Anatomy
2 questionsA fracture of the middle cranial fossa may result in an injury of the
A meningomyelocele is most commonly situated in the
UPSC-CMS 2012 - Anatomy UPSC-CMS Practice Questions and MCQs
Question 31: A fracture of the middle cranial fossa may result in an injury of the
- A. Sixth cranial nerve (Correct Answer)
- B. Tenth cranial nerve
- C. Eighth cranial nerve
- D. Eleventh cranial nerve
Explanation: ***Sixth cranial nerve*** - The **abducens nerve (CN VI)** passes through the **Dorello's canal (or petroclival ligament)**, located in the vicinity of the middle cranial fossa. - Fractures in this region can lead to **stretching or compression** of the abducens nerve, resulting in **lateral rectus palsy** and *diplopia*. *Tenth cranial nerve* - The **vagus nerve (CN X)** exits the skull via the **jugular foramen**, located in the **posterior cranial fossa**. - Injury to this nerve is less likely with a fracture specifically confined to the middle cranial fossa. *Eighth cranial nerve* - The **vestibulocochlear nerve (CN VIII)** courses through the **internal auditory meatus** in the **petrous part of the temporal bone**, which is part of the posterior cranial fossa. - While acoustic trauma or petrous bone fractures can affect it, it's not a primary concern with general middle cranial fossa fractures. *Eleventh cranial nerve* - The **spinal accessory nerve (CN XI)** exits the skull through the **jugular foramen**, similar to the vagus nerve, placing it in the **posterior cranial fossa**. - Damage to this nerve would primarily cause weakness in the **sternocleidomastoid** and **trapezius muscles**, and is not typically associated with isolated middle cranial fossa fractures.
Question 32: A meningomyelocele is most commonly situated in the
- A. Thoracic spine
- B. Dorsolumbar spine
- C. Cervical spine
- D. Lumbosacral spine (Correct Answer)
Explanation: ***Lumbosacral spine*** - The **lumbosacral region** (L5-S1) is the most frequent anatomical site for meningomyelocele due to the timing of neural tube closure. - This area is the last portion of the **neural tube** to close, making it more susceptible to defects if closure is incomplete [1]. *Thoracic spine* - While meningomyeloceles can occur in the thoracic region, it is far less common than in the lumbosacral area [1]. - Defects in the thoracic spine are usually associated with a higher level of neurological impairment [1]. *Dorsolumbar spine* - This term encompasses the lower thoracic and upper lumbar regions; while possible, it is not the most common singular site. - The lumbosacral region has a higher prevalence of meningomyelocele formation. *Cervical spine* - Meningoceles and meningomyeloceles in the cervical spine are much rarer. - These defects often present with different neurological findings compared to lumbosacral lesions, such as upper limb weakness.
Anesthesiology
1 questionsA pulmonary artery (Swan-Ganz) catheter measures all of the following except
UPSC-CMS 2012 - Anesthesiology UPSC-CMS Practice Questions and MCQs
Question 31: A pulmonary artery (Swan-Ganz) catheter measures all of the following except
- A. Pulmonary artery wedge pressure (PAWP)
- B. Left ventricular end diastolic volume (LVEDV) (Correct Answer)
- C. Mixed venous oxygen saturation (SvO2)
- D. Cardiac output (CO)
Explanation: ***Left ventricular end diastolic volume (LVEDV)*** - While a Swan-Ganz catheter can measure **pulmonary artery wedge pressure (PAWP)**, which is a surrogate for **left ventricular end-diastolic pressure (LVEDP)**, it cannot directly measure **left ventricular end-diastolic volume (LVEDV)**. - LVEDV requires imaging techniques like **echocardiography** or **cardiac MRI** for direct measurement. *Pulmonary artery wedge pressure (PAWP)* - The Swan-Ganz catheter can measure **PAWP**, which reflects **left atrial pressure** and, in the absence of mitral valve disease, - Is an estimate of **left ventricular end-diastolic pressure (LVEDP)**, therefore assessing left ventricular preload. *Mixed venous oxygen saturation (SvO2)* - The catheter has a fiberoptic sensor that can continuously measure **SvO2** from the pulmonary artery. - **SvO2** provides an assessment of the balance between oxygen supply and demand. *Cardiac output (CO)* - **Cardiac output** is commonly measured using the **thermodilution method** via the Swan-Ganz catheter. - A bolus of saline is injected into the right atrium, and temperature changes are detected in the pulmonary artery to calculate flow.
ENT
2 questionsThe treatment of choice for a mastoid fracture with immediate complete facial nerve paralysis is
Which one of the following conditions produces sensorineural deafness ?
UPSC-CMS 2012 - ENT UPSC-CMS Practice Questions and MCQs
Question 31: The treatment of choice for a mastoid fracture with immediate complete facial nerve paralysis is
- A. Sling operation
- B. Steroid therapy
- C. Mastoidectomy with nerve grafting
- D. Nerve decompression (Correct Answer)
Explanation: ***Nerve decompression*** - For a mastoid (temporal bone) fracture causing **facial nerve paralysis**, surgical **nerve decompression** is the treatment of choice when surgery is indicated. - Most cases of facial nerve paralysis from temporal bone fractures result from **nerve compression or edema** within the fallopian canal, not complete transection. - **Decompression** relieves pressure on the nerve, allowing recovery of function, and is performed via **mastoidectomy** to access the facial nerve in its intratemporal course. - Indications for surgical decompression include **immediate complete paralysis** with evidence of nerve degeneration on electrodiagnostic testing, or failed conservative management. *Mastoidectomy with nerve grafting* - **Nerve grafting** is reserved for cases where the facial nerve is **completely transected or severed**, which is rare in temporal bone fractures. - Most temporal bone trauma causes nerve injury from compression or hematoma, not complete anatomical discontinuity requiring grafting. - Grafting would only be considered after direct visualization confirms irreparable nerve transection. *Steroid therapy* - High-dose **corticosteroids** are actually the **first-line treatment** for facial nerve paralysis following temporal bone fractures, especially in cases of **delayed or incomplete paralysis**. - Steroids reduce **inflammation and edema** around the injured nerve and are often effective for **delayed-onset paralysis**. - However, they are typically used as conservative management rather than the definitive "treatment of choice" when immediate complete paralysis occurs. *Sling operation* - A **sling operation** (facial reanimation surgery) is used for **long-standing, irreversible facial paralysis** when nerve recovery is no longer possible. - It provides **static facial support** but does not restore nerve function. - This is not appropriate for acute management of traumatic facial nerve injury.
Question 32: Which one of the following conditions produces sensorineural deafness ?
- A. Atelectatic middle ear
- B. Eustachian tube blockage
- C. Tympanic membrane rupture
- D. Mixed otosclerosis (Correct Answer)
Explanation: ***Mixed otosclerosis*** - **Otosclerosis** is a bone remodeling disease primarily affecting the **ossicles** and **otic capsule**. - **Mixed otosclerosis** involves both **stapes fixation (conductive component)** and **cochlear involvement (sensorineural component)**. - Among the given options, this is the **only condition that produces sensorineural hearing loss**, although it presents as a mixed hearing loss with both conductive and sensorineural components. - The **cochlear otosclerosis** component causes the sensorineural deafness through involvement of the **otic capsule** and **cochlear structures**. *Atelectatic middle ear* - This condition involves the collapse of the **tympanic membrane** onto the ossicles due to **negative middle ear pressure**. - It causes **pure conductive hearing loss** by impairing sound transmission through the middle ear, with no sensorineural component. *Eustachian tube blockage* - Blockage of the **Eustachian tube** leads to **negative pressure** in the middle ear space. - This results in **pure conductive hearing loss** due to impaired movement of the tympanic membrane and ossicles, with no sensorineural component. *Tympanic membrane rupture* - A rupture in the **tympanic membrane** creates a direct opening between the external ear canal and the middle ear. - This condition causes **pure conductive hearing loss** by disrupting the normal sound conduction mechanism, with no sensorineural component.
Obstetrics and Gynecology
3 questionsConsider the following statements regarding HCG : 1. HCG is a glycoprotein with two subunits α and β. 2. HCG levels reach the maximum between the 60th and 70th day in a normal pregnancy. 3. HCG is secreted by the syncytiotrophoblast. Which of the statements given above is/are correct ?
Which one of the following statements is not correct regarding the haemodynamic changes occurring during a pregnancy?
A multiparous patient has been diagnosed to have foetal demise on a sonographic examination at 16 weeks of pregnancy. The ideal method for termination is
UPSC-CMS 2012 - Obstetrics and Gynecology UPSC-CMS Practice Questions and MCQs
Question 31: Consider the following statements regarding HCG : 1. HCG is a glycoprotein with two subunits α and β. 2. HCG levels reach the maximum between the 60th and 70th day in a normal pregnancy. 3. HCG is secreted by the syncytiotrophoblast. Which of the statements given above is/are correct ?
- A. 2 and 3 only
- B. 1 and 2 only
- C. 1 and 3 only
- D. 1, 2 and 3 (Correct Answer)
Explanation: ***Correct: 1, 2 and 3*** - **Human Chorionic Gonadotropin (HCG)** is a **glycoprotein hormone** composed of **alpha (α) and beta (β) subunits**, making statement 1 correct - HCG is primarily secreted by the **syncytiotrophoblast** cells of the placenta, confirming statement 3 - In a normal pregnancy, HCG levels typically **peak between 60-70 days (8-10 weeks)** after the last menstrual period, supporting statement 2 - All three statements are factually accurate regarding HCG structure, secretion, and physiological levels *Incorrect: 2 and 3 only* - This option incorrectly excludes statement 1 about HCG being a glycoprotein with α and β subunits - The structural composition of HCG as a heterodimeric glycoprotein is a fundamental characteristic *Incorrect: 1 and 2 only* - This option incorrectly excludes statement 3 about syncytiotrophoblast being the source of HCG - The syncytiotrophoblast is the outer layer of the trophoblast responsible for HCG secretion *Incorrect: 1 and 3 only* - This option incorrectly excludes statement 2 about HCG peak timing during pregnancy - Understanding that HCG peaks at 8-10 weeks (60-70 days) is crucial for monitoring early pregnancy
Question 32: Which one of the following statements is not correct regarding the haemodynamic changes occurring during a pregnancy?
- A. The cardiac output is increased
- B. The serum colloid pressure is decreased
- C. The stroke volume is increased
- D. The systemic vascular resistance is increased (Correct Answer)
Explanation: ***The systemic vascular resistance is increased*** - During normal pregnancy, **systemic vascular resistance (SVR)** actually **decreases** due to vasodilation induced by factors like **prostaglandins** and **nitric oxide**. - A decrease in systemic vascular resistance helps accommodate the increased blood volume and cardiac output, ensuring adequate perfusion to the uteroplacental unit and other organs. *The cardiac output is increased* - **Cardiac output (CO)** progressively **increases** during pregnancy, peaking in the second and third trimesters. - This increase is primarily due to a rise in both **heart rate** and **stroke volume**. *The serum colloid pressure is decreased* - **Serum colloid osmotic pressure** (oncotic pressure) **decreases** in pregnancy due to a disproportionate increase in plasma volume relative to the increase in albumin production. - This leads to **dilutional hypoalbuminemia**, contributing to physiological edema. *The stroke volume is increased* - **Stroke volume (SV)** significantly **increases** during pregnancy, driven by increased end-diastolic volume and enhanced myocardial contractility. - This rise in stroke volume is a major contributor to the overall increase in cardiac output.
Question 33: A multiparous patient has been diagnosed to have foetal demise on a sonographic examination at 16 weeks of pregnancy. The ideal method for termination is
- A. High vaginal insertion of dinoprostone gel (Correct Answer)
- B. Extra-amniotic ethacridine
- C. Dilation and evacuation (D&E)
- D. Hysterectomy with tubectomy
Explanation: ***High vaginal insertion of dinoprostone gel*** - **Dinoprostone gel** (PGE2) is a **prostaglandin** that softens the cervix and stimulates uterine contractions, making it an ideal agent for medical induction in cases of fetal demise, particularly in the second trimester. - Its **vaginal insertion** allows for controlled, localized delivery and absorption, promoting efficient uterine evacuation while minimizing systemic side effects. *Extra-amniotic ethacridine* - **Ethacridine lactate** is typically used for **mid-trimester abortion** by direct instillation into the extra-amniotic space. - While effective, it carries a higher risk of infection and uterine rupture compared to prostaglandin administration for fetal demise at 16 weeks. *Dilation and evacuation (D&E)* - **D&E** is a surgical procedure commonly used for **second-trimester abortions**, involving cervical dilation and surgical removal of uterine contents. - While an option, medical induction with prostaglandins is generally preferred for **fetal demise** at 16 weeks due to lower risks of uterine injury and adhesions, as well as providing a more natural expulsion process. *Hysterectomy with tubectomy* - **Hysterectomy with tubectomy** (removal of the uterus and fallopian tubes) is a major surgical procedure that is **not indicated** for termination of pregnancy due to fetal demise. - It is reserved for severe medical conditions or desires for permanent sterilization, given its irreversible nature and significant surgical risks.
Pediatrics
1 questionsWhich is the most common laryngeal abnormality that produces laryngeal stridor in a newborn?
UPSC-CMS 2012 - Pediatrics UPSC-CMS Practice Questions and MCQs
Question 31: Which is the most common laryngeal abnormality that produces laryngeal stridor in a newborn?
- A. Congenital vocal cord paralysis
- B. Congenital web
- C. Laryngomalacia (Correct Answer)
- D. Congenital subglottic stenosis
Explanation: ***Laryngomalacia*** - **Laryngomalacia** is the most common cause of **congenital laryngeal stridor**, accounting for 60-70% of cases. - It results from the **floppiness of supraglottic structures** (epiglottis and arytenoids) that collapse inward during inspiration, causing stridor. *Congenital vocal cord paralysis* - While it can cause stridor, **congenital vocal cord paralysis** is much less common than laryngomalacia. - It typically results from neurological issues, and the stridor quality may differ. *Congenital web* - A **congenital web** is a rare cause of stridor, usually presenting with a **high-pitched persistent stridor** and often a weak cry. - The severity depends on the extent of the web across the glottis. *Congenital subglottic stenosis* - **Congenital subglottic stenosis** is the third most common cause of congenital stridor (after laryngomalacia and vocal cord paralysis). - It is characterized by narrowing of the airway below the vocal cords and often presents with biphasic stridor and recurrent croup-like symptoms.
Pharmacology
1 questionsWhich of the following local anaesthetics causes irreversible cardiac arrest if it is given intravenously ?
UPSC-CMS 2012 - Pharmacology UPSC-CMS Practice Questions and MCQs
Question 31: Which of the following local anaesthetics causes irreversible cardiac arrest if it is given intravenously ?
- A. Lignocaine
- B. Cocaine
- C. Bupivacaine (Correct Answer)
- D. Prilocaine
Explanation: ***Bupivacaine*** - Bupivacaine is known for its **cardiotoxicity**, which can lead to severe and often irreversible **cardiac arrest** if inadvertently administered intravenously. - This is due to its high potency, slow dissociation from cardiac sodium channels, and increased lipid solubility, leading to prolonged cardiac depression. *Lignocaine* - While lignocaine (lidocaine) can cause cardiac toxicity in overdose, it is generally considered less cardiotoxic than bupivacaine, and cardiac arrest is more readily reversible. - It is commonly used intravenously as an antiarrhythmic, indicating a safer cardiac profile at therapeutic doses. *Cocaine* - Cocaine is a vasoconstrictor and stimulant; its primary cardiovascular effects are **tachycardia**, hypertension, and arrhythmias due to inhibition of norepinephrine reuptake, rather than direct myocardial depression leading to irreversible cardiac arrest from intravenous injection in the same manner as bupivacaine. - Cocaine toxicity can cause myocardial ischemia and infarction, but not the same profound, irreversible cardiac depression seen with bupivacaine. *Prilocaine* - Prilocaine is associated with **methemoglobinemia** as a dose-dependent side effect, especially in large doses, due to its metabolite o-toluidine. - While it can cause cardiovascular depression at very high doses, it does not have the same potent and often irreversible direct negative inotropic effects on the heart as bupivacaine.