Électrolytes et minéraux (Biochimie) Flashcards
1
Q
Which of the following are important regulators of extracellular water volume:
- hypothalamic control of thirst
- renin angiotensin - aldosterone system
- pituitary release of anti-diuretic hormone (ADH)
- atrial naturetic peptide (ANP)
A
1 -hypothalamic control of thirst
2 - renin angiotensin - aldosterone system
3 - pituitary release of anti-diuretic hormone (ADH)
4 - atrial naturetic peptide (ANP)
1
Q
Le contrôle du taux de calcium dépend de:
A
- fonctionnement normal des parathyroides, des reins et des intestins
- de l’apport adéquat en calcium et en vitamine D
2
Q
In regard to the colligative perperties of a solution, the addition of solutes to a solution will ______ the vapor pressure of that solution:
- increase
- decrease
- not affect
- there is not enough information provided to answer this question
A
2 - decrease
2
Q
Quels sont les causes de l’hypersidérémie:
A
(augmentaiton du fer)
- destruction élevée des globules rouges (anémie hémolytique)
- érythropoièse diminuée ou inefficace (anémie pernicieuse…)
- arrèt de la synthèse de l’hème (empoisonnement au plomb…)
- sortie du fer des réserves (nécorse hépatique)
- apport exagéré au défaut d’absorption (ingestion exagérée, hémochromatose)
- anémie mégaloblastique et pernicieuse
3
Q
Which of the following statements concerning electrolytes and electrolyte measurement is not correct:
- routine laboratory analysis of electrolytes includes measurement of sodium, potassium, chloride, and bicarbonate
- ion selective electrode measurements are based on the measurement of the potential difference between the ISE and the reference electrode
- specimen tubes for electrolyte analysis should be opened as soon as possible after collection, then centrifuged, and the serum or plasma separated promptly
- specimen requirements for electrolyte analysis use of unhemolyzed serum or plasma
A
3 - specimen tubes for electrolyte analysis should be opened as soon as possible after collection, then centrifuged, and the serum or plasma separated promptly
4
Q
Quels sont les rôles du calcium:
A
- contraction musculaire
- diminue l’irritabilité neuromusculaire
- essentiel à la coagulation sanguine
4
Q
Quel est la valeur sérique du calcium:
A
2.00-2.60 mmol/L
5
Q
The significant electrolyte changes observed in metabolic alkalosis include:
- sodium unchanged/chloride increased
- sodium unchanged/chloride decreased
- sodium increased/chloride increased
- sodium decreased/chloride decreased
- sodium increased/chloride decreased
A
2 - sodium unchanged/chloride decreased
5
Q
Quel est le deuxième cation le plus abondant dans le LIC:
A
Le magnésium (après le potassium)
5
Q
Combient du fer plasmatique est contenu dans la ferritine:
A
Normalement, 1%
6
Q
A sweat chloride of 70 mEq/L is indicative of which of the following diseases:
- cystic fibrosis
- myasthenia gravis
- Cushing’s syndrome
- syndrome of inappropriate ADH secretion
A
1 - cystic fibrosis
7
Q
Quelle est la forme active du magnésium:
A
La forme ionisée (libre)
8
Q
Quelle est la méthode de référence pour le chlore:
A
Titration coulométrique
9
Q
Comment est fait la répartiton du calcium dans le corps:
A
- 99% se retrouve dans les os (et dents) sous forme d’hydroxy-apatite, un complexe de calcium et de phosphore
- 1% est dans le sang et LEC
10
Q
The ability of an indicator electrode ot respond to a single species of ion and not any other is referred to as:
- sensitivity
- accuracy
- precision
- selectivity
A
4 - selectivity
11
Q
Monitoring the current at an electrolytic electrochemical cell that is generated at a fixed voltage and is proportional to the concentration of analyte present in the test sample in solution is referred to as:
- coulometry
- potentiometry
- osmometry
- amperometry
A
4 - amperometry
12
Q
A common mutation that accounts many of the symptoms observed in individuals with cystic fibrosis is a:
- total gene deletion of the cystic fibrosis gene resulting in loss of a cell surface receptor only in the pancreas and lungs
- CAG triplet expansion at the 5’ end of the gene leading to excess amino acid residues
- gene deletion on the X chromosome resulting in loss of an intracellular receptor protein
- amino acid deletion in the cystic fibrosis transmembrane conductance regulator (CFTR) gene resulting in the loss of electrolyte transport across cell membranes
A
4 - amino acid deletion in the cystic fibrosis transmembrane conductance regulator (CFTR) gene resulting in the loss of electrolyte transport across cell membranes
13
Q
Quels sont les valeurs critiques du calcium:
A
- hypocalcémie: 1.50 mmol/L
- hypercalcémie: 3.00 mmol/L
13
Q
Le dosage du fer sérique, de la TIBC et du coefficient de saturation sont utilses seulement pour quoi:
A
Pour détecter des surcharges chroniques en fer et des empoisonnements au fer chez l’enfant.
14
Q
Which electrolyte is most significantly affected by hemolysis:
- sodium
- potassium
- chloride
- bicarbonate
A
2 - potassium
15
Q
Hypernatremia commonly occurs with:
- decreased synthesis of antidiuretic hnormone (ADH)
- decreased aldosterone
- edema
- all of the above are correct
A
1 - decreased synthesis of antidiuretic hnormone (ADH)
15
Q
Comment fonctionne la parathormone (PTH) et calcitrol dans la régulation du calclium:
A
- libère du calcium et du PO4 à partir de l’os en stimulant la résorption (dégradation des os) de l’os par les ostéoclastes et ostéocytes
- conserve le calcium en augmentant la réabsorption du calcium par les tubules rénaux
- en facilitant l’excrétion du phosphore en inhibant sa réabsorption rénale; la diminution de la concentration du phosphore stimule et relâche encore plus du calcium et phosphore des os
- en stimulant la formation de calcitrol par les reins; cette vitamine augmente l’absorption intestinale du calcium et phosphate alimentaire et augmente l’effet du PTH sur la résorption des os
15
Q
Quelle est la méthode de routine du dosage de magnésium:
A
Spectrophotométrie après chélation par la calmagite ou le bleu de méthylthymol.
16
Q
Quels sont les méthodes de dosage du phosphate:
A
- réaction avec le molybdate - Fiske et Subbarow
- méthodes enzymatiques (Trinder)
17
Quel hormone s'oppose au système rénine-angiotensine et permet le controle du volume et de la pression osmotique:
Peptide natriurétique auriculaire (ANP)
18
The CO2 electrode works by (multiple):
1. measuring a potentiometric change
2. measuring a change in current
3. measuring a change in pH
4. using an enzymatic reaction with CO2
1 - measuring a potentiometric change
3 - measuring a change in pH
19
A normal serum osmolality is:
1. 150-350 mOsm/kg
2. 247-263 mOsm/kg
3. 285-298 mOsm/kg
4. 325-348 mOsm/kg
3 - 285-298 mOsm/kg
20
The most common laboratory method of sodium/potassium measurement is:
1. atomic absorption spectrophotometry
2. spectrophotometry
3. direct ion-selective electrode measurement
4. enzyme assay
3 - direct ion-selective electrode measurement
20
The hormone responsible for maintenance of ion balance through its action on the renal tubules is:
1. renin
2. aldosterone
3. erythropoietin
4. antidiuretic hormone
2 - aldosterone
20
An optical sensor used in a analytical instruments to measure pH, blood bases, and electrolytes is referred to as a:
1. potentiometer
2. optode
3. affinity type sensor
4. coulemoter
2 - optode
21
La mesure des électrolytes fournit un indice de la distribution des liquides. Nommez deux autres analyses qui permettent d'apprécier le degré de concentration ou de dilution du volume sanguin:
1. hématocrite
2. osmolalité
21
The measurement of the voltage difference between two half-cells immersed in solution is referred to as:
1. coulometry
2. turbidimetry
3. potentiometry
4. amperometry
3 - potentiometry
22
Which of the following changes will be seen in dehydration:
1. increase in aldesteron
2. increase in antidiuretic hormone
3. increase in atrial natriuretic peptide
1 - increase in aldesteron
2 - increase in antidiuretic hormone
22
Que contient la solution du colorant o-crésolphtaléine complexone:
1. 8-hydroxyquinoline pour lier le magnésium et éliminer son interférence
2. urée pour diminuer la turbidité des spécimens lipémiques et augmenter l'intensité de la couleur du complexe
3. éthanol pour diminuer l'absorbance du blanc
4. KCN pour éliminer l'interférence des métaux lourds et stabiliser le complexe coloré
23
Quelle est le principe du dosage de magnésium:
Mg + calmagite ------\> (pH 11) rouge (540 nm)
24
Quels sont les effets cliniques de l'hypercalcémie:
1. reins: précipité de calcium
2. effets sur l'excitabilité neuromusculaire: diminution de l'excitabilité des muscles
3. effets sur le coeur: risque d'arrêt cardiaque
25
What is the largest fluid compartment:
1. plasma water
2. interstitial fluid
3. intracellular fluid
4. transcellular water
5. intercellular water
3 - intracellular fluid
26
Which statements is/are false concerning the chloridometer:
1. generating anode generates silver ions
2. electrons from the generating electrodes combine with hydrogen ions to form hydrogen gas
3. automatic timer is initiated at the start of the silver ion generation
4. AgCl is sensed by the detector electrode
2 - electrons from the generating electrodes combine with hydrogen ions to form hydrogen gas
4 - AgCl is sensed by the detector electrode
27
Quel est la valeur critique du phosphore:
0.33 mmol/L
28
Comment on retrouve le magnésium dans le sérum:
* 30% est lié aux protéines
* 55% existe sous forme libre ou ionisé
* 15% est complexé avec les phosphates et citrates
29
The electrolyte exclusion effect is:
1. an underestimation of electrolyte concentration by indirect potentiometry
2. an overestimation of electrolyte concentration by flame photometry
3. the exlusion of certain solids by increased activity of electrolytes when determining concentration of those solides
4. the exlusion of electrolytes in certain measurements when pH, PCO2 and PO2 are elevated in arterial blood
1 - an underestimation of electrolyte concentration by indirect potentiometry
30
Quels sont les causes d'hyposidérémie:
1. apport insuffisant (anémie ferriprive, malabsorption du fer)
2. pertes de fer exagérées (saignement chronique ou aigue, fin de la grossesse)
3. libération difficile du fer des réserves (infeciton, cancer, arthrite rhumatoide)
31
Les symptomes de la carence en fer sont largement attribuables à:
L'anémie hypochrome (faiblesse, fatigue, étourdissement, palpitations, rythme cardiaque accéléré).
32
Quels sont les différentes méthodes de dosage du calcium:
1. chélation avec l'o-crésolphtaléine complexone
2. chélation par absorption atomique
3. dosage du calcium inonisé par électrodes
4. réflectance - Kodak
32
Quels sont les cations les plus importants dans le LEC:
1. Na
2. K
3. Ca
4. Mg
33
A 24 hour old infant is tested for sweat chloride because her older brother had cystic fibrosis. After iontophoresis of pilocarpine nitrate and collection of sweat onto a gauze pad, the sample is analyzed by coulometric titration. The value of the sweat chloride was assessed at 18 mmol/L (5-35 mmol/L). The nexzt day, the infant's physician calls the laboratory to report that the infant has meconium ileus and serious difficulty in breathing. She states that the parents reported the infant's skin tasted salty. What type of error has occured:
1. the specimen likely evaporated before bein analyzed in the laboratory
2. the infant was tested at too young of an age for quality results to be obtained
3. the specimen was collected over a site of a rash and contaminated with serous fluid
4. the lower limit of the analytical measurement range was not high enlught to detect an elevated sweat chloride
2- the infant was tested at too young of an age for quality results to be obtained
33
Par quoi se fait la régulation du calcium:
1. PTH: hormone de la parathyroide
2. vitamine D: dont la forme active est le calcitrol
3. calcitonine: hormone de la thyroide
34
Quel sont les valeurs de références du magnésium dans le sérum:
0.70-1.05 mmol/L
34
Quel est la méthode de routine pour la ferritine:
Méthodes immunologiques
36
L'oedème s'explique par quoi:
Soit une augmentation de la pression hydrostatique soit par une diminution de la pression oncotique.
37
Which one of the following is used both as an internal reference element in potentiometric ion-specific electrodes and as an external reference electrode half-cell of constant potential required to complete a potentiometric cell:
1. calomel
2. mercury vapor
3. silver/silver chloride
4. platinum
3 - silver/silver chloride
37
Plusieurs technqiues sont utilisées pour étudier le métabolisme du fer:
1. frottis sanguin permet d'évaluer les modifications morphologiques des globules rouges et les indices érythrocytaires
2. compartiment plasmatique est évalué par la détermination du:
* taux du fer sérique
* capacité totale de fixation du fer
* taux de saturation de la Transferrine
3. l'évaluation des réserves se fait par la mesure de la ferritine sérique
38
In potentiometric measurements, the voltage difference between the indicator and reference electrodes is proportional to:
1. ion concentration (mmol/L)
2. ion activity
3. log of ion concentration (mmol/L)
4. log of ion activity
5. ion concentration (mg/L)
4 - log of ion activity
39
Comment se fait la régulation du phosphore:
1. PTH: diminution (éliminé par les reins; augmentation de la résorption des os, calcium et phosphore)
2. vitamine D: augmentation de l'absorption intestinale et la réabsorption rénale
3. calcitonine: diminution (inhibe la dégradation de os)
4. GH: augmentation (réabsorption rénal lors du sommeil)
41
A commonly used glass electrode that is used as a reference electrode in pH measurements is the _____ electrode:
1. calomel
2. mercury vapor
3. silver/silver chloride
4. platinum
1 - calomel
42
Quel est le plus important des métaux à l'état de trace:
Le fer
42
Quel fer est toxique:
Le fer à l'état libre donc tout le fer est lié à des protéines.
43
Combien de calcium est-il absorbé:
25-30% du calcium ingéré est absorbé, le reste est perdu dans les selles.
44
The type of electrode that represents the potential changes in an ion species that is present in the solution in which it is immersed is the _____ electrode:
1. reference
2. indicator
3. gas-sensing
4. polymer
2 - indicator
44
Qu'est ce qui peut causer l'hypermagnésémie:
1. insuffisances rénales chroniques
2. sels de magnésium utilisés pour traiter la constipation
46
Quels sont les effets de l'hypermagnésémie:
1. Hypotonie musculaire
2. troubles cardiaques
47
Comment calcule-ton le coefficient de saturation:
Coefficient de saturation de transferrine = fer sérique total / capacité totale de fixation
48
The PCO2 electrode reduces O2 to H2O and measures the resulting decrease in current:
1. true
2. false
2 - false
48
In the PCO2 electrode, all of the following are true except:
1. carbon dioxide from the sample chamber diffuses through a membrane and dissolves in electrolyte solution
2. the PCO2 electrode measures pH change caused by the production of carbonic acid
3. the measuring electrode is a CO2 specific electrode
4. the measuring and reference electrodes are combined into one unit
5. the CO2 measurement can be related to total CO2
3 - the measuring electrode is a CO2 specific electrode
49
La formation de NADPH est mesuré à quel longueur d'onde:
340 nm
50
Edema is the result of:
1. increased extracellular sodium
2. decreased extracellular sodium
3. increased plasma volume
4. decreased plasma volume
5. none of the above
1 - increased extracellular sodium
51
Quel est le principe de la mesure de la capacité de fixation et du coefficient de saturation de la transferrine:
1. Une quantité connue de Fe+++ (citrate d'ammonium ferrique) en excès, de facon à saturer complètement la transferrine est ajoutée au spécimen de sérum
2. l'excès de fer non lié à la transferrine est enlevé par addition d'une résine échangeuse d'ions
3. l'échantillon est centrifugé et le surnageant est analysé pour déterminer le contenu en fer (cette valeur est le TIBC)
4. tu doit aussi faire le dosage de fer total avec la méthode routine
5. pourcentage de saturation = 100 x fer sérique/TIBC
53
In regard to the colligiative properties of a solution, the addition of solutes to a solution will _____ the freezing point of that solution:
1. increase
2. decrease
3. not affect
4. there is not enough information provided to answer this question
1 - increase
54
Which of the following conditions are among the requirements for a Nernst equilibrium potential to exist for a given charged ion species across a semipermeable membrane, as in an ion-selective electrode:
1. the semipermeable membrane must be permeable to many ion species
2. a concentration gradient for a given chargedion species must exist across that membrane
3. if a membrane is permeable to two different ion species, then the ion activity of both species can be measured
4. the membrane potential across a semipermeable membrane must be constantly changing
2 - a concentration gradient for a given chargedion species must exist across that membrane
55
Which of the electrolytes are regulated in part by dietary intake:
1. chloride
2. potassium
3. sodium
4. all of the above
4 - all of the above
55
Wchich of the following devices are considered to be of the amperometric - coulometric type:
1. PO2 electrode
2. pH electrode
3. Chloridometer (Cotlove)
4. PCO2 electrode
1 - PO2 electrode
3 - Chloridometer (Cotlove)
55
Quel est la valeur sérique du phosphore:
0.90-1.81 mmol/L
56
To stimulate sweating for a quantitative sweat test, _____ is iontophoresed into skin.
1. a person of the opposite sex
2. pilocarpine nitrate
3. epinephrine
4. alcohol
2 - pilocarpine nitrate
58
The statement which most correctly describes the measurement of pH with a glass electrode is:
1. hydrogen ions pass through a special kind of permeable glass
2. the internal and external half-cells have the same potential
3. a special kind of glass sensitive to hydrogen ions is used
4. the temperature knob on the pH meter compensates for the influence of temperature
5. temperature is not involved with pH measurements
3 - a special kind of glass sensitive to hydrogen ions is used
59
Low serum potassium levels are usually associated with all of the following except:
1. low total body potassium
2. low intracellular potassium
3. intracellular sodium increase
4. extracellular alkalosis
5. increased urinary potassium excretion
3 - intracellular sodium increase
59
Deficits of body sodium are associated with:
1. renal disease
2. gastrointestinal losses
3. hypoaldosteronism
4. congestive heart failure
1 - renal disease
2 - gastrointestinal losses
3 - hypoaldosteronism
59
The renin-angiotensin-aldosterone system is initiated by the release of renin from which organ:
1. brain
2. lungs
3. liver
4. kidney
4 - kidney
60
Which of the following electrolytes is likely to be found decreased in metabolic alkalosis:
1. sodium
2. potassium
3. chloride
4. bicarbonate
3 - chloride
61
Hyponatremia can be caused by:
1. equal losses of sodium and water
2. water retention in excess of sodium retention
3. sodium retention in excess of water retention
4. sodium loss in excess of water loss
2 - water retention in excess of sodium retention
4 - sodium loss in excess of water loss
63
An overweight 65 year old single woman from a rural farming area was brought to the emergency department by her neighbor. The woman had a large abscess on the bottom of her foot; she was irritable and complained of blurred vision and of being thirsty. Her breathing was rapid. The neighbor said that the only medication the woman was using was for blood pressure and sometimes an aspirin. After 20 minutes, the patient lost consciousness but was responsive to painful sitmulus. Blood and urine samples were collected. Arterial blood gas results were: pH 7.2; PCO2 47mmHg; HCO3 8 mmol/L. Blood glucose was 340 mg/dL and potassium and triglyceride were elevated. Would this individual have an increased, decreased or normal anion gap:
1. increased
2. decreased
3. normal
4. there is not enough information to determine anion gap
1 - increased
64
Quelle est la saturation normale de la transferrine:
Dans le plasma à l'état normal, la transferrine transporte environ le tiers de tout le fer qu'uelle est capable de fixer. Le 2/3 est la capacité latente de fixation.
65
Comment fonctionne la calcitonine dans la régulation du calclium:
1. Un taux élevé de calcium ionisé plasmatique bloque la sécrétion de PTH par rétroaction négative et stimule sa sécrétion de calcitonine.
2. la calcitonine inhibe l'action de la PTH et la vitamine D; donc elle inhibe l'activité des ostéoclastes, empêchant la résoption de l'os
66
Quels sont les conditions de prélèvement du fer:
1. rejeter tout spécimen hémolysé
2. le matériel de prélèvement, la vaisselle et les réactifs doivent être totalement exempts de fer donc lavage à l'acide
3. exclure les anticoagulants chélateurs comme le citrate, l'EDTA et le fluorure-oxalate
4. héparine est le seul anticoagulatn acceptable
67
Expliquer les particularités spéciales dont il faut reconnaitre pour le prélèvement et intégrité des spécimens sanguins concernant les électrolytes:
* il ne faut pas fermer et ouvrir le poing avant le prélèvement du potassium (augmente de 10-20% en cause de la contraction des muscles)
* Il doit avoir un minimum de stase (hémoconcentration faussement augmente tout les électrolytes)
* doit être libre d'hémolyse
* il ne doit pas avoir une longue attente avant de centrifuger et séparer le culot (les globules rouges peut popper out des potassium)
* si on utilise le plasma pour doser le potassium, on doit utiliser l'héparine de lithium
* l'urine doit être une collecte 24 heures pour éviter les variations diurnes
68
Quel est le rôle du polyvinylpyrrolidone dans le dosage du magnésium:
Neutralise l'effet des protéines sur la coloration
70
All of the following are causes of hyponatremia with concomitant decreased plasma osmolality and euvolemia except:
1. decreased serum aldosterone
2. hypothyroidism
3. diarrhea
4. decreased serum ADH
2 - hypothyroidism
71
The correct formula for calculating osmolality is:
1. 1.86 X Na + glucose + urea
2. 1.86 X Na + glucose + urea + 9
3. 1.86 X Na + glucose/18 + urea/18 + 9
4. Na + glucose + urea
2 - 1.86 X Na + glucose + urea + 9
73
Vol Tammetry:
1. voltometry of a dropping Hg electrode
2. the measurement of current passing through a solution at a given charge
3. measurement of charge
4. measurement of current at a constant potential
5. measurement of current as a function of potential
1 - voltometry of a dropping Hg electrode
74
Which of the following disease states is indicated when the osmolal gap exceeds zero:
1. decreased urea
2. decreased sodium
3. low serum albumin
4. elevated serum glucose
4 - elevated serum glucose
75
A KC1 salt bridge, widely utilized in electrochemical cells, has all of the following functions except:
1. lowers liquide-junction potentials
2. conducts electricity
3. allows ions to migrate
4. measures the potential between two solutions
4 - measures the potential between two solutions
76
The high extracellular concentration of this cation contributes to the osmotic strength of extracellular fluid:
1. chloride
2. potassium
3. sodium
4. bicarbonate
3 - sodium
76
Quelle est la méthode de référence pour le dosage du magnésium sérique:
Absoprtion atomique
77
Quels sont les conditions des spécimens de phosphore utilisé dans la méthode de Fiske et Subarow:
* sérum ou plasma hépariné
* Le sérum ou plasma doit être séparé des cellules 1 heure après la collection du spécimen.
* l'hémolyse doit être évitée car la concentration du phosphore ionisé dans les globules rouges est 7 fois celle du plasma et l'hémoglobine, par sa couleur, interfère dans la réaction
* l'urine doit être recueillie dans un flacon à l'acide, sans détergent
78
Coulometry:
1. voltometry of a dropping Hg electrode
2. the measurement of current passing through a solution at a given charge
3. measurement of charge
4. measurement of current at a constant potential
5. measurement of current as a function of potential
3 - measurement of charge
79
Comment calcule-ton la capacité totale de fixation de la transferrine:
Capacité totale de fixation = capacité latente + fer sérique totale
81
An electrochemical technique used to measure chloride in serum or plasma is:
1. a Guthrie test
2. amperometry
3. coulometry
4. voltammetry
3 - coulometry
82
The osmolarity of extracellular fluid is mostly dependent on:
1. potassium
2. sodium
3. calcium
4. magnesium
5. lithium
2 - sodium
83
Pourquoi le dosage du fer sérique seul est de peu d'utilité pour établir un diagnostic:
Car il y a trop de changements soudains.
85
Hypokalemia may be seen in all of the following except:
1. decreased potassium intake
2. initiation of insulin therapy
3. vomiting and diarrhea
4. adrenal gland failure
4 - adrenal gland failure
86
What is the anion gap, given the following serum electrolyte data:
Na = 132 mmol/L
Cl = 90 mmol/L
HCO3 = 22 mmol/L
K = 4 mmol/L
1. 10 mmol/L
2. 18 mmol/L
3. 20 mmol/L
4. 60 mmol/L
3 - 20 mmol/L
87
Qu'est ce qui peut causer un oedème:
* augmentation de la pression hydrostatique
* diminution de la pression oncotique
* augmentation d'albumine
* ingestion de beaucoup de sel
* tumeur
* grossesse
* maladies congestive du coeur
88
Incorporation of \_\_\_\_\_\_, a neutral antibiotic, into a polyvinyl chloride membrane allows for the manufacture of an ion-selective electrode that is highlly selective for potassium:
1. tetracycline
2. nonactin
3. valinomycin
4. erythromycin
3 - valinomycin
90
The PCO2 electrode of a blood gas instrument measures:
1. reduction of CO2 at the cathode
2. change in pH of the electrode solution
3. the time required for CO2 to pass through a special membrane
4. partial pressure of CO2
2 -change in pH of the electrode solution
4 - partial pressure of CO2
91
Quels sont les interférences possibles dans la méthode par o-crésolphtaléine complexone:
* faux négatifs: bilirubine à forte concentration
* faux positifs: acétaminophène
93
Which of the following describes the correct meaning of anion gap = 15 mEq/L
1. there is a 15 mEq/L gap between the major measured cations and major measured anions
2. there is a 15 mEq/L gap between the physiologically active cations in the body and the physiologically active anions in the body
3. there are 15 mEq/L more cations than anions in the plasma sample tested
4. there are 15 mEq/L more anions than cations in the plasma sample tested
1 - there is a 15 mEq/L gap between the major measured cations and major measured anions
94
Pression artérielle normale:
120/80
95
Is the anion gap 20 mmol/L within healthy reference interval:
1. yes
2. no
2 - no
95
Total body water represents about what percent of body weight in adults:
1. 80
2. 70
3. 60
4. 50
5. 40
3 - 60
96
Comment se fait le transport du fer dans l'organisme:
Il est transporté dans le plasma à l'état ferrique (Fe+++) attaché à une protéine, la transferrine (sidérophilline).
96
Quels sont les facteurs qui peuvent affecter le taux de fer sérique:
1. sexe: plus haut chez l'homme
2. variations cycliques
* rythme circadien: plus élevée le matin que le soir
* variations mensuelles chez la femme
* stress mentale et physique
3. grossesse et contraceptifs oraux
97
In the Nernst equation, EO represents:
1. measured volume
2. gas content
3. electrons
4. transferred
5. Faraday constant
6. standard half cell potential
6 - standard half cell potential
98
Ion selective electrodes are used in _____ measurements:
1. calorimetric
2. amperometric
3. potentiometric
4. conductivity
3 - potentiometric
99
A biosensor that used both enzyme detection and an ion-specific electrode could be examining:
1. urea using urease and the production of ammonium ions
2. glucose using glucose oxidase and the production of bicarbonate ions
3. cholesterol using cholesterol oxidase with production of fluorescent cations
4. bilirubin using bilirubin oxidase and the prodcution of hydrogen ions
1- urea using urease and the production of ammonium ions
100
Le calcium plasmatique se retrouve sous trois formes:
1. le calcium ionisé ou libre, la seule forme physiologiquement active: 45%
2. environ 15% du calcium est lié, non ionisé, complexé au citrate, lactate, phosphate et bicarbonate
3. environ 40% est le calcium non diffusible qui est lié aux protéines plasmatiques, principalement l'albumine
101
Quels sont les causes d'hypocalcémie:
1. hypoalbuminémie (plus commune)
2. hypoparathyroidisme: bas niveau de PTH
3. diminution de l'apport en calcium et en vitamine D
4. hypomagnésémie: inhibition de la sécrétion glandulaire de PTH, affaiblie l'action de PTH aux sites récepteurs sur les os et cause une résistance à la vitamine D
5. pancréatite aigue: augmentation de la formation d'un complexe avec les lipides par l'enzyme lipase
6. maladie rénale, métabolisme inadéquat de la vitamine D
102
Quelle est la méthode routine du dosage du calcium:
Chélation avec l'o-crésolphtaléine complexone
103
Quelle est le type de membrane dans l'électrode pour le dosage de calcium inoisé:
Membrane échangeur d'ions
104
Quels sont les rôles du magnésium:
1. activateur (cofacteur) de plusieurs enzymes
2. affecte l'excitabilité neuromusculaire
105
Quels sont les cations les plus importants dans le LIC:
1. K
2. Mg
107
Ion selective electrodes measure potential difference across a membrane using the principles of:
1. coulometry
2. potentiometry
3. amperometry
4. conductivity
2 - potentiometry
108
The cation with the lowest intracellular concentration is:
1. potassium
2. sodium
3. calcium
4. magnesium
5. chloride
3 - calciummn
108
Quel est le rôle du KCN dans le dosage du magnésium:
Il complexe les métaux lourds (Fe)
110
Comment le pH affecte la quantité de calcium dans le plasma:
Si le pH augmente, il y a plus d'hydroxyle de présent, les protéines deviennent négatifs et lient plus de calcium (positif).
111
Quelle est la méthode historique du dosage du chlore:
Nitrate mercurique (titration)
112
Which of the following conditions will cause an increased anion gap:
1. salicylate intoxication
2. controlled diabetes mellitus
3. decreased albumin concentration
4. severe diarrhea
1 - salicylate intoxication
112
Intracellular water accounts for about what percent of an adult's body weight:
1. 60
2. 50
3. 40
4. 30
5. 20
3 - 40
113
Polarography:
1. voltometry of a dropping Hg electrode
2. the measurement of current passing through a solution at a given charge
3. measurement of charge
4. measurement of current at a constant potential
5. measurement of current as a function of potential
1 - voltometry of a dropping Hg electrode
115
Quels sont les causes d'hypercalcémie:
1. hyperparathyroidisme (95% des cas): tumeurs provoque une hypersécrétion de PTH
2. excès de vitamine D: augmente l'absorption intestinale du calcium et la réabsorption rénale
3. cancer des os: destruction du tissu osseux qui libère le calcium
4. tumeurs: sécrètent un facteur qui stimule les récepteurs de PTH
117
Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are released into the bloodstream from the ______ and are used clinically to evaluate the possibility of \_\_\_\_\_\_\_\_.
1. heart, congestive heart failure
2. brain, hydrocephalus
3. heart, myocardial infarction
4. brain, congestive heart failure
1 - heart, congestive heart failure
118
Quel est le 4e cation en importance dans l'organisme dans le LEC:
Le magnésium (après le Na, le K et le Ca)
120
The anion with the highest extracellular concentration is:
1. protein
2. bicarbonate
3. chloride
4. phosphate
5. lactate
3 - chloride
121
The combination of hyponatremia and hypo-osmolality could be caused by which of the following:
1. adrenocortical insufficiency such as hypoaldosteronism
2. excessive vomiting and diarrhea
3. syndrome of inappropriate ADH secretion (SIADH)
4. both 1 and 3
3 - syndrome of inappropriate ADH secretion (SIADH)
122
Quel est le seuil d'hypertension:
140/90
123
The urine level of which electrolyte will distinguish excess diuretic use or self-induced vomiting from Barter's syndrome:
1. sodium
2. potassium
3. chloride
4. bicarbonate
3 - chloride
125
Which of the following laboratory results will be seen with the increased release of ANP and BNP:
1. urine sodium level will increase
2. antidiuretic hormone level will increase
3. aldosterone level will decrease
1 - urine sodium level will increase
3 - aldosterone level will decrease
127
Quel est le poids d'eau chez un adulte:
60%
129
Insulin release will stimulate cellular uptake of which of the following electrolytes:
1. sodium
2. potassium
3. chloride
4. bicarbonate
2 - potassium
130
Plusieurs facteurs influencent l'absorption intestinale du fer:
1. l'activité érythropoiétique générale
2. le niveau des réserves corporelles
3. la concentration de la ferritine dans la muqueuse intestinale
131
Conductometry:
1. voltometry of a dropping Hg electrode
2. the measurement of current passing through a solution at a given charge
3. measurement of charge
4. measurement of current at a constant potential
5. measurement of current as a function of potential
2 - the measurement of current passing through a solution at a given charge
133
Amperometry:
1. voltometry of a dropping Hg electrode
2. the measurement of current passing through a solution at a given charge
3. measurement of charge
4. measurement of current at a constant potential
5. measurement of current as a function of potential
4 - measurement of current at a constant potential
134
The cation with the highest intracellular concentration is:
1. potassium
2. sodium
3. calcium
4. magnesium
5. lithium
1 - potassium
134
Comment se fait la régulation du magnésium plasmatique:
Le rein est l'organe responsable du maintien de la balance en magnésium. Il peut conserver le magnésium lorsque l'apport est faible et excréter l'excès lorsque l'apport est élevé.
135
Quels sont les types de mises en réserve du fer:
La ferritine et l'hémosidérine.
136
Hypertension critique:
160/95
137
Quel est le rôle de l'EDTA dans le dosage du magnésium:
Élimination de l'interférence du Ca en le chélatant.
138
Quel est le principe du dosage du fer:
1. Le fer est dissocié de la tranferrine par un tampon acide
2. se fait réduire à l'état ferreux (Fe++)
3. il y a formation d'un complexe avec des chromogènes, et coloré rose
4. les deux chromogènes utilisés sont le Bathophénanthroline sulfonée et Ferrozine
139
Quels sont les causes d'hypophosphatémie:
1. hyperparathyroidisme: augmentation de PTH
2. rachitisme: déficience en vitamine D
3. maladies rénales avec une diminution de l'absorption du phosphore (Fanconi)
140
Quel est le meilleur indicateur pour des carences en fer:
Le dosage de la ferritine
142
Quel est le principal cation des liquides intracellulaires:
Potassium
144
Valeurs de références de sodium:
* sérum: 135-145 mmol/L
* hyponatrémie: 120 mmol/L
* hypernatrémie: 160 mmol/L
145
Combien de sodium le corps a-t-il besoin:
1-2 mmol par jour
147
Quel méthode de dosage du chlore est exacte et précise:
Mercurique (Schales & Schales)
électrode sélection d'un ion
148
la sensation de soif apparait à quelle OSM:
300
150
As the concentration of macromolecules such as lipids and proteins increases:
1. methods that measure ions in plasma water will show an increase in the concentration/activity measured, although the physiological activity is normal
2. methods that measures ions in plasma water will show a decrease in the concentration/activity measured, although the physiological activity is normal
3. methods that measure ions in total plasma volume will show an increase in the concentration/activity measured, although the physiological activity is normal
4. methods that measure ions in total plasma volume will show a decrease in the concentration/activity measured, although the physiological activity is normal
4 - methods that measure ions in total plasma volume will show a decrease in the concentration/activity measured, although the physiological activity is normal
151
Hemolysis of a sample will most likely affect wich one of the following electrolytes and why:
1. sodium; it is present in equal amounts both intracellularly and extracellularly
2. potassium: it is localized mainly within cells, particularly RBC
3. chloride: it is the major intracellular anion and present in high amounts in RBC
4. bicarbonate; it moves out of cells into plasma
2 - potassium: it is localized mainly within cells, particularly RBC
153
Acute metabolic acidosis resulting from acid with an associated anion promotes an increase in the plasma level of which electrolyte:
1. sodium
2. potassium
3. chloride
4. bicarbonate
2 - potassium
154
Effets de l'hypomagnésémie:
1. hyperexcitabilité
2. tétanie
3. convulsions
4. changement à l'électrocardiogramme
155
Quel est le principe de la chélation avec l'o-crésolphtaléine complexone:
le colorant o-crésolphtaléine complexone se lie au calcium en solution alcaline pour former un complexe coloré rouge (578 nm)
156
Total body water represents about what percent of body weight in neonates:
1. 40
2. 50
3. 60
4. 70
5. 80
5 - 80
157
Osmolality is defined as the number of:
1. moles per liter of solution
2. equivalents per liter of solution
3. of osmotic substances per kilogram of solution
4. moles of osmotic substances per liter of solution
3 - of osmotic substances per kilogram of solution
158
Which of the following laboratory results is usually associated with cystic fibrosis:
1. sweat chloride concentration greater than 60 mmol/L
2. sweat chloride less than or equal to 10 mmol/L
3. sweat chloride concentration greater than 160 mmol/L
4. sweat chloride concentration between 40-60 mmol/L
1 - sweat chloride concentration greater than 60 mmol/L
160
The antibiotic Valinomycin has a high affinity for:
1. sodium
2. lithium
3. potassium
4. calcium
5. magnesium
3 - potassium
161
Quels sont les effets cliniques de l'hypocalcémie:
1. augmentation de l'excitabilité neuromusuclaire
2. arrêt cardiaque
3. cataractes
163
Quel est le colorant indicateur dans la méthode réflectance-Kodak:
Arsenazo III
165
Which one of the following voltage potentials occurs as the result of chemical equilibrium involving electron transfer reactions:
1. electrode potential
2. positive potential
3. hydrogen potential
4. redox potential
4 - redox potential
166
Causes de l'hypomagnésémie:
1. diarrhées sévères et prolongées
2. alcoolisme
3. malnunitrion et malabsorption
167
Quelle est la concentration du magnésium dans le sang:
1% du montant dans les globules rouges
168
A PCO2 electrode:
1. used coulometric titration to measure the absolute level of CO2 in blood through the combination of CO2 iwth water
2. is a potentiometric cell in which carbon dioxide gas from the sample diffuses through a membrane and forms carbonic acid
3. measures the ability of carbonate ions in solution to carry current under the influence of a potential difference
4. uses a gas-permeable membrane to detect CO2 with very high selectivity over other easily reduced species that might be present in a given sample
2 - is a potentiometric cell in which carbon dioxide gas from the sample diffuses through a membrane and forms carbonic acid
169
Arsenazo III est un indicateur de couleur dans quelle méthode:
Réflectance - Kokak (dosage de calcium(
170
Hypokalemia (\< 3.0 mmol/L) is considered a serious health threat because:
1. the heart rate increases, leading to weakness, difficulty in breathing, and eventual cardiac arrest
2. the heart rate slows because of the lowered excitability of cardiac smooth muscle, leading to possible cardiac standstill
3. the body gains water through the kidney reabsorption, leading to severe edema
4. arterial pH will decrease (increased H concentration), leading to metabolic acidosis
1 - the heart rate increases, leading to weakness, difficulty in breathing, and eventual cardiac arrest
171
The cation with the highest extracellular concentration is:
1. potassium
2. sodium
3. calcium
4. magnesium
5. lithium
2 - sodium
172
The plasma volume in 70 kg adults is approximately:
1. 2000 ml
2. 2500 ml
3. 3000 ml
4. 3500 ml
5. 4000 ml
4 - 3500 ml
173
Quels sont les causes d'hyperphosphatémie:
1. hypoparathyroidisme : PTH diminue, diminution de l'excrétion rénale des phosphates
2. hypervitaminose D: augmente l'absorption intestinale du phosphore
3. insuffisance rénale: augmentation de la rétention du phosphore
4. hypersécrétion de l'hormone de croissance (GH) qui augmente la réabsorption rénale des phosphates
174
The plasma volume of a 3200g neonate is approximately:
1. 150 ml
2. 250 ml
3. 350 ml
4. 500 ml
5. 1000 ml
1 - 150 ml
175
An overweight 65 year old single woman from a rural farming area was brought to the emergency department by her neighbor. The woman had a large abscess on the bottom of her foot; she was irritable and complained of blurred vision and of being thirsty. Her breathing was rapid. The neighbor said that the only medication the woman was using was for blood pressure and sometimes an aspirin. After 20 minutes, the patient lost consciousness but was responsive to painful sitmulus. Blood and urine samples were collected. Arterial blood gas results were: **pH 7.2**; **PCO2 47mmHg**; **HCO3 8 mmol/L**. Blood **glucose was 340 mg/dL** and **potassium and triglyceride were elevated**. Why is the patients potassium elevated.
1. initial stages of gangrene cause hemolysis of erythrocytes and elevated serum potassium
2. chronic obstructive pulmonary disease (COPD) with damaged alveoli leads to the movement of potassium into the extracellular fluid
3. the elevated potassium is an artifact due to the elevated glucose
4. potassium moves out of the cell in acidosis as the excess H ions movie in
4 - potassium moves out of the cell in acidosis as the excess H ions movie in
175
The K ion electrode has an absolute specificity for K and therefore has interferences from no other cation:
1. true
2. false
2- false
176
Quel est le poids d'eau chez en enfant:
80%
177
Potentiometry (multiple:
1. is the measurement of the electrical potential difference between two electrodes in an electrochemical cell
2. measures voltage
3. application include pH and PCO2 measurements
4. principles aure used for measuring potassium using valinomycin membrane
1 - is the measurement of the electrical potential difference between two electrodes in an electrochemical cell
2 - measures voltage
3 - application include pH and PCO2 measurements
4 - principles aure used for measuring potassium using valinomycin membrane
178
Quel est le principe de la réaction avec le molybdate - Fiske et Subbarow:
Ammonium phosphomolybdate transformé en bleu de molybdène (340 nm)
179
Quels protéines sont actifs:
Ceux qui ne sont pas liés aux protéines
181
Quels sont les causes d'un excès de fer:
1. augmentation de l'absorption intestinale: erreur congénitale dans l'absoprtion (hémochromatose)
2. excès alimentaires
3. apport excessif par voie parentérale
* transfusions sanguines multiples
4. anémie sidéroblastique
182
Quel est la valeur sérique du calcium ionisé:
1.15-1.29 mmol/L
183
The most abundant extracellular anion is:
1. chloride
2. bicarbonate
3. sodium
4. potassium
1 - chloride
184
Which one of the following is not measured with an enzyme-based biosensor with a light sensing fibre optic probe:
1. cholesterol
2. PO2
3. bilirubin
4. DNA segments
4 - DNA segments
185
Quelle est la méthode de référence du dosage de calcium:
Chélation par absorption atomique
186
The anion with the highest intra-cellular concentration is:
1. protein
2. bicarbonate
3. chloride
4. lactate
5. none of the above
1 - protein
187
Extracellular fluid volume is normally largely governed by:
1. sodium
2. urea
3. glucose
4. phosphate
5. magnesium
1 - sodium
188
Ion selective electrodes (multiple):
1. allow ion exchange on surface resulting in a change of potential
2. are pH dependent
3. are themperature dependent
4. do not require a reference electrode
1 - allow ion exchange on surface resulting in a change of potential
2 - are pH dependent
3 - are themperature dependent
189
Les principaux facteurs responsables de la carence en fer sont:
1. un apport insuffisant d'aliments riches en fer
2. un défaut d'absorption du fer
3. des pertes de sang aigu ou chronique
190
The technique used to determine the absolute amount of electroactive substance by measuring the amount of current passing between two electrodes in an electrochemical cell during a titration reaction is referred to as:
1. amperometry
2. coulometry
3. potentiometry
4. turbidimetry
2 - coulometry
