FMGE 2019 Practice Questions

Q: Ventricles are lined by?

Ependymal cells. Ependymal cells - Ependymal cells are a type of glial cell that form the epithelial lining of the ventricles of the brain and the central canal of the spinal cord [3]. - They possess cilia that help circulate the cerebrospinal fluid (CSF) and microvilli involved in CSF absorption. Schwann cells - Schwann cells are responsible for forming the myelin sheath around axons in the peripheral nervous system (PNS) [4]. - They do not line the ventricles, which are part of the central nervous system [2]. Oligodendrocytes - Oligodendrocytes are glial cells that form the myelin sheath around axons in the central nervous system (CNS) [1], [4]. - While they are CNS cells, their primary function is myelination, not lining the ventricular system [1]. Astrocytes - Astrocytes are the most abundant and diverse glial cells in the CNS, providing structural support, metabolic regulation, and forming the blood-brain barrier. - They are found throughout the brain parenchyma but do not directly line the ventricular cavities.

Q: A farmer with pinpoint pupils, increased secretions and urination. What is the most likely diagnosis?

Organophosphate poisoning. ***Organophosphate poisoning*** - **Pinpoint pupils (miosis)**, **increased secretions** (salivation, lacrimation, bronchial secretions), and **urination** are classic signs of cholinergic crisis caused by organophosphate toxicity [1]. - The patient's profession as a **farmer** increases the likelihood of exposure to pesticides, which often contain organophosphates [1], [2]. *Alcohol poisoning* - While alcohol poisoning can cause CNS depression, it does not typically present with **pinpoint pupils** or **increased secretions** like salivation and urination. - Common signs include **ataxia**, **slurred speech**, **nausea**, and **vomiting**. *Opioid poisoning* - Opioid poisoning also causes **pinpoint pupils** and **CNS depression**, but it typically leads to **decreased secretions** and **urinary retention**, not increased urination [2]. - **Respiratory depression** is a hallmark feature, which is not highlighted here as a primary symptom. *Atropine poisoning* - Atropine is an anticholinergic agent, meaning it would cause the opposite effects of organophosphate poisoning [2]. - Symptoms would include **dilated pupils (mydriasis)**, **dry mouth**, **decreased secretions**, and **urinary retention**.

Q: All of the following are types of Primary headache except:

Temporal arteritis. ***Temporal arteritis*** - **Temporal arteritis** is a **secondary headache** caused by inflammation of the **temporal arteries**, not a primary headache type [1]. - It is often associated with symptoms like **jaw claudication**, **scalp tenderness**, and is more common in elderly individuals. *Migraine* - **Migraine** is a common type of **primary headache**, characterized by moderate to severe pain, often unilateral and pulsating [1]. - It can be accompanied by symptoms like **nausea, vomiting**, and sensitivity to light and sound [1]. *Tension* - **Tension-type headache** is the most common type of **primary headache**, typically described as a mild to moderate, bilateral, pressing or tightening pain [1]. - It usually lacks associated symptoms like nausea or vomiting, which differentiates it from migraine. *Cluster* - **Cluster headache** is a severe form of **primary headache**, known for its excruciating unilateral pain, often around the eye or temple [1]. - It is characterized by specific autonomic symptoms on the affected side, such as **lacrimation, rhinorrhea, and ptosis** [1].

Q: Which of the following is an advantage of contact lenses over normal glasses?

Improved peripheral vision. ***Improved peripheral vision*** - Contact lenses sit directly on the cornea, moving with the eye and eliminating the **frame obstruction** and **edge distortions** associated with glasses. - This provides a wider and more natural **field of view**, enhancing peripheral vision. *Reduced prismatic effect* - While contact lenses do reduce the **magnification/minification** compared to glasses, the prismatic effect is a specific distortion most pronounced in **strong thick spectacle lenses** and can induce visual discomfort, which contact lenses inherently minimize. - This effect is due to the distance between the spectacle lens and the eye, which contact lenses eliminate. *Decreased risk of infection* - Wearing contact lenses inherently carries a **higher risk of eye infections** if proper hygiene and care are not meticulously followed. - Unlike glasses, contact lenses require regular cleaning, disinfection, and proper storage to prevent bacterial or fungal contamination. *UV protection (in specific lenses)* - While some contact lenses incorporate **UV-blocking agents**, this is not a universal feature of all contact lenses and is also available in many spectacle lenses. - UV protection from contact lenses primarily shields the cornea and iris but does not fully protect the surrounding ocular tissues like glasses (especially wrap-around styles) can.

Q: Which of the following is a monoclonal antibody used in cancer treatment?

Rituximab. ***Rituximab*** - **Rituximab** is a **chimeric monoclonal antibody** that targets the **CD20 protein** found on the surface of normal and malignant **B lymphocytes**. - It is widely used in the treatment of various **lymphomas** and **leukemias**, as well as autoimmune diseases, by inducing the death of CD20-positive B cells. *Cisplatin* - **Cisplatin** is a **platinum-based chemotherapy drug** that works by forming **DNA adducts**, leading to DNA damage and apoptosis of cancer cells. - It is used in various solid tumors but is not a monoclonal antibody; it's a **cytotoxic agent**. *5-fluorouracil* - **5-fluorouracil (5-FU)** is an **antimetabolite chemotherapy drug** that interferes with DNA and RNA synthesis, thereby inhibiting cell division. - It is a **pyrimidine analog** and not a monoclonal antibody. *Methotrexate* - **Methotrexate** is a **folate analog antimetabolite** that inhibits **dihydrofolate reductase**, interfering with DNA synthesis and cell proliferation. - It's a conventional chemotherapy agent and immunosuppressant, not a monoclonal antibody.

Q: NaCl symporter is present in which part of the nephron?

DCT. ***DCT*** - The **NaCl symporter** (also known as the **Na-Cl co-transporter** or NCC) is located in the **luminal membrane** of cells in the **distal convoluted tubule (DCT)**. - This transporter is responsible for reabsorbing approximately 5-10% of filtered sodium and chloride, and it is the target of **thiazide diuretics**. *PCT* - The **proximal convoluted tubule (PCT)** is responsible for bulk reabsorption of Na+ through various mechanisms, including Na+/H+ exchangers and Na+-glucose co-transporters, but not the specific NaCl symporter found in the DCT. - While significant NaCl reabsorption occurs here, it is primarily driven by different transport proteins. *Loop of Henle* - The **thick ascending limb of the loop of Henle** uses the **Na-K-2Cl co-transporter (NKCC2)** for Na+ reabsorption, which is distinct from the NaCl symporter. - This segment is the target for **loop diuretics**. *Collecting duct* - The **collecting duct** reabsorbs Na+ primarily through the **epithelial sodium channel (ENaC)**, which is regulated by aldosterone. - While reabsorption of sodium occurs, the specific NaCl symporter is not present in this segment.

Q: Which of the following causes hypoxic hypoxia?

Pneumonia. ***Pneumonia*** - Pneumonia causes **hypoxic hypoxia** by impairing **gas exchange** in the lungs due to inflammation and fluid accumulation in the alveoli, leading to reduced oxygen uptake. - This results in a **low partial pressure of oxygen (PaO2)** in the arterial blood, even with normal oxygen-carrying capacity and tissue perfusion. *HCN poisoning* - **Hydrogen cyanide (HCN) poisoning** causes **histotoxic hypoxia**, where cells are unable to utilize oxygen despite adequate delivery, by inhibiting **cytochrome c oxidase** in the electron transport chain. - It does not directly reduce the amount of oxygen in the blood or its delivery to tissues. *CO poisoning* - **Carbon monoxide (CO) poisoning** causes **anemic hypoxia** by binding to hemoglobin with a much higher affinity than oxygen, forming **carboxyhemoglobin (COHb)**. - This reduces the **oxygen-carrying capacity** of the blood and shifts the oxygen-hemoglobin dissociation curve to the left, but it is not a direct problem with alveolar gas exchange or oxygen partial pressure. *Circulatory shock* - **Circulatory shock** causes **stagnant or ischemic hypoxia**, characterized by reduced blood flow and oxygen delivery to tissues due to systemic circulatory failure. - While it results in tissue oxygen deprivation, the primary issue is impaired perfusion rather than a defect in the initial oxygenation of blood in the lungs or the blood's capacity to carry oxygen.

Q: A man presents to the emergency department with a head injury following a vehicular accident. What is the investigation of choice?

NCCT. ***NCCT*** - **Non-contrast Computed Tomography (NCCT)** of the head is the **investigation of choice** for acute head trauma due to its rapid acquisition, wide availability, and excellent sensitivity for detecting acute hemorrhage, fractures, and mass effects. - It rapidly identifies life-threatening conditions such as **epidural, subdural, and intracerebral hemorrhages**, which require immediate intervention. *MRI* - **MRI** is superior for detecting subtle brain tissue injuries, diffuse axonal injury, and non-hemorrhagic lesions but is generally **not the first-line investigation** in acute trauma due to longer scan times, limited availability in the emergency setting, and inability to detect acute hemorrhage as clearly as CT. - Its use is typically reserved for follow-up studies or when CT findings are inconclusive or specific soft tissue detail is required. *CECT* - **Contrast-enhanced CT (CECT)** of the head is reserved for specific indications like evaluating vascular lesions (e.g., aneurysms, arteriovenous malformations) or tumors, which are generally **not the primary concern** in the initial assessment of acute head trauma. - Administering contrast agents can delay imaging, may pose risks to patients with renal impairment or allergies, and does not significantly improve the detection of acute traumatic hemorrhage compared to NCCT. *X-ray* - **X-rays** of the skull are useful for detecting **skull fractures**, but they provide **limited information** regarding intracranial injuries or soft tissue damage, which are critical in head trauma. - They have largely been superseded by CT scans, which offer a more comprehensive view of both bony structures and intracranial contents.

Q: Investigations used for CSF rhinorrhea are all except:

Skull X-ray. ***Skull X-ray*** - A **skull X-ray** is generally not useful for diagnosing **CSF rhinorrhea** as it lacks the detailed soft tissue resolution needed to identify CSF leaks. - It cannot visualize small defects in the skull base or detect the presence of CSF distinct from other nasal secretions. *CT cisternogram* - A **CT cisternogram** is a highly effective imaging modality for localizing **CSF leaks**, involving an intrathecal injection of contrast followed by CT scanning. - It can pinpoint the exact site of the leak in the skull base, which is crucial for surgical planning. *Beta-2 transferrin* - **Beta-2 transferrin** is a protein found almost exclusively in **cerebrospinal fluid (CSF)**, making its detection in nasal discharge diagnostic of CSF rhinorrhea. - This biochemical test offers high specificity for confirming the presence of CSF. *Nasal endoscopy* - **Nasal endoscopy** allows direct visualization of the nasal cavity and can help identify the source of the leak, especially if active dripping is observed. - During the procedure, the Valsalva maneuver or changes in head position can sometimes provoke or increase the flow of CSF, aiding in localization.

Q: A patient who underwent gastrectomy develops sweating and diarrhea within 20 minutes after eating. What could be the cause?

Early dumping syndrome. ***Early dumping syndrome*** - Occurs **15-30 minutes after eating** in patients who have undergone **gastric surgery**, such as gastrectomy, due to rapid emptying of hyperosmolar chyme into the small intestine. - Symptoms include **sweating**, **diarrhea**, **nausea**, **cramping**, and **tachycardia** due to fluid shifts and hormonal responses. *Late dumping syndrome* - Typically occurs **1-3 hours after eating**, not within 20 minutes. - It is characterized by **hypoglycemia** due to an exaggerated insulin response to the rapid absorption of glucose, leading to symptoms like weakness, confusion, and tremor. *Hyperglycemia* - While a rapid influx of glucose can initially cause hyperglycemia, the symptoms described (sweating, diarrhea) are more indicative of the systemic effects of rapid gastric emptying rather than simple hyperglycemia itself. - Hyperglycemia post-meal is a normal physiological response, and the constellation of symptoms points to a post-surgical complication. *Hypoglycemia* - Hypoglycemia is characteristic of **late dumping syndrome**, occurring hours after a meal, not within 20 minutes. - The symptoms of early dumping syndrome are primarily driven by fluid shifts and neurovascular responses, not low blood glucose.

Question 1

Ventricles are lined by?

Accepted Answer

Ependymal cells

Answer

Schwann cells

Answer

Oligodendrocytes

Answer

Astrocytes

Question 2

A farmer with pinpoint pupils, increased secretions and urination. What is the most likely diagnosis?

Accepted Answer

Organophosphate poisoning

Answer

Alcohol poisoning

Answer

Opioid poisoning

Answer

Atropine poisoning

Question 3

All of the following are types of Primary headache except:

Accepted Answer

Temporal arteritis

Answer

Migraine

Answer

Tension

Answer

Cluster

Question 4

Which of the following is an advantage of contact lenses over normal glasses?

Accepted Answer

Improved peripheral vision

Answer

Reduced prismatic effect

Answer

Decreased risk of infection

Answer

UV protection (in specific lenses)

Question 5

Which of the following is a monoclonal antibody used in cancer treatment?

Accepted Answer

Rituximab

Answer

Cisplatin

Answer

5-fluorouracil

Answer

Methotrexate

Question 6

NaCl symporter is present in which part of the nephron?

Accepted Answer

DCT

Answer

PCT

Answer

Loop of Henle

Answer

Collecting duct

Question 7

Which of the following causes hypoxic hypoxia?

Accepted Answer

Pneumonia

Answer

HCN poisoning

Answer

CO poisoning

Answer

Circulatory shock

Question 8

A man presents to the emergency department with a head injury following a vehicular accident. What is the investigation of choice?

Accepted Answer

NCCT

Answer

MRI

Answer

CECT

Answer

X-ray

Question 9

Investigations used for CSF rhinorrhea are all except:

Accepted Answer

Skull X-ray

Answer

CT cisternogram

Answer

Beta-2 transferrin

Answer

Nasal endoscopy

Question 10

A patient who underwent gastrectomy develops sweating and diarrhea within 20 minutes after eating. What could be the cause?

Accepted Answer

Early dumping syndrome

Answer

Late dumping syndrome

Answer

Hyperglycemia

Answer

Hypoglycemia

FMGE 2019

Anatomy

Internal Medicine

Ophthalmology

Pharmacology

Physiology

Radiology

Surgery