Saturday 29 March 2014

FCPS part 1 Medicine solved mcqs with explanation Q13



Q13: ECG of a patient shows progressively increasing PR intervals followed by dropped beat. What is the condition?
a) Third degree heart block
b) Mobitz Type 1
c) Sinus arrhythmia
d) Mobitz Type 2


Correct Answer: b


Explanation:
Heart blocks are of three types:
  1. First degree heart block: PR interval prolonged (>200 ms)
  2. Second degree heart block:
  • Mobitz Type 1: Progressive lengthening of the PR interval until a beat is dropped (a P wave not followed by a QRS complex).
  • Mobitz Type 2: Dropped beats that are not preceded by a change in the length of the PR interval
     3. Third degree heart block: The atria & ventricles beat independently of each other.

FCPS part 1 Medicine solved mcqs with explanation Q12



Q12: A woman living at a hill station has had an uncomplicated pregnancy. She is brought to the hospital at the onset of labour. An ultrasound scan is performed which shows no fetal abnormality. The baby can still have which of the following conditions?
a) Transposition of great vessles
b) Patent ductus arteriosis
c) Limb defects
d) Tetrology of Fallot

Correct Answer: b

Explanation:
During fetal period, the ductus arteriosus shunts blood from the right to the left. It connects the pulmonary trunk with the aorta. Blood entering the pulmonary trunk from the right ventricle is shunted through ductus arteriosus into aorta. As the baby is born, the circulatory changes that occur also include closure of the ductus arteriosus. Closure of the ductus arteriosus is promoted by increase oxygen tension (when baby starts breathing) which decrease prostaglandin (PG) synthesis. At hill stations, the atmospheric oxygen pressure is low. A baby born and staying during the first few days of his life under such circumstances would lead to a decrease in oxygen tension and so failure of ductus arteriosus to close. Patency of ductus arteriosus can also be maintained by high PG levels such with use of indomethacin (a PG synthesis inhibitor). In summary low oxygen tension and high PG levels cause PDA.

Friday 28 March 2014

FCPS part 1 Medicine solved mcqs with explanation Q11



Q11: Which of the followings is increased in first response?
a) IgM
b) IgD
c) IgE
d) IgG


Correct Answer: a


Explanation:
IgM is the antibody produced in primary response to an antigen. IgG is the main antibody in secondary response. IgM also fixes complement but does not cross placenta.

FCPS part 1 Medicine solved mcqs with explanation Q10



Q10: Which of the followings cross placenta?
a) IgM
b) IgA
c) IgG
d) IgD

Correct Answer: c

Explanation:
Of all the immunoglobins only IgG is the only antibody that crosses placenta. It is main antibody in secondary response and the most abundant one. It fixes complement, opsonized bacteria, neutralizes bacterial toxins and viruses.

FCPS part 1 Medicine solved mcqs with explanation Q9



Q9: Gastroesophageal junction competence is increased by:
a) Lying supine
b) Paralysis of the diaphragm
c) Use of Morphine
d) Use of Metoclopromide
e) Increased intra-abdominal pressure


Correct Answer: d


Explanation:
Metoclopromide is D2 receptor antagonist that increased the resting tone of GIT, increases contractility & increases Lower esophageal junction tone. It is clinically used for Diabetic & post-surgery gastroparesis. Toxicity includes parkinsonian effects, restlessness, drowsiness, fatigue, depression, nausea, diarrhea. Contraindicated in patients with small bowel obstruction.
Other option under this question actually decrease the GE junction tone.