Biochemistry
2 questionsIdentify the type of inhibition shown in the graph.
Which source and cell produce testosterone?
FMGE 2023 - Biochemistry FMGE Practice Questions and MCQs
Question 41: Identify the type of inhibition shown in the graph.
- A. Competitive inhibition
- B. Allosteric Inhibition
- C. Uncompetitive inhibition
- D. Noncompetitive inhibition (Correct Answer)
Explanation: ***Noncompetitive inhibition***- This inhibition type is characterized by a decrease in **$V_{max}$** but no change in the **$K_m$** value, meaning the inhibitor reduces the enzyme's efficiency but not its affinity for the substrate.- The inhibitor typically binds reversibly to an **allosteric site** (not the active site), affecting the enzyme's catalytic functionality whether the substrate is bound or not.*Competitive inhibition*- Competitive inhibition is characterized by an **increased $K_m$** (decreased apparent affinity) while the **$V_{max}$** remains unchanged.- The inhibitor binds directly to the **active site**, competing with the substrate, and the effect can be overcome by increasing substrate concentration.*Allosteric Inhibition*- Allosteric inhibition is a general mechanism where a molecule binds to a site other than the active site (**allosteric site**), changing the enzyme's conformation and activity.- While noncompetitive and uncompetitive inhibitions are types of allosteric regulation, "noncompetitive inhibition" is the specific and most accurate term for the observed kinetic behavior (decreased $V_{max}$, constant $K_m$).*Uncompetitive inhibition*- This type involves the inhibitor binding only to the **enzyme-substrate complex (ES)**, resulting in a proportional decrease in both **$V_{max}$** and **$K_m$**.- On a Lineweaver-Burk plot, this is shown by parallel lines, highly distinguishing it from noncompetitive inhibition where the lines intersect on the X-axis.
Question 42: Which source and cell produce testosterone?
- A. Dihydrotestosterone and Leydig cells
- B. FSH and Leydig cells
- C. Cholesterol and Leydig cells (Correct Answer)
- D. Cholesterol and Sertoli cells
Explanation: ***Cholesterol and Leydig cells***- **Testosterone** is a steroid hormone, and like all steroid hormones (glucocorticoids, mineralocorticoids, estrogen), it is derived from the precursor molecule, **cholesterol**.- The primary source of testosterone production in the male testes is the **Leydig cells** (interstitial cells), stimulated by **Luteinizing Hormone (LH)**.*Cholesterol and Sertoli cells*- While **cholesterol** is the accurate precursor (source), **Sertoli cells** are mainly responsible for supporting **spermatogenesis** and producing **androgen-binding protein (ABP)** and **inhibin**.- Sertoli cells regulate the testicular microenvironment and are primarily stimulated by **FSH**, not for testosterone synthesis.*Dihydrotestosterone and Leydig cells*- **Dihydrotestosterone (DHT)** is a potent *metabolite* formed from testosterone via the enzyme **5-alpha reductase**, not the precursor for testosterone synthesis itself.- Although **Leydig cells** are the site of testosterone production, the initial source must be **cholesterol**, making DHT incorrect.*FSH and Leydig cells*- **FSH** (Follicle-Stimulating Hormone) primarily targets the **Sertoli cells** to promote sperm development and inhibin production.- The pituitary hormone that stimulates **Leydig cells** to synthesize testosterone from cholesterol is **Luteinizing Hormone (LH)**.
Community Medicine
1 questionsThe SAFE strategy given by WHO forms the mainstream of the management of Trachoma. What does the S in the acronym represent?
FMGE 2023 - Community Medicine FMGE Practice Questions and MCQs
Question 41: The SAFE strategy given by WHO forms the mainstream of the management of Trachoma. What does the S in the acronym represent?
- A. Spectacles
- B. Symbol
- C. Symptom
- D. Surgery (Correct Answer)
Explanation: ***Surgery*** - The 'S' in the WHO's SAFE strategy for Trachoma management stands for **Surgery**, which is essential for correcting **trichiasis** (in-turned eyelashes). - Surgery prevents irreversible vision loss by stopping the eyelashes from rubbing against and scarring the **cornea**. *Symptom* - Management of specific **symptoms** is generally an element of clinical treatment but does not represent a component of the comprehensive population-level intervention strategy known as SAFE. - The SAFE approach focuses on addressing the **infectious agent** (Antibiotics) and transmission factors (Facial cleanliness, Environmental improvement) for elimination. *Spectacles* - **Spectacles** are used for correcting refractive errors (like myopia or hyperopia) and are not a therapeutic measure for active **Chlamydia trachomatis** infection or trichiasis. - The goal of SAFE is elimination of the infectious cause and treatment of the blinding sequelae, not visual **refractive correction**. *Symbol* - A **symbol** is an abstract representation and does not constitute a concrete public health or clinical intervention necessary for the elimination of trachoma. - The other components (**Antibiotics**, **Facial cleanliness**, **Environmental improvement**) are tangible actions aimed at disease control and prevention.
ENT
3 questionsA patient presented with unilateral nasal obstruction associated with watery nasal discharge and bleeding. A diagnosis of inverted papilloma is made. Which of the following is true about this condition?
A 5-year-old child presents with sudden severe ear pain and hearing loss. On otoscopy, you observe hemorrhagic bullae on an inflamed tympanic membrane. What is the most likely diagnosis?
A patient presents with a thick nasal discharge and headache. Examination reveals hypertrophy of the inferior turbinate with a mulberry appearance. Which of the following is the most likely diagnosis?
FMGE 2023 - ENT FMGE Practice Questions and MCQs
Question 41: A patient presented with unilateral nasal obstruction associated with watery nasal discharge and bleeding. A diagnosis of inverted papilloma is made. Which of the following is true about this condition?
- A. Malignant and invasive
- B. Benign and non-invasive
- C. Malignant and non-invasive
- D. Benign and invasive (Correct Answer)
Explanation: ***Benign and invasive*** Inverted papilloma (Schneiderian papilloma) is a **benign epithelial tumor** that characteristically exhibits **locally invasive behavior**, making option D correct. **Key features of inverted papilloma:** - **Benign histology** but behaves aggressively - **Locally invasive** - grows into underlying stroma and can erode bone - Unilateral presentation (cardinal feature) - Origin from lateral nasal wall/maxillary sinus - High recurrence rate (10-30%) if incompletely excised - **Malignant transformation risk: 5-15%** (usually to squamous cell carcinoma) - Requires complete surgical excision with wide margins **Clinical presentation (as in this case):** - Unilateral nasal obstruction (most common) - Epistaxis (bleeding) - Watery rhinorrhea - Fullness/mass sensation *Incorrect: Malignant and invasive* While inverted papilloma is invasive, it is histologically benign, not malignant. However, surveillance is needed due to malignant transformation potential. *Incorrect: Benign and non-invasive* Though benign, inverted papilloma is NOT non-invasive. Its locally aggressive behavior with invasion into adjacent structures distinguishes it from simple benign polyps. *Incorrect: Malignant and non-invasive* This option is incorrect on both counts - inverted papilloma is benign (not malignant) and invasive (not non-invasive).
Question 42: A 5-year-old child presents with sudden severe ear pain and hearing loss. On otoscopy, you observe hemorrhagic bullae on an inflamed tympanic membrane. What is the most likely diagnosis?
- A. Myringitis bullosa (Correct Answer)
- B. Serous otitis media
- C. Acute otitis media
- D. Myringitis granulosa
Explanation: ***Myringitis bullosa*** - This diagnosis is strongly suggested by the otoscopic image showing **hemorrhagic or serous bullae (blisters)** on an inflamed tympanic membrane, which is the pathognomonic feature of this condition. - It is an acute inflammation of the tympanic membrane, often associated with viral or bacterial infections (e.g., **Mycoplasma pneumoniae**, Influenza virus), and typically presents with sudden, severe otalgia and hearing loss. *Serous otitis media* - This condition, also known as otitis media with effusion, is characterized by the presence of fluid in the middle ear space, leading to a **dull, retracted tympanic membrane** with visible **air-fluid levels or bubbles**, not bullae on the surface. - It typically presents with conductive hearing loss and a feeling of fullness in the ear, but lacks the severe inflammation and bullae seen in the image. *Acute otitis media* - The classic sign of acute otitis media is a **bulging, erythematous, and opaque tympanic membrane** due to purulent effusion in the middle ear, with loss of normal landmarks. - While bullae can occasionally form in severe cases of AOM, the primary feature is the bulging eardrum, and the prominent, multiple vesicles seen here are more specific to myringitis bullosa. *Myringitis granulosa* - This is a chronic inflammatory condition characterized by the presence of **granulation tissue** on the lateral surface of the tympanic membrane. - It typically presents with persistent otorrhea and conductive hearing loss, and the otoscopic appearance is of a raw, granular surface, which is distinctly different from the fluid-filled bullae shown in the image.
Question 43: A patient presents with a thick nasal discharge and headache. Examination reveals hypertrophy of the inferior turbinate with a mulberry appearance. Which of the following is the most likely diagnosis?
- A. Common cold
- B. Hypertrophic rhinitis (Correct Answer)
- C. Nasal polyp
- D. Atrophic rhinitis
Explanation: ***Hypertrophic rhinitis***- This is a form of **chronic rhinitis** where persistent inflammation leads to irreversible changes, including mucosal and sub-mucosal fibrosis and hypertrophy.- The inferior turbinate hypertrophy becomes nodular, leading to the characteristic irreversible **"mulberry appearance"** on examination, correlating with thick discharge and obstruction.*Atrophic rhinitis*- This condition involves **atrophy** (shrinking) of the nasal mucosa and associated turbinates, leading to wide nasal passages, crusting, and often a foul smell (**ozena**).- The examination would show diminished turbinate size and a patent nasal cavity, which contradicts the finding of turbinate hypertrophy.*Common cold*- While causing discharge and headache, the discharge is typically watery (**rhinorrhea**) initially, progressing to mucoid, and the illness is acute and self-limiting.- It does not cause permanent or marked **fibrotic hypertrophy** of the inferior turbinates with a mulberry appearance, which is a sign of chronic inflammation.*Nasal polyp*- Nasal polyps are pale, glistening, freely mobile, non-tender masses that typically resemble **peeled grapes** and usually arise from the middle meatus.- Polyps represent edematous mucosa and are distinct from the fixed, hyperplastic tissue constituting the hypertrophied inferior turbinate itself.
Microbiology
1 questionsWhich of the following hepatitis viruses is likely to get transmitted via fecal-oral route?
FMGE 2023 - Microbiology FMGE Practice Questions and MCQs
Question 41: Which of the following hepatitis viruses is likely to get transmitted via fecal-oral route?
- A. Hepatitis A (Correct Answer)
- B. Hepatitis B
- C. Hepatitis C
- D. Hepatitis D
Explanation: ***Hepatitis A***- Hepatitis A virus (HAV) is primarily spread through the **fecal-oral route**, typically via consumption of food or water contaminated with feces.- It causes an **acute**, self-limiting infection that rarely results in chronic liver disease.*Hepatitis B*- Hepatitis B virus (HBV) is transmitted mainly through **parenteral** (exposure to infected blood), sexual contact, or perinatal (mother-to-child) routes.- Unlike HAV, HBV is a major cause of **chronic hepatitis**, cirrhosis, and hepatocellular carcinoma.*Hepatitis C*- Hepatitis C virus (HCV) transmission is predominantly **parenteral**, most commonly associated with intravenous drug use, blood transfusions (historically), and shared needles.- HCV is the leading cause of chronic viral hepatitis globally and frequently establishes persistent infection.*Hepatitis D*- Hepatitis D virus (HDV) is a defective RNA virus that requires **Hepatitis B surface antigen (HBsAg)** for its replication and assembly.- HDV is transmitted parenterally (same routes as HBV) and not via the fecal-oral route.
Physiology
1 questionsWhat is the cause of LH (Luteinizing Hormone) surge?
FMGE 2023 - Physiology FMGE Practice Questions and MCQs
Question 41: What is the cause of LH (Luteinizing Hormone) surge?
- A. LH
- B. Progesterone
- C. FSH
- D. Estradiol (Correct Answer)
Explanation: ***Estradiol*** - The cause of LH surge- During the late follicular phase, the dominant follicle secretes increasingly high levels of **Estradiol** (a potent estrogen). When these levels remain high for a prolonged period (typically 48–50 hours) above a critical threshold, it switches from exerting negative feedback to **positive feedback** on the hypothalamus and anterior pituitary. - This positive feedback stimulates a massive release of **GnRH** and, subsequently, a sudden, sharp, increase in **LH** secretion, known as the LH surge, which prepares the dominant follicle for ovulation. *FSH* - FSH is essential for initiating the **follicular development** (growth and maturation of ovarian follicles) preceding the surge, but it is not the direct trigger for the LH surge. - Although FSH levels also rise slightly during the surge (known as the **FSH surge**), this rise is secondary to the primary positive feedback mechanism driven by Estradiol. *Progesterone* - Progesterone levels are typically low during the late follicular phase when the LH surge occurs; its primary rise happens **after ovulation** during the luteal phase. - While Progesterone contributes to the total feedback loop around the surge, it cannot initiate the surge itself, and its main role is preparing the **endometrium** and supporting a potential pregnancy. *LH* - LH (*Luteinizing hormone*) is the hormone whose concentration surges; it is the **effect** of the positive feedback loop, not the underlying cause. - The rise in LH concentration is a direct response of the **anterior pituitary** to the high levels of Estradiol acting upon it.
Surgery
2 questionsA 2-year-old was brought to the emergency department with difficulty swallowing for the last few hours. The X-ray is given below. Which is the next best step to manage this patient?
Which of the following is associated with CSF otorrhea?
FMGE 2023 - Surgery FMGE Practice Questions and MCQs
Question 41: A 2-year-old was brought to the emergency department with difficulty swallowing for the last few hours. The X-ray is given below. Which is the next best step to manage this patient?
- A. Bronchoscopy
- B. Esophagoscopy (Correct Answer)
- C. Heimlich's manoeuvre
- D. Tracheostomy
Explanation: ***Esophagoscopy*** - The X-ray shows a circular radiopaque object, the classic **"coin sign"** on an anteroposterior view, which is characteristic of a foreign body lodged in the **esophagus**. - **Esophagoscopy** is the definitive procedure for both visualizing and safely removing the foreign object, especially important if it is a button battery which can cause rapid mucosal injury. *Bronchoscopy* - This procedure is indicated for the removal of foreign bodies from the **airways** (trachea or bronchi), not the esophagus. - A tracheal foreign body would typically present with **respiratory distress** (stridor, wheezing) and would appear as a thin line on an AP X-ray because it would be oriented in the sagittal plane. *Tracheostomy* - A tracheostomy is a surgical procedure to create an alternative airway and is reserved for severe **upper airway obstruction** or the need for long-term mechanical ventilation. - This patient's primary problem is **dysphagia** (difficulty swallowing) due to an esophageal obstruction, not an airway emergency requiring a surgical airway. *Heimlich's manoeuvre* - This is an emergency first-aid procedure used for acute **choking** caused by a foreign body obstructing the airway, leading to an inability to breathe or speak. - The patient is not described as actively choking and has a stable airway; therefore, this maneuver is inappropriate and could cause harm.
Question 42: Which of the following is associated with CSF otorrhea?
- A. Battle sign (Correct Answer)
- B. Traumatic rupture of the tympanic membrane
- C. Penetrating injury to the eye
- D. Fracture of the roof of the nose
Explanation: ***Battle sign***- **Battle sign** (ecchymosis over the mastoid process) is highly indicative of a **basilar skull fracture**, specifically involving the **temporal bone**.- Fractures of the petrous portion of the temporal bone often breach the **dura mater** and middle ear cavity, leading directly to leakage of cerebrospinal fluid (**CSF otorrhea**).*Traumatic rupture of the tympanic membrane*- While rupture of the **tympanic membrane (TM)** is often present, it is usually a consequence of the underlying **temporal bone fracture**, not the primary source of the CSF leak.- CSF otorrhea fundamentally requires a fracture allowing communication between the **subarachnoid space** and the middle ear; TM rupture solely allows fluid egress.*Penetrating injury to the eye*- These injuries involve the orbit and structures of the eye, typically causing orbital trauma, globe rupture, or associated **facial fractures**.- They are not the usual mechanism for basilar skull fractures involving the **middle cranial fossa** or temporal bone, which are necessary for CSF otorrhea.*Fracture of the roof of the nose*- Fractures of the skull base involving the anterior cranial fossa, such as the **cribriform plate** (roof of the nose), classically cause **CSF rhinorrhea** (CSF leakage through the nose).- This anatomical location is functionally separate from the temporal bone pathology required to produce **CSF otorrhea**.