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114 terms

Lymphatic system

STUDY
PLAY
False
(T/F) Tissue grafts harvested from an unrelated person are called xenografts
Allografts
Tissue grafts harvested from an unrelated person
False
(T/F) The final disposal of cell debris as inflammation subsides is performed by neutrophils
Macrophages
The central actors in the final disposal of cell debris as inflammation subsides
True
(T/F) Like all blood cells, lymphocytes originate from hemocytoblasts contained within bone marrow
True
(T/F) The daughter cells of B cells, called plasma cells, release antibodies
False
(T/F) Lymph fluid exits a lymph node at the indented hilus (also called hillum) via afferent lymphatic vessels
efferent
Lymph fluid exits a lymph node at the indented hilus (hilum) via which lymphatic vessels?
False
(T/F) Antibodies are substances capable of exciting the immune system and provoking the immune response
Antigens
What substances are capable of exciting the immune system and provoking the immune response?
True
(T/F) Macrophages arise from monocytes formed within bone marrow
True
(T/F) Some pathologists consider limitation of joint movement an additional fifth cardinal sign of inflammation
True
(T/F) Chemicals secreted by white blood cells and macrophages exposed to foreign substances that can increase body temperature are called pyrogens
pyrogens
Chemicals secreted by white blood cells and macrophages exposed to foreign substances that can increase body temperature
True
(T/F) The nonspecific defense by which complement proteins attach to sugars or proteins on the surface of foreign cells is called complement fixation
Complement fixation
The nonspecific defense by which complement proteins attach to sugars or proteins on the surface of foreign cells
True
(T/F) The flaplike mini-valves of the lymphs capillaries act like one-way swinging doors that allow lymph fluid to enter the lymph capillaries but not exit
True
(T/F) Our immune system can be affected by severe stress
False
(T/F) Natural killers are unique phagocytic defense cells that can kill cancer cells and virus-infected body cells well before the immune system is activated
Natural killer cells
They roam the body in blood and lymph. They are a unique group of lymphocytes that can lyse and kill cancer cells, virus-infected cells, and some other nonspecific targets well before the adaptive arm of the immune system is enlisted in the fight. Unlike the lymphocytes of the adaptive system, which can recognize and eliminate only specific virus-infected or tumor cells, natural killer cells are far less picky. They can act spontaneously against any such target by recognizing certain sugars on the "intruder's" surface as well as its lack of certain "self" cell surface molecules. NK cells are NOT phagocytic. They attack the target cell's target membrane and release a lytic chemical called perforins. Shortly thereafter, the target cell's membrane and nucleus disintegrate. NK cells also release powerful inflammatory chemicals
Natural killer cells
Which cells are a unique group of lymphocytes that can lyse and kill cancer cells, virus-infected cells, and some other nonspecific targets well before the adaptive arm of the immune system is enlisted in the fight?
Natural killer cells
Which cells can act spontaneously against any virus-infected or tumor cells by recognizing certain sugars on the "intruder's" surface as well as its lack of certain "self" cell surface molecules?
Natural killer cells
Which cells are NOT phagocytic and attack target cell's target membrane and release a lytic chemical called perforins that disintegrates the target cell's membrane and nucleus? These cells also release powerful inflammatory chemicals
False
(T/F) The fact that cancer-infiltrated lymph nodes are swollen and also painful helps distinguish cancerous lymph nodes from those infected by microorganisms
True
(T/F) Cancer-infiltrated lymph nodes are NOT painful
True
(T/F) Microorganism infected lymph nodes ARE painful
False
(T/F) IgM is the main antibody of primary and secondary responses
IgG
What is the main antibody of primary and secondary responses?
Gastric juice
Contains concentrated hydrochloric acid and protein-digested enzymes that destroy pathogens within the stomach
Cilia
Propels debris-laden mucus away from the lower respiratory passages
Mucus
Traps microorganisms in respiratory and digestive tracts
Nasal hairs
Filters and traps microorganisms within inhaled air
Keratin
Provides resistance against acids, alkalis, and bacterial enzymes
Lacrimal secretions
Contains lysozyme
Acid mantle
Inhibits growth of bacteria and fungi in female reproductive tract
IgG
Which antibody crosses the placenta and provides passive immunity to the fetus?
IgE
Which antibody triggers the release of histamine and mediates the inflammatory and some allergic responses?
IgD
Which antibody is believed to be the cell surface receptor of an immunocompetent B cell?
IgM
Which antibody is a potent agglutinating agent?
IgA
Which antibody bathes and protects mucosal surfaces from attachment of pathogens
Peyer's patches
Which lymphoid organ is found in the small intestine?
Tonsils
Small masses of lymphoid tissue that ring the pharynx (the throat), where they are found in the mucosa. Their job is to trap and remove any bacteria or other foreign pathogens entering the throat. They carry out this function so efficiently that sometimes they become congested with bacteria and become red, swollen, and sore; a condition called tonsilitis
Tonsilitis
Condition where tonsils become very congested with bacteria and become red, swollen, and sore
Spleen
Which lymphoid organ is located in the left side of the abdominal cavity, just beneath the diaphragm, and curls around the anterolateral aspect of the stomach?
Spleen
A soft, blood-rich organ that filters and cleanses blood of bacteria, viruses, and other debris. It provides a site for lymphocyte proliferation and immune surveillance, but its most important function is to destroy worn-out red blood cells and return some of their breakdown products to the liver.
Thymus
What lymphoid mass is found low in the throat overlying the heart?
Thymus
This lymphoid organ functions at peak levels only during youth. It produces hormones, thymosin and others that function in the programming of certain lymphcytes so they can carry out their protective roles in the body (The programming enables the lymphocytes to distinguish between our own cells and substances that are foreign to the body)
Active, artificially acquired immunity
Regarding acquired immunity, the introduction into a recipient of dead or attenuated pathogens, via a vaccine, is an example of which of the following?
Passive, artificially acquired immunity
Injection of immune serum (gamma globulin)
Active, naturally acquired immunity
Infection; contact with pathogen
Passive, naturally acquired immunity
Antibodies pass from mother to fetus via placenta or to infant in her milk
Basophils
What type of cells are not present in a lymph node?
(a) Basophils
(b) Plasma cells
(c) Lymphocytes
(d) Macrophages
(e) B cells
lymph node
Plasma cells, lymphocytes, macrophages, and b cells are all present in which structure?
Neutralization
A process that occurs when antibodies bind to specific sites on bacterial exotoxins or viruses that can cause cell injury, thus blocking the harmful effects
Agglutination
Clumping of (foreign) cells, induced by cross-linking of antigen-antibody complexes. Occurs when mismatched blood is transfused and is the basis of tests used for blood typing
Precipitation
Formation of insoluble complexes that settle out of solution. Occurs when the cross-linking process involves soluble antigenic molecules
Interferons
Nonspecific body defense designed to prevent the spread of viruses to uninfected adjacent tissues
Complement
A group of plasma proteins that normally circulate in inactive forms; when activated by complement fixation, causes lysis of foreign cells and enhances phagocytosis and inflammation
Fever
Abnormally high body temperature, a systemic response to invading microorganisms triggered by pyrogens. Causes the liver and spleen to gather up nutrients like iron and zinc that bacteria need to multiply. It increases the metabolic rate of tissue cells in general, speeding up repair processes
All of the above
Which of the following is NOT an element of nonspecific immune responses?
(A) mucous membranes
(B) fever
(C) neutrophils
(D) All of the above
IgE antibodies
Acute hypersensitivity or allergy is due to which antibodies?
Activated macrophages
Macrophages presented with antigens by dendritic cells. They are true "killers" that are insatiable phagocytes and secrete bactericidal chemicals
Memory B cells
Respond to repeated exposures to the antigen that caused their production. Daughter cell of B cells
Complement cascade
Can be triggered by
• Classical pathway: Antigen: antibody complexes
• MB-Lectin pathway: Lectin binding to pathogen surfaces
• Alternative pathway: pathogen surfaces
specific
B cell production of antibodies is a ________ immune response
nonspecific
Acid barriers in stomach, inflammation, and neutrophils are part of the ___________ immune response
Natural killer cell
Type of cell that does not require specific antigen activation to become active
Cytotoxic T cells
Effector T cells responsible for attacking and lysing infected and cancerous cells
Helper T cells
Type of T cell that is specifically targeted by HIV
Suppressor T cells
Also called regulatory T cells, they release chemicals that suppress the activity of both T and B cells. They are vital for winding down and finally stopping the immune response after an antigen has been successfully inactivated or destroyed. Helps prevent uncontrolled or unnecessary immune system activity
Helper T cells
Type of T lymphocyte that orchestrates cellular immunity by direct contact with other immune cells and by releasing chemicals called cytokines; also helps to mediate the humoral response by interacting with B cells
Cytokines
Chemical messengers released by Helper T cells that are involved in immunity and enhance the immune and inflammatory responses. They act indirectly to rid the body of antigens by:
(1) stimulating cytotoxic T cells and B cells to grow and divide
(2) attracting other types of white blood cells
(3) enhancing the ability of macrophages to engulf and destroy microorganisms
Allograft
Graft taken from a person other than an identical twin
Xenograft
Tissue graft harvested from a different animal species, such as transplanting a baboon heart into a human being
Isograft
Tissue graft donated by a genetically identical person, the only example being an identical twin
Autograft
Tissue graft transplanted from one site to another in the same person
Thymus
What lymphoid organ is well developed before birth?
Haptens
Also called incomplete antigens, they are small molecules that can link up with our own proteins. Chemicals that act as haptens are found in certain drugs, poison ivy, animal dander, and even in some detergents, hair dyes, cosmetics, and other commonly used household and industrial products
Plasma cells
Daughter cells of B cells that produce and release antibodies and are found in lymph nodes
Trabeculae
Strands that extend inward from the fibrous capsule that surrounds lymph nodes that divide the lymph node into a number of compartments
Chemotaxis
Movement of a phagocytes and white blood cells in a direction corresponding to a chemical gradient of increasing or decreasing concentration of histamines and kinins
Immunoglobulins
Also called antibodies or Igs, they are a specialized substance produced by the body that can provide immunity against a specific antigen. They are soluble proteins secreted by activated B cells or by their plasma-cell offspring in response to an antigen, and they are capable of binding specifically with that antigen
Anaphylactic shock
A rare body-wide, or systemic, acute allergic response that occurs when the allergen directly enters the blood and circulates rapidly through the body, as might happen with certain bee stings, spider bites, or an injection of a foreign substance (such as horse serum, penicillin, or other drugs that act as haptens) into susceptible individuals. Food allergies (peanut or wheat allergies) may also trigger anaphylaxis. Causes contraction of the smooth muscles of the lung passages and sudden vasodilation (and fluid loss), which may cause circulatory collapse and death within minutes. Epinephrine is used to reverse the histamine mediated effects
Opsonization
When the cell membranes of foreign cells become sticky so they are easier to phagocytize
Blood plasma
A straw colored, sticky fluid which is 90% water and contains over 100 different dissolved solutes such as nutrients, gases, hormones, wastes and products of cell activity, ions and proteins
Lymph
A colorless fluid derived from blood collected from tissue spaces containing white blood cells that bathes the tissues and drains through the lymphatic system towards the heart into the bloodstream.
Lymph node
Structure: Vary in shape and size, but most are kidney-shaped, less than 1 inch long and "buried" in the connective tissue that surrounds them. Each is surrounded by a fibrous capsule from which strands called trabeculae extende
Function: Remove foreign material such as bacteria and tumor cells from the lymphatic stream and produce lymphocytes that function in the immune response
Hilus
A depressed area where vessels enter and leave an organ. Intended region of lymph nodes that lymph exits out of via efferent lymphatic vessels
Immunocompetent
Capability of a B cell or T cell to respond to a specific antigen by binding to it with antigen-specific receptors that appear on the lymphocyte's surface
Serum
An amber-colored, protein-rich liquid that separates out when blood coagulates. The blood serum of an animal, used esp. to provide immunity to a pathogen or toxin by inoculation or as a diagnostic agent
LFT
Liver Function Test
Pus
Creamy yellow substance formed in wound that's a mixture of dead or dying neutrophils, broken-down tissue cells, and living and dead pathogens
Autoimmune disease
Occurs when immune system loses its ability to distingusih friend from foe, that is to tolerate self-antigens while recognizing and attacking foreign antigens. One of several diseases, in which the body produces antibodies and sensitized T cells that attack and damage its own tissues
Examples:
• Rheumatoid arthritis (RA) - joints are systematically destroyed
• Myasthenia gravis, which impairs communication between nerves and skeletal muscles
• Multiple sclerosis (MS), which destroys the white matter (myelin sheaths) of the brain and spinal cord
• Graves' disease, in which the thyroid gland produces excessive amounts of thyroxine
• Type 1 diabetes mellitus, which destroys pancreatic beta cells, resulting in deficient production of insulin
• Systemic lupus erythematosus (SLE), a systemic disease that occurs mainly in young women and particularly affects the kidneys, heart, lungs, and skin
• Glomerulonephritis, a severe impairment of kidney funciton
Histamine
Released from mast cell granules when allergen binds to IgE on mast cells. It causes blood vessels to dilate and become leaky, which produces edema; stimulates release of large amounts of mucus; causes smooth muscles to contract
Interleukins
Types of cytokines. Some stimulate T cells and B cells to proliferate; activates NK cells. Others suppress immune response
Inflammatory response
Prevents the spread of damaging agents to nearby tissues, disposes of cell debris and pathogens, and sets the stage for repair
Specific defense system
Mounts the attack against particular foreign substances. Although certain body organs (lymphoid organs and blood vessels) are intimately involved with the immune response, the immune system is a functional system rather than an organ system in anatomical sense. It's "structures" are a variety of molecules and trillions of immune cells that... Third line of defense. Consists of lymphocytes, antibodies, macrophages and other antigen-presenting cells
Nonspecific defense system
Responds immediately to protect the body from all foreign substances, whatever they are. You could say that we come fully equipped with our innate defenses, which are provided by intact skin and mucous membranes, by the inflammatory response, and by a number of proteins produced by body cells. Reduces the workload of the second protective arm, the adaptive defense system. Consists of first line of defense; skin, mucous membranes, secretions of skin and mucous membranes and Second line of defense: Phagocytic cells, Natural killer cells, Antimicrobial proteins, the inflammatory response, and fever
hypothalamus
Body's "thermostat." Normally set at about 98.6ºF
Kinins
Inflammatory chemical that (1) cause blood vessels in the involved area to dilate and capillaries to become leaky; (2) activate pain receptors, and (3) attract phagocytes and white blood cells to the area
Peyer's patches
Lymphoid follicles situated along the wall of the small intestine that trap antigens from the gastrointestinal tract and provide sites where B and T cells can interact with antigen
Inflammation
Signs of this are pain, swelling, redness, heat, and limitation of joint movement
Edema
Abnormal accumulation of fluid in body parts or tissues; causes swelling. Occurs when leaky fluid along with plasma fluids are not carried back to the blood
pathogens
Harmful agents, Agents, especially microorganisms such as viruses, bacteria, or fungi, that infect a host and cause disease
Allergens
A toxicant that overactivates the immune system, causing an immune response when one is not necessary.
MALT
Mucosa-associated lymphoid tissue
fibrin
Clotting barrier, A blood protein essential to blood clotting. The conversion of fibrinogen to its active form (fibrin) is among the final steps in clot formation, and is triggered by thrombin.
afferent lymphatic vessels
What brings the lymph into the lymph node?
antigen presentation
The process by which an MHC molecule binds to a fragment of an intracellular protein antigen and carries it to the cell surface, where it is displayed and can be recognized by a T cell.
clotting cells
platelets; thrombocytes
diapedesis
passage of blood cells (especially white blood cells) through intact capillary walls and into the surrounding tissue
fever
An elevation of body temperature that accelerates tissue metabolism and the activity of defenses
monocytes
3-8% of leukocytes; largest leukocyte; U- or kidney-shaped nucleus; leave circulation, enter tissue, differentiate into macrophages. 2nd WBC at site of infection; increase with chronic infections
macrophage
Found within the lymph nodes, they are phagocytes that destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream.