Free Intercollegiate MRCS Part A Practice Questions

Sample Practice Questions

Try these 10 sample questions from the Intercollegiate MRCS Part A practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1An infant has a congenital defect in which spinal tissue protrudes through an incompletely closed vertebral column. Which embryological process is most directly involved?

   1. A.Formation and closure of the neural tubeCorrect answer: A
   2. B.Partition of the atrioventricular canal
   3. C.Rotation of the primitive midgut
   4. D.Descent of the developing testes

   Explanation: OpenStax states: "A deficiency of maternal folate in the first weeks of pregnancy can result in neural tube defects, including spina bifida" Spina bifida is a neural tube defect. The other processes concern cardiac septation, intestinal positioning and gonadal descent, rather than closure of spinal neural structures.

   Reference: OpenStax Anatomy and Physiology 2e — 28.2, Organogenesis

2. 2Which fluid compartment contains both plasma and interstitial fluid?

   1. A.Intracellular fluid
   2. B.Extracellular fluidCorrect answer: B
   3. C.Transcellular fluid
   4. D.Cytosolic fluid

   Explanation: OpenStax states: "Extracellular fluid has two primary constituents: the fluid component of the blood (called plasma) and the interstitial fluid (IF)" Plasma and interstitial fluid are extracellular. Cytosol is intracellular; transcellular fluid is a specialized smaller subdivision rather than the whole compartment containing both.

   Reference: OpenStax Anatomy and Physiology 2e — 26.1, Fluid Compartments

3. 3What is the term for programmed cell death?

   1. A.Necrosis
   2. B.Hypertrophy
   3. C.Metaplasia
   4. D.ApoptosisCorrect answer: D

   Explanation: National Cancer Institute states: "programmed cell death, or apoptosis" Apoptosis is programmed cell death. Necrosis is injury-related cell death; hypertrophy enlarges cells and metaplasia changes the differentiated cell type.

   Reference: National Cancer Institute: What Is Cancer? — Differences between Cancer Cells and Normal Cells

4. 4Which antibiotic resistance is specifically denoted by the abbreviation MRSA?

   1. A.Resistance to vancomycin
   2. B.Resistance to methicillinCorrect answer: B
   3. C.Resistance to erythromycin
   4. D.Resistance to gentamicin

   Explanation: NHS: Antibiotic resistance states: "MRSA (methicillin-resistant Staphylococcus aureus)" MRSA means methicillin-resistant Staphylococcus aureus. Resistance to vancomycin, erythromycin or gentamicin may be clinically relevant, but none is the resistance specifically denoted by this abbreviation.

   Reference: NHS: Antibiotic resistance — Antibiotic resistance

5. 5Which type of radiation is used to produce conventional CT images?

   1. A.Ultrasound waves
   2. B.Radiofrequency pulses alone
   3. C.X-raysCorrect answer: C
   4. D.Infrared radiation

   Explanation: NHS states: "the radiation from the X-rays" CT uses X-rays. Ultrasound uses sound waves, MRI uses magnetic fields and radiofrequency pulses, and infrared radiation is not the basis of conventional CT imaging.

   Reference: NHS: CT scan — Possible complications

6. 6A screening study includes 100 people with a disease and 200 without it. The test is positive in 80 affected people and 40 unaffected people. What is the test's sensitivity?

   1. A.66.7%
   2. B.80.0%Correct answer: B
   3. C.88.9%
   4. D.20.0%

   Explanation: UK National Screening Committee: Screening glossary states: "The ability of a screening test to correctly identify true positive results" Sensitivity = true positives / all affected people × 100 = 80/100 × 100 = 80.0%. Positive predictive value is 80/(80+40) = 66.7%; negative predictive value is 160/(160+20) = 88.9%; the false-negative proportion is 20/100 = 20.0%.

   Reference: UK National Screening Committee: Screening glossary — Sensitivity

7. 7A patient with obstructive jaundice has a stone confirmed in the common bile duct. Which procedure can directly clear the duct?

   1. A.Magnetic resonance cholangiopancreatography
   2. B.Endoscopic retrograde cholangio-pancreatographyCorrect answer: B
   3. C.Hepatobiliary radionuclide scanning
   4. D.Transabdominal ultrasonography

   Explanation: NHS: Gallstones states: "If gallstones are found in your common bile duct, you may have a procedure called endoscopic retrograde cholangio-pancreatography (ERCP) to clear the bile duct." ERCP can provide therapeutic duct clearance. MRCP, radionuclide scanning and ultrasound provide diagnostic information but do not extract the stone.

   Reference: NHS: Gallstones — Treatment for gallstones

8. 8During the initial ABCDE assessment of an injured patient, a life-threatening airway obstruction is identified. How should this finding affect the assessment sequence?

   1. A.Complete all five assessment stages before intervening
   2. B.Treat the airway threat before moving to the next stageCorrect answer: B
   3. C.Obtain the full past medical history before intervening
   4. D.Finish the detailed limb examination before intervening

   Explanation: Resuscitation Council UK: The ABCDE Approach states: "Treat life-threatening problems before moving to the next part of assessment." ABCDE is an assessment-and-treatment approach: the immediate airway threat is addressed before progressing. Completing the entire survey, a full history or a detailed limb examination first would delay treatment of the identified life-threatening problem.

   Reference: Resuscitation Council UK: The ABCDE Approach — Underlying principles

9. 9An infant with pyloric stenosis is dehydrated and has abnormal electrolyte results. Which sequence is appropriate before pyloromyotomy?

   1. A.Operate immediately without correcting dehydration
   2. B.Withhold fluids until vomiting has ceased spontaneously
   3. C.Feed normally and postpone all intravenous treatment
   4. D.Correct dehydration and electrolyte imbalance before surgeryCorrect answer: D

   Explanation: Great Ormond Street Hospital states: "If the child is dehydrated, he or she will need a ‘drip’ of fluids for a while before the operation. This will make sure that the child’s blood contains the right balance of salts and minerals, and treats the dehydration. The child will have the operation once his or her blood test results are normal." Correct dehydration and electrolyte imbalance before pyloromyotomy. Operating without correction or withholding needed fluid does not follow this stabilisation-first sequence.

   Reference: Great Ormond Street Hospital: Pyloric stenosis — How is pyloric stenosis treated?

10. 10An adult patient refuses a proposed operation. The surgeon considers the choice unwise. Under GMC guidance, what does that disagreement alone establish about the patient's decision-making capacity?

    1. A.It establishes incapacity because surgery was recommended
    2. B.It establishes incapacity if the consequences may be serious
    3. C.It does not establish that the patient lacks capacityCorrect answer: C
    4. D.It transfers the decision automatically to the patient's family

    Explanation: General Medical Council: Mental capacity states: "You must not assume a patient lacks capacity to make a decision solely because of their age, disability, appearance, behaviour, medical condition (including mental illness), beliefs, their apparent inability to communicate, or because they choose an option that you consider unwise." An unwise choice alone does not prove incapacity. Serious consequences and disagreement with clinical advice do not themselves establish inability to decide, and neither automatically gives relatives authority to decide. Capacity must be considered for the particular decision and time.

    Reference: General Medical Council: Mental capacity — Presumption of capacity; quoted Decision making and consent paragraph 81