-
Question 1
Correct
-
All of the following statements regarding metronidazole are correct except:
Your Answer: Metronidazole reduces the anticoagulant effect of warfarin.
Explanation:The anticoagulant effect of warfarin is enhanced by metronidazole. If use of both cannot be avoided, one must consider appropriately reducing the warfarin dosage. With alcohol, metronidazole can cause a disulfiram-like reaction, with symptoms like flushing, headaches, dizziness, tachypnoea and tachycardia, nausea and vomiting. The common side effects of metronidazole include a metallic taste and gastrointestinal irritation, in particular nausea and vomiting. These side effects are more common at higher doses. This drug has high activity against anaerobic bacteria and protozoa, and is well absorbed orally. For severe infections, the intravenous route is normally reserved.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 2
Correct
-
Which of the following vitamins is not paired correctly with its deficiency syndrome:
Your Answer: Vitamin B12 - Wernicke-Korsakoff syndrome
Explanation:Clinical Effects of vitamin deficiency include:
Vitamin C – Scurvy
Thiamine (Vitamin B1) – Beriberi/Wernicke-Korsakoff syndrome
Vitamin B12 – Megaloblastic anaemia/Subacute combined degeneration of spinal cord
Folate – Megaloblastic anaemia
Vitamin D – Osteomalacia/Rickets
Vitamin K – Defective clotting
Vitamin A – Blindness -
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 3
Correct
-
The parasympathetic supply to the rectum is from which of the following:
Your Answer: Pelvic splanchnic nerves
Explanation:Parasympathetic supply is from the pelvic splanchnic nerves (S2 – S4) and inferior hypogastric plexus.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 4
Incorrect
-
Regarding skeletal muscle contraction, which of the following statements is CORRECT:
Your Answer: The force of contraction of a muscle is controlled by increasing the number of contracting muscle fibres.
Correct Answer: The force of contraction of a muscle can be controlled by increasing recruitment of motor units.
Explanation:Each motor unit contracts in an all or nothing fashion, i.e. if a motor unit is excited, it will stimulate all of its muscle fibres to contract. The force of contraction of a muscle is controlled by varying the motor unit recruitment (spatial summation), and by varying the firing rate of the motor units (temporal summation). During a gradual increase in contraction of a muscle, the first units start to discharge and increase their firing rate, and, as the force needs to increase, new units are recruited and, in turn, also increase their firing rate. For most motor units, the firing rate for a steady contraction is between 5 and 8 Hz. Because the unitary firing rates for each motor unit are different and not synchronised, the overall effect is a smooth force profile from the muscle. Increasing the firing rate of motor units is temporal summation where the tension developed by the first action potential has not completely decayed when the second action potential and twitch is grafted onto the first and so on. If the muscle fibres are stimulated repeatedly at a faster frequency, a sustained contraction results where it is not possible to detect individual twitches. This is called tetanus.
-
This question is part of the following fields:
- Basic Cellular
- Physiology
-
-
Question 5
Incorrect
-
Regarding fat digestion, which of the following statements is CORRECT:
Your Answer: Micelles are arranged so they have a lipid-soluble coat with a polar core.
Correct Answer: Chylomicrons are exocytosed from enterocytes to enter lacteals and thus the lymphatic system.
Explanation:Dietary fat is chiefly composed of triglycerides (esters of free fatty acids and glycerol which may be saturated or unsaturated). The essential fatty acids are linoleic acid and alpha-linoleic acid, which cannot be manufactured in the body. Dietary fat provides 37 kJ (9 kcal) of energy per gram. Fats are digested almost entirely in the small intestine and are only released from the stomach into the duodenum at the rate at which they can be digested.
Pancreatic lipase is the most significant enzyme for fat digestion. In the duodenum fat is emulsified by bile acids, a process where larger lipid droplets are broken down into much smaller droplets providing a greater surface area for enzymatic digestion. Micelles are arranged so that hydrophobic lipid molecules lie in the centre, surrounded by bile acids arranged such the outer region is hydrophilic. Dietary and synthesised lipids are incorporated into chylomicrons in the Golgi body, which are exocytosed from the basolateral membrane to enter lacteals and thus the lymphatic system. -
This question is part of the following fields:
- Gastrointestinal
- Physiology
-
-
Question 6
Correct
-
In the small intestine, there is a deep gap between each villus that leads to the crypt of Lieberkühn, a tubular intestinal gland.
What is the primary function of these glands?
Your Answer: Production of an alkaline intestinal juice
Explanation:In the small intestine, there is a deep gap between each villus that leads to the crypt of Lieberkühn, a tubular intestinal gland. These glands create an alkaline intestinal juice that is a mixture of water and mucus with a pH of 7.4-7.8. Intestinal juice is released in a volume of 1-2 litres per day in response to distention of the small intestine or the irritating effects of chyme on the intestinal mucosa.
-
This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
-
-
Question 7
Correct
-
Regarding shingles, which of the following statements is CORRECT:
Your Answer: You can catch chickenpox from a patient with shingles.
Explanation:After primary infection, VZV remains latent in sensory ganglia and in about 20% of patients will reactivate resulting in shingles, a painful vesicular rash in the related dermatome. Shingles usually affects older people and the immunocompromised. Shingles lesions are infectious to non-immune individuals who are at risk of developing chickenpox. Shingles can not be contracted directly from chickenpox, or from other cases of shingles. Shingles is treated with systemic antiviral treatment to reduce the severity and duration of pain, reduce complications, and reduce viral shedding.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 8
Incorrect
-
Dysuria and urinary frequency are symptoms of a 29-year-old woman. A urine dipstick is used to detect the presence of blood, protein, leucocytes, and nitrites in the urine. You diagnose a urinary tract infection and give antibiotics to the patient.
In the United Kingdom, which of the following antibiotics has the highest percentage of E.coli resistance?Your Answer: Co-amoxiclav
Correct Answer: Trimethoprim
Explanation:In the United Kingdom, antibiotic resistance is becoming a significant factor in the treatment of urinary tract infections and pyelonephritis. E. coli (the main causative organism of both urinary tract infections and acute pyelonephritis) resistance to the following antibiotics in laboratory-processed urine specimens is:
30.3 percent trimethoprim (varies by area from 27.1 to 33.4 percent )
19.8 percent co-amoxiclav (varies by area from 10.8 to 30.7 percent )
Ciprofloxacin (Cipro): 10.6% (varies by area from 7.8 to 13.7 percent )
Cefalexin has a concentration of 9.9%. (varies by area from 8.1 to 11.4 percent ) -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 9
Correct
-
What is the direct mechanism of action of digoxin as a positive inotrope:
Your Answer: Inhibition of Na+/K+ ATPase pump
Explanation:Digoxin directly inhibits membrane Na+/K+ ATPase, which is responsible for Na+/K+ exchange across the myocyte cell membrane. This increases intracellular Na+ and produces a secondary increase in intracellular Ca2+ that increases the force of myocardial contraction. The increase in intracellular Ca2+ occurs because the decreased Na+ gradient across the membrane reduces the extrusion of Ca2+ by the Na+/Ca2+ exchanger that normally occurs during diastole. Digoxin and K+ ions compete for the receptor on the outside of the muscle cell membrane, and so the effects of digoxin may be dangerously increased in hypokalaemia.
-
This question is part of the following fields:
- Cardiovascular
- Pharmacology
-
-
Question 10
Incorrect
-
A blood culture was performed from a sample taken from a patient. It was noted that a Gram-negative coccus organism was grown.
Among the following microorganisms, which is considered an example of a Gram-negative coccus?Your Answer: Escherichia coli
Correct Answer: Neisseria menigitidis
Explanation:Staphylococcus aureus = Gram-positive coccus
Bacillus cereus = Gram-positive bacillus
Campylobacter jejuni = Gram-negative bacillus
Escherichia coli = Gram-negative bacillusIn Gram staining, crystal violet is a purple stain that is used to stain the bacteria first. The stained bacteria are decolorized and then stained with a red stain, which is safranin. Bacteria with thick cell walls keep the purple stain and are called Gram-positive. Thin-walled bacteria are easily decolorized so when safranin, the red stain, is placed on the organisms, they become red or Gram-negative.
Neisseria species appear as Gram-negative diplococci because they form pairs and their adjacent ends are flattened that is why they are also described to have a coffee-bean or kidney-bean shape. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
