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Move from Theory to Application
UWorld's Preclinical QBank helps you connect foundational science concepts to patient-based questions from the start of your MBBS journey. Explore realistic question formats, strengthen your applied understanding, and learn why every answer option is correct or incorrect with detailed answer explanations.
Question
A 26-year-old woman with recently diagnosed hypertension dies suddenly due to intracranial hemorrhage. On autopsy, both carotid arteries appear tortuous distally with alternating areas of fibromuscular webs and aneurysmal dilation. Microscopic examination shows absence of the internal elastic lamina in the aneurysmal segments. Which of the following is the most likely additional finding in this patient?
| A. Adrenal tumor | |
| B. Coarctation of the aorta | |
| C. Hypertrophic cardiomyopathy | |
| D. Renal artery stenosis | |
| E. Thyroid follicular hyperplasia |
Explanation
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Fibromuscular dysplasia |
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Manifestations |
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Presentation |
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Diagnosis |
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RAS = renal artery stenosis; TIA = transient ischemic attack. |
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This young woman with recent-onset hypertension died of an intracranial hemorrhage, likely from a ruptured aneurysm. This, in conjunction with the characteristic pathology findings of fibromuscular webs alternating with aneurysmal dilation and loss of the internal elastic lamina, is consistent with fibromuscular dysplasia (FMD). FMD is a nonatherosclerotic disease characterized by abnormal tissue growth within arterial walls, leading to arterial stenosis, tortuosity, aneurysms, or dissections. FMD typically occurs in women age <55. Angiography (ie, percutaneous, CT, MRI) is diagnostic and typically demonstrates a string-of-beads appearance in multifocal disease.
FMD can involve any artery but most commonly the renal, cerebral (eg, carotid, vertebral), and visceral arteries. Up to 80% of patients develop renal artery stenosis, which limits renal perfusion and leads to activation of the renin-angiotensin-aldosterone system. The resultant hypertension is often the earliest sign of the disease. Other presentations are related to locations of the dysplastic artery; cerebrovascular involvement (ie, headache, stroke, aneurysm rupture), mesenteric ischemia, or limb claudication may be seen.
(Choices A and B) Adrenal tumors that can present with severe hypertension include pheochromocytoma and aldosterone- or cortisol-secreting adrenocortical adenomas. Coarctation of the aorta also causes hypertension, with blood pressure higher in the upper versus lower limbs. Due to the elevated blood pressure, these diseases can cause headaches and intraparenchymal hemorrhage in predisposed individuals, but they are not associated with fibromuscular webs or aneurysm formation.
(Choice C) Hypertrophic cardiomyopathy may present with sudden death in young patients due to left ventricular outflow obstruction; histology demonstrates hypertrophied myocytes and interstitial fibrosis. However, hypertrophic cardiomyopathy is not associated with aneurysm formation.
(Choice E) Thyroid follicular hyperplasia can cause hyperthyroidism (eg, Graves disease, thyroid adenoma). This commonly causes tachycardia, tremor, and palpitations but would not cause aneurysm formation.
Educational objective:
Fibromuscular dysplasia is characterized by abnormal tissue growth within arterial walls, resulting in stenotic and tortuous arteries that can cause tissue ischemia and are prone to aneurysm formation. Pathology typically demonstrates alternating fibromuscular webs and aneurysmal dilation with absent internal elastic lamina (string-of-beads appearance). Renovascular hypertension occurs due to renal artery stenosis and activation of the renin-angiotensin-aldosterone system.
- Renal artery stenosis
Question
A 28-year-old previously healthy presents with episodic fevers, night sweats, and weight loss for several months. Temperature is 37.2 C. Physical examination is normal with the exception of cervical lymphadenopathy. A lymph node biopsy is performed, and histopathologic findings are seen in the exhibit. Which of the following is the most likely diagnosis?
| A. Burkitt lymphoma | |
| B. Follicular lymphoma | |
| C. Hodgkin lymphoma | |
| D. Large B-cell lymphoma | |
| E. Multiple myeloma |
Explanation
This patient most likely has classic Hodgkin lymphoma (HL). The typical presentation is either nontender lymphadenopathy or lymphadenopathy incidentally detected on routine chest x-ray. Many patients develop associated systemic B symptoms (fevers, night sweats, weight loss). HL has a bimodal age distribution with a peak in the 20s (or younger in some countries) and another in the 60s. The complete blood count and peripheral blood smear are usually unremarkable.
A lymph node biopsy can distinguish HL from benign causes of lymphadenopathy. The key to diagnosing classic HL is detecting the characteristic Reed-Sternberg (RS) cell on hematoxylin and eosin preparation. RS cells have ample cytoplasm, a multilobed nucleus or multiple nuclei, and inclusion-like nucleoli. RS cells are seen against a background of lymphocytes, histiocytes, and eosinophils in classic HL.
(Choice A) Burkitt lymphoma often presents as a mass in the abdomen/pelvis (or the jaw in the endemic [African] form, which has a peak incidence in boys around age 5). However, histology would show a monotonous population of medium-sized lymphoid cells with many tingible body macrophages, giving a "starry sky" appearance. High numbers of mitotic cells and apoptotic bodies are seen.
(Choice B) Follicular lymphoma shows aggregates of closely packed, neoplastic lymph node follicles. Two major cell types, centrocytes (small cleaved cells) and centroblasts (large noncleaved cells), are observed. Older adults tend to be affected. Waxing and waning painless lymphadenopathy (typically without B symptoms) is common.
(Choice D) Large B-cell lymphoma is characterized by diffuse sheets of large, atypical lymphoid cells with nuclei at least 5 times the size of small lymphocytes. RS cells against a background of mixed inflammation is not a characteristic histologic feature of large B-cell lymphoma.
(Choice E) Multiple myeloma, a plasma cell dyscrasia characterized by proliferation of clonal plasma cells, is predominantly a disease of the elderly. It is characterized by osteolytic lesions, although spread to nodal and extranodal sites can occur.
Educational objective:
The presence of Reed-Sternberg (RS) cells on lymph node biopsy is a diagnostic feature of classic Hodgkin lymphoma. RS cells have abundant cytoplasm, a multilobed nucleus or multiple nuclei, and inclusion-like nucleoli.
- Hodgkin lymphoma
Question
Muscles derived from the first pharyngeal arch are innervated by the trigeminal nerve (CN V). All of the following muscles are supplied by this nerve EXCEPT:
| A. Levator veli palatini | |
| B. Mylohyoid | |
| C. Tensor tympani | |
| D. Tensor veli palatini |
Explanation
Each pharyngeal arch is an embryologic unit that gives rise to a characteristic set of anatomic structures (eg skeletal elements, ligaments, muscles, arteries) and is associated with a specific cranial nerve. The muscles derived from each arch retain the innervation of that arch's associated cranial nerve throughout development. There are 6 pharyngeal arches, and all but the fifth contribute to adult structures.
The first pharyngeal arch is associated with the mandibular division of the trigeminal nerve (CN V), which innervates all muscles derived from this arch. These include the muscles of mastication (masseter, temporalis, medial pterygoid, and lateral pterygoid), as well as the mylohyoid, tensor tympani, tensor veli palatini, and the anterior belly of the digastric (Choices B, C, and D). This shared innervation reflects their common embryologic origin and accounts for the resulting chewing impairment, weakened jaw opening or lateral movement, and impaired sound dampening caused by CN V3 lesions.
The remaining pharyngeal arches follow the same developmental principle:
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The second arch is innervated by the facial nerve (CN VII) and gives rise to the muscles of facial expression: stapedius, stylohyoid, and posterior belly of the digastric.
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The third arch is supplied by the glossopharyngeal nerve (CN IX) and forms the stylopharyngeus.
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The fourth and sixth arches are innervated by the vagus nerve (CN X) and contribute to the cricothyroid, levator veli palatini, and pharyngeal constrictors via the superior laryngeal branch, and the intrinsic muscles of the larynx, except the cricothyroid, via the recurrent laryngeal branch.
Educational objective:
Each pharyngeal arch is innervated by a specific cranial nerve, and its muscular derivatives retain that innervation throughout development. The first arch is supplied by the trigeminal nerve (CN V) and innervates the muscles of mastication, mylohyoid, tensor tympani, tensor veli palatini, and anterior belly of the digastric. The levator veli palatini is innervated by the vagus nerve (CN X), derived from the fourth pharyngeal arch.
- The pharyngeal apparatus: Pharyngeal arches, pouches, and clefts
Question
A 6-year-old, previously healthy girl presents with fever, abdominal pain, and diarrhea for the past day. The symptoms began abruptly with high fever, as well as cramping periumbilical pain, and were quickly followed by low-volume diarrhea mixed with blood and mucus. Temperature is 38.9 C. Physical examination reveals mild, diffuse abdominal tenderness with no guarding or rebound tenderness. Stool occult blood testing is positive, with numerous leukocytes in the stool. Culture of stool yields gram-negative, oxidase-positive, curved rods. Which of the following is the most likely pathogen responsible for this patient's symptoms?
| A. Campylobacter jejuni | |
| B. Escherichia coli | |
| C. Salmonella serovar Enteritidis | |
| D. Shigella flexneri | |
| E. Vibrio cholerae |
Explanation
Campylobacter jejuni is a motile, oxidase-positive, gram-negative, curved rod that is a leading cause of bacterial gastroenteritis. This pathogen resides in the gastrointestinal tract of a wide range of mammals and is transmitted via the fecal-oral route. Most cases arise when humans ingest contaminated food, particularly undercooked poultry or unpasteurized milk, but a minority are caused by close contact with domesticated animals (eg, dogs, farm animals).
C jejuni is enteroinvasive and typically causes fever, abdominal pain, and diarrhea that may be bloody. Stool studies usually reveal inflammation (ie, blood, leukocytes); culture of stool (enriched media at 42 C [107.6 F] and microaerophilic conditions) is diagnostic. Most cases are self-limited and resolve within a week with supportive treatment.
(Choice B)Escherichia coli causes many forms of gastroenteritis, including enterotoxin-mediated watery diarrhea (enterotoxigenic), Shiga toxin–mediated hemorrhagic colitis (enterohemorrhagic), and invasive colitis (enteroinvasive). Although this pathogen is a gram-negative enteric rod, it is oxidase negative and not described as curved.
(Choice C) Nontyphoidal Salmonella (eg, S serovar Enteritidis) is a common cause of bacterial gastroenteritis. This enteroinvasive pathogen frequently causes self-limited abdominal pain, fever, and watery diarrhea; bloody diarrhea is less common but can occur. However, Salmonella is oxidase negative and not described as curved.
(Choice D)Shigella is a highly virulent bacterium that is often transmitted via the fecal-oral route. It causes inflammatory colitis with fever, abdominal pain, and mucoid, bloody, and/or watery diarrhea. However, Shigella is oxidase negative and is not described as curved.
(Choice E)Vibrio cholerae is a curved, oxidase-positive, gram-negative enteric rod and can therefore occasionally be misidentified as a Campylobacter species. However, V cholerae causes massive watery diarrhea (due to cholera toxin) that is noninflammatory (ie, no fecal leukocytes or erythrocytes).
Educational objective:
Campylobacter jejuni is an oxidase-positive, gram-negative, curved rod that is a leading cause of gastroenteritis. The pathogen is a zoonotic organism most commonly contracted by consuming contaminated, undercooked poultry. The infection is marked by fever, abdominal pain, and diarrhea that may be bloody.
- Campylobacter
Question
A 60-year-old woman with a history of recurrent urinary tract infections has left flank pain and hematuria. CT scan of the abdomen is shown in the exhibit. Urinalysis for this patient would most likely show which of the following?
| A. 4+ protein | |
| B. Numerous eosinophils | |
| C. pH 8.0 | |
| D. Red blood cell casts | |
| E. Specific gravity 1.002 |
Explanation
This patient's imaging shows an atrophic left kidney associated with a large, hyperdense mass filling the renal pelvis. These findings are consistent with a chronic staghorn calculus, a type of kidney stone that occurs in patients with recurrent upper urinary tract infection caused by urease-producing organisms (eg, Proteus, Klebsiella). Hydrolysis of urea yields ammonia, which alkalinizes the urine (ie, pH >7) and facilitates precipitation of struvite crystals (magnesium ammonium phosphate).
Because of the large quantities of urea excreted in urine, struvite stones can grow rapidly into a branched staghorn calculus that fills the renal calyces and pelvis. Symptoms are usually related to the underlying infection (eg, fever, mild costovertebral pain, hematuria); renal colic (ie, severe flank/groin pain) is uncommon because large stones are unable to pass into the ureter and cause acute obstruction. Over time, the affected kidney can atrophy due to recurrent infection and chronic obstructive nephropathy.
(Choice A) Trace or weakly positive (eg, 1 or 2+) proteinuria can be seen in a variety of disorders (eg, hematuria due to kidney stones, urinary tract infection) due to disruption of the urothelium; however, a strongly positive result (eg, 3 or 4+) is more specific for glomerular protein loss (eg, amyloidosis, diabetic nephropathy) and is not usually due to stones.
(Choice B) Eosinophiluria is typically associated with acute interstitial nephritis, which is most commonly triggered by exposure to certain medications (eg, beta-lactam antibiotics, nonsteroidal anti-inflammatory drugs). Patients typically have a rash, fever, and acute kidney injury, but this condition is not associated with staghorn calculi.
(Choice D) Red cell casts and dysmorphic red blood cells form when erythrocytes traverse the renal tubules and indicate a glomerular bleeding source (eg, glomerulonephritis). Staghorn calculi can cause hematuria with morphologically normal red cells due to irritation of the urothelium, but do not cause glomerular bleeding.
(Choice E) Urine specific gravity correlates with urine concentration and is influenced by hydration status and regulatory hormone (eg, antidiuretic hormone) levels. Kidney stones most commonly form in concentrated urine (eg, >1.015), which results in supersaturation of salts and crystal precipitation. A specific gravity of ≤1.003 indicates dilute urine, and it is unlikely that a patient with an acute stone would have such a low specific gravity.
Educational objective:
Struvite stones are typically seen in patients with recurrent upper urinary infection by urease-producing organisms (eg, Proteus, Klebsiella). Hydrolysis of urea yields ammonia, which alkalinizes the urine and facilitates precipitation of magnesium ammonium phosphate. Urinalysis shows hematuria and elevated urine pH.
- Nephrolithiasis
Question
A 65-year-old man with a history of atrial fibrillation has had numbness of his left hand for the past 3 weeks. When the eyes are closed, he is unable to recognize the letters written on his left hand with a stylus. Muscle strength is normal in all extremities. Deep tendon reflexes are 2+. Gait is normal. This patient most likely has a lesion in which of the following locations of the brain?
| A. A | |
| B. B | |
| C. C | |
| D. D | |
| E. E |
Explanation
This patient has isolated numbness of his left hand and graphesthesia, which are suspicious for a lesion impacting the right somatosensory cortex. A small lesion of the somatosensory cortex leads to contralateral deficits impacting the corresponding area of the body. Higher-level sensory processing (ie, cortical sensory signs) can also be impaired. This may include loss of the following:
- Two-point discrimination
- Stereognosis, or the ability to recognize an object only through touch
- Ability to perceive multiple stimuli at the same time (loss of this is called extinction)
- Graphesthesia, or the ability to recognize numbers or letters traced on the palm
The primary somatosensory cortex is located on the postcentral gyrus, which is posterior to the central sulcus and superior to the lateral sulcus.
(Choice B) The area just anterior to the central sulcus (precentral gyrus) is the primary motor cortex. A lesion in this area would lead to weakness according to the somatotopic organization of the cortex.
(Choice C) This area indicates the frontal eye fields, an area that directs gaze to produce conjugate horizontal gaze. An ischemic lesion in this area would lead to gaze deviation toward the side of the lesion (ie, rightward deviation if the right hemisphere is impacted).
(Choice D) This is the occipital cortex, the area of the primary visual cortex. A lesion in this area would cause cortical blindness.
(Choice E) A lesion impacting the cerebellum typically leads to ataxia and vertigo.
Educational objective:
A lesion of the somatosensory cortex, located just posterior to the central sulcus, leads to contralateral sensory deficits and cortical sensory signs.
- Neuroanatomy: Cortical lobe function, basic tracts, arterial anatomy, and neurolocalization
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Practise 2,000+ recall and scenario-based questions across the foundational sciences, such as Anatomy, Physiology, Cell Biology, Pathology basics, and more. Apply classroom knowledge at a level that will make your transition to clinical years easier.
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Give Yourself Every Advantage on Your MBBS Journey
Score Higher on Your Prof Exams
MBBS Years 1-2 present a lot of new information in a short period of time. By applying these concepts as you learn them with targeted practice questions, you’re more likely to remember them and improve your performance on Prof exams.
Be Fully Prepared for Clinical Postings
The transition to clinical years can be overwhelming. Through case-based practice and stronger critical-thinking skills, you can reduce stress and walk into wards knowing how to apply important basic science principles.
Learn to Think Like a Doctor
Success in medicine requires more than memorisation. By working through clinical scenarios, you'll learn how to connect basic science concepts to patient presentations, strengthen clinical reasoning, and bridge the gap between theory and practice.
Is the Preclinical QBank Right for You?
Why MBBS Students Trust UWorld
India Preclinical QBank Pricing
Frequently Asked Questions (FAQs)
Understanding the Preclinical QBank
What is the Preclinical QBank and who is it for?
The UWorld Preclinical QBank is designed for MBBS Year 1 and Year 2 students in India who want to strengthen their understanding of foundational medical sciences through clinically relevant practice. It covers high-yield subjects like Anatomy, Physiology, Biochemistry, Pathology, and others, and helps students move beyond memorisation to apply concepts with confidence. With detailed explanations for every recall and case-based question, students can build a stronger foundation for Prof exams, clinical postings, and future licensing exams.
How is a Preclinical QBank different from studying medical textbooks?
Textbooks help you learn concepts, but QBanks help you apply them. The Preclinical QBank uses recall and case-based questions to connect theory to real clinical scenarios, improving your ability to think critically. This type of active learning is essential for Prof exams, clinical postings, and real-world medical decision-making.
What is the difference between the Preclinical and Clinical QBank?
- The Preclinical QBank focuses on foundational sciences for early MBBS years, with simpler, guided clinical application.
- The India Clinical QBank is designed for later years and involves advanced, multi-step clinical reasoning.
- Together, the QBanks support a complete learning journey from building fundamentals to mastering clinical decision-making.
Getting Started & Using the QBank
Should MBBS Year 1 students start using a Preclinical QBank?
Yes. In fact, starting in Year 1 gives you a major advantage. Early question practice helps you apply concepts as you learn them, instead of revisiting everything later under exam pressure. The Preclinical QBank is specifically designed for beginners, so you can start alongside your current subjects and build strong conceptual understanding and problem-solving skills from the beginning.
How should I use the India Preclinical QBank?
Use the Preclinical QBank alongside your MBBS coursework to apply concepts through recall questions and case-based scenarios. Review the answer explanations, and use the Medical Library to clarify concepts and fill knowledge gaps. Add digital notes to My Notebook for later revision, and create custom SmartCards to improve your retention. As you progress to clinical years, the UWorld India Clinical QBank offers more advanced application.
Can I use the India Preclinical QBank on mobile?
Yes. The Preclinical QBank is fully accessible on iOS and Android, with all features available on mobile. Your progress syncs across devices, so you can study anytime, anywhere, whether between lectures, at home, or during short study sessions.
Improving Exam Performance & Learning Outcomes
How can the India Preclinical QBank help MBBS students improve exam performance?
The Preclinical QBank helps you develop the application-based thinking that toppers use to stand out. By practising case-based questions alongside your lectures, you build stronger conceptual clarity, sharper problem-solving skills, and the clinical mindset that sets high performers apart from Day 1.
How does the India Preclinical QBank simplify the foundational sciences?
The Preclinical QBank clarifies complex topics in the foundational sciences using a range of scenarios, including manageable clinical scenarios, with clear answer explanations. This active approach helps you truly understand and connect concepts instead of just memorising them, making even the toughest subjects less intimidating.
How does the India Preclinical QBank help students prepare for MBBS Prof exams?
The Preclinical QBank helps students prepare for MBBS Prof exams by strengthening their understanding of high-yield concepts through regular question practice. Working through exam-style questions alongside classroom learning helps students improve recall, apply concepts more confidently, and feel better prepared for the pressure and format of MBBS Prof exams.
Building a Strong Foundation for Future Success
How does the India Preclinical QBank prepare me for clinical years?
The Preclinical QBank introduces light clinical context from the very beginning, training you to link basic sciences to real patient care. This early foundation makes the jump to clinical postings in Year 3 smoother and helps you perform better once ward work begins.
What are the long-term benefits of using the UWorld India Preclinical QBank?
Students who consistently use the UWorld Preclinical QBank:
- Build stronger clinical reasoning skills
- Improve long-term retention of foundational medical sciences
- Identify knowledge gaps earlier in MBBS
Regular practice with clinically relevant, case-based questions helps students transition more confidently into clinical years while preparing for Prof exams, postings, and future licensing exams.