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Question 1
Correct
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With regards to arterial oxygen content, which of the following contributes most from a quantitative perspective?
Your Answer: Haemoglobin concentration
Explanation:The amount of oxygen carried by 100 ml of blood is called the arterial oxygen content (CaO2)and is normally 17-24 ml/dL and can be determined by this equation:
CaO2 = oxygen bound to haemoglobin + oxygen dissolved in plasma
CaO2 = (1.34 Ă— Hgb Ă— SaO2 Ă— 0.01) + (0.003 Ă— PaO2)
where:
1.34 = Huffner’s constant (D) – Huffner’s constant does not change and its magnitude relatively small.
Hgb is the haemoglobin level in g/dL and SaO2 is the percent oxyhaemoglobin saturation of arterial blood
PaO2 is (0.0225 = ml of O2 dissolved per 100 ml plasma per kPa, or 0.003 ml per mmHg).Quantitatively, the amount of oxygen dissolved in plasma is 0.3 mL/dL.
Henry’s law states that at constant temperature, the amount of gas dissolved at equilibrium in a given quantity of a liquid is proportional to the pressure of the gas in contact with the liquid.
Given a haemoglobin concentration of 15 g/dL and a SaO2 of 100% and a PaO2 of 13.3 kPa, the amount of oxygen bound to haemoglobin is 20.4 mL/100mL.
Cardiac output is an important determinant of oxygen delivery but does not influence the oxygen content of blood.
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This question is part of the following fields:
- Basic Physics
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Question 2
Incorrect
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Which of the following statements is true regarding oxygen?
Your Answer: Is stored in cylinders with a white and black shoulder and a French grey body
Correct Answer: Forms molecules containing either two or three atoms
Explanation:Oxygen is formed by a molecule of oxygen and two molecules of hydrogen with a molecular formula of H2O
The critical temperature is defined as a temperature above which the substance cannot be liquefied, no matter how much pressure is applied.
Water has a critical temperature of -118.6oC. So, it cannot be liquified at room temperature.Medical oxygen cylinder is stored in a cylinder with a white shoulder and black body. Meanwhile, medial air is stored in cylinders with a white and black shoulder and a French grey body.
The partial pressure of air at a high altitude is less but the relative concentration remains constant.
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This question is part of the following fields:
- Basic Physics
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Question 3
Incorrect
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Very large SI units are easily expressed using mathematical prefixes.
One terabyte is equal to which of the following numbers?Your Answer: 1,000,000,000,000,000 bytes
Correct Answer: 1,000,000,000,000 bytes
Explanation:To denote large measured units, the following SI mathematical prefixes are used:
1 deca = 10 bytes (101)
1 hecto (h) = 100 bytes
1 kilo (k)= 1,000 bytes
1 mega (M) = 1,000,000 bytes
1 giga (G) = 1,000,000,000 bytes
1 Tera (T) = 1,000,000,000,000 bytes
1 Peta (P) = 1,000,000,000,000,000 bytes -
This question is part of the following fields:
- Basic Physics
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Question 4
Incorrect
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Many of the processes we deal with in anaesthesia are exponential.
What is the underlying mathematical principle of an exponential process?Your Answer: Euler's number
Correct Answer: The rate of change of x is dependent on the magnitude of x
Explanation:The magnitude of x determines the rate of change of x. First-order drug kinetics is a good example. Most drugs’ plasma levels are controlled by an exponential process. The rate of change in drug metabolism is proportional to the current plasma concentration (so-called non-linear kinetics).
A tear-away function is just one type of exponential relationship (y = ex), in which e is Euler’s number, x is the power, and e is the base. Natural logarithms rely on Euler’s number.
Euler’s number is a mathematical constant, not a mathematical principle. It’s referred to as an irrational number. This is a number that cannot be expressed as a simple fraction or a ratio.
A line or curve that acts as the limit of another line or curve is known as an asymptote. A washout exponential curve, for example, where the value y represents the plasma concentration of a drug in a single compartment model against time on the x axis. This descending curve approaches but never touches the x axis. This curve is asymptotic to the x axis, which is the curve’s asymptote. An asymptote isn’t just a characteristic of exponential curves.
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This question is part of the following fields:
- Basic Physics
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Question 5
Incorrect
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The child-Pugh scoring system can be used, if risk classifying a patient with chronic liver disorder earlier to anaesthesia.
Which one is the best combination of clinical signs and examinations used within the Child-Pugh scoring system?Your Answer: Ascites, grade of encephalopathy, albumin, ammonia and INR
Correct Answer: Ascites, grade of encephalopathy, albumin, bilirubin and INR
Explanation:In the Child-Pugh classification system, the following 5 components are determined or calculated in order:
Ascites
Grade of encephalopathy
Serum bilirubin (?mol/L)
Serum Albumin (g/L)
Prothrombin time or INR
Raised liver enzymes are not the component of the classification system.
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This question is part of the following fields:
- Basic Physics
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Question 6
Incorrect
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Very small SI units are easily expressed using mathematical prefixes.
One femtolitre is equal to which of the following volumes?Your Answer: 0.000, 001 L
Correct Answer: 0.000, 000, 000, 000, 001 L
Explanation:Small measurement units are denoted by the following SI mathematical prefixes:
1 deci = 0.1
1 milli = 0.001
1 micro = 0.000001
1 nano = 0.000000001
1 pico = 0.000000000001
1 femto = 0.000000000000001 (used to measure red blood cell volume)
1 atto = 0.000000000000000001 -
This question is part of the following fields:
- Basic Physics
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Question 7
Incorrect
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Suppose the afterload and myocardial contractility remain unchanged, which of the following factors in the pressure-volume loop indicates an increase in the preload of the left ventricle?
Your Answer: Increased end-systolic volume
Correct Answer: Increased end-diastolic volume
Explanation:If the afterload and myocardiac contractility remains unchanged, an increase in the preload can be attributed to an increase in end-diastolic volume.
Preload can be defined as the initial stretching of the cardiac myocytes prior to contraction. Preload, therefore, is related to muscle sarcomere length. Because sarcomere length cannot be determined in the intact heart, other indices of preload are used such as ventricular end-diastolic volume or pressure. When venous return to the heart is increased, the end-diastolic pressure and volume of the ventricles are increased, which stretches the sarcomeres, thereby increasing their preload.
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This question is part of the following fields:
- Basic Physics
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Question 8
Incorrect
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Regarding gas laws, which one best explains the ability of a Bourdon gauge to measure temperature?
Your Answer: Gay-Lussac's law
Correct Answer: Charles's law
Explanation:Charles’ Law states that there is a direct correlation between temperature and volume, where pressure and amount gas are constant. As temperature increases, volume also increases.
Boyle’s Law states that Pressure is inversely proportional to volume, assuming that temperature and amount of gas are constant. As volume increases, pressure decreases. In Dalton’s law of partial pressure, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressure of the gases in mixture.
According to Henry’s Law for concentration of dissolved gases, at a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid. An equivalent way of stating the law is that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid.
Gay-Lussac’s Law states that the pressure of a given mass of gas varies directly with the absolute temperature of the gas, when the volume is kept constant. This law is very similar to Charles’ Law, with the only difference being the type of container. Whereas the container in a Charles’ Law experiment is flexible, it is rigid in a Gay-Lussac’s Law experiment.
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This question is part of the following fields:
- Basic Physics
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Question 9
Incorrect
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Regarding thermocouple, which of the following best describes its properties?
Your Answer: Resistance at the measuring junction is proportional to temperature
Correct Answer: The electromotive force at the measuring junction is proportional to temperature
Explanation: -
This question is part of the following fields:
- Basic Physics
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Question 10
Incorrect
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Which of the following derived SI units is correctly expressed as their base units?
Your Answer: Joule: m.kg.s-2
Correct Answer: Volt: m2.kg.s-3.A-1
Explanation:The following units are derived SI units of measurement.
Energy or work: kg.m2.s-2
The Joule (J) is the energy transferred to an object when a force of one newton acts on that object in the direction of its motion through a distance of one meter or N.m.Power: kg.m2.s-3
The Watt (W) = rate of transfer of energy or Joule per second J/s.Force: kg.m.s-2
One Newton (N) which is the international unit of measure for force = 1 kilogram meter per second squared. 1 Newton of force is the force required to accelerate an object with a mass of 1 kilogram 1 meter per second per second.Volt: kg.m2.s-3.A-1
The volt (V) is defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power or W/A.Pressure: kg.m-1.s-2
A pascal (Pa) is force per unit area or N/m2. -
This question is part of the following fields:
- Basic Physics
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