test 3 toxicology
Terms
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- What will determine how much of a toxicant will be distributed to a specific target organ?
- Time-dependant toxicokinetic processes
- Defined as adverse effects or diseased states manifested in specific organs in the body
- Target organ toxicity
- Toxicity may be enhanced by these two things
-
Distribution features - deliver a high concentratio of the toxicant to the target organ
inherant features - render target organ highly susceptible to the toxicant - Observed differences in target organ toxicity are most likely due to ________ and _________ differences in _______.
- Observed differences in target organ toxicity are most likely due to structural and functional differences in cells that make up organ tissues
- Cells differ in many ways including (7)
-
*energy consumption
*rate of cellular division
*active and passive transport characteristics
*realationship to cell barriers and extracellular matricies
*presence of intracellular components
*repair mechanisms
*biotransformation capacity - This is what causes each organ to respond to a toxicant in a different way
- Cellular specialization
- Not all organs are affected to the same extent by a toxicant (T/F)
- true
- a single toxicant may have only one target organ (T/F)
- false; may have seveeral target organs
- several toxicants may have the same target organ (T/F)
- true
- the highest concentration of a toxicant is always found in the target organ
- false; is NOT always found in the target organ
- the concentration of a toxicant in a target organ is a result of________
- all the TOXICOKINETIC processes
- The immune system consists of a network of organs which include
-
*bone marrow
*thymus
*spleen
*lymph nodes - these and other cells are derived from the organs of the immune system
- lymphocytes
- T cells are derived from _____
- the pluripotent cells in the bone marrow
- T cells are processed through the ______
- thymus
- T lymphocytes constitute what percentage of circulating lymphocytes
- 70%
- On contact with antigens from APCs, these become activated and responsible for mediated cellular immunity.
- T lymphocytes
- give two examples of antigen -presenting cells (APCs)
-
macrophages
B cells - B cells are derived from______
- pluripotent cells in the bone marrow
- Pluripotent cells are generated from____
- Lymphoid stem cells
- B cells are processed through ____
- Bursal equivalent tissues
- Give examples of Bursal equivalen tissues
-
*bone marrow
*lymph nodes
*lymphoid tissues in gut (appendix, cecum , Peyer's patches) - B lymphocytes constitute what percentage of circulating lymphocytes
- 30%
- The primary immune response is initiated by contatct of _______ with B cells.
- antigen
- Some B cells become _____ which retain the surface immunoglobulin receptors, others become ______
-
memory cells
plasma cells - Memeory cells have Ig__ and Ig__ on their surface
-
IgM
IgD - Exposure of memory cells to the same antigen at a later time results in _______
- secondary immune response
- Null cells lack ________ and participate in ______.
-
*characteristic surface markers of T and B cells
*Nonspecific immune system functions - These are a null cell which have spontaneous cytolytic activity especially leukemia and carcinoma cells.
- Natural killer (NK) cells
- From what are macrophages derived?
- the stem cell pool in the bone marrow
- After thry are release from the marrow acrophages appear in the blood as what? in the tissues as what?
- monocytes
- After thry are release from the marrow acrophages appear in the tissues as what?
- histiocytes
- On contact with a foriegn body, Macrophages engulf it becoming______
- activated macrophages
- Activated macrophages are rich in________
- hydrolytic enzymes
- These are derived from the bone marrow, are located in the skin, and act as APCs.
- Langerhans cells
- Langerhans cells serve to process________ and initiate ______
-
dermal antigens
contact allery - Name the three types of immune responses
-
*Immunosuppresion
*Hypersensitivity and alergy
*Autoimmunity - TCDD is an
- immunotoxin
- TCDD supresses ______immune functions while sparing ____ immmune functions.
-
specifc
non-specific - Name three types of non specific immune system cells.
-
NK cells
Macrophages
Langerhans cells - The immunotoxicity of TCDD is mediated through binding to the _____ on lymphoid cells
- Ah receptors
- The two most common Hypersensitivity reactions are
-
Type 1 - immediate
Type 4 - delayed - Type 1 hypersensitivity reaction is delayed (T/F)
- false, type 1 is immediate
- Type 1 In a type one reaction, the first exposure to the antigen induces the production of this type of antibody
- IgE
- Subsequent exposure to antigen in a type on reaction triggers the release of these four substances
-
histamine
heparin
seratonin
prostaglandins - Type one reactions recsult in clinical malfestations such as
-
asthma
rhinitis
urticaria
anaphylaxis - Type 2 hypersensitivity reaction is very common (t/f)
- false; it is not common at all, lowry said he only saw one case in his career.
- Type 2 hypersensitivity reaction is characterized by cytolysis through______ or________.
- IgG or IgM
- The targets of a Type 2 hypersensitivity rxn are typically
-
*erythrocytes
*leukocytes
*platelets
*progenitor cells of the above three - The result of cytolysis in a type 2 hypsens rxn are
-
hemolytic anemia
leucopenia
thrombocytopenia - Type 3 hypersensitivity rxn is less common (t/f)
- true
- Type 3 hypersensitivity rxn is also known as
- Arthus reaction
- In a type 3 hypersensitivity rxn the antigen-antibody complexes are deposited where?
- vascular endothelium
- Damaged blood vessesl in a type 3 hypersensitivity rxn may cause
-
*lupus erythematous (procainamide)
*glomular nephritis (gold) - Type 4 hypersensitivity rxn is delayed (t/f)
- true
- What mediates a type 4 hypersensitivity rxn?
- T (cells rather than antibodies)
- Perivascular infiltration of monocytes, lymphocytes, and lymphoblasts is characteristic of which type of hypersensitivity reaction?
- type 4
- When the immune system produces antibodies to endogeous antigens it is called
- autoimmunity
- Hemolytic anemia is due to the phagocytosis of erythrocytes because of ________
- the presence of antibodies of endogenous antigens on the erythrocytes
- Hemolytic anemia is an autoimmune diease (t/f)
- true
- Evidence does not show a specific chemical that directly causes an autoimmune response(t/f)
- true
- Auto immune diseases are all thought to be caused by a virus (t/f)
- true
- Name three types of autoimmune diseases
-
AIDS
rheumatoid arthritis
Lupus - this refers to the disease states in the respiratry system brought about by the inhalatio of gasses, vaoprs, liquid droplets and particulates
- pulmunotoxicity
- Inhalational toxicants may effect what three areas?
-
nasopharyngeal
thracheobronchial
alveolar - how small must a particulate be to go into the depp lung
- 0.5 microns
- The respiratory lining is not highly susceptible to toxic substances (t/f)
- false it IS highly susceptible
- what two factors dimish the barrier quality of the repiratory epithelium
-
*Eptheilial cells are not always statified
*Epithelial cells are not keratinized - what type of epithelium is present in pharynx?
- stratified squamous
- what type of epithelium os present in tracheobronchial region?
- cilliated columnar
- Varied pulmunotoxicities are a reflection of the charactersitic assemblage of more than 40 different cell types present in the repiratory system (T/F)
- True
- An inflamatory response in the lungs leads to what two things?
-
*Contraction of the smooth musculature
*Adema - Contraction of the smooth musculature and adema are two conditions that together reduce what?
- The cross sectional area of the air passageway in the lungs which in turn reduces the flow of air.
- Some pulmunotoxicants target specific cells (T/F)
- true
- Clara cells are located in the region of the________.
- terminal bronchioles
- Pulmunotoxicity sometimes reflects the damage to specific cell populations which leads to which two things that decrease pulmonary function
-
*impairment of the mucocilliary escalator
*necrosis - Narrowing of the air passageways in response to stimuli including allernes, infections, exercise and drugs is called
- Asthma
- Occupational asthma develops when on contact with the substance the smooth muscles surrounding the _______ contract reducing their cross-sectional area which restricts the flow of air
- bronchioles
- Diffuse alveolar dammage(DAD) is clinically known as
- adult respiratory distress syndrome(ARDS)
- This results when the cells lining the alveoli and alveolar capilaries allow protein rich fluid to leak into the tiny spaces betwen the capillary and alveolus.
- ARDS adult respiratory distress syndrome
- cells lining the alveoli are called
- pneumocytes
- cells lining the alveolar capillaries are
- endothelial cells
- Protein rich fluid leaking into the spaces between the capillary and the alveolus leads to which three things
-
*destruction of type 1 pneumocytes
*inflammatory responses
*pulmonary fibrosis - pulmunotoxicity resulting from the inhalation of dust is called
- pneumoconiosis
- in upon inhalation of duat, the particulate matter enter the alveoli, they may stimulate the formation of________
- pulmonary fibrosis
- What is the most common type of cancer in the US
- Lung Cancer
- Carcinogens are directly linked to lung cancer (T/F)
- false; they are causally linked to lung cancer
- Type 1 is the immediate hypersensitivity reaction mediateed by what class of antibodies?
- IgE
- IgE is a cytophilic antibody exhibiting a high affinity for the membranes of _______ cells which are normally present in the airway mucosa
- mast
- Binding of anitgen to antibody on mast cell membrane initiates what?
- expcytosis of mast cell granules
- Histamine and the release of other active mediators causes what?
-
vasodilation
increased vascular permeability
tissue edema
discharge of copious amounts of mucos secretions
contraction of smooth muscle of airway - Type 1 reaction ususally occur within minutes (T/F)
- true
- Hay fever is an example of a type 1 reaction (T/F)
- true
- Antigens in a type one reaction ususally include pollens, organic dusts, or animal hairs.
- true
- Asthma caused by inhaled external antigens is called
- extrinsic asthma
- extrinsic asthma is usually triggered by
- exogenous environmental agents
- extrinisc asthma does not necessarily occur more often in people based on ocupation (t/f)
- false, ocupationally related
- what is suberosis?
- bronchiol asthma and allergic alveolitis caused by cork dust
- Intrinsic astma attacks are propogated by factors like
- exercise, infection, emotional stress
- intrinsic asthma can be conssidered within the scope of environmental disease (t/f)
- true
- Type 2 immune reactions are autoimmune reactions(t/f)
- true
- Environmental agents have been implicated in type 2 reactions (t/f)
- false