Chapter 3 - Absorption, Distribution, Excretion of Xenobiotics Flashcards
A high urinary pH would favor the excretion of…
A. Organic acids
B. organic bases
C. Neutral organic compounds
D. None of the above
A. Organic acids
Toxicants most likely to be reabsorbed after being filtered at the glomerulus are…
A. Organic anions
B. organic cations
C. Neutral polar molecules
D. Highly lipid-soluble molecules
D. Highly lipid-soluble molecules
Diuretics can enhance the renal elimination of compounds that…
A. Are of a molecular weight greater than 70 kDa
B. are ion trapped in the tubular lumen
C. Are highly lipid soluble
D. Are highly protein bound
B. are ion trapped in the tubular lumen
The amt of a volatile liquid excreted by the lungs is…
A. Inversely proportional to its lipid-water partition coefficient
B. directly proportional to its vapor pressure
C. Directly proportional to its molecular weight
D. Inversely proportional to cardiac output
B. directly proportional to its vapor pressure
Kernicterus results from…
A. Enzyme induction leading to decreased glucocorticoid levels
B. excess ingestion of foods containing tyramine
C. Displacement of bilirubin from plasma proteins
D. Malabsorption of fat-soluble vitamins
C. Displacement of bilirubin from plasma proteins
All of the following could influence the gastrointestional absorption of xenobiotics except…
A. pH
B. intestinal microflora
C. Presence of food
D. Time of day
D. Time of day
The rate of diffusion of a xenobiotic across the GI tract is proportional to all of the following except…
A. Hepatic blood flow
B. surface area
C. Permeability
D. Residence time
A. Hepatic blood flow
Which of the following is not absorbed in the colon?
A. Water
B. sodium ions
C. Glucose
D. Hydrogen ion
C. Glucose
Nanoparticles are considered to have diameters smaller than…
A. 100 um
B. 10 um
C. 1 um
D. 0.1 um
D. 0.1 um
All of the following are true of nanoparticles except…
A. They are capable of exposing the lung to a large number of particles
B. they are capable of exposing the lung to large particle surface area
C. Because of turbulance, very few reach the alveoli
D. They are the focus of recent toxicologic research
C. Because of turbulance, very few reach the alveoli
All of the following are significantly stored in bone matrix except…
A. Lead
B. diaquat
C. Strontium
D. Fluoride
B. diaquat
All of the following can cross the placenta except…
A. Heparin
B. rubella virus
C. Spirochetes
D. IgG antibody
A. Heparin
Methylmercury crosses the BBB bycombining with cysteine and forming a molecule similar to
…
A. Glycine
B. glutamine
C. Taurine
D. Methionine
D. Methionine
Which of the following statements is true?
A. The BBB of a 70 year old is more permeable than that of a premature infant
B. chemicals/drugs can be excreted into the urine by active secretion
C. The kidney lacks cytochrome P450 enzymes
D. All mammalian placentas have the same number of tissue layers
B. chemicals/drugs can be excreted into the urine by active secretion
All of the following is true of breast milk except…
A. Acidic cmpds may be more conc in milk than plasma
B. Toxicants can be passed from mother to offspring
C. Toxicants can be passed from cows tohumans
D. DDT, PCBs, and PBBs can be found in human milk
A. Acidic cmpds may be more conc in milk than plasma
Active transport is characterized by all of the following except…
A. Movement against a concentration gradient
B. energy requirement
C. Nonsaturability
D. Competitive inhibition
C. Nonsaturability
All of the following are true of facilitated diffusion except…
A. Does not require energy
B. movement against a concentration gradient
C. Saturability
D. Involvement of a carrier
B. movement against a concentration gradient
A transport process that removes particles from alveoli is…
A. Phagocytosis
B. phospholipids
C. Mediated through BCRP
D. Mediated through MDR1/P-gp
A. Phagocytosis
P-gp, MRP2, and BCRP on enterocyte brush-border membranes function as…
A. Influx transporters
B. bile acid binders
C. Metal transporters
D. Efflux transporters
D. Efflux transporters
Substrates for P-gp include all of the following except…
A. Cyclosporin
B. paclitaxel
C. Ethanol
D. Colchicine
C. Ethanol
The transfer of toxicants by simple diffusion from areas of high concentration to areas of low conc is called…
A. Dalton’s law
B. Priestley’s law
C. Fick’s law
D. Henderson’s law
C. Fick’s law
The fluid character of cell membranes is somewhat dependent on the amount of…
A. Saturated fatty acids
B. transmembrane proteins
C. Ion channels
D. Unsaturated fatty acids
D. Unsaturated fatty acids
Aqueous pores are primarily involved in the transport of…
A. Small hydrophobic molecules
B. large hydrophobic molecules
C. Small hydrophyllic molecules
D. Large hydrophyllic molecules
C. Small hydrophyllic molecules