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  • Question 1 - A 60-year-old man, with a history of excessive alcohol intake, presents for the...

    Incorrect

    • A 60-year-old man, with a history of excessive alcohol intake, presents for the first time in the emergency department with acute abdominal pain in the epigastric region.

      On examination, the man is sweating and has a high-grade fever. His heart rate is 140/min and a BP of 92/59 mmHg.

      The patient is diagnosed with acute pancreatitis. Which of the following is a complication you are most likely to see in this patient?

      Your Answer: Bulky, greasy stools

      Correct Answer: Blue discolouration of the flank regions

      Explanation:

      Bulky, greasy stools are associated with improper digestion that can be expected if the pancreas loses its exocrine function. This is common in long-term chronic pancreatitis but since this is the patient’s first presentation with such symptoms, this complication is unlikely.

      Peripheral neuropathy is a common complication of chronic diabetes but has been reported with cases of chronic pancreatitis too.

      Abdominal distention with shifting dullness is a classic symptom of underlying ascites. Ascites is a complication of many diseases but it is not common with the acute first-time presentation of pancreatitis.

      Option E: This points towards abdominal obstruction but in the absence of the more common symptoms, nausea and bilious vomiting, this is unlikely.

      Option A: Grey Turner’s sign is the pooling of blood in the retroperitoneal space between the last rib and the top of the hip. The pancreas is a retroperitoneal organ and inflammation of the pancreas can cause retroperitoneal haemorrhage. The sign takes 24-48 hours to develop and can predict a severe attack of acute pancreatitis. The patient has presented with acute pancreatitis due to his history of high alcohol intake, and acute on chronic is unlikely as this is his first presentation. He also has low blood pressure and an increased heart rate, which suggest blood loss with acute pancreatitis.

    • This question is part of the following fields:

      • Anatomy
      17.2
      Seconds
  • Question 2 - Which of the following is incorrect with regards to atrial natriuretic peptide? ...

    Correct

    • Which of the following is incorrect with regards to atrial natriuretic peptide?

      Your Answer: Secreted mainly by the left atrium

      Explanation:

      Atrial natriuretic peptide (ANP) is secreted mainly from myocytes of right atrium and ventricle in response to increased blood volume.
      It is secreted by both the right and left atria (right >> left).

      It is a 28 amino acid peptide hormone, which acts via cGMP
      degraded by endopeptidases.

      It serves to promote the excretion of sodium, lowers blood pressure, and antagonise the actions of angiotensin II and aldosterone.

    • This question is part of the following fields:

      • Physiology And Biochemistry
      41.4
      Seconds
  • Question 3 - Which of these structures will cause the biggest reduction in hepatic blood flow...

    Correct

    • Which of these structures will cause the biggest reduction in hepatic blood flow when occluded surgically?

      Your Answer: Portal vein

      Explanation:

      The portal vein arises from the splenic and mesenteric veins, and is the biggest vessel in the portal venous system, accounting for about 75% of the hepatic blood flow.

      It is responsible for draining blood from parts of the gastrointestinal system, the spleen, the pancreas and the gallbladder into the liver.

    • This question is part of the following fields:

      • Anatomy
      17.5
      Seconds
  • Question 4 - Bacteria and viruses that are smaller than 0.1 ?m in diameter can be...

    Correct

    • Bacteria and viruses that are smaller than 0.1 ?m in diameter can be filtered out using heat and moisture exchanger (HME) with a typical pore size 0.2 ?m.

      Choose the most appropriate mechanisms of particle capture for most bacteria and viruses.

      Your Answer: Diffusion

      Explanation:

      Warming, humidifying, and filtering inspired anaesthetic gases is done by heat and moisture exchangers (HME) and breathing system filters. They are made of glass fibres materials and are supported by a sturdy frame. Pleating increases the surface area to reduce resistance to air flow and boost efficiency.

      Filters’ effectiveness is determined by the amount and size of particles they keep out of the patient’s airway. The efficiency of filters might be classified as 95, 99.95, or 99.97 percent. Pores with a diameter of 0.2 µm are common. The following are examples of typical particle sizes:
      Red blood cell – 5 µm
      Lymphocyte – 5-8 µm
      Viruses – 0.02-0.3 µm
      Bacteria – 0.5-1 µm
      Depending on particle size, gas flow speed, and charge, particles are collected via a number of processes. Mechanical sieve, interception, diffusion, electrostatic filtration, and inertial impaction are some of the options:

      Sieve:
      The diameter of the particle the filter is supposed to collect is smaller than the apertures of the filter’s fibres.

      Interception:
      When a particle following a gas streamline approaches a fibre within one radius of itself, it becomes attached and captured.
      Diffusion:

      A particle’s random (Brownian) zig-zag path or motion causes it to collide with a fibre.
      By attracting and capturing a particle from within the gas flow, it generates a lower-concentration patch within the gas flow into which another particle diffuses, only to be captured. At low gas velocities and with smaller particles (0.1µm diameter), this is more common.

      Electrostatic:

      These filters use large diameter fibre media and rely on electrostatic charges to improve fine particle removal effectiveness.

      Impaction due to inertia:

      When a particle is too large to respond fast to abrupt changes in streamline direction near a filter fibre, this happens. Because of its inertia, the particle will continue on its original course and collide with the filter fibre. When high gas velocities and dense fibre packing of the filter media are present, this sort of filtration mechanism is most prevalent.

    • This question is part of the following fields:

      • Anaesthesia Related Apparatus
      7.6
      Seconds
  • Question 5 - Which measurements is the most accurate for predicting fluid responsiveness? ...

    Correct

    • Which measurements is the most accurate for predicting fluid responsiveness?

      Your Answer: Change in stroke volume following passive straight leg raise

      Explanation:

      The passive leg raising (PLR) manoeuvre is a method of altering left and right ventricular preload and it is done with real-time measurement of stroke volume. It is a simple, quick, relatively unbiased, and accurate bedside test to guide fluid management and avoid fluid overload.

      Pulse pressure variation (PPV), Stroke volume variation (SVV), superior vena cava diameter variation (threshold 36%) and end-expiratory occlusion test are used for dynamic tests of fluid responsiveness.

      PPV is derived peripherally from the arterial pressure waveform.

      Stroke volume variation (SVV) can be derived peripherally through pulse contour analysis of the arterial waveform. PPV and SVV have a threshold of 12% but since they are not used in patients who have cardiac arrhythmias, are spontaneous breathing, and in ventilated patients with low lung compliance and tidal volumes, they are of limited value.

      The tests of fluid responsiveness’ accuracy is determined by calculating the area under the receiver operating characteristic curve (UROC) obtained by plotting the sensitivity of the parameter in predicting fluid responsiveness vs. 1-specificity.

      Under optimal conditions, the ability to determine the need for fluid is best with PPV>SVV>LVEDA>CVP.

      Central venous pressure (CVP) is a static test of preload (not preload responsiveness) and a key determinant of cardiac function. The left ventricular end-diastolic area (LVEDA) a static test of fluid responsiveness, is derived using echocardiography

    • This question is part of the following fields:

      • Clinical Measurement
      41.2
      Seconds
  • Question 6 - You draw a patient's blood sample from the median cubital vein in the...

    Correct

    • You draw a patient's blood sample from the median cubital vein in the antecubital fossa.

      Which of the following veins also connects to the cephalic vein other than the median cubital vein?

      Your Answer: Basilic vein

      Explanation:

      The upper limb venous drainage is divided into superficial and deep. The superficial veins are accessible to draw blood for investigations. The cephalic, basilic, and median cubital veins are superficial veins.

      The median cubital vein connects the cephalic vein and basilic vein. It is located anteriorly in the antecubital fossa and is preferred for venepuncture due to its palpability and ease of access.

      The basilic vein and cephalic vein are the primary veins that drain the upper limb. They begin as the dorsal venous arch. The basilic vein originates from the ulnar side, while the cephalic vein originates from the radial side of the dorsal arch of the upper limb.

    • This question is part of the following fields:

      • Anatomy
      28.9
      Seconds
  • Question 7 - Which of the following causes a left shift of the haemoglobin dissociation curve?...

    Incorrect

    • Which of the following causes a left shift of the haemoglobin dissociation curve?

      Your Answer: Respiratory acidosis

      Correct Answer:

      Explanation:

      With respect to oxygen transport in cells, almost all oxygen is transported within erythrocytes. There is limited solubility and only 1% is carried as solution. Thus, the amount of oxygen transported depends upon haemoglobin concentration and its degree of saturation.

      Haemoglobin is a globular protein composed of 4 subunits. Haem is made up of a protoporphyrin ring surrounding an iron atom in its ferrous state. The iron can form two additional bonds – one is with oxygen and the other with a polypeptide chain.
      There are two alpha and two beta subunits to this polypeptide chain in an adult and together these form globin. Globin cannot bind oxygen but can bind to CO2 and hydrogen ions.
      The beta chains are able to bind to 2,3 diphosphoglycerate. The oxygenation of haemoglobin is a reversible reaction. The molecular shape of haemoglobin is such that binding of one oxygen molecule facilitates the binding of subsequent molecules.

      The oxygen dissociation curve (ODC) describes the relationship between the percentage of saturated haemoglobin and partial pressure of oxygen in the blood.
      Of note, it is not affected by haemoglobin concentration.

      Chronic anaemia causes 2, 3 DPG levels to increase, hence shifting the curve to the right

      Haldane effect – Causes the ODC to shift to the left. For a given oxygen tension there is increased saturation of Hb with oxygen i.e. Decreased oxygen delivery to tissues.
      This can be caused by:
      -HbF, methaemoglobin, carboxyhaemoglobin
      -low [H+] (alkali)
      -low pCO2
      -ow 2,3-DPG
      -ow temperature

      Bohr effect – causes the ODC to shifts to the right = for given oxygen tension there is reduced saturation of Hb with oxygen i.e. Enhanced oxygen delivery to tissues. This can be caused by:
      – raised [H+] (acidic)
      – raised pCO2
      -raised 2,3-DPG
      -raised temperature

    • This question is part of the following fields:

      • Physiology And Biochemistry
      16.3
      Seconds
  • Question 8 - A graph is created to show the exponential relationship between bacterial growth (y-axis)...

    Correct

    • A graph is created to show the exponential relationship between bacterial growth (y-axis) and time (x-axis).

      Which of the following statements is most true about this kind of exponential relationship?

      Your Answer: y = ex

      Explanation:

      The relationship between bacterial growth and time is a tear-away exponential. The mathematical relationship between y and x in this case is:

      y = ex

      Where: the power is x, and the base is e.

      Euler’s number (e) is a mathematical constant that is the base for all logarithms occurring naturally. Its value is 2.718.

      The statement X increasing with an increase in Y is proportional to Y refers to the change in y in terms of x when considering any exponential relationship.

      This is not a build-up exponential, and that is mathematically stated as y = 1-e-kt.

      The negative x axis being a horizontal asymptote and the y intercept being 0, 1 are examples of tearaway exponentials , but do not describe an exponential process.

    • This question is part of the following fields:

      • Statistical Methods
      1.9
      Seconds
  • Question 9 - All of the following statements are true regarding calcium except: ...

    Correct

    • All of the following statements are true regarding calcium except:

      Your Answer: Serum calcium accounts for 10% of total body calcium stores

      Explanation:

      Calcium is a very important ion and is involved in:
      -cell homeostasis
      -coagulation
      -muscle contraction
      -neuronal impulse transmission/membrane stabilization
      -bone formation and skeletal strength
      -secretion processes

      99% is found in bone and 1% in the plasma. Of the 1% that is in the plasma
      -45% is free ionized calcium
      -45% is bound to proteins, mainly Albumin
      -10% is present as an anion complex

      Reduced levels of IONIZED calcium give rise to features of hypocalcaemia , resulting in increased excitability of membranes. This results when the total calcium concentration goes below 2 mmol/L.

      Features of mild to moderate hypocalcaemia are:
      -paraesthesia (peri-oral, fingers)
      -tetany
      -spasm
      -muscle cramps
      -ECG changes (prolonged QT)
      -Trousseau’s sign (inflation of tourniquet induces carpopedal spasm)
      -Chvostek’s sign (tapping the facial nerve – cranial nerve VII – causes facial muscle twitch/spasm)

      Features of severe hypocalcaemia are:
      -cardiogenic shock and congestive cardiac failure due to reduced myocardial contractility
      respiratory distress due to bronchospasm, agitation, confusion, seizures

      Features of hypercalcaemia (remember ‘bones, stones, groans and psychic moans’):
      -Abdominal pain
      -Vomiting
      -Constipation
      -Polyuria
      -Polydipsia
      -Depression
      -Lethargy
      -Anorexia
      -Weight loss
      -Hypertension
      -Confusion
      -Pyrexia
      -Calcification in the cornea
      -Renal stones
      -Renal failure
      -Decreased Q-T interval
      -Cardiac shock/collapse

    • This question is part of the following fields:

      • Physiology And Biochemistry
      26.8
      Seconds
  • Question 10 - A 50-year-old female is having her central venous pressure (CVP) measured. A long...

    Correct

    • A 50-year-old female is having her central venous pressure (CVP) measured. A long femoral line was inserted that passes from the common iliac vein into the inferior vena cava.

      At which level of vertebra does this occur?

      Your Answer: L5

      Explanation:

      The inferior vena cava is formed by the union of the right and left common iliac veins. This occurs at the L5 vertebral level. The IVC courses along the right anterolateral side of the vertebral column and ascends through the central tendon of the diaphragm at the T8 vertebral level.

    • This question is part of the following fields:

      • Anatomy
      17
      Seconds
  • Question 11 - A 10-year-old girl complains of right iliac fossa pain, and a provisional diagnosis...

    Incorrect

    • A 10-year-old girl complains of right iliac fossa pain, and a provisional diagnosis of appendicitis is made.

      Which of the following embryological structures gives rise to the appendix?

      Your Answer: Hindgut

      Correct Answer: Midgut

      Explanation:

      The midgut gives rise to the appendix.
      At week 6, the caecal diverticulum appears and is the precursor for the cecum and vermiform appendix. The cecum and appendix undergo rotation and descend into the right lower abdomen. The appendix can take up various positions:
      1. Retrocecal appendix: behind the cecum
      2. Retrocolic appendix: behind the ascending colon
      3. Pelvic appendix: appendix descends into the pelvis

      The appendix grows in length so that at birth, it is long and worm-shaped, or vermiform. After birth, the caecal wall grows unequally, and the appendix comes to lie on its medial side.

      The midgut develops into the distal duodenum, jejunum, ileum, cecum, appendix, ascending colon, and proximal 2/3 of the transverse colon.

    • This question is part of the following fields:

      • Anatomy
      11.5
      Seconds
  • Question 12 - Which of the following statements is true about monoamine oxidase (MOA) enzymes? ...

    Incorrect

    • Which of the following statements is true about monoamine oxidase (MOA) enzymes?

      Your Answer: They catalyse the formation of amines

      Correct Answer: Type A and type B are found in the liver and brain

      Explanation:

      Monoamine oxidase (MOA) enzymes are responsible for the catalyses of monoamine oxidative deamination. It assists the degradation of serotonin, norepinephrine (NE) and dopamine.

      They are found in the mitochondria of most central and peripheral nerve tissues.

      There are 2 different types:

      Type A: Whose main function it to inactivate dopamine, tyramine, norepinephrine and 5-hydroxytryptamine. In addition to the nervous system, it is also found in the liver, brain gastrointestinal tract, pulmonary endothelium and placenta
      Type B: Whose main function is to inactivate dopamine, tyramine, tryptamine and phenylethylamine. In addition to the nervous system, it is also found in the liver, brain (especially in the basal ganglia) and blood platelets.

    • This question is part of the following fields:

      • Pathophysiology
      32.7
      Seconds
  • Question 13 - With a cervical dilation of 7 cm, a 33-year-old term primigravida is in...

    Correct

    • With a cervical dilation of 7 cm, a 33-year-old term primigravida is in labour. She is otherwise in good health. She's been in labour for 14 hours and counting.

      The cardiotocograph shows late foetal pulse decelerations, and a pH of 7.24 was found in the recent foetal scalp blood sample.

      Which of the following is true about this patient's care and management?

      Your Answer: Monitor for downward trend in fetal scalp blood pH as caesarean section is not indicated at the present time

      Explanation:

      Once the decision to deliver a baby by caesarean section has been made, it should be carried out with a level of urgency commensurate with the baby’s risk and the mother’s safety.

      There are four types of caesarean section urgency:

      Category 1: A threat to the life of the mother or the foetus. 30 minutes to make a delivery decision
      Category 2 : Maternal or foetal compromise that is not immediately life threatening. In most cases, the decision to deliver is made within 75 minutes.
      Category 3 – Early delivery is required, but there is no risk to the mother or the foetus.
      Category 4: Elective delivery at a time that is convenient for both the mother and the maternity staff.

      There may be evidence of foetal compromise in the example above (late foetal pulse decelerations and a borderline pH).

      Blood samples from the foetus:
      normal: 7.25 or above
      borderline: 7.21 to 7.24
      abnormal: 7.20 or below

      When a foetal deceleration occurs, the mother should be given oxygen, kept in a left lateral position, and given a tocolytic if the foetal deceleration is hyper stimulating. Maintaining adequate hydration will reduce the likelihood of a caesarean section.

    • This question is part of the following fields:

      • Pathophysiology
      335.8
      Seconds
  • Question 14 - Which of the following is an expected change in pulmonary function seen during...

    Correct

    • Which of the following is an expected change in pulmonary function seen during a moderate asthma attack?

      Your Answer: Decreased forced expiratory volume in 1 sec (FEV1)

      Explanation:

      Asthma is a lung condition that causes reversible narrowing and swelling of airway passages. It is classified by the frequency and severity of symptoms.

      The following are symptoms of moderate asthma:

      Symptoms include cough, wheezing, chest tightness, or difficulty breathing which occurs daily
      Decreased activity levels due to flare-ups
      Night-time symptoms 5 or more times a month
      Lung function test FEV1 is 60-80% of predicted normal values
      Peak flow has more than 30% variability

      With moderate asthma attacks, the arterial pCO2 levels may decrease, but as severity increases, so does the pCO2, reaching normal levels, and then exceeding them in severe asthma attacks.

      Airway obstruction increases the functional residual capacity.

      Concentration of serum bicarbonate would not increase in moderate asthma, but it could possibly increase in life-threatening asthma via the same mechanism as what increases arterial PCO2.

      FEV1 is a good measure of airway obstruction. and is reduced in acute asthma attacks.

      In the case of a pneumothorax, a decrease in arterial PO2 is higher.

    • This question is part of the following fields:

      • Pathophysiology
      20
      Seconds
  • Question 15 - You are preparing to anaesthetize a 27-year-old woman for an acute diagnostic laparoscopy...

    Correct

    • You are preparing to anaesthetize a 27-year-old woman for an acute diagnostic laparoscopy to rule out appendicitis.

      She has no medical history and does not take any medications on a regular basis. You're going to do a quick sequence induction.

      Which method of preoxygenation is the most effective and efficient?

      Your Answer: Mapleson A circuit with a fresh gas flow of 100 ml/kg

      Explanation:

      Professor Mapleson classified non-rebreathing circuits based on the position of the APL valve, which controls fresh gas flow.

      The Mapleson A (Magill) circuit is most effective in spontaneous breathing, requiring only 70-100 ml/kg (the patient’s minute volume) of fresh gas flow. The patient inhales fresh gas from the reservoir bag and tubing during inspiration. During expiration, the patient adds dead space gas (gas that hasn’t been exchanged) to the tubing and reservoir bag in addition to the fresh gas flow. At the patient’s end, alveolar gas is vented through the APL valve. During the expiratory pause, the fresh gas flow causes more gas to be released.

      The Mapleson A is inefficient during controlled ventilation. Venting occurs during inspiration rather than during the expiratory phase, as it does during spontaneous ventilation. As a result, unless a high fresh gas flow of >20 L/minute is used, alveolar gas is rebreathed.

      During spontaneous ventilation, the Mapleson D circuit is inefficient.

      The oxygen concentration in a Hudson mask is insufficient to allow for adequate pre-oxygenation.

    • This question is part of the following fields:

      • Anaesthesia Related Apparatus
      34.1
      Seconds
  • Question 16 - The population incidence of a disease is best described by? ...

    Correct

    • The population incidence of a disease is best described by?

      Your Answer: The number of new cases of a disease per population in a defined period

      Explanation:

      The incidence of a disease is the number of new cases of the disease in a population over a defined time period.

      The prevalence of a disease is the number of cases of the disease in a population over a defined time period describes. It is NOT the number of new cases.

      The number of new cases of a disease only, has no denominator (time period or population) from which to derive an incidence.

      The number of new cases of a disease seeking medical treatment is the incidence of patients seeking medical treatment NOT the incidence of the disease in a population.

      The death rate from a disease is the number of patients dying from the disease in a population.

    • This question is part of the following fields:

      • Statistical Methods
      22.4
      Seconds
  • Question 17 - A 45-year-old woman gives a two-week history of fatigue, muscle cramps, and paraesthesia...

    Incorrect

    • A 45-year-old woman gives a two-week history of fatigue, muscle cramps, and paraesthesia of her fingers and toes. She has low serum calcium and low serum parathyroid hormone levels on investigations.

      She appears slightly confused, likely due to hypocalcaemia, and cannot give a full account of her past medical history, but can recall that she recently was admitted to the hospital.

      What is the most likely cause of her hypoparathyroidism?

      Your Answer: Parathyroid adenoma

      Correct Answer: Thyroidectomy

      Explanation:

      The most common cause of hypoparathyroidism is injury or removing the parathyroid glands. They can be injured accidentally during surgery to remove the thyroid as they are located posterior to the thyroid gland.

      A result of both low parathyroid hormone and low calcium is likely to mean that the parathyroid glands are not responding to hypocalcaemia. The hypocalcaemia can cause confusion, and the stay in the hospital is likely to refer to her surgery.

      While a parathyroid adenoma is fairly common and can cause hypoparathyroidism, it much more likely causes hyperparathyroidism.

      Chronic kidney disease is likely to cause hypocalcaemia, which would increase parathyroid hormone production in an attempt to increase calcium levels, causing hyperparathyroidism. Vitamin D is activated by the kidneys and then binds to calcium to be absorbed in the terminal ileum so that a deficiency would cause hyperparathyroidism.

    • This question is part of the following fields:

      • Anatomy
      314.6
      Seconds
  • Question 18 - A post-operative patient was brought to the recovery room after completion of dilation...

    Incorrect

    • A post-operative patient was brought to the recovery room after completion of dilation and curettage. Her medical history revealed that she was maintained on levodopa for Parkinson's disease. The nurses administered ondansetron 4 mg and dexamethasone 8 mg prior to transfer from the operating room to the recovery room. However, an additional antiemetic agent is warranted.

      Which of the following agents should be prescribed to the patient?

      Your Answer: Ondansetron 4 mg IV

      Correct Answer: Cyclizine 50 mg IV

      Explanation:

      The Beers criteria, a US set of criteria for good prescribing in the older patient, preclude the use of metoclopramide in Parkinson’s disease. The Adverse Reactions Register of the UK Committee on Safety of Medicines (CSM) for the years 1967 to 1982 contained 479 reports of extrapyramidal reactions in which metoclopramide was the suspected drug; 455 were for dystonic-dyskinetic reactions, 20 for parkinsonism and four for tardive dyskinesia. Effects can occur within days of initiation of treatment and may take months to wear off.

      Other antiemetics are available, such as cyclizine (Valoid), domperidone and ondansetron, which would be more appropriate to use in those with Parkinson’s disease.

      Cyclizine is a piperazine derivative with histamine H1 receptor antagonist and anticholinergic activity. It is used for the treatment of nausea, vomiting, (particularly opioid-induced vomiting), vertigo, motion sickness, and labyrinthine disorders.

      Prochlorperazine is an antipsychotic known to cause tardive dyskinesia, tremor and parkinsonian symptoms and is therefore likely to exacerbate Parkinson’s disease. Prochlorperazine is not favoured for older patients because of the increased risk of stroke and transient ischaemic attack (TIA).

      Droperidol and phenothiazine are also potent antagonists on D2 receptors and must also be avoided.

    • This question is part of the following fields:

      • Pharmacology
      7.2
      Seconds
  • Question 19 - Concerning platelets one of the following is true ...

    Incorrect

    • Concerning platelets one of the following is true

      Your Answer: In a normal person are predominately found in the spleen (more than 60%)

      Correct Answer: Are formed in the bone marrow from megakaryocytes

      Explanation:

      Platelets are fragments of megakaryocytes and they are encapsulated by membrane.

      They have no nucleus but are metabolically active and are able to express membrane receptors and release stored substances when triggered. adenosine diphosphate and serotonin are 2 of its content.

      Because they have no nucleus, they are not able to produce new proteins. This is why aspirin and other drugs affect function for their entire lifespan after exposure. Its lifespan is approximately 9-10 days in normal individuals.

      Platelets does NOT PRODUCE prostacyclin but are able to produce nitric oxide, prostaglandins and thromboxane.

    • This question is part of the following fields:

      • Pathophysiology
      7.6
      Seconds
  • Question 20 - A cannula is inserted into the cephalic vein of a 30-year-old man. Which...

    Correct

    • A cannula is inserted into the cephalic vein of a 30-year-old man. Which of the following structures does the cephalic vein pass through?

      Your Answer: Clavipectoral fascia

      Explanation:

      The cephalic vein is one of the primary superficial veins of the upper limb. The superficial group of upper limb veins begin as an irregular dorsal arch on the back of the hand.

      The cephalic vein originates in the anatomical snuffbox from the radial side of the arch and travels laterally up, within the superficial fascia to join the basilic vein via the median cubital vein at the elbow.

      Near the shoulder, it passes between the deltoid and pectoralis major muscles. It pierces the coracoid membrane (continuation of the clavipectoral fascia) to terminate in the axillary vein’s first part.

    • This question is part of the following fields:

      • Anatomy
      28.1
      Seconds
  • Question 21 - Which statement most accurately describes the action of increasing the gain in ultrasound...

    Incorrect

    • Which statement most accurately describes the action of increasing the gain in ultrasound imaging?

      Your Answer: Decreases frequency of emitted ultrasound

      Correct Answer: Amplifies the returning signal

      Explanation:

      A higher frequency ultrasound comes with a better resolution of the digital image. Ultrasound with a frequency of 15 MHz is best used in imaging of superficial organs such as the thyroid gland, muscles, tendons and breasts whereas deep organs are better imaged using a lower frequency of 2-7MHz because of its ability for deeper penetration but lower resolution. These low frequency probes are also used to diagnose ascites, pleural effusions or can be used in echocardiography.

      The US probe emits and then absorbs a reflected wave. Similar to brightness control, increasing the gain will amplify the return signal which is then attenuated by the tissue. This increases the signal to noise ratio.
      A high frame rate, which basically means the number of times an image is updated onto the screen per second, improves the resolution of a moving 3D image which has become more accurate as the computing power has increased.

      Widening of the image field can be obtained by altering the penetration depth which is obtained by changing the frequency of the US beam

    • This question is part of the following fields:

      • Anaesthesia Related Apparatus
      29.7
      Seconds
  • Question 22 - An otherwise fit 7-year-old boy for an elective tonsillectomy is seen holding a...

    Incorrect

    • An otherwise fit 7-year-old boy for an elective tonsillectomy is seen holding a bottle of sugared orange squash at anaesthetic assessment . He appears to have consumed 120 mL of the bottle's contents.

      What is the minimal safe fasting time prior to proceeding with a general anaesthetic in this patient?

      Your Answer: 6 hours

      Correct Answer: 1 hour

      Explanation:

    • This question is part of the following fields:

      • Pathophysiology
      14.2
      Seconds
  • Question 23 - Post thyroidectomy, a 50-year-old male singer noticed some hoarseness in his voice. Now,...

    Correct

    • Post thyroidectomy, a 50-year-old male singer noticed some hoarseness in his voice. Now, he presents to his general physician as it has been the same for the past few weeks.

      A complication is noted in the post-thyroidectomy report regarding an injury to the external laryngeal nerve.

      Which muscle has been affected due to loss of innervation by the damaged nerve, and whose improper functioning can lead to hoarseness in the patient's voice?

      Your Answer: Cricothyroid

      Explanation:

      All of the muscles of the larynx are innervated by the recurrent laryngeal nerve, except the cricothyroid muscle.

      Cricothyroid muscle is located deep in the anterior neck, between the cricoid and thyroid cartilage and is innervated by the external laryngeal nerve. Any injury to this muscle can cause paralysis and lead to hoarseness. When cricothyroid muscle contracts, it leads to tightening, stretching and thinning of the vocal folds. This produces higher-pitched sounds during vocalization.

      A patient experiencing hoarseness due to possible injury to the external laryngeal nerve should be reassured that the hoarseness will resolve in time due to increased compensation from the other muscles.

    • This question is part of the following fields:

      • Anatomy
      26.7
      Seconds
  • Question 24 - Metabolization of many drugs used in anaesthesia involves the cytochrome P450 (CYP) isoenzymes.

    The...

    Incorrect

    • Metabolization of many drugs used in anaesthesia involves the cytochrome P450 (CYP) isoenzymes.

      The CYP enzyme most likely to be subject to genetic variability and thus cause adverse drug reactions is which of these?

      Your Answer: CYP2E1

      Correct Answer: CYP2D6

      Explanation:

      Approximately 25% of phase-1 drug reactions is made responsible by CYP2D6.

      As much as a 1,000-fold difference in the ability to metabolise drugs by CYP2D6 can happen between phenotypes, and this may result in adverse drug reactions (ADRs).

      The metabolism of antiemetics, beta-blockers, codeine, tramadol, oxycodone, hydrocodone, tamoxifen, antidepressants, neuroleptics, and antiarrhythmics is also as a result of CYP2D6.

      Patients who take drugs that are metabolised by CYP2D6 but have poor CYP2D6 metabolism are more likely to have ADRs. People with ultra-rapid CYP2D6 metabolism may have a decreased drug effect due to low plasma concentrations of these drugs.

      All the other CYP enzymes are subject to genetic polymorphism. Variants are less likely to lead to adverse drug reactions.

    • This question is part of the following fields:

      • Physiology
      31.5
      Seconds
  • Question 25 - Because this benzodiazepine has a half-life of 2-4 hours, it is preferred for...

    Incorrect

    • Because this benzodiazepine has a half-life of 2-4 hours, it is preferred for clinical use.

      This benzodiazepine has which of the following properties that no other benzodiazepine has?

      Your Answer: It can be reversed using an inverse agonist

      Correct Answer: It is water soluble at a pH of 3.5 and lipid soluble at a pH of 7.4

      Explanation:

      Midazolam is the benzodiazepine in question. It’s the only benzodiazepine that undergoes tautomeric transformation (dynamic isomerism). The molecule is ionised and water soluble at pH 3.5, but when injected into the body at pH 7.4, it becomes unionised and lipid soluble, allowing it to easily pass through the blood brain barrier.

      The half-life of midazolam is only 2-4 hours.

      It is a GABAA receptor agonist because it is a benzodiazepine. GABAA receptors are found in abundance throughout the central nervous system, particularly in the cerebral cortex, hippocampus, thalamus, basal ganglia, and limbic system. GABAA receptors are ligand-gated ion channels, with the inhibitory neurotransmitter gamma-aminobutyric acid as the endogenous agonist. It is a pentameric protein (2, 2 and one subunit) that spans the cell membrane, and when the agonist interacts with the alpha subunit, a conformational change occurs, allowing chloride ions to enter the cell, resulting in neuronal hyperpolarization.

      For status epilepticus, midazolam is not the drug of choice. Lorazepam is the benzodiazepine of choice for status epilepticus.

    • This question is part of the following fields:

      • Pharmacology
      25.5
      Seconds
  • Question 26 - Which of the following statements is not correct regarding Noradrenaline? ...

    Incorrect

    • Which of the following statements is not correct regarding Noradrenaline?

      Your Answer: Metabolised by Monoamine Oxidase

      Correct Answer: Predominantly work through effects on ?-adrenergic receptors

      Explanation:

      Noradrenaline also called norepinephrine belongs to the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter.

      They have sympathomimetic effects acting via adrenoceptors (?1, ?2,?1, ?2, ?3) or dopamine receptors (D1, D2).

      May cause reflex bradycardia, reduce cardiac output and increase myocardial oxygen consumption

    • This question is part of the following fields:

      • Pharmacology
      20
      Seconds
  • Question 27 - Which of the following statements is true regarding oxygen? ...

    Incorrect

    • Which of the following statements is true regarding oxygen?

      Your Answer: Percentage in the air is reduced at high altitude

      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.

    • This question is part of the following fields:

      • Basic Physics
      31.2
      Seconds
  • Question 28 - During exercise, muscle blood flow can increase by 20 to 50 times.

    Which mechanism...

    Incorrect

    • During exercise, muscle blood flow can increase by 20 to 50 times.

      Which mechanism is the most important for increased blood flow?

      Your Answer: Sympathetic cholinergic stimulation

      Correct Answer: Local autoregulation

      Explanation:

      Skeletal muscle blood flow is in the range of 1-4 ml/min per 100 g when at rest. Blood flow can reach 50-100 ml/min per 100 g during exercise. With maximal vasodilation, blood flow can increase 20 to 50 times.

      The adrenal medulla releases catecholamines and increases neural sympathetic activity during exercise. Normally, alpha-1 and alpha-2 would cause vasoconstriction in the muscle groups being used, but vasodilatory metabolites override these effects, resulting in a so-called functional sympathectomy. Local hypoxia and hypercarbia, nitric oxide, K+ ions, adenosine, and lactate are some of the stimuli that cause vasodilation.

      However, the splanchnic and cutaneous circulations, which supply inactive muscles, vasoconstrict.

      Sympathetic cholinergic innervation of skeletal muscle arteries is found in some species (such as cats and dogs, but not humans). Vasodilation is induced by stimulating smooth muscle beta-2 adrenoreceptors, but at rest, the alpha-adrenoreceptor effects of adrenaline and noradrenaline predominate. During exercise, the skeletal muscle pump promotes venous emptying, but it does not necessarily increase blood flow.

    • This question is part of the following fields:

      • Physiology
      15.9
      Seconds
  • Question 29 - A pre-operative evaluation for a trans-sphenoidal pituitary adenectomy is being performed on a...

    Incorrect

    • A pre-operative evaluation for a trans-sphenoidal pituitary adenectomy is being performed on a 57-year-old woman. Her vision is causing her problems.

      A macroadenoma compressing the optic chiasm is visible on MRI.

      What is the most likely visual field defect to be discovered during an examination?

      Your Answer: Central visual loss

      Correct Answer: Bitemporal hemianopia

      Explanation:

      The pituitary gland plays a crucial role in the neuro-endocrine axis. It is located at the base of the skull in the sella turcica of the sphenoid bone. It is connected superiorly to the hypothalamus, third ventricle, and visual pathways, and laterally to the cavernous sinuses, internal carotid arteries, and cranial nerves III, IV, V, and VI.

      Pituitary tumours make up about 10-15% of all intracranial tumours. The majority of adenomas are benign. Over-secretion of pituitary hormones (most commonly prolactin, growth hormone, or ACTH), under-secretion of hormones, or localised or generalised pressure effects can all cause symptoms.

      Compression of the optic chiasm can result in visual field defects, the most common of which is bitemporal hemianopia. This is caused by compression of the nasal retinal fibres, which carry visual impulses from temporal vision across the optic chiasm to the contralateral sides before continuing to the optic tracts.

      The interruption of the visual pathways distal to the optic chiasm causes a homonymous visual field defect. The loss of the right or left halves of each eye’s visual field is referred to as homonymous hemianopia. It’s usually caused by a middle or posterior cerebral artery territory stroke that affects the occipital lobe’s optic radiation or visual cortex.

      Binasal hemianopia is a condition in which vision is lost in the inner half of both eyes (nasal or medial). It’s caused by compression of the temporal visual pathways, which don’t cross at the optic chiasm and instead continue to the ipsilateral optic tracts. Binasal hemianopia is a rare complication caused by the internal carotid artery impinging on the temporal (lateral) visual fibres.

      A monocular visual loss (that is, loss of vision in only one eye) can be caused by a variety of factors, but if caused by nerve damage, the damage would be proximal to the optic chiasm on the ipsilateral side.

      A central scotoma is another name for central visual field loss. Every normal mammalian eye has a scotoma, also known as a blind spot, in its field of vision. The optic disc is a region of the retina that lacks photoreceptor cells and is where the retinal ganglion cell axons that make up the optic nerve exit the retina. When both eyes are open, visual signals that are absent in one eye’s blind spot are provided for the other eye by the opposite visual cortex, even if the other eye is closed.

      Scotomata can be caused by a variety of factors, including demyelinating disease such as multiple sclerosis, damage to nerve fibre layer in the retina, methyl alcohol, ethambutol, quinine, nutritional deficiencies, and vascular blockages either in the retina or in the optic nerve.

      Bilateral scotoma can occur when a pituitary tumour compresses the optic chiasm, causing a bitemporal paracentral scotoma, which then spreads out to the periphery, causing bitemporal hemianopsia. A central scotoma in a pregnant woman could be a sign of severe pre-eclampsia.

    • This question is part of the following fields:

      • Pathophysiology
      12.5
      Seconds
  • Question 30 - The passage of glucose into the brain is facilitated by which transport method?...

    Correct

    • The passage of glucose into the brain is facilitated by which transport method?

      Your Answer: Facilitated diffusion

      Explanation:

      Glucose transport is a highly regulated process accomplished mostly by facilitated diffusion using carrier proteins to cross cell membranes.

      There are many transporters, but the most important are known as glucose transporters (GLUTs).

      Stresses in various form of acute and chronic forms affect the activity of glucose transporters.
      They are responsive to many types of metabolic stress, including hypoxia, injury, hypoglycaemia, numerous metabolic inhibitors, stress hormones, and other influences such as growth factors.

      Numerous signalling pathways appear to be involved in transporter regulation.

      New evidence suggests that stresses regulating GLUTs are not only acute biological stresses. In addition, chronic low-grade inflammation, and their associated chronic diseases also lead to altered glucose transport. These include obesity, type 2 diabetes, cardiovascular disease, and the growth and spread of many tumours that are affected by altered glucose transporters. Some of these glucose transport effects are compensatory, while others are pathogenic.

      Ultimately, deliberate manipulation of GLUTs could be used as treatment for some of these chronic diseases.

    • This question is part of the following fields:

      • Physiology
      16.4
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Anatomy (5/8) 63%
Physiology And Biochemistry (2/3) 67%
Anaesthesia Related Apparatus (3/3) 100%
Clinical Measurement (1/1) 100%
Statistical Methods (2/2) 100%
Pathophysiology (4/6) 67%
Pharmacology (3/3) 100%
Physiology (2/3) 67%
Basic Physics (0/1) 0%
Passmed