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158 Cards in this Set
- Front
- Back
What is a trace element?
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Found as 1 microgram per gram of tissue.
Function as enzyme cofactors. |
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How much IRON is in the body?
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3-5 g of iron in the body
~2-2.5 g in hemoglobin ~ 130 mg in myoglobin ~8 mg in tissues (bound to enzymes) ~3-5 mg found in plasma –bound to transferrin, albumin and free hemoglobin Also stored as ferritin and hemosiderin in BM, liver and spleen |
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On average, how much iron is lost per day in adults?
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1 mg
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What enzyme reduces iron from the ferric to the ferrous state?
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Ferric reductase. Ferrous iron allows hemoglobin to bind reversibly to oxygen and CO2.
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What oxidizes iron from the ferrous to the ferric state and why?
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Ceruloplasmin so iron can be transferred by transferrin.
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How much iron is lost per day with each menstrual cycle? Each pregnancy?
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Menstrual Cycle: 20 - 40 mg
Pregnancy: 600 - 900 mg |
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What is hemochromatosis?
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excess absorption of iron from normal diet. Increase in serum iron and ferritin, Decrease in transferrin.
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What does hemochromatosis lead to?
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Iron accumulation in tissues, altered liver function, and causes hyperpigmentation. Treat with therapeutic phlebotomy.
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How can iron status be determined?
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Measuring hemoglobin or serum iron (diurnal variation, cannot be hemolyzed).
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What is the formula for TIBC in mg/dL?
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serum transferrin(mg/dL) X 1.25
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What is the formula for % saturation?
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(total iron/TIBC) X 100
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How does copper travel through the body?
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Through the blood bound to albumin or histidine for transport to liver, brain, heart, and kidneys.
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T/F
Half of dietary copper is excreted through feces. |
True.
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What happens to the copper that is not excreted?
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Most is incorporated as ceruloplasmin, an acute phase reactant.
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What usually causes an iron deficiency and what does this cause?
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premature infants, malnutrition, chronic diarrhea.
results in decreased hemoglobin and collagen production. |
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T/F
Zinc is 2nd to iron in importance as a trace element? |
True
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T/F
Zinc is higher in concentration in plasma or serum than in erythrocytes. |
False.
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What levels of lead are toxic to adults and children?
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Adults: 30 mg/dL
Children: 10 mg/dL |
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How is lead exposed to the body? What is the final storage of lead that is not excreted?
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Exposure is respiratory or gastrointestinal.
Final Storage: ~ 5% soft tissues ~ 95% bones |
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What is selenium a component of?
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Glutathion peroxidase and T-5 deiodinase
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How is selenium incorporated into our diet?
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Organ meats, seafood, cereals, dairy products, fruits, and vegetables.
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Where is low selenium often found? How do you treat it?
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Parts of China resulting in Keshan disease or Kashian-Bek disease. Selenium replacement completely corrects problem.
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The majority of iron in whole blood is found where?
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Bound to hemoglobin.
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Blood specimens for iron and TIBC are drawn early in the morning because, why?
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Iron exhibits diurnal variation.
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What is likely to occur first in IDA?
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Decreased serum ferritin.
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What protein binds ferric iron and is increased in IDA?
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Transferrin.
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What is the method of choice for detecting ALL trace metals?
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Atomic absorption spectroscopy
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What are considered macronutrients?
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proteins, lipids and carbs.
provides information about duration of malnutrition. |
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What are micronutrients?
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vitamins and minerals.
assessment of kidney, liver, heart and bone. |
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What are the nitrogenous biomarkers of nutritional status?
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creatinine, albumin, retinol-binding protein, transferrin, iron, and transthyretin.
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How long is albumin's half life?
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18 - 20 days
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What does hypoalbuminemia indicate?
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protein deficiency and hydration status.
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T/F
Retinol-binding protein correlates with protein energy status. |
True
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What is transferrin's half-life?
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8 days; sensitive marker of recent protein energy.
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T/F
Transthyretin is the least sensitive of all the biomarkers. |
False. Transthyretin carries thyroid hormones and has a half life of 1-2 days, making it VERY SENSITIVE!
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T/F
A negative nitrogen balance is recommended for therapy of certain disorders. |
FALSE! A positive nitrogen balance is recommended.
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What are the FAT SOLUBLE vitamins?
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A, D, E, K
absorbed and stored for long periods. |
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What is Vitamin A also known as?
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retinal, retinol, retinoic acid
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What are dietary sources of Vitamin A?
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liver, organ meats, fish oil, yellow to orange fruits and green leafy vegetables.
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What does a deficiency in Vitamin A lead to?
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night blindness and abnormal growth.
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What is another name for Vitamin D?
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Cholecalciferol
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How does the body obtain Vitamin D?
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exposure to sunlight, irradiated foods, and commercially prepared milk.
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What is the RDA for Vitamin D?
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5 mg/day
deficiency leads to rickets in children or osteomalacia in adults. |
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What vitamin is also known as alpha-tocopherol?
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Vitamin E
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T/F
Vitamin E is only attained through dietary intake. |
True.
egg yolks, vegetables, and legumes. |
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What are benefits of Vitamin E?
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Functions as an antioxidant and is critical for neurological structure and function. Protects erythrocyte membrane from oxidant stress.
Deficiency can lead to hemolytic anemia. |
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What is another name for Vitamin K?
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Phylloquinone
supplied partly by diet and partly synthesized by intestinal bacteria. |
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T/F
Vitamin K is essential in formation of coagulation factors. |
True.
prothrombin, Factors VII, IX and X, protein C and S |
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What are dietary sources of Vitamin K?
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cabbage, cauliflower, spinach, pork, liver, soy beans, and vegetable oils.
Deficiency leads to hemorrhage. |
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What is ascorbic acid?
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Vitamin C
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What are some benefits of Vitamin C?
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reducing agent, functions in synthesis of collagen, and aids in biosynthesis of some neurotransmitters. considered important in reducing the risk of Certain Cancers and Common Cold.
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What are the major dietary sources of Vitamin C?
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Citrus fruits and vegetables.
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What does a long term deficiency of Vitamin C cause?
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Scurvy.
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What is the function of the B complex?
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Most serve as enzyme cofactors functioning to transport atoms between molecules in enzyme coupled reactions.
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What vitamins make up the B complex?
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thiamine - B1, riboflavin - B2, niacin, pantothenic acid, biotin, pyridoxine B6, folates, and cyanocobalamin B12.
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What can a Vitamin B12 deficiency lead to?
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Pernicious anemia
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What does a Vitamin B12 and folate deficiency lead to?
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megaloblastic anemia
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What is the reference range of serum folate?
RBC folate? |
Serum folate: 2.6 - 12.2 mg/L
RBC folate: 103 - 411 mg/L |
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What enzyme breaks down starch?
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Amylase.
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What cells is pepsin released from?
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Chief cells.
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What acid is secreted from parietal cells and stimulates gastrin?
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HCl
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What stimulates the release of bile form the gall bladder?
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Cholecystokinin.
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Where does absorption take place in the body?
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Small intestine.
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Glucagon, insulin, and somatostatin are produced where in the body?
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Pancreas in the islets of langerhans.
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T/F
Sodium bicarbonate is in the pancreas and functions to neutralize gastric fluid. |
True.
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What are the proteolytic enzymes?
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Trypsin, chymotrypsin, elastase, carboxypeptidase, nuclease, and secretin.
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What are the pancreatic hormones and where are they located?
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Amylase, lipase, peptidases, disaccharidases. Located in the islets of langerhans.
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What are the symptoms of malabsorption?
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Weight loss, bruising, flatulance, bloating, diarrhea, steatorrhea
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What disease is characterized by an inherited autoimmune intolerance to gluten?
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Celiac disease.
Ag-Ab complex deposits in intestinal mucosa, causes a specific lesion. Leads to poor absorption and irritation of stomach. |
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T/F
Tropical sprue is an inherited disease that causes abnormalities of the small bowel. |
False.
It is Acquired. |
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What condition is also known as toxic megacolon?
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Ulcerative Colitis.
Chronic inflammation disorder. Mucosa of rectum and left colon are most affected. |
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What is Crohn's disease?
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Chronic inflammation of intestine of unknown etiology that can lead to intestinal obstruction. Ileum and colon are most affected.
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What is the function of chief cells?
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production of pepsinogen
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What syndrome causes a gastrin producing tumor in the pituitary and parathyroid glands?
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Zollinger Ellison syndrome
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T/F
50% of the gastrinomas are malignant and 25% of the malignant have multiple tumors. |
True.
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What is the most common carbohydrate malabsorption disorder?
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Lactose Intolerance.
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____% of people affected by lactose intolerance show diminished lactase activity after first few years of life.
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70%
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What test is used to detect gastrinomas?
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gastrin stimulation test
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What do normal fecal lipids consist of?
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60% fatty acids
30% sterols 10% tri-acyl glycerols |
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What does increased fecal fat indicate?
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Biliary obstruction or malabsorption
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What 2 stains are used to stain fat globules?
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Sudan III and Sudan IV
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What are the reference ranges for qualitative (random) and quantitative (72 hr collection) fecal fat analysis?
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Qualitative: 40- 50 droplets/hpf
Quantitative: >/= 6g/day |
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What does the D-Xylose test assess and how much passes through the intestinal mucosa?
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Assesses mucosal absorption of small intestine.
Approximately 60% taken in an oral dose will pass through intestinal mucosa. |
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What does low absorption of D-Xylose indicate?
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Disorders of the small intestine.
Crohn's, malabsorption, celiac, etc. |
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What type of procedure is the D-Xylose reaction?
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Spectrophotometric
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Describe the reaction of D-Xylose.
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xylose is measured by heating the protein free specimen to convert xylose to fufural. Which then combines with a chromagen for measurement.
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What is the reference range for a 5g oral dose of D-Xylose?
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Normal >/= 1.4 g
Borderline 1.2 - 1.4 g Abnormal < 1.2 g |
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What is pancreatitis?
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Viral, autoimmune, tumor, or toxin related to destruction of acinar cells of pancreas. Reflux of bile and duodenal contents into pancreas lead to release of pancreatic enzymes into the blood stream.
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T/F
Chronic pancreatitis is reversible and has a low mortality rate. |
False.
Chronic pancreatitis is irreversible with a high mortality rate. |
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A rapid increase in serum amylase, urine amylase, and serum lipase indicates what disorder?
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Acute Pancreatitis.
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What is the most common single-gene inherited disease in people of Northern European heritage?
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Cystic Fibrosis.
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What causes cystic fibrosis to occur?
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Cystic fibrosis mutant gene – CFTR (cystic fibrosis transmembrane-conductance regulator) occurs on chromosome 7.
70% of cases are F508 |
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What does the cystic fibrosis mutation cause?
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All exocrine secretions to have less water.
-salty sweat -malabsorption |
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What is the reference range for the sweat chloride screening test?
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Normal <35 mmol/L
CF > 60 mmol/L |
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How is sweat stimulated in the sweat chloride test?
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Iontophoresis of pilocarpine
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T/F
Amylase requires Cl and Ca for full activity. |
True.
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Which analytic method measures the rate of hydrolysis of starch by amylase using turbidometry or nephelometry?
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Amyloclastic.
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What does the saccarogenic method measure?
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Rate of production of monosaccharides or disaccharides produced in the reaction when amylase reacts with the substrate.
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What is the reaction formula for the saccharogenic method?
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4-NP-(glucose)7 + a-amylase --> 4-NP-(glucose)4,3,2 + (glucose)5,4,3
4-NP-(glucose)4,3,2 + a-glucosidase --> 4-NP-(glucose)4 + X-glucose + 4-NP |
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What is the formula for the methods for lipase?
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triglycerides + lipase --> fatty acids + glycerol
glycerol + ATP(Mg+2) + glycerol kinase --> glycerol- 1-phosphate + ADP glycerol-1-phosphate + O2 + glycerol oxidase --> DHAP + H2O2 H2O2 + 4-AAP + dye-precursor --> H2O + quinonimine dye (colored) |
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What is a tumor/neoplasm?
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Abnormal/uncontrolled proliferation of cells.
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Benign vs. Malignant
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Benign: remains confined to primary site.
Malignant: capable of invading surrounding tissue and metastasizing through circulatory and lymphatic systems. |
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What is the term for loss of cell differentiation and change in cell/tissue structure?
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Anaplasia
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What is a carcinoma?
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malignant growth from skin/organ.
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What is an adenoma?
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benign growth arising from glandular epithelium.
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What are the desirable traits of a tumor marker?
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- Specific for type of cancer
- Always present with that cancer - Amount correlates with tumor load - Short half-life - Levels should have prognostic value |
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What should a good screening test have?
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- high diagnostic sensitivity
- low rate of false negatives |
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What should a confirmatory test have?
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- high diagnostic specificity
- low rate of false positives |
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What are types of tumor markers?
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- enzymes and isoenzymes
- hormones, neurotransmitters and their metabolites - receptors - proteins - genetic markers |
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What cancers is Carcinoembryonic Antigen (CEA) elevated in?
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-colon - ovarian
- lung - uterine - gastric - prostate - breast - pancreatic |
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What are some problems with CEA and what is it most useful for?
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Problems: elevated in nonmalignant conditions
Useful: establishing prognosis and monitoring therapy and reoccurance of disease. |
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What is the only tissue-specific marker?
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Prostate Specific Antigen (PSA)
-serine protease produced by epithelial of prostate. - not specific for prostate cancer - also elevated in Benign Prostatic Hyperplasia |
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What hormone is also known as the "pregnancy hormone"?
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Human Chorionic Gonadotropin (HCG)
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What can HCG be used for besides detecting pregnancy?
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Monitoring trophoblastic pathologies and germ cell tumors of the testes and ovaries.
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What tumor marker is synthesized in the yolk sac, fetal liver, GI tract and kidney?
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Alpha-fetoprotein (AFP)
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What is AFP used for?
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A marker for neural tube defects and a screening tool for down syndrome. Moderate elevations in liver disease.
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What is Cancer Antigen 15-3?
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Glycoprotein on mammary epithelium.
Increased in breast cancer - also increased in pancreatic, lung, ovarian, colorectal, and liver cancer |
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What is CA 15-3 primarily used for?
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Monitoring patients after surgery.
Used in combination with CA 27-29 for monitoring reocurrance. |
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Clinical assays for most tumor markers are important for:
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Monitoring the course of a known cancer.
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The most specific tumor marker for prostatic cancer is:
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PSA
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CA 125 is elevated in the serum of patients with:
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ovarian cancer
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What is the oncofetal antigen marker for liver cancer?
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AFP
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T/F
CA 125 is useful for diagnosis but limited in monitoring disease state. |
False.
Limited use in diagnosis but useful in conjunction with CEA. Useful in monitoring disease in ovarian cancer patients. |
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What is CA 19-9?
|
- blood group antigen
- specific for pancreatic cancer but also present in other gastrointestinal cancers. - used to monitor therapy and predict reoccurance. |
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Name the cancer/affected body part associated with each enzyme/isoenzyme.
Prostatic acid phosphatase |
prostate cancer
|
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CK-BB
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prostate and stomach cancer
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ALP
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bone and liver
|
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Amylase/Lipase
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pancreatic
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What is the difference between endocrine and paracrine hormones?
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Endocrine travel away from the site they were produced.
Paracrine are released into interstitial space, target close to production. |
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What are the physiological functions of hormones?
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- Maintenance of internal environment
- Reproduction - Growth and Development - Energy storage, production and utilization |
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What are characteristics of protein hormones?
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- from amino acids
- water soluble - short half-life (5 - 60 minutes) |
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What are characteristics of steroid hormones?
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- synthesized from cholesterol
- lipid soluble; require transport proteins - long half-life (60 - 100 minutes) |
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What are amines?
|
Hormones with characteristics of protein and steroid hormones.
Ex: catecholamines and thyroxine |
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What happens when a hormone binds to a cell receptor?
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- This leads to the production of a second generation messenger which mediates the hormone's effect on intracellular enzymes and/or gene's expression.
- provides target organ specificity |
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What is a G Protein receptor?
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monomeric proteins with an extracellular domain and cytoplasmic domain.
- use guanine nucleotide-binding proteins as the interface with target proteins |
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What are protein kinase receptors?
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Contain intrinsic hormone-activated tyrosine kinase activity.
- direct catalysts of phosphorylation rxn Ex: insulin receptor |
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Describe how steroid hormones work.
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Steroid hormones bind to an inactive receptor
Shape change occurs, becomes activated Complex binds to DNA at hormone response elements "biologically active" |
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How do thyroid hormones work?
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Thyroid hormones bind to specific chromatin receptors
Chemical change activation/repression of gene transcription |
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T/F
Exposure of high concentrations of hormone may decrease number and affinity of surface receptors. |
True.
This is referred to as "down regulation" or "desensitization". |
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T/F
Hormones have no affect on each other. |
False.
Some hormones can influence others but most hormones only influence their own receptors. Ex: estrogen can increase the binding of oxytocin |
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What is "specificity spill-over"?
|
Hormones may have varying affinity levels; strong for their receptors, weak for others.
|
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T/F
Secretions of hormones are continuously released at a constant rate throughout the day. |
False.
The secretions are rhythmic and occur in bursts. - vary over minutes, hours, days, or weeks |
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How does the hypothalamus play into the the secretion of hormones?
|
produces several neurosecretory factors that stimulate or inhibit the release of corresponding hormones from the anterior pituitary.
- the hormones from the anterior pituitary then act on other target endocrine glands |
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Does the following describe negative or positive feedback?
Stimulating hormone induces production of a specific hormone. Elevated levels of this hormone turns off the release of the stimulating hormone. |
Negative feedback
|
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What is the positive feedback mechanism?
|
Stimulating hormone induce production of a specific hormone. Elevated levels of this hormone induces MORE stimulating hormone to be released.
|
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Describe the Adenohypophysis (anterior lobe of pituitary gland).
|
- Composed of nests of different cell types that secrete different hormones or tropins.
- provides secondary level of control - hormone secretion is controlled by hypothalamus - referred to as master gland, due to the many hormones it secretes. Ex: PRL, GH, FSH, LH, TSH, ACTH |
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Describe the Neurohypohysis (posterior lobe of pituitary gland).
|
- closely associated with hypothalamus, connected via a stalk
- does not synthesize any hormones - primarily stores and releases hormones produced by hypothalamus - serves as storage area for oxytocin and ADH |
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What cells in the anterior pituitary produce the protein hormone, prolactin?
|
Lactotrophs
|
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What chain of events follows a decrease in Prolactin Inhibitory Factor (dopamine)?
|
Increase in Prolactin RF from hypothalamus --> Increase in Prolactin form anterior pituitary --> Increase in milk production by mammary glands
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T/F
Prolactin is also present normally in men, children, and non-lactating women. |
True.
<20 ng/mL |
|
What is a prolactinoma?
|
Prolactin producing tumor which causes HYPERPROLACTINEMIA.
Hyperprolactinemia leads to galactorhea and gynecomastia. |
|
What hormone is secreted by the somatotroph cells in the anterior pituitary and stimulates growth and metabolism for whole body?
|
Growth Hormone (GH) aka somatotropin
- controlled by hypothalamic GHRH |
|
Acromegaly is characterized by what traits?
|
excess GH in adults causing enlarged bones
|
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What disorder is caused by excess GH pre-puberty?
|
Gigantism
|
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What disorder causes small, proportional stature in children but has no effect on adults?
|
Dwarfism: pre-puberty deficiency of GH
|
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What hormone plays a critical role in lactation, labor, and parturition?
|
Oxytocin
- contraction action in parturition - ejaculation of milk |
|
What areas of the body does oxytocin play major roles in?
|
Smooth muscle
- uterus - mammary gland |
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Elevated levels of GH are useful in diagnosis of _____?
|
Acromegaly
|