Anatomy
1 questionsWhich part of thalamus is related to motor control?
FMGE 2018 - Anatomy FMGE Practice Questions and MCQs
Question 161: Which part of thalamus is related to motor control?
- A. Ventrolateral thalamus (Correct Answer)
- B. Ventral posteromedial
- C. Ventral posterolateral
- D. Lateral geniculate nucleus
Explanation: ***Ventrolateral thalamus*** - The **ventrolateral (VL) nucleus** of the thalamus is a key relay station for **motor control**, receiving input from the **basal ganglia** and **cerebellum** and projecting to the motor cortex [1]. - It plays a crucial role in the planning, initiation, and coordination of **voluntary movements**. *Ventral posteromedial* - The **ventral posteromedial (VPM) nucleus** is involved in processing **somatosensory information** from the face and taste sensations. - It does not primarily contribute to motor control pathways. *Ventral posterolateral* - The **ventral posterolateral (VPL) nucleus** relays **somatosensory information** from the body (limbs and trunk) to the primary somatosensory cortex. - Its main function is sensory perception, not motor control. *Lateral geniculate nucleus* - The **lateral geniculate nucleus (LGN)** is exclusively involved in the **visual pathway**, receiving input from the retina and projecting to the primary visual cortex. - It has no direct role in motor control.
Biochemistry
1 questionsAtherosclerosis is associated with:
FMGE 2018 - Biochemistry FMGE Practice Questions and MCQs
Question 161: Atherosclerosis is associated with:
- A. Histidine
- B. Lysine
- C. Homocysteine (Correct Answer)
- D. Leucine
Explanation: ***Homocysteine*** - Elevated plasma levels of **homocysteine**, known as hyperhomocysteinemia, are an independent **risk factor for atherosclerosis** and cardiovascular disease. - While the precise mechanism is complex, homocysteine is thought to promote endothelial damage, oxidative stress, and lipid peroxidation, contributing to **plaque formation**. *Histidine* - **Histidine** is an essential amino acid involved in various metabolic processes, including the synthesis of **histamine** and carnosine. - It is not directly associated with the pathogenesis or risk factors for atherosclerosis. *Lysine* - **Lysine** is an essential amino acid important for **protein synthesis** and many bodily functions. - There is no established direct link between lysine levels and the development or progression of atherosclerosis. *Leucine* - **Leucine** is a branched-chain amino acid (BCAA) crucial for **muscle protein synthesis** and energy metabolism. - While some studies hint at associations between BCAAs and metabolic health, leucine itself is not a known direct risk factor or etiologic agent for atherosclerosis.
ENT
2 questionsYoung's operation is done for:
A 15 years old Male presented with history of fever since 2 days, unable to swallow the food with muffled voice. On examination it is noted right tonsil is shifted to midline. What is the diagnosis:
FMGE 2018 - ENT FMGE Practice Questions and MCQs
Question 161: Young's operation is done for:
- A. Allergic rhinitis
- B. Vasomotor rhinitis
- C. Atrophic rhinitis (Correct Answer)
- D. Antrochoanal polyp
Explanation: ***Atrophic rhinitis*** - **Young's operation** is a surgical procedure specifically designed to treat **atrophic rhinitis**. - The goal of the surgery is to narrow the nasal passages by creating a **synechia** (adhesion) to reduce airflow and improve the humidification and temperature of inspired air. *Allergic rhinitis* - Allergic rhinitis is primarily managed with **medical therapy**, including antihistamines, nasal corticosteroids, and allergen avoidance. - Surgical intervention, if considered, typically involves procedures like turbinate reduction, not Young's operation, and is less common for this condition. *Vasomotor rhinitis* - Vasomotor rhinitis is a **non-allergic, non-infectious condition** characterized by fluctuating nasal congestion and rhinorrhea, often triggered by irritants or temperature changes. - Treatment usually involves **medical management** with anticholinergics or nasal corticosteroids, and sometimes turbinate reduction, but not Young's operation. *Antrochoanal polyp* - An antrochoanal polyp is a benign growth originating in the **maxillary sinus** and extending into the choana. - The primary treatment is **surgical removal**, typically via endoscopic sinus surgery, which is distinct from Young's operation.
Question 162: A 15 years old Male presented with history of fever since 2 days, unable to swallow the food with muffled voice. On examination it is noted right tonsil is shifted to midline. What is the diagnosis:
- A. Quincy (Correct Answer)
- B. Acute tonsillitis
- C. Parapharyngeal abscess
- D. Acute retropharyngeal abscess
Explanation: ***Quincy (Peritonsillar abscess)*** - This patient's presentation with **fever**, **dysphagia**, **muffled voice** (hot potato voice), and **tonsil shifted to the midline** is classic for a **peritonsillar abscess (Quincy)**. - The affected tonsil is pushed **medially toward the midline** by the collection of pus between the tonsillar capsule and the superior constrictor muscle. - The uvula is typically deviated to the **contralateral side**, and patients often have **trismus** and difficulty opening the mouth. - This is the **most common deep neck space infection** and typically follows acute tonsillitis. *Parapharyngeal abscess* - A **parapharyngeal abscess** would present with **severe trismus**, **neck swelling**, **torticollis**, and **bulging of the lateral pharyngeal wall**. - While it can push the tonsil medially, it more characteristically causes **anterolateral displacement** of the entire pharyngeal wall rather than isolated tonsillar displacement. - Patients typically have more pronounced **systemic toxicity** and **neck involvement** than seen with peritonsillar abscess. *Acute tonsillitis* - **Acute tonsillitis** presents with **bilateral tonsillar enlargement**, exudates, and pharyngeal erythema. - It does not cause **displacement of the tonsil to the midline** or significant **muffled voice**. - While fever and dysphagia are present, the physical examination finding of tonsillar shift indicates a suppurative complication (abscess formation). *Acute retropharyngeal abscess* - An **acute retropharyngeal abscess** occurs in the retropharyngeal space behind the posterior pharyngeal wall. - It presents with **neck stiffness**, **stridor**, **drooling**, **bulging of the posterior pharyngeal wall**, and **reluctance to extend the neck**. - It would **not cause visible displacement of the tonsil to the midline** as the abscess is in a different anatomical space. - More common in **young children** (under 5 years) than adolescents.
Microbiology
1 questionsWhich one of the following is a major component in activation of the complement alternative pathway?
FMGE 2018 - Microbiology FMGE Practice Questions and MCQs
Question 161: Which one of the following is a major component in activation of the complement alternative pathway?
- A. C2
- B. C3 (Correct Answer)
- C. C4
- D. C1
Explanation: ***C3*** - **C3** is a central component in all complement pathways. In the alternative pathway, spontaneous hydrolysis of **C3** leads to C3(H2O), initiating the formation of the **C3 convertase**. - This **C3 convertase** (C3bBb) further cleaves more **C3** into C3a and C3b, amplifying the pathway and leading to downstream complement activation. *C2* - **C2** is a crucial component of the **classical** and **lectin pathways**, where it is cleaved by C1s or MASP-2, respectively, to form C2b and C2a. - **C2a** then combines with C4b to form the **C3 convertase** (C4b2a) of these pathways; it does not play a direct role in initiating the alternative pathway. *C4* - **C4** is primarily involved in the **classical** and **lectin pathways**, where it is cleaved by C1s or MASP-2 to form C4a and C4b. - **C4b** binds to pathogens or immune complexes and then associates with C2a to form the **C3 convertase** (C4b2a), which is not part of the alternative pathway initiation. *C1* - **C1** is the initiating complex of the **classical complement pathway** and is composed of C1q, C1r, and C1s. - It recognizes and binds to antibody-antigen complexes or pathogen surfaces, but it has no direct role in the **alternative pathway activation**.
Ophthalmology
2 questionsSarcoidosis is associated with
Campimetry is used to measure:
FMGE 2018 - Ophthalmology FMGE Practice Questions and MCQs
Question 161: Sarcoidosis is associated with
- A. Keratitis
- B. Cataract
- C. Anterior uveitis (Correct Answer)
- D. Ectopia lentis
Explanation: ***Anterior uveitis*** - **Anterior uveitis**, particularly chronic granulomatous anterior uveitis, is the most common ocular manifestation of **sarcoidosis**. - It results from **non-caseating granulomas** affecting the iris and ciliary body. - Sarcoidosis can also cause intermediate uveitis, posterior uveitis, and panuveitis, but anterior uveitis is most frequently seen. - Characteristic findings include mutton-fat keratic precipitates and iris nodules (Koeppe and Busacca nodules). *Keratitis* - **Keratitis** (inflammation of the cornea) is less commonly associated with sarcoidosis compared to uveitis. - While ocular sarcoidosis can rarely cause interstitial keratitis or band keratopathy, direct corneal inflammation is not a hallmark feature. *Cataract* - **Cataracts** are not directly caused by sarcoidosis itself, but can be a complication of chronic uveitis or prolonged corticosteroid treatment. - The disease process of sarcoidosis does not primarily involve cataract formation. *Ectopia lentis* - **Ectopia lentis** (lens dislocation) is a rare condition usually associated with genetic disorders like **Marfan syndrome** or homocystinuria. - It is not a recognized ocular manifestation of sarcoidosis.
Question 162: Campimetry is used to measure:
- A. Squint
- B. Field of Vision (Correct Answer)
- C. Pattern of retina
- D. Malignant melanoma
Explanation: ***Field of Vision*** - **Campimetry** is a diagnostic test specifically designed to map and assess a person's **field of vision**, identifying blind spots or areas of diminished sight. - This technique is crucial for detecting and monitoring conditions that affect the optic nerve or visual pathways, such as **glaucoma** or neurological disorders. *Squint* - A **squint**, also known as strabismus, refers to a misalignment of the eyes. - Its assessment primarily involves tests of **ocular motility** and alignment, such as the cover test, rather than perimetry. *Pattern of retina* - The **pattern of the retina** is evaluated through direct visualization using an **ophthalmoscope** or other retinal imaging techniques like fundus photography or optical coherence tomography (OCT). - These methods provide structural information about the retina, not its functional visual field. *Malignant melanoma* - **Malignant melanoma** (in the context of the eye) is a tumor that can affect various parts of the eye, including the choroid, iris, or conjunctiva. - Its diagnosis involves clinical examination, imaging studies (**ultrasound**, OCT, **fluorescein angiography**), and sometimes biopsy, not primarily visual field testing.
Physiology
2 questionsHistamine is secreted by:
Delivery of stimulus above threshold intensity leads to a constant amplitude of AP and is known as:
FMGE 2018 - Physiology FMGE Practice Questions and MCQs
Question 161: Histamine is secreted by:
- A. Enterochromaffin-like cell (ECL cell) (Correct Answer)
- B. Chief cell
- C. Oxyntic cell
- D. Parietal cell
Explanation: ***Enterochromaffin-like cell (ECL cell)*** - **Enterochromaffin-like (ECL) cells** are located in the gastric mucosa and are the primary source of histamine in the stomach. - Histamine released by ECL cells stimulates **parietal cells** to secrete hydrochloric acid. - Note: ECL cells are distinct from enterochromaffin (EC) cells, which primarily secrete serotonin. *Chief cell* - **Chief cells** primarily secrete pepsinogen, the inactive precursor of the digestive enzyme pepsin. - They also produce gastric lipase, which aids in fat digestion. *Oxyntic cell* - The term **oxyntic (or parietal) cell** refers to the same cell type responsible for secreting hydrochloric acid and intrinsic factor. - They do not directly secrete histamine; instead, their acid secretion is stimulated by histamine. *Parietal cell* - **Parietal cells** are responsible for secreting hydrochloric acid and intrinsic factor, crucial for vitamin B12 absorption. - Their acid secretion is stimulated by acetylcholine, gastrin, and **histamine** (released from ECL cells).
Question 162: Delivery of stimulus above threshold intensity leads to a constant amplitude of AP and is known as:
- A. Electrotonic potential
- B. All or none law (Correct Answer)
- C. Absolute refractory period
- D. Relative refractory period
Explanation: ***All or none law*** - The **all-or-none law** states that if a stimulus reaches or exceeds the **threshold intensity**, a neuron will fire an action potential of a constant, maximal amplitude. - If the stimulus is below the threshold, no action potential will fire, meaning there is no partial or submaximal action potential. *Electrotonic potential* - **Electrotonic potentials** are subthreshold, local changes in membrane potential that decay with distance and time. - They are **graded**, meaning their amplitude is proportional to the stimulus intensity, unlike the fixed amplitude of an action potential. *Absolute refractory period* - The **absolute refractory period** is the time during an action potential when the membrane is completely unresponsive to further stimulation, no matter how strong. - This period is due to the **inactivation of voltage-gated sodium channels**, preventing another action potential from being generated. *Relative refractory period* - The **relative refractory period** is the time following the absolute refractory period when a **larger-than-normal stimulus** is required to elicit another action potential. - This occurs because some potassium channels are still open, and the membrane is hyperpolarized, making it harder to reach the threshold.
Psychiatry
1 questionsEctopia lentis in a child is seen in which of the following diseases?
FMGE 2018 - Psychiatry FMGE Practice Questions and MCQs
Question 161: Ectopia lentis in a child is seen in which of the following diseases?
- A. Sarcoidosis
- B. Wilson disease
- C. Homocystinuria (Correct Answer)
- D. Alkaptonuria
- E. Marfan syndrome
Explanation: ***Homocystinuria*** - Ectopia lentis (lens dislocation) is a characteristic feature of **homocystinuria**, often presenting at a young age. - The dislocation in homocystinuria is typically **inferomedial (inferonasally)** due to weakened zonular fibers. - Homocystinuria is an **inborn error of methionine metabolism** with elevated homocysteine levels. *Marfan syndrome* - While **Marfan syndrome** is the most common cause of ectopia lentis, the lens typically dislocates **superiorly and temporally**. - Marfan syndrome is a connective tissue disorder but is not primarily a metabolic disorder like homocystinuria. - Both conditions can present with ectopia lentis, but the direction of dislocation and associated features differ. *Sarcoidosis* - Ocular manifestations of sarcoidosis usually include **uveitis**, **conjunctivitis**, and **retinal vasculitis**, but not typically ectopia lentis. - Sarcoidosis is a multisystem granulomatous disease and is rare in young children presenting with ectopia lentis. *Wilson disease* - **Kayser-Fleischer rings**, which are deposits of copper in the cornea, are pathognomonic for Wilson disease. - Ocular involvement in Wilson disease does not typically involve ectopia lentis. *Alkaptonuria* - This condition is characterized by the accumulation of **homogentisic acid**, leading to **ochronosis** (black pigmentation) in cartilaginous tissues and urine that turns black on standing. - Ocular manifestations can include scleral pigmentation, but ectopia lentis is not a feature of alkaptonuria.