D) lacteals
The tonsil located on the posterior surface of the tongue is the ________ tonsil. A) palatine B) pharyngeal C) tubal D) lingual
D) lingual
Small, bean-shaped organs abundant in the cervical, axillary, and inguinal regions. A) lymphatic capillaries B) afferent lymphatic vessels C) lymphatic ducts D) lymph nodes E) lacteals
D) lymph nodes
Which of the following is not a part of MALT? A) lymphoid tissue in the appendix B) lymphoid tissue in the tonsils C) aggregated lymphoid nodules D) lymphocytes in the spleen
D) lymphocytes in the spleen
Which of the following substances is NOT typically perceived as an antigen: A) pollen grains B) virus particles C) fungi D) self-antigens E) bacteria
D) self-antigens
Recycles red blood cells and initiates immune responses. A) tonsils B) lymph nodes C) MALT D) spleen E) thymus
D) spleen
The ________ stores blood platelets. A) lymph node B) thymus C) tonsil D) spleen
D) spleen
Edema is A) a form of cancer. B) an infection of the lymphatic vessels. C) an infection of the lymph nodes. D) the accumulation of excess tissue fluid in loose connective tissue.
D) the accumulation of excess tissue fluid in loose connective tissue.
In humans, B lymphocytes originate in A) the thymus. B) the appendix. C) all lymphoid tissue. D) the bone marrow.
D) the bone marrow
Which one of the following is NOT a mechanism that aids lymph return: A) smooth muscle contractions within the lymphatic vessels B) milking action of skeletal muscles C) pressure changes within the thorax D) the pumping action of the heart E) presence of valves within the larger lymph vessels
D) the pumping action of the heart
A patient with lymphangitis presents with visible red lines on the skin that are tender to the touch. The best explanation for this sign is that A) lack of movement has caused pooling of lymph in the vessels, which compromised the lymphatic valves, resulting in varicose lymph vessels. B) red blood cells have infiltrated the lymphatic system. C) the spleen has overdegraded red blood cells, releasing iron into the lymphatic system. D) the vasa vasorum on the surface of infected lymph vessels has become inflamed and congested with blood.
D) the vasa vasorum on the surface of infected lymph vessels has become inflamed and congested with blood
Lymph capillaries differ from blood capillaries in all of the following ways except that A) they are more permeable than most blood capillaries. B) they carry lymph instead of blood. C) they are blind-ended. D) their walls consist of endothelial cells.
D) their walls consist of endothelial cells
Which one of the following is NOT true of the constant (C) regions of antibodies: A) they are the same or nearly the same B) they form the ʺstemʺ of an antibody C) they determine how an antibody class will carry out its immune role D) they form an antigen-binding site E) they determine the specific type of antibody class formed
D) they form an antigen-binding site
Which one of the following is NOT true of lymph nodes: A) they contain macrophages B) they act as filters along the lymphatic vessels C) they remove foreign materials from the lymph fluid D) they have valves similar to those found in veins E) they contain lymphocytes
D) they have valves similar to those found in veins
Lymphoid tissue contains all of the following elements except A) T cells. B) B cells. C) follicles. D) thick collagen fibers
D) thick collagen fibers
Duct of the lymphatic system that drains the body's entire lower half. A) lumbar trunk B) intestinal trunk C) bronchomediastinal trunk D) thoracic duct E) right lymphatic duct
D) thoracic duct
Blockage of the ________ duct would prevent drainage only from the ________ and lumbar trunks. A) right lymphatic; jugular B) right lymphatic; subclavian C) thoracic; axillary D) thoracic; intestinal
D) thoracic; intestinal
The lymph organ that lies in the superior part of the thoracic mediastinum is the A) cervical lymph node. B) spleen. C) tonsil. D) thymus.
D) thymus
Crypts of the tonsils A) are filled with lymphoid tissue. B) are specialized lymphatic capillaries. C) contain all the progeny of a single activated B lymphocyte. D) trap bacteria and particulate matter.
D) trap bacteria and particulate matter
Antigen presentation is essential for the activation and clonal selection of: A) antibodies B) B cells C) plasma cell D) antigen-presenting cells E) T cells
E) T cells
The migration of phagocytes and white blood cells to an inflamed area along a chemical gradient is called: A) diapedesis B) perforins C) complement fixation D) immunity E) chemotaxis
E) chemotaxis
Blind-end invaginations of tonsil epithelium that trap bacteria and particulate matter. A) aggregated lymphoid nodules B) tonsils C) MALT D) lacteals E) crypts
E) crypts
Which one of the following is NOT one of the four most common indicators of the inflammatory response: A) redness B) heat C) swelling D) pain E) fever
E) fever
The bodyʹs temperature-regulating ʺthermostatʺ that can be reset upward in response to pyrogens is located in the: A) medulla oblongata B) thalamus C) cerebellum D) pineal gland E) hypothalamus
E) hypothalamus
Tissues invaded by viruses, which attempt to replicate themselves by taking over cellular machinery, secrete small proteins called __________ to protect nearby cells and hinder further multiplication of the viruses. A) kinins B) histamine C) interleukins D) pyrogens E) interferon
E) interferon
IgA: A) is passed from mother to fetus during pregnancy B) is involved in allergies C) is the most abundant antibody in blood plasma D) can fix complement E) is mainly found in mucus and secretions such as tears and saliva
E) is mainly found in mucus and secretions such as tears and saliva
The fluid that is forced out of the capillary beds by hydrostatic and osmotic pressures and into the tissue spaces is called: A) venous blood B) arterial blood C) interstitial fluid D) plasma E) lymph
E) lymph
Large lymphatic vessel that if present, is comprised of the right subclavian trunk, right jugular trunk and right bronchomediastinal trunk. A) cisterna chyli B) MALT C) spleen D) thoracic duct E) right lymphatic duct
E) right lymphatic duct
The largest lymphoid organ. A) thymus B) tonsils C) aggregated lymphoid nodules D) lymph nodes E) spleen
E) spleen
Which lymphatic organʹs major job is to destroy worn-out red blood cells and return some of the products to the liver: A) tonsils B) Peyerʹs patches C) thymus gland D) tonsils E) spleen
E) spleen
The inflammatory process begins with release of chemicals, which do all of the following EXCEPT: A) attract phagocytes to the area B) cause capillaries to become leaky C) activate pain receptors D) dilate blood vessels E) stimulate release of lysozyme
E) stimulate release of lysozyme
Which one of the following is NOT true of basic antibody structure: A) they consist of four amino acid chains B) the heavy chains are identical C) the heavy chains are about 400 amino acids long D) they are linked together by disulfide bonds E) the light chains are often of differing lengths
E) the light chains are often of differing lengths
True or False: An antibody is a substance capable of provoking an immune response.
FALSE
True or False: Natural killers are unique phagocytic defense cells that can kill cancer cells and virus-infected body cells well before the immune system is activated.
FALSE
True or False: The antibody a mother passes to her fetus is IgM.
FALSE
True or False: The tonsils, spleen, thymus gland, and Peyerʹs patches are referred to as mucosa-associated lymphatic tissue (MALT).
FALSE
True or False: There are three major immunoglobulin classes: IgM, IgA, and IgD.
FALSE
True or False: Tissue grafts harvested from an unrelated person are called xenografts.
FALSE
True or False: Allergies, or hypersensitivities, are normal immune responses.
FALSE
True or False: The final disposal of cell debris as inflammation subsides is performed by neutrophils.
FALSE
True or False: The thymus gland, found around the trachea, programs certain lymphocytes
FALSE
If lymphatic vessels are surgically removed, the resulting edema is permanent because these vessels cannot regenerate True or False?
False
Lacteals are the micro-valves present in lymph collecting vessels. True or False?
False
Lymph capillaries are open-ended like drinking straws. True or False?
False
Lymph is propelled through the lymph vessels by the force of the heartbeat. True or False?
False
The right lymphatic duct drains the intestinal trunk. True or False?
False
The spleen atrophies during adulthood. True or False?
False
Bathes and protects mucosal surfaces from attachment of pathogens
IgA
Believed to be cell surface receptor of immunocompetent B cell
IgD
Triggers the release of histamine
IgE
Crosses placenta and provides passive immunity to fetus
IgG
Main antibody of primary and secondary responses
IgG
First immunoglobulin class released to plasma by plasma cells during primary response
IgM
Potent agglutinating agent
IgM
The five major immunoglobulin classes are __________.
IgM, IgA, IdD, IgG, IgE
Describe the process of T cell activation and the significance of the blood-thymus barrier.
Immature lymphocytes that originate in the bone marrow, travel to the thymus, where they mature into T lymphocytes. In the thymus they develop immunocompetence, the ability to recognize a specific antigen. These naive cells however, only become fully activated when they experience an antigen challenge. In this process the T cell is presented with its specific antigen by a macrophage or dendritic cell.
Explain three current theories that attempt to explain why self-tolerance breaks down in autoimmune disorders.
Inefficient lymphocyte programming is one theory that suggests self-reactive B or T cells escape to the rest of the body. Another theory is that self-proteins appear within the circulation that were not previously exposed to the immune system, thus initiating an immune response. These ʺhiddenʺ antigens are found in sperm cells, the eye lens, and thyroid proteins. Another theory is that antibodies produced against foreign antigens cross-react with selfantigens such as when streptococcal bacteria cross-react with heart antigens causing rheumatic fever.
Tumorlike lesions of the skin and some internal organs caused by a type of herpesvirus is called ________.
Kaposi's sarcoma
________ are lymphatic structures that collect fat-laden fluids from the intestinal tract.
Lacteals
________ flows in one direction, toward the heart
Lymph
Explain the origin and pathway of lymph.
Lymph fluid arises from blood plasma that has been forced out of the capillary beds by osmotic and hydrostatic pressures. The fluid left behind is called interstitial fluid. The interstitial fluid is then picked up by lymph capillaries, after which it is called lymph. Lymph is routed up the lymphatic vessels until it is finally returned to the venous system through either the right lymphatic duct or the thoracic duct.
Explain why lymph from the right upper limb is drained into vessels on the right side of the neck, whereas lymph from the right lower limb is drained into vessels on the left side of the neck.
Lymph from the right upper limb drains into the right subclavian trunk, which may then empty into the right lymphatic duct. These lymphatic vessels often return lymph fluid to the venous blood proximal to the union of the right internal jugular vein and right subclavian vein. In contrast, lymph from both lower limbs drains into the lumbar trunks, which empty into the thoracic duct at the cisterna chyli. In this manner, lymph from the right lower limb will drain, along with three-quarters of the body, into the vessels of the left side of the neck.
How does the structure and the function of lymph-collecting vessels compare to those of veins? What tunics do they have in common?
Lymph-collecting vessels transport fluids toward the heart in the same manner as veins. Both structures have three tunics, but the walls of the lymphatic vessels are thinner. Both structures transport low-pressure fluids and consequently have one-way pocket valves to prevent retrograde flow, although valves are more numerous in lymphatic vessels. They both rely on movement of the skeletal muscles to help propel their respective fluids.
Peyerʹs patches and the tonsils are part of the collection of small lymphoid tissues that protect the upper respiratory and digestive tracts from infection and are referred to as __________.
MALT (mucosa-associated lymphatic tissue)
autoimmunity
MS, RA, lupus, myasthenia gravis
inner (deep) cortex
NO lymphatic nodules - mostly T-cells and dendritic cells; lymphocytes leave the blood stream and enter the lymph node here
Located in the wall of the small intestines
Peyerʹs patches
Describe several of the protective chemicals produced by the skin and mucous membranes.
Skin produces acid secretions that inhibit bacterial growth, and sebum contains chemicals that are toxic to bacteria. Vaginal secretions are highly acidic. The stomach mucosa secretes hydrochloric acid and protein-digesting enzymes, both of which can kill pathogens. Saliva and tears contain lysozyme, an enzyme that destroys bacteria. Mucus is a sticky mucous membrane secretion that traps microorganisms.
1st signal in T-cell activiation
T-cell receptors recognize and bind to antigen fragments presented in antigen-MHC complexes
memory T-cells
T-cells (Th or Tc) that remain from a proliferated clone after a cell mediated immune response - allows for rapid response in the case of a subsequent infection
self-recognition
T-cells' ability to recognize one's own MHC proteins - pos. selection
True or False: Allografts are tissue grafts taken from an unrelated person.
TRUE
True or False: Chemicals secreted by white blood cells and macrophages exposed to foreign substances that can increase body temperature are called pyrogens.
TRUE
True or False: Extremely weakened pathogens that are still alive are attenuated.
TRUE
True or False: Fever is a systemic response triggered by pyrogens.
TRUE
True or False: Like all blood cells, lymphocytes originate from hemocytoblasts contained within red bone marrow.
TRUE
True or False: Lymph in the right arm is returned to the heart via the right lymphatic duct.
TRUE
True or False: Macrophages arise from monoctyes formed within the bone marrow.
TRUE
True or False: Memory cells are descendants of an activated B or T cell.
TRUE
True or False: Our immune system can be affected by severe stress.
TRUE
True or False: Some pathologists consider limitation of joint movement to be an additional fifth cardinal sign of inflammation.
TRUE
True or False: The flaplike minivalves of the lymph capillaries act like one-way swinging doors that allow lymph fluid to enter the lymph capillaries but not exit.
TRUE
True or False: The nonspecific defense by which complement proteins attach to sugars or proteins on the surface of foreign cells is called complement fixation.
TRUE
True or False: The process that occurs when antibodies clump foreign cells is called agglutination.
TRUE
True or False: Antibodies are also referred to as immunoglobulins.
TRUE
True or False: Artificially acquired passive immunity is conferred when one receives immune serum for poisonous snake bites.
TRUE
True or False: Autoimmune diseases occur when the immune system loses its ability to tolerate self-antigens while still recognizing and attaching foreign antigens.
TRUE
True or False: The daughter cells of B cells, called plasma cells, release antibodies.
TRUE
delayed hypersensitivity (type IV)
Tcell mediated rxns; contact dermatitis - poison ivy
Identify the four most common indicators and major symptoms of an acute inflammatory response and explain their origins
The four most common indicators of the inflammatory response are redness, heat, swelling, and pain. Redness and heat are a result of dilation of blood vessels that increase blood flow to the injured area. Swelling occurs when increased permeability of the capillaries allows plasma to leak from the bloodstream into the tissue spaces. The excess fluid, or edema, triggers the activation of pain receptors in the area, accounting for the pain associated with an injury.
Identify and describe the functions of the lymphatic system.
The lymphatic system recovers tissue fluid and leaked plasma proteins and returns them to the bloodstream. By doing so, the system eliminates local variations in the chemical composition and volume of tissue fluid. The lymphatic system also distributes hormones, antibodies and cells of the immune system. Lastly, it picks up dietary fats from the intestines and transports them into the bloodstream.
Describe the methods the body uses to help return lymph to the heart.
The return of lymph to the heart is aided by: 1. the milking action of the skeletal muscles, 2. pressure changes in the thorax during breathing, 3. smooth muscles in the walls of the larger lymphatics contract rhythmically.
Patients often complain to their physician of "swollen glands" in their neck. What is the proper name of these "glands," and what is the significance of their swelling?
These structures are properly known as lymph nodes, specifically cervical lymph nodes if they are located in the neck. The nodes contain large numbers of macrophages and lymphocytes. Large numbers of pathogens trapped in the lymph nodes can cause the node to enlarge and become tender.
Deep lymphatic collecting vessels of the abdominal cavity travel alongside deep arteries True or False?
True
Epithelial cells within the thymus secrete hormones that are important to lymphocyte development. True or False?
True
Lymph capillaries are absent from the central nervous system. True or False?
True
Lymph transports fats absorbed from the small intestine to the vena cava True or False?
True
Lymphangitis is inflammation of a lymphatic vessel True or False?
True
The thymus increases in mass through childhood and then atrophies during adulthood. True or False?
True
The thymus is the only lymphatic organ that does not directly fight antigens. True or False?
True
To activate lymphocytes, bacteria must penetrate the epithelium of tonsils True or False?
True
Vaccination mimics acquired immunity. True or False?
True
cytotoxic rxns
Type II incompatible blood type transfusions
costimulation
a T-cell needs a second signal at the time of binding to become activated; may be a cytokine (IL-2) or various plasma membrane molecules
specific resistance: immunity
ability of body to defend itself against particular pathogens or foreign tissues
immunocompetence
ability to carry out immune responses if properly stimulated
fever
abnormally high body temp. that occurs when hypothalamic thermostat is reset by pyrogens (endogenous or exogenous); intensifies effects of interferons; inhibits growth of certain microbes speeds up body rxns that air repair
Right lymphatic duct
about 1/2 inch long - receives lymph from upper right side of body and drains into R subclavian vein
Inhibits growth of bacteria and fungi
acid mantle
leukotrienes
activate WBCs
memory B-cells
activated B-cells that do not differentiate into plasma cells, but remain ready to respond to future infections
lymphotoxin
activates enzymes within a target cell that fragments its DNA
secretion of y-interferon
activates other phagocytic cells
Lymphocyte ________ results in immune cells that have gained the ability to attack specific antigens.
activation
cell-mediated immunity begins with
activation of a small number of T-cells by a specific antigen (antigen recognition and costimulation needed to be activated) once activated, T-cells undergo proliferation and differentiation into a clone of effector cells
When B cells encounter antigens and produce antibodies against them, we exhibit __________.
active immunity
path of lymph flow
afferent vessels (many) subcapsular space trabecular sinus medullary sinus efferent lymphatic vessels (one or two)
The clumping of foreign cells, a type of antigen-antibody reaction, is called __________.
agglutination
NK cells
aka large granular lymphocytes; immunological surveillance of tissues originate within and complete their development within the red bone marrow
Antigen presenting cells
all phagocytic cells of monocyte-macrophage group - microglia, dust cells, Kupffer cells dendritic cells of skin, lymph nodes and spleen are APCs that aren't phagocytic - use pinocytosis
Antigens that produce abnormally vigorous immune responses whereby the immune system causes tissue damage as it fights off a perceived threat that would otherwise be harmless are called __________.
allergens or hypersensitivities
interferons
alpha, beta, gamma active vs. viruses; stimulate NK and macrophages
Systemic (bodywide) acute allergic response caused by allergens that directly enter the blood, as with certain bee stings or spider bites, is called __________.
anaphylactic shock
stimulation of inflammation
antibodies stimulate the activity of basophils and mast cells
activation of B-cell
antigen binds to B-cell receptors - which are chemically similar to antibodies secreted by plasma cells; B-cells can respond to unprocessed antigen, but response intensified when APCs involved
sensitization
antigen taken into B-cell
immobilizing bacteria
antigen-antibody complexes adhere to cilia or flagella
immune complex disorders (type III)
antigen-antibody complexes form and attach to walls of blood vessels leading to inflammation; serum sickness, arthritis, vasculitis
antibody mediated immunity primarily effective against
antigens present in body fluids and extracellular pathogens (bacteria)
internal defense - 2nd line of defense
antimicrobial proteins of blood and interstitial fluid
Aggregated lymphoid nodules and the ________ contain dense concentrations of lymphoid tissue and are associated with the distal structures of the digestive tract.
appendix
thymus reaches max size
around ages 10-14 yrs old - involution during adulthood - adiopose and areolar connective tissue replace glandular epithelium after puberty
neutrophils
arrive first but die quickly, followed by monocytes which transform into wandering macrophages
mucosa associated lymphoid tissue (MALT)
associated w/ GI tract - included appendix and Peyer's patches (aggregated lymphoid nodules) found in small intestine
adhesion
attachment of phagocyte to target (microbe or foreign material)
loss of self tolerance leads to
autoimmunity
thymus
bi-lobed organ located in mediastinum connective tissue encloses each lobe separately - extensions of the capsule (trabeculae or septa) penetrate inward and divide lobes into lobules - deeply stained outer cortex and lightly stained central medulla
lymph node filtration
biological filtration of lymph - at least 99% of antigens present are removed
lymphedema
blockage of lymphatic drainage from a limb - swelling eventually becomes permanent
flow of lymph
blood capillaries interstitial spaces lymphatic capillaries lymphatic vessels lymphatic trunks lymphatic ducts subclavian veins
Lymph fluid and some plasma proteins originate (escape) from the __________.
blood plasma
red pulp
blood-filled venous sinuses and splenic cords - site of removal of old RBCs and platelets by macrophages; platelet storage up to 1/3 of total # RBC production during fetal life - stores iron recycled from RBCs lymphocytes are found here
The ________ prevents premature activation of immature thymic lymphocytes.
blood-thymus barrier
tolerance
body's own cells normally do not elicit an immune response - autoimmunity
before leaving the bone marrow
both B and T cells produce antigen receptors
after sensitization,
broken down and combine with MHC-II; the complex moves to cell membrane where it's recognized by Th cell - this is constimulation required for B-cell prolif and differentiation; Th cell then releases cytokines that promote B-cell activation
stroma of spleen
capsule with collage and elastic fibers, trabeculae, reticular fibers and fibroblasts
active fragments C3a, C4a and C5a
cause arteriole dilation, histamine release and phagocytic chemotaxis
prostaglandins
cause fever
kinins
cause pain
interleukin-1
causes fever and T-helper cell proliferation - stimulates production of IL-2
specific immunity
cell-mediated - T-cell antibody-mediated - B-cell responses
germinal center of lymph node
center of secondary lymphatic nodule containing B-cells, dendritic cells and macrophages
cytokines
chemical messengers (small protein hormones) of the immune system
chemotaxis
chemically stimulated movement of phagocytes to damaged area
The process by which WBCs and phagocytes migrate to an area experiencing acute inflammation is called __________.
chemotaxis
Propels debris-laden mucus away from lower respiratory passages
cilia
The lumbar and intestinal trunks unite at the ________ of the thoracic duct.
cisterna chyli
lymph
clear, pale yellow fluid except in lacteals (creamy, white chyle)
When an antigen binds to B cell surface receptors, it becomes sensitized (activated) and undergoes __________.
clonal selection
enhancement of phagocytosis
coating of antibodies and complement proteins
pus
collection of dead cells and fluid - drained and dispersed or destroyed and absorbed; abscess - accumulation of pus; necrosis - dead tissue
The binding of complement proteins to certain sugar or proteins on a foreign cellʹs surface is called __________.
complement fixation
residual bodies
contain material that cannot be degraded further
inner medulla of lymph node
contains B-cells/plasma cells - organized into elongated masses known as medullary cords - migrating from cortex - also contains macrophages
outer cortex of lymph node
contains egg-shaped aggregates of B-cells called lymphatic follicles (nodules), primary lymphatic nodules consist chidfly of B-cells and secondary lymphatic nodules - sites of plasma cell and memory B cell formation - form in response to antigenic challenge
cortex of thymus
contains large numbers of T-cells and pre-T-cells, dendritic cells (APC's), reticular epithelial cells and macrophages
medulla of thymus
contains widely-scattered, more mature T-cells, dendritic cells and macrophages and no blood-thymus barrier in this area
classical and alternative pathways end with
conversion of C3 to C3b
after costimulation,
cytokine production begins
Killer T cells, which kill virus-invaded body cells, are also called __________.
cytotoxic T cells
The process by which neutrophils squeeze through capillary walls is called __________.
diapedesis
lymphatic system transports
dietary lipids and fat-soluble vitamins to the blood (lacteals)
if memory B-cells exposed to same antigen 2nd time
differentiate into plasma cells
classical pathway of complement system
discovered first, beings with binding of antigen to antibody - most rapid and effective way of activation Antigen-Ig complex ---> formation of C3 convertase ---> MAC (membrane attack complex) C5b, C6, C7, C8, C9
prevention of bacterial and viral adhesion
dissolved antibodies in bodily fluids coat epithelia and interfere with pathogen's ability to enter cells
alternative pathway of complement system
doesn't involve antibodies - begins when several complement proteins interact in the plasma pathogen surface antigen --->formation of C3 convertase ----> peptides to increase inflammation and chemotaxis C3a, C4a, C5a
lumbar trunk
drain lower limbs, pelvic wall/viscera, and kidneys
L & R bronchomediastinal trunk
drain thorax and part of liver
intestinal trunk
drains GI organs, spleen and part of liver
L & R jugular
drains head and neck
L & R subclavian
drains upper limbs
versatility
due to diversity of lymphocytes and the variability in the structure of synthesized antibodies
respiratory pump
during inhalation, abdominal pressure is greater than thoracic pressure. lymph flows toward thoracic region during exhalation, pressure difference reversed BUT valves prevent backflow
Excess accumulations of fluid, which impair the exchange of materials within the tissues, is called __________.
edema
Lymph exits the lymph node via the __________ vessels.
efferent lymphatic
lymphoid tissues
egg-shaped masses of lymphatic tissue NOT surrounded by a capsule; scattered throughout the connective tissue of mucous membranes lining GI, urinary, reproductive and respiratory tracts
T-cells exit thymus gland as
either CD4+ (helper T cells) or CD8+ (cytotoxic T) cells CD = cluster of differentiation
anchoring filaments
elastic fibers attaching lymphatic endothelial cells to surrounding tissues - pull on cells to allow excess tissue fluid to enter
A tropical disease that results when parasitic worms clog the lymphatic vessels is called __________.
elephantiasis
some activated B-cells
enlarge, divide and differentiate into a clone of antibody secreting plasma cells
non-specific 1st line of defense
epidermis, mucous membranes, nose hairs, cilia, body hair; most infections occur at mucosal membrane surface
lymphatic systems drains...
excess interstitial fluid (fluid between cells) and returns it to the bloodstream
edema
excessive buildup of interstitial fluid caused by obstruction of lymphatic flow or an increase in capillary blood pressure
phagocytic evasion
extracellular capsules prevent adherance (pneumonia) production of toxins that kill WBCs (food poisoning) inhibition of formation of phagolyosome (TB)
interleukin-1
fever causing cytokine - an endogenous pyrogen - released by active macrophages; exogenous pyrogens include bacterial toxins and bacterial cell walls
endogenous antigens
foreign antigens synthesized within a body cell - viral proteins, abnormal proteins from cancer cells fragments of these antigens assoc. w/ MHC-I molecules within an infected cell; complex moves to membrane and displayed at cell surface
exogenous antigens
found in fluids outside body cells processed by APCs - located in areas where antigens are likely to penetrate non-specific defenses once antigen is processed, APCs migrate to lymph nodes via lymphatic vessels
MHC-class 1
found on all cells except RBCs
MHC-class 2
found only on surface of APCs, thymic cells, and activated T-cells
T-cells only recognize...
fragments of antigenic proteins that are presented with MHC self antigens
stroma
framework - capsule, reticular fibers, fibroblasts, trabeculae
Contains concentrated hydrochloric acid and protein-digested enzymes that destroy pathogens within the stomach
gastric juice
genetic recombination
gene segments are put together in different combinations as lymphocytes develop in the thymus and bone marrow - allows for diversity of antigen receptors in T-cells and B cells
Troublesome small molecules or incomplete antigens that may mount an attack that is harmful rather than protective are called __________.
haptens
lymph capillaries different from blood capillaries
have thinner walls have larger diameters have flattened or irregular outline in sectional view originate as closed end pockets basal lamina incomplete or absent
AIDS cripples the immune system by interfering with the activity of cells called __________.
helper T cells
Antibodies constitute an important part of blood proteins and are also referred to as __________.
immunoglobulins
lymph flow through node
in one direction only and enters through afferent lymphatic vessels
neutralizing antigen
inactivation of some bacterial toxins - prevents attachment of some viruses
histamines
increase capillary permeability
hilus
indented region from which efferent vessels emerge and blood vessels enter and leave
subgroups of cytokines
interleukins (lymphocytes and macrophages) and interferons
cell-mediated immunity is primarily effective against
intracellular pathogens - fungi, parasites, viruses some cancers foreign tissue transplants
transferrins
iron-binding proteins
blood-thymus barrier
isolates developing T-cells more the general circulation as they develop
The paired ________ drain lymph from the head and neck.
jugular trunks
Provides resistance against acids, alkalis, and bacterial enzymes
keratin
tumor necrosis factor
kills tumor cells stimulates activity of T-cells and eosinophils
Contains lysozyme
lacrimal secretions
NOT antigenic
large molecules with simple, repeating subunits plastics, cellulose
lymphatic trunks
larger vessels - include: lumbar intestinal L & R bronchomediastinal L & R subclavian L & R jugular
thoracic (left lymphatic duct)
largest - about 18 inches long - begins as cisterna chyli - empties into L subclavian vein - receives lymph from L side of head, chest, L upper limb, and entire body inferior to ribs
spleen
largest lymphatic organ between stomach and diaphragm filters BLOOD, not lymph covered by dense conn. tissue capsule and visceral peritoneum
fragment C3b
leads to opposition - enhances phagocytosis
splenic artery
leads to trabecular arteries - trabecular veins drain into splenic vein; hilum - groove between gastric and renal areas
lymph nodes
located along lymphatic vessels - about 600 - not in CNS - surrounded by capsule of dense conn. tissue that extends intot eh node - capsular extensions (trabeculae) of collagen fibers divide node into compartments and provide support
B-cells can recognize and bind to antigens in
lymph, blood or interstitial fluid
white pulp
lymphatic tissue - mostly macrophages and lymphocytes site of specific immune responses and removal of bloodborne pathogens by macrophages; purple color due to nuclei of darkly stained lymphocytes
B cells remain in
lymphatic tissues and secrete antibodies
ex. of cells that secrete cytokines
lymphocytes APCs fibrocytes monocytes endothelial/liver/kidney cells
lymphocytes
make up 20-30% of circulating WBCs include T-cells, B-cells and natural killer cells
fragments C5b, C6, C7, C8 & C9
membrane attack complex results similar to perforin
memory
memory cells produced that remain inactive until one is exposed to a a previously encountered antigen
phagolysosome
merger of phagosome and lysosome
lymphatic (terminal) capillaries
microscopic closed end tubes located between cells - unite to form larger lymphatic vessels not found in vascular tissue (cartilage, epidermis, cornea) or CNS, bone marrow, and portions of spleen
skeletal muscle pump
milking action of skeletal muscles compresses lymphatic vessels and veins
IgE
monomers; blood; on mast cells/basophils; involved in allergic rxns
formation of lymph
more fluid exits capillaries than is reabsorbed by them - this fluid is derived from blood plasma, enters the lymphatic system (contains only small amnts of plasma proteins)
Traps microorganisms in respiratory and digestive tracts
mucus
Filters and traps microorganisms within inhaled air
nasal hairs
types of immunity
naturally acquired active naturally acquired passive artificially acquired active artificially acquired passive innate immunity - genetically determined - present at birth - doesn't require antigen exposure
The binding of antibodies to specific sites on bacterial exotoxins or viruses is called __________.
neutralization
emigration of phagocytes
neutrophils stick to endothelial lining - diapedesis - squeezing through blood vessel wall - their metabolic rate increases - respiratory burst releases toxic compounds that destroy pathogens emigration depends on chemotaxis - cytokines released by neutrophils attract other neutrophils and macrophages
secondary response
new encounters w/ same antigen result in rapid prolif of memory cells; accelerated; intense; mainly IgG response
natural killer cells
non-specific 510% lymphocytes; active against wide variety of microbes; fast acting; release perforins; attack cells w/ abnormal MHC antigens (cancer cells, virally infected cells); immunological surveillance
fever
non-specific accelerates tissue metabolism and immune system function
inflammation
non-specific localized response that limits injury or infection
phagocytosis
non-specific neutrophils, eosinophils, and macrophages (fixed and wandering or free); fixed macrophages (histiocytes) include Kupffer cells and microglia; free macrophages include alveolar macrophages (dust cells)
inflammation
non-specific, localized defensive response of the body to tissue damage; response is similar regardless of insult (infection, trauma, chem exposure, etc.) 4 classic signs: red, hot, swollen, painful
specificity
occurs because T & B cells response to the unique molecular structure of a given antigen
thymus is a site for neg. selection
of T-cells - those that attack self-proteins are eliminated - only 1-5% of T-cells survive pos. and neg. selection
thymus is a site for pos. selection
of pre-T-cells - those that can recognize and interact with self-MHC proteins survive
One effect of complement fixation that causes the cell membranes of foreign cells to become sticky so that they are easier to phagocytize is called __________.
opsonization
endothelial cells of lymphatic capillary wall
overlap to allow tissue fluid to flow in but not out
The ________ tonsils are the ones most often infected and removed during a tonsillectomy.
palatine
Harmful or disease-causing microorganisms from which nonspecific defenses protect the body are called __________.
pathogens
lymph originates as
plasma - has much lower concentration of proteins
complement
plasma proteins that enhance immune, allergic and inflammatory rxns
interleukin-2
prime trigger of T-cell proliferation; needed for virtually all immune responses; pos. feedback mechanism
reticular epithelial cells of thymus cortex
produce thymic hormones and maintain blood-thymus barrier
perforin
protein released via exocytosis from Tc cells - results in cytolysis - forms holes in plasma membrane of target cell - extracellular fluid enters and cell bursts
T-cells only respond to antigens that contain
protein; B-cells can respond to antigens regardless of chemical make-up
interferons
proteins released by virally infected cells that interfere w/ viral replication - type of chemical messenger called a cytokine
most antigens are ____ but these also act as antigens
proteins; nucleic acids, lipoproteins, glycoproteins and some large polysaccharides
antigens
provoke immune responses - recognized as foreign - specificity and memory
ingestion
pseudopods engulf microbe and fuse - microbe is contained within phagosome
anergy
recognition without costimulation; prolonged state of inactivation
helper T-cells CD4+
recognize antigen-MHC II complexes on surface of APCs - docks with PAC to achieve costimulation - activate B cells - stimulates activity of NK and macrophages
cytotoxic T-cells - display CD8+
recognize antigen-MHC-I complexes on surface of virally infected cells, some tumor cells and cells of a tissue transplant; to become cytotlytic, need costimulation by IL-2 or other cytokines produced by Th cells. may take >2 days for Tc to increase to effective levels
constant region of antibody
remainder of H and L chains - nearly same in all antibodies of same class
lymphatic vessels
resemble veins thinner walls and more valves
activation, proliferation and differentitation of T-cells occurs in
secondary lymphatic organs lymph nodes, MALT tissue, spleen
suppressor T-cells
secrete suppression factors (unknown cytokines) - act after initial immune response; takes longer to activate these T-cells
Cells studded with protein molecules found on our own cells that do not trigger an immune response within us (but may within others) are called __________.
self-antigens (autoantigens)
MHC complex
self-antigens --> transmembrane glycoproteins - also called HLA human leukocyte antigens; found on all cells except RBCs
anergy
self-reactive T-cells remain alive BUT are unresponsive to antigenic stimulation
deletion
self-reactive T-cells undergo apoptosis
secondary lymphatic organs
sites where most immune responses occur - lymph nodes, lymph nodules (lack connective tissue capsule) and spleen
primary lymphatic organs
sites where stem cells divide and become immunocompetent red bone marrow and thymus
haptens
smaller substance that has reactivity BUT lacks immunogenicity - must combine with a carrier molecule to stimulate immune response
agglutinating and precipitating rxns
soluble antigens may come out of a solution - form immune complexes
lacteals
specialized lymphatic capillaries of the small intestines - carry dietary lipids
Filters and cleanses the blood of bacteria, viruses, and other debris
spleen
Located on the left side of the abdominal cavity
spleen
The role of the __________ in the lymphatic system is to remove worn-out blood cells and return some of the products to the liver
spleen
routes for antigens to reach lymphatic tissues
spleen lymph nodes MALT tissues
interleukin-2
stimulates growth and activation of T-cells and NK cells
parenchyma
superficial cortex and deeper medulla
non-specific defenses
tears, saliva urine flow defectaion vomiting vaginal secretions sebum, skin acidity (fatty acids/lactic acid) gastric juice perspiration lysozyme
T-cells only respond to peptide-MHC complexes if
the peptide fragment is from a foreign protein
The ________ duct drains three-quarters of the body
thoracic
The ________ is the site of T cell maturation
thymus
Located overlying the heart
thymus gland
variable regions of antibody
tips of H and L chains - this is the antigen binding site - most antibodies have 2 variable regions
Congestion of the tonsils with bacteria results in ________.
tonsillitis
Located in the pharynx (throat)
tonsils
Trap and remove bacteria and pathogens entering the throat
tonsils
The fibrous capsule of lymph nodes contains strands called __________ that divide the no de into compartments.
trabeculae
The tonsils located just behind the openings of the pharyngotympanic tubes in the pharynx are the ________ tonsils.
tubal
tonsils
usually 5 - pharyngeal (adenoid) palatine (2) lingual (2)
basic stages of inflammatory response
vasodilation and increased capillary permeability -- increased blood flow due to vasodilation causes heat and redness - increased permeability causes swelling and allows WBCs, antibodies and clotting factors to leave bloodstream to reach injured area pain - results from neuron injury and microbial toxins
T-cells that leave thymus
via bloodstream - colonize other lymphatic organs
B-cells
when stimulated, differentiate into plasma cells; produce antibodies originate within and complete their development within the red bone marrow
Lymphoid tissues that enclose the central arteries of the spleen are collectively called ________.
white pulp
parenchyma
white pulp vs. red pulp
trabecular sinus is located
within cortex of lymph node
sinuses
within lymph node - irregular channels with branching reticular fibers, lymphocytes and marcophages
