FMGE 2019 Practice Questions

Q: Which is a product of purine metabolism?

Uric acid. ***Uric acid*** - **Uric acid** is the final breakdown product of **purine metabolism** in humans. - It's formed from the oxidation of **xanthine** by the enzyme **xanthine oxidase**. *Xanthine* - **Xanthine** is an intermediate compound in the purine metabolic pathway, but not the final product in humans. - It is converted to **uric acid** via the enzyme **xanthine oxidase**. *Beta alanine* - **Beta-alanine** is a **non-proteogenic amino acid** and is a breakdown product of **pyrimidine metabolism**, not purine. - It is involved in the synthesis of **carnosine**, a buffer in muscle tissue. *Urea* - **Urea** is the primary end product of **protein (amino acid) metabolism** in mammals, representing the main way the body excretes **nitrogen**. - It is produced in the **urea cycle** in the liver and is unrelated to purine breakdown.

Q: Melanin is derived from which amino acid?

Tyrosine. ***Tyrosine*** - **Melanin synthesis** (melanogenesis) begins with the hydroxylation of **tyrosine** to DOPA (dihydroxyphenylalanine), catalyzed by the enzyme **tyrosinase**. - Subsequent steps involve the oxidation of DOPA and its derivatives to form various types of melanin, such as **eumelanin** (black/brown) and **pheomelanin** (red/yellow). *Phenylalanine* - **Phenylalanine** is an essential amino acid that can be converted to tyrosine in the body by the enzyme **phenylalanine hydroxylase**. - While it's a precursor to tyrosine, it's not directly converted to melanin; rather, it must first be hydroxylated to tyrosine. *Alanine* - **Alanine** is a non-essential amino acid involved in glucose metabolism and protein synthesis. - It is not a precursor for melanin synthesis. *Tryptophan* - **Tryptophan** is an essential amino acid that is a precursor for **serotonin**, **melatonin**, and **niacin** (Vitamin B3). - It is not involved in the biosynthesis of melanin.

Q: Which is not seen in Tumour lysis Syndrome?

Hypophosphatemia. ***Hypophosphatemia*** - **Tumor lysis syndrome (TLS)** is characterized by the rapid breakdown of tumor cells, leading to the release of intracellular components into the bloodstream. - This process typically results in **acute hyperphosphatemia**, not hypophosphatemia, due to the high phosphate content within tumor cells. *Hyperkalemia* - **Hyperkalemia** is a hallmark of TLS because potassium, a major intracellular cation, is released in large quantities as tumor cells lyse. - Excess potassium can lead to potentially life-threatening cardiac arrhythmias. *Hyperuricemia* - **Hyperuricemia** occurs in TLS because nucleic acids (DNA and RNA) released from dying tumor cells are metabolized into purines, which are then converted to uric acid [1]. - High uric acid levels can precipitate in the renal tubules, leading to **acute kidney injury** [1]. *Hypocalcemia* - **Hypocalcemia** develops in TLS secondary to the acute hyperphosphatemia. - The excess phosphate binds with serum calcium to form **calcium-phosphate precipitates**, effectively lowering the concentration of free ionized calcium.

Q: A patient presents with convergent squint in one eye. Vision in the squinting eye is 6/60, and vision in the non-squinting eye is also 6/60. What is the most appropriate next step in management?

Refraction and treat underlying cause of poor vision. ***Refraction and treat underlying cause of poor vision*** - When **both eyes have equally poor vision (6/60)** with a convergent squint, this suggests a **bilateral pathology** affecting visual acuity, not simply a refractive accommodative esotropia. - The **first step** is comprehensive **cycloplegic refraction** to determine if refractive error contributes to the poor vision. - **Equally important** is identifying the **underlying cause** of bilateral vision loss (6/60 in both eyes), which could be: - **Bilateral amblyopia** (though unusual to have equal severity) - **Uncorrected high refractive error** (hypermetropia causing accommodative esotropia) - **Cataracts** (congenital or developmental) - **Retinal pathology** or **optic nerve disorders** - Only after identifying and treating the underlying cause can definitive management of the squint be planned. *Glasses* - While **glasses** may be part of the treatment if refractive error is found, **prescribing glasses alone** without first performing refraction and investigating why both eyes have 6/60 vision is incomplete management. - This option is too narrow and doesn't address the need to identify the underlying pathology causing bilateral poor vision. *Squint surgery* - **Squint surgery** addresses ocular misalignment but does **not improve vision**. - Surgery should only be considered **after** refractive correction, treatment of amblyopia (if present), and management of any underlying pathology. - Operating without addressing the cause of poor vision would be premature. *Botulinum toxin* - **Botulinum toxin** is used for certain types of strabismus as a temporary or alternative to surgery. - Like surgery, it addresses alignment but **not visual acuity**. - The priority is to improve vision and identify the underlying cause before considering alignment procedures.

Q: Which of the following ions is important in irreversible cell injury?

Calcium. ***Calcium*** - An increase in intracellular **calcium** concentration is a critical event in irreversible cell injury, activating various destructive enzymes like **phospholipases**, **proteases**, **endonucleases**, and ATPases [1]. - This influx of calcium can occur due to mitochondrial dysfunction (leading to impaired calcium sequestration) or damage to the plasma membrane [1]. *Sodium* - While important for maintaining **osmotic balance** and cell volume, dysregulation of sodium primarily contributes to **cellular swelling** (hydropic change), which is an early and often reversible sign of cell injury [1]. - Increased intracellular sodium typically leads to water influx, but its direct role in irreversible damage is secondary to calcium. *Chloride* - Changes in chloride ion distribution are often secondary to sodium dysregulation and play a role in maintaining **charge neutrality** and osmotic balance across the cell membrane. - It is not directly implicated as a primary mediator of the **enzyme activation cascade** that leads to irreversible cell damage. *Potassium* - **Potassium** is the major intracellular cation; its leakage out of the cell is a consequence of cell membrane damage, indicating loss of membrane integrity. - While significant **potassium efflux** is a sign of severe injury, it is not the initiator of the irreversible damage pathway, unlike calcium. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Cellular Responses to Stress and Toxic Insults: Adaptation, Injury, and Death, pp. 57-62.

Q: In marasmus, which of the following is characteristically seen?

Severe muscle wasting. ***Severe muscle wasting*** - **Severe muscle wasting** and **loss of subcutaneous fat** are hallmark features of marasmus, giving the child a characteristic **"skin and bones"** appearance. - Children present with **visible ribs**, **sunken cheeks**, and **prominent bony landmarks** due to depletion of both fat and muscle stores from chronic energy deficiency. *Hepatomegaly* - **Hepatomegaly** is a characteristic feature of **kwashiorkor**, not marasmus, caused by **fatty infiltration** of the liver due to impaired lipoprotein synthesis. - In marasmus, the liver is typically **normal or reduced in size** as fat stores are mobilized and utilized for energy needs. *Edema* - **Pitting edema** is a hallmark feature of **kwashiorkor**, resulting from severe protein deficiency causing **hypoalbuminemia** and reduced plasma oncotic pressure. - Marasmus is characterized by **absence of edema** because the protein deficiency is proportionally less severe compared to the overall caloric deficiency. *Voracious appetite* - Children with marasmus typically have **poor appetite** and **feeding difficulties**, not increased hunger, due to severe weakness and apathy. - The **energy depletion** and **muscle wasting** significantly reduce the child's interest in food and ability to consume adequate amounts.

Q: What is the most common anterior mediastinal tumor?

Thymoma. ***Thymoma*** - **Thymomas** are the most common primary tumor of the **anterior mediastinum** in adults. - They originate from the epithelial cells of the **thymus gland**, which is located in the anterior mediastinum. *Bronchogenic cyst* - **Bronchogenic cysts** are typically found in the **middle mediastinum**, although they can occasionally occur in the anterior or posterior mediastinum. - They are congenital anomalies resulting from abnormal budding of the **tracheobronchial tree**. *Neurofibroma* - **Neurofibromas** are nerve sheath tumors that typically occur in the **posterior mediastinum**, arising from spinal nerves. - They are often associated with **neurofibromatosis type 1**. *Pericardial cyst* - **Pericardial cysts** are benign, fluid-filled sacs most commonly found in the **middle mediastinum**, specifically in the cardiophrenic angle. - They are usually asymptomatic and are often discovered incidentally.

Question 1

Which is a product of purine metabolism?

Accepted Answer

Uric acid

Answer

Xanthine

Answer

Beta alanine

Answer

Urea

Question 2

Melanin is derived from which amino acid?

Accepted Answer

Tyrosine

Answer

Phenylalanine

Answer

Alanine

Answer

Tryptophan

Question 3

What is a target couple?

Accepted Answer

Currently married couple where the wife is in reproductive age (15-49 years)

Answer

Couple using contraception

Answer

Couple with 3 children

Answer

Couple that is eligible for practicing family planning

Question 4

Which is not seen in Tumour lysis Syndrome?

Accepted Answer

Hypophosphatemia

Answer

Hyperkalemia

Answer

Hyperuricemia

Answer

Hypocalcemia

Question 5

A patient presents with convergent squint in one eye. Vision in the squinting eye is 6/60, and vision in the non-squinting eye is also 6/60. What is the most appropriate next step in management?

Accepted Answer

Refraction and treat underlying cause of poor vision

Answer

Glasses

Answer

Squint surgery

Answer

Botulinum toxin

Question 6

Which of the following ions is important in irreversible cell injury?

Accepted Answer

Calcium

Answer

Sodium

Answer

Chloride

Answer

Potassium

Question 7

In marasmus, which of the following is characteristically seen?

Accepted Answer

Severe muscle wasting

Answer

Hepatomegaly

Answer

Edema

Answer

Voracious appetite

Question 8

What is the most common anterior mediastinal tumor?

Accepted Answer

Thymoma

Answer

Bronchogenic cyst

Answer

Neurofibroma

Answer

Pericardial cyst

Question 9

In an accident case, after the arrival of medical team, all should be done in early management except;

Accepted Answer

Check BP

Answer

Glasgow coma scale

Answer

Stabilization of cervical vertebrae

Answer

Check Respiration

Question 10

A 6-year-old boy came to the hospital with complaints of sore throat and difficulty in swallowing. His left tonsil was pushed medially and had swelling over the left side upper part of neck. What will be the diagnosis?

Accepted Answer

Peritonsillar abscess

Answer

Ludwig's angina

Answer

Retropharyngeal abscess

Answer

Parapharyngeal abscess

FMGE 2019

Biochemistry

Community Medicine

Internal Medicine

Ophthalmology

Pathology

Pediatrics

Surgery