Anatomy
6 questionsWhat is the typical length of the anal canal in adults?
Superior wall of middle ear is formed by ?
What is the most dependent part of the peritoneal cavity in a female in the standing position?
What is Galen's anastomosis?
All pass through jugular foramen except
Which muscle is the deepest in the anterior neck region?
NEET-PG 2013 - Anatomy NEET-PG Practice Questions and MCQs
Question 141: What is the typical length of the anal canal in adults?
- A. 10 - 15 mm
- B. 15 - 20 mm
- C. 25 - 30 mm
- D. 35 - 40 mm (Correct Answer)
Explanation: ***35 - 40 mm*** - The **anal canal** in adults typically measures between **3.5 to 4.0 cm** (35 to 40 mm) in length. - This length is measured from the **anorectal ring** to the **anal verge**. *10 - 15 mm* - This length is too short for the **adult anal canal**; it's approximately one-third of the actual length. - Such a short measurement would be anatomically incorrect and clinically significant for various colorectal conditions. *15 - 20 mm* - This measurement is still significantly shorter than the average length of the **adult anal canal**. - A canal this short would likely be pathological or developmental in origin. *25 - 30 mm* - While closer, this range is still generally below the accepted average length of the **adult anal canal**. - Precise anatomical measurements are crucial for diagnostic and surgical procedures in proctology.
Question 142: Superior wall of middle ear is formed by ?
- A. Tegmen tympani (Correct Answer)
- B. Jugular bulb
- C. Tympanic membrane
- D. Carotid wall
Explanation: ***Tegmen tympani*** - The **tegmen tympani** is a thin plate of **petrous temporal bone** that forms the roof or superior wall of the middle ear cavity. - This structure separates the middle ear from the **middle cranial fossa** and its contents, including the **temporal lobe of the brain**. *Jugular bulb* - The **jugular bulb** is the dilated superior portion of the **internal jugular vein** and forms part of the **floor (inferior wall)** of the middle ear cavity, not the superior wall. - Its close proximity to the middle ear makes it vulnerable to injury during otologic surgery. *Tympanic membrane* - The **tympanic membrane** (eardrum) forms the **lateral wall** of the middle ear cavity, separating it from the external auditory canal. - It is crucial for **sound transmission** by vibrating in response to sound waves. *Carotid wall* - The **carotid wall** forms the **anterior wall** of the middle ear cavity and is related to the **internal carotid artery** as it narrows through the carotid canal. - This wall is not the superior boundary of the middle ear.
Question 143: What is the most dependent part of the peritoneal cavity in a female in the standing position?
- A. Vesicouterine pouch
- B. Paracolic gutter
- C. Pouch of Douglas (Correct Answer)
- D. None of the options
Explanation: ***Pouch of Douglas*** - The **rectouterine pouch** (Pouch of Douglas) is the most dependent part of the peritoneal cavity in females when standing. - It lies between the **rectum posteriorly** and the **uterus anteriorly**, extending down to the posterior fornix of the vagina [1]. - Due to gravity, any free fluid in the peritoneal cavity (blood, pus, ascitic fluid) collects here in the upright position. - **Clinical significance:** This is why culdocentesis (needle aspiration through the posterior vaginal fornix) can detect intraperitoneal fluid [1]. *Vesicouterine pouch* - Located between the **uterus posteriorly** and the **bladder anteriorly** [1]. - It is **superior** to the Pouch of Douglas and therefore not the most dependent part. - Fluid would collect in the Pouch of Douglas before reaching this pouch in a standing position. *Paracolic gutter* - The **paracolic gutters** are peritoneal recesses lateral to the ascending and descending colon. - While they can collect fluid, they are **not the lowest point** in the peritoneal cavity in an upright position. - The right paracolic gutter can serve as a pathway for fluid to spread between the pelvis and subphrenic spaces. *None of the options* - This is incorrect as the **Pouch of Douglas** is definitively the most dependent part of the peritoneal cavity in females in the standing position. - It is a well-established anatomical fact taught in all standard anatomy textbooks.
Question 144: What is Galen's anastomosis?
- A. Recurrent laryngeal nerve and external laryngeal nerve
- B. Internal laryngeal nerve and recurrent laryngeal nerve (Correct Answer)
- C. None of the options
- D. Recurrent laryngeal nerve and sympathetic trunk
Explanation: ***Internal laryngeal nerve and recurrent laryngeal nerve*** - **Galen's anastomosis** (also known as **ansa Galeni**) is the connection between the **internal laryngeal nerve** (a sensory branch of the superior laryngeal nerve) and the **recurrent laryngeal nerve** (motor branch of the vagus nerve). - This anastomosis occurs in the **laryngeal mucosa** and allows for communication between these two important nerves. - The **internal laryngeal nerve** provides **sensory innervation** to the larynx above the vocal cords, while the **recurrent laryngeal nerve** provides **motor innervation** to most intrinsic laryngeal muscles (except cricothyroid). - This anastomosis is clinically significant in understanding the complex innervation patterns of the larynx. *Recurrent laryngeal nerve and external laryngeal nerve* - While both nerves are branches of the vagus nerve and innervate laryngeal structures, this connection does not constitute **Galen's anastomosis**. - The recurrent laryngeal nerve innervates intrinsic laryngeal muscles (except cricothyroid), while the external laryngeal nerve innervates the **cricothyroid muscle** and is motor in nature. *None of the options* - This option is incorrect because the correct definition of **Galen's anastomosis** is provided in the first option. *Recurrent laryngeal nerve and sympathetic trunk* - While there may be sympathetic contributions to laryngeal innervation, this does not represent **Galen's anastomosis**. - The sympathetic trunk provides autonomic innervation but the specific named anastomosis refers to the connection between the internal laryngeal and recurrent laryngeal nerves.
Question 145: All pass through jugular foramen except
- A. Mandibular nerve (Correct Answer)
- B. Vagus nerve
- C. Internal jugular vein
- D. Glossopharyngeal nerve
Explanation: ***Mandibular nerve*** - The **mandibular nerve** (CN V3) exits the skull through the **foramen ovale**, not the jugular foramen. - It is a branch of the **trigeminal nerve** and is responsible for motor innervation to muscles of mastication and sensory innervation to the lower face and mouth. *Glossopharyngeal nerve* - The **glossopharyngeal nerve** (CN IX) is one of the three cranial nerves that exit through the **jugular foramen**. - It provides motor, sensory, and parasympathetic innervation including taste from posterior third of tongue and motor to stylopharyngeus muscle. *Vagus nerve* - The **vagus nerve** (CN X) is one of the major cranial nerves that exits the skull through the **jugular foramen**. - It provides extensive motor, sensory, and parasympathetic innervation to the head, neck, thorax, and abdomen. *Internal jugular vein* - The **internal jugular vein** is formed at the jugular foramen by the continuation of the **sigmoid sinus**, and it exits the skull through this foramen. - It is one of the primary venous drainage pathways for the brain.
Question 146: Which muscle is the deepest in the anterior neck region?
- A. Sternocleidomastoid
- B. Platysma
- C. Longus colli (Correct Answer)
- D. Trapezius
Explanation: ***Longus colli*** - The **longus colli** muscle is the **deepest muscle** located in the anterior neck region, running along the front of the cervical vertebral column from C1 to T3. - It lies in the **prevertebral layer**, deep to all other anterior neck structures including the carotid sheath, visceral compartment, and superficial muscles. - Its position directly anterior to the vertebral bodies makes it the deepest anterior neck muscle. *Platysma* - The platysma is the **most superficial muscle** of the neck, located just beneath the skin in the superficial fascia. - It is not a deep muscle and lies superficial to all other neck muscles. *Sternocleidomastoid* - The sternocleidomastoid is enclosed within the **investing layer of deep cervical fascia**, making it relatively superficial. - While prominent in the anterior and lateral neck, it is not the deepest anterior neck muscle. *Trapezius* - The trapezius is a large, **superficial muscle of the back and posterior neck**. - It is not located in the anterior neck and is a superficial, not deep, muscle.
Internal Medicine
1 questionsCryoprecipitate is useful in which of the following conditions?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 141: Cryoprecipitate is useful in which of the following conditions?
- A. Hemophilia A
- B. Thrombosthenia
- C. Warfarin reversal
- D. Afibrinogenemia (Correct Answer)
Explanation: ***Afibrinogenemia*** - Cryoprecipitate is rich in **fibrinogen**, factor VIII, factor XIII, von Willebrand factor, and fibronectin. It is the only blood product with a substantial concentration of fibrinogen. - **Afibrinogenemia** (or hypofibrinogenemia) is a condition characterized by low or absent levels of fibrinogen, a critical clotting factor that cryoprecipitate replaces effectively. *Hemophilia A* - Hemophilia A is a deficiency of **Factor VIII**. While cryoprecipitate contains factor VIII, **recombinant Factor VIII concentrates** are the preferred treatment due to better safety (reduced risk of viral transmission) and more precise dosing [1]. - Cryoprecipitate was historically used for Hemophilia A before the availability of safer, more specific factor concentrates [2]. *Thrombosthenia* - Thrombasthenia is a platelet function disorder characterized by defective **glycoprotein IIb/IIIa receptors** on platelets, leading to impaired platelet aggregation. - Cryoprecipitate does not contain platelets or factors that directly correct platelet function, making **platelet transfusions** the treatment of choice for severe bleeding in thrombasthenia. *Warfarin reversal* - Warfarin reversal is primarily achieved using **Vitamin K**, which restores levels of functional clotting factors II, VII, IX, and X. - For rapid reversal in emergencies, **prothrombin complex concentrate (PCC)** is preferred because it contains high concentrations of these vitamin K-dependent factors, addressing the primary deficiency caused by warfarin [1].
Pharmacology
3 questionsWhich of the following statements is true regarding omalizumab?
Which of the following drugs is known to have low first pass metabolism?
Which of the following drugs is used for Smoking Cessation?
NEET-PG 2013 - Pharmacology NEET-PG Practice Questions and MCQs
Question 141: Which of the following statements is true regarding omalizumab?
- A. Anti-IgE
- B. Given subcutaneously
- C. Used as add-on therapy in moderate to severe asthma prophylaxis
- D. All of the options (Correct Answer)
Explanation: ***All of the options*** is correct because each statement is true: **Anti-IgE** - Omalizumab is a **humanized monoclonal antibody** that specifically targets and binds to **free IgE** in the circulation - By binding free IgE, it prevents IgE from attaching to **high-affinity receptors** on mast cells and basophils - This reduces the allergic cascade and prevents release of inflammatory mediators **Given subcutaneously** - Omalizumab is administered via **subcutaneous injection** only - Dosing is typically every **2 to 4 weeks** based on patient's body weight and baseline IgE levels - Not available in oral or intravenous formulations for asthma treatment **Used as add-on therapy in moderate to severe asthma prophylaxis** - FDA approved as **add-on maintenance treatment** for patients aged ≥6 years with **moderate to severe persistent allergic asthma** - Indicated when asthma is **inadequately controlled** with inhaled corticosteroids - Reduces frequency of asthma exacerbations and improves asthma control - Also approved for chronic spontaneous urticaria All three statements accurately describe omalizumab's mechanism, administration route, and clinical indication, making **"All of the options"** the correct answer.
Question 142: Which of the following drugs is known to have low first pass metabolism?
- A. Lidocaine
- B. Propranolol
- C. Theophylline (Correct Answer)
- D. Morphine
Explanation: ***Theophylline*** - **Theophylline** exhibits **low first-pass metabolism**, meaning a significant portion of the orally administered drug reaches systemic circulation unchanged. - This characteristic contributes to its relatively **high bioavailability** when given orally. *Lidocaine* - **Lidocaine** undergoes extensive **first-pass metabolism** in the liver, leading to very low oral bioavailability. - Due to this, it is typically administered **parenterally** (e.g., intravenously or topically) to achieve therapeutic concentrations. *Propranolol* - **Propranolol** is known for its significant **first-pass metabolism**, which results in a much lower bioavailability after oral administration compared to intravenous. - This extensive metabolism necessitates higher oral doses to achieve the same therapeutic effect as parenteral administration. *Morphine* - **Morphine** also undergoes substantial **first-pass metabolism** in the liver, where it is primarily glucuronidated. - This leads to a lower oral bioavailability compared to other routes of administration and contributes to a higher oral dose requirement.
Question 143: Which of the following drugs is used for Smoking Cessation?
- A. Bupropion (Correct Answer)
- B. Methadone
- C. Buprenorphine
- D. Naltrexone
Explanation: ***Bupropion*** - **Bupropion** is an antidepressant that is also approved as a smoking cessation aid. It works by inhibiting the reuptake of **dopamine** and **norepinephrine**, which can help reduce nicotine cravings and withdrawal symptoms. - It is often prescribed as a first-line pharmacotherapy for smoking cessation, with a typical treatment duration of 7-12 weeks. *Buprenorphine* - **Buprenorphine** is a partial opioid agonist primarily used to treat opioid addiction. It is not indicated for smoking cessation. - While it can help manage withdrawal symptoms from opioids, it has no direct mechanism of action that would reduce nicotine dependence or cravings. *Methadone* - **Methadone** is a full opioid agonist primarily used for the treatment of opioid use disorder (OUD) and chronic pain management. It is not used for smoking cessation. - Its mechanism involves binding to opioid receptors to prevent withdrawal symptoms and reduce cravings for other opioids. *Naltrexone* - **Naltrexone** is an opioid antagonist used primarily for the treatment of alcohol dependence and opioid use disorder. It is not indicated for smoking cessation. - It blocks the effects of opioids and reduces alcohol cravings, but does not affect nicotine pathways or dependence.