Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Pathology of Body #9
Chapter 9
| Question | Answer |
|---|---|
| State two reasons for the appearance of overflow metabolites in the urine. | Overflow metabolites appear in urine when chemicals either override the reabsorption ability of the renal tubules or they are not normally reabsorbed from the filtrate because they are inly present in minute amounts. |
| Name two physical characteristics of urine that can alert medical personnel to the possibility of a metabolic disorder. | Maple Syrup disease gives urine a sweet syrup odor, and urine of a patient with Melanuria turns black when it is exposed to air. |
| List four metabolic disorders associated with the phenylalanine-tyrosine metabolic pathway. | 1) Phenylketonuria (PKU), 2) Tyrosyluria 3) Melanuria 4) Alkaptonuria |
| Why do laws require PKU testing of all newborns? | Mandatory testing is required as the disease is estimated to occur in 1 of every 10,000 to 20,000 births and causes severe mental retardation if undetected. If detected, the disease is controllable. |
| Why are the original PKU newborn tests performed on blood rather than urine? | Phenylalanine levels often take 2 to 6 weeks to reach a detectable level in urine, and during this time period mental damage could occur. |
| Name the enzyme lacking in persons with PKU. | phenylalanine hydroxylase |
| When performing the Guthrie test, does the presence of increased phenylalanine inhibit the growth of B. subtilis? Why or why not? | Increased levels of phenylalanine counteracts the action of beta-2-thienylalanine, and inhibitor of B. subtilis. |
| What is the purpose for testing urine with ferric chloride from people with PKU? | Urine Testing for those with PKU is to check for the presence of other amino acids. |
| State three possible causes of tyrosyluria. Which is usually the least serious? | Type 1) Deficiency of the enzyme fumarylacetoacotate hydrolase (FAH) 2) lack of the enzyme tyrosineaminotransferase 3) Lack of the enzyme p-hydroxyphenylpyruvic acid dioxygenase. Type 2 is generally the least serious of the three. |
| What is the significance of an orange-red color in the nitrosonaphthol test? | The presence of an orange –red color when testing for nitrosonaphthol shows a positive reaction and indicates that further testing is needed. |
| Why is increased urinary homogentisic acid called alkaptonuria? | The name alkaptonuria comes from the fact that the urine containing homogentisic acid darkened after becoming alkaline from standing at room temperature. |
| Why does the presence of homogentisic acid produce a positive Clinitest result? | The yellow precipitate produced in the Clinitest indicates the presence of a reducing substance. |
| What is the significance of a urine that turns black following exposure to air and reacts with sodium nitroprusside and Ehrlich reagent? Why is this of medical importance? | |
| Describe the ferric chloride tube test in PKU, tyrosyluria, alkaptonuria, and Melanuria. | The Ferric chloride tube test is useful for detecting the presence of amino acids which can indicate the presence of a metabolic disorder. Further tests and observations can diagnose the exact disorder. |
| How did maple syrup urine disease get its name? | Due to the rapid accumulation of ketone acids, the urine produces a strong sharp sweet smell resembling maple syrup. |
| What chemical test in the routine urinalysis is associated with a positive DNPH reaction? | The ketone test is associated with a positive PNPH reaction. |
| Which organic acidemia produces urine with an odor of “sweaty feet”? Which reacts with p-nitroaniline? | Isovaleric Acidemia produces urine with an odor of sweaty feet, while Methylmalonic acidemia reacts with p-nitroaniline. |
| Why are intestinal disorders associated with blue urine? How does the significance of a blue diaper differ from that of a blue urine specimen in an adult? | |
| What is the significance of a urine that turns purple on addition of nitrous acid and 1- nitroso-2-naphthol? How could this be a false-positive result? | Urine that turns purple with the addition of 1-nitroso2-naphthol can detect an increase in the amount of 5-HIAA produced by the body. The darker the color (purple to black) the greater the likelihood |
| Why is cystinosis considered an inborn error of metabolism and cystinuria is not? | |
| Why are cystine crystals and not lysine crystals found in the urine in cystinuria? | |
| How can cystinuria be differentiated from homocystinuria in the laboratory? |
Created by:
piadavis