-
Question 1
Correct
-
Which of the following is true regarding the mechanism of action of daptomycin?
Your Answer: Interferes with the outer membrane of gram positive bacteria resulting in cell death
Explanation:Daptomycin alters the curvature of the membrane, which creates holes that leak ions. This causes rapid depolarization, resulting in loss of membrane potential. Thus it interferes with the outer membrane of gram-positive bacteria resulting in cell death.
-
This question is part of the following fields:
- Pharmacology
-
-
Question 2
Correct
-
What can an outbreak of flu that has spread globally be termed as?
Your Answer: Pandemic
Explanation:An epidemic is declared when the increase in a give disease is above a certain level in a specific interval of time.
An endemic is the general, usual level of a disease in a population at a particular time.
A pandemic is an epidemic that is spread across many countries and continents.
-
This question is part of the following fields:
- Statistical Methods
-
-
Question 3
Correct
-
A 63-year old man has palpitations and goes to the emergency room. An ECG shows tall tented T waves, which corresponds to phase 3 of the cardiac action potential.
The shape of the T wave is as a result of which of the following?Your Answer: Repolarisation due to efflux of potassium
Explanation:Cardiac conduction
Phase 0 – Rapid depolarization. Opening of fast sodium channels with large influx of sodium
Phase 1 – Rapid partial depolarization. Opening of potassium channels and efflux of potassium ions. Sodium channels close and influx of sodium ions stop
Phase 2 – Plateau phase with large influx of calcium ions. Offsets action of potassium channels. The absolute refractory period
Phase 3 – Repolarization due to potassium efflux after calcium channels close. Relative refractory period
Phase 4 – Repolarization continues as sodium/potassium pump restores the ionic gradient by pumping out 3 sodium ions in exchange for 2 potassium ions coming into the cell. Relative refractory period
-
This question is part of the following fields:
- Physiology And Biochemistry
-
-
Question 4
Correct
-
A project is being planned to assess the effects of a new anticoagulant on the coagulation cascade. The intrinsic pathway is being studied and the best measurement to be recorded is which of the following?
Your Answer: aPTT
Explanation:The intrinsic pathway is best assessed by the aPTT time.
D-dimer is a fibrin degradation product which is raised in the presence of blood clots.
A 50:50 mixing study is used to assess if a prolonged PT or aPTT is due to factor deficiency or a factor inhibitor.
The thrombin time is a test used to assess fibrin formation from fibrinogen in plasma. Factors that prolong the thrombin time include heparin, fibrin degradation products, and fibrinogen deficiency.
Intrinsic pathway – Best assessed by APTT. Factors 8,9,11,12 are involved. Prolonged aPTT can be seen in haemophilia and use of heparin.
Extrinsic pathway – Best assessed by Increased PT. Factor 7 involved.
Common pathway – Best assessed by APTT & PT. Factors 2,5,10 involved.
Vitamin K dependent factors are factors 2,7,9,10
-
This question is part of the following fields:
- Physiology And Biochemistry
-
-
Question 5
Incorrect
-
All of the following statements about dopamine are FALSE except:
Your Answer: At a dose of 5-10 mcg/kg/min its action is mainly at the alpha adrenoceptors.
Correct Answer:
Explanation:Dopamine (DA) is a dopaminergic (D1 and D2) as well as adrenergic ? and ?1 (but not ?2 )agonist.
The D1 receptors in renal and mesenteric blood vessels are the most sensitive: i.v. infusion of a low dose of DA dilates these vessels (by raising intracellular cyclic adenosine monophosphate).
Moderately high doses produce a positive inotropic (direct ?1 and D1 action + that due to NA release), but the little chronotropic effect on the heart.
Vasoconstriction (?1 action) occurs only when large doses are infused.
At doses normally employed, it raises cardiac output and systolic BP with little effect on diastolic BP. It has practically no effect on nonvascular ? and ? receptors; does not penetrate the blood-brain barrier – no Central nervous system effects.
Dopamine is less arrhythmogenic than adrenaline
Regarding dopamine part of the dose is converted to Noradrenaline in sympathetic nerve terminals.
-
This question is part of the following fields:
- Pharmacology
-
-
Question 6
Incorrect
-
The average diastolic blood pressure of a control group was found out to be 80 with a standard deviation of 5 in a study aimed at exploring the efficiency of a novel anti-hypertensive drug. The trial was randomised.
Making an assumption that the data is normally distributed, find out the number of patients that had diastolic blood pressure over 90.Your Answer: 10%
Correct Answer: 3%
Explanation:Since the data is normally distributed, 95% of the values lie with in the interval 70 to 90. This can be calculated as follows:
Interval= Mean ± ( 2 times standard deviation)
= 80 ± 2(5)
= 80 ± 10
= 70 & 90The rest of the 5% are distributed symmetrically beyond 90 and below 70 which means 2.5% of the values lie above 90.
-
This question is part of the following fields:
- Statistical Methods
-
-
Question 7
Incorrect
-
A 72-year-old female is diagnosed with acute mesenteric ischemia.
On CT angiogram, the origin of the superior mesenteric artery is stenosed.
At which vertebra level does the superior mesenteric artery branch from the aorta?Your Answer: L3
Correct Answer: L1
Explanation:The superior mesenteric artery branches from the abdominal aorta just 1-2 cm below the origin of the celiac trunk. It lies posterior to the body of the pancreas and splenic vein and is separated from the aorta by the left renal vein. It passes forwards and inferiorly, anterior to the uncinate process of the pancreas and the third part of the duodenum, to enter the root of the small bowel mesentery and supply the midgut.
The important landmarks of vessels arising from the abdominal aorta at different levels of vertebrae are:
T10 – oesophageal opening in the diaphragm
T12 – Coeliac trunk, aortic hiatus in the diaphragm
L1 – Left renal artery
L2 – Testicular or ovarian arteries
L3 – Inferior mesenteric artery
L4 – Bifurcation of the abdominal aorta
-
This question is part of the following fields:
- Anatomy
-
-
Question 8
Incorrect
-
Obeying Boyle's law and Charles's law is a characteristic feature of an ideal gas.
The gas which is most ideal out of the following options is?Your Answer: Xenon
Correct Answer: Helium
Explanation:The ideal gas equation makes the following assumptions:
The gas particles have a small volume in comparison to the volume occupied by the gas.
Between the gas particles, there are no forces of interaction.
Individual gas particle collisions, as well as gas particle collisions with container walls, are elastic, meaning momentum is conserved.
PV = nRT
Where:P = pressure
V = volume
n = moles of gas
T = temperature
R = universal gas constantHelium is a monoatomic gas with a small helium atom. The attractive forces between helium atoms are small because the helium atom is spherical and has no dipole moment. Because helium atoms are spherical, collisions between them approach the ideal state of elasticity.
Most real gases behave qualitatively like ideal gases at standard temperatures and pressures. When intermolecular forces and molecular size become important, the ideal gas model tends to fail at lower temperatures or higher pressures. It also fails to work with the majority of heavy gases.
Helium, argon, neon, and xenon are noble or inert gases that behave the most like an ideal gas. Xenon is a noble gas with a much larger atomic size than helium.
-
This question is part of the following fields:
- Pharmacology
-
-
Question 9
Correct
-
A 70-year-old female presented with a productive cough and is prescribed a bacteriostatic antibiotic?
Which of the following best explains the mechanism of action of bacteriostatic drugs?Your Answer: Protein synthesis inhibition
Explanation:Cell membrane pore formation, Bacterial DNA damage, Peptidoglycan cross-linking inhibition, and peptidoglycan synthesis inhibitor are always lethal and such mechanisms are possible only in bactericidal drugs. But Protein synthesis inhibition would only prevent cell replication or cell growth and is responsible for bacteriostatic effects of the drug.
-
This question is part of the following fields:
- Pharmacology
-
-
Question 10
Correct
-
Which compound of ketamine hydrochloride has the most significant anaesthetic property or effect?
Your Answer: (S)-ketamine
Explanation:Ketamine is usually used as a racemic mixture, i.e. (R/S)-ketamine. For over 20 years, use of the more potent (S)-enantiomer by anaesthesiologists has become a preferred option due to the assumption of increased anaesthetic and analgesic properties, a more suitable control of anaesthesia, and of an improved recovery from anaesthesia.
The use of ketamine in anaesthesia and psychiatry may be accompanied by the manifestation of somatic and especially psychomimetic symptoms such as perceptual disturbances, experiences of dissociation, euphoria, and anxiety.
-
This question is part of the following fields:
- Pharmacology
-
00
Correct
00
Incorrect
00
:
00
:
00
Session Time
00
:
00
Average Question Time (
Mins)