Anatomy
2 questionsWhich of the following statements is true regarding an epidural hematoma?
Base of sphenoid fuses with occiput at the age of -
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 421: Which of the following statements is true regarding an epidural hematoma?
- A. Inside the brain
- B. Between skull and dura mater (Correct Answer)
- C. Between skull and outermost periosteal layer
- D. Between scalp and outer skull layer
Explanation: ***Between skull and dura mater*** - An **epidural (extradural) hematoma** occurs when bleeding accumulates in the **potential space between the skull and the dura mater** [1]. - More precisely, it forms between the **periosteal layer of dura** (adherent to skull) and the **meningeal layer of dura**, stripping the dura away from the skull. - This typically results from a tear in the **middle meningeal artery** following traumatic head injury, classically from a **temporal bone fracture**. - Classic presentation: **lucid interval** followed by deterioration with **biconvex (lentiform) appearance** on CT scan [1]. *Inside the brain* - Bleeding *inside the brain parenchyma* itself is an **intracerebral hemorrhage**, not an epidural hematoma. - Caused by hypertension, trauma, vascular malformations, or hemorrhagic stroke. - CT shows intraparenchymal blood collection, not extra-axial. *Between skull and outermost periosteal layer* - This is anatomically **not a potential space** since the periosteal layer of dura is **firmly adherent** to the inner table of the skull. - An epidural hematoma actually strips this periosteal layer *away* from the skull, creating the space. - This option is incorrectly phrased and anatomically impossible as stated. *Between scalp and outer skull layer* - Bleeding *between the scalp and outer skull surface* is a **subgaleal hematoma** (crosses suture lines) or **cephalhematoma** in neonates (limited by suture lines). - These are **extracranial** collections, superficial to the skull bones. - Completely different from an **intracranial** epidural hematoma.
Question 422: Base of sphenoid fuses with occiput at the age of -
- A. 20 years (Correct Answer)
- B. 30 years
- C. 40 years
- D. 50 years
Explanation: ***20 years*** - The **spheno-occipital synchondrosis** typically fuses by the age of **20 to 25 years**, marking the cessation of growth in the cranial base. - This fusion is an important indicator of skeletal maturity and is often used in **forensic anthropology** for age estimation. *30 years* - Fusion of the **spheno-occipital synchondrosis** beyond the early twenties is considered late and is not the typical age for this event. - By 30 years, most cranial sutures and synchondroses are already fused. *40 years* - At 40 years of age, the **spheno-occipital synchondrosis** would have been completely fused for many years, making this an incorrect age for the fusion process itself. - This age is well past the usual developmental timeframe for cranial base closure. *50 years* - Fusion at 50 years would be an **anomalous finding** as this synchondrosis is known to fuse much earlier in life. - By this age, the skull is fully mature, and fusion events of this nature have long since completed.
Biochemistry
1 questionsWhat is the classification of Carcinoembryonic Antigen (CEA)?
NEET-PG 2015 - Biochemistry NEET-PG Practice Questions and MCQs
Question 421: What is the classification of Carcinoembryonic Antigen (CEA)?
- A. Glycoprotein (Correct Answer)
- B. Lipoprotein
- C. Phosphoprotein
- D. Nucleoprotein
Explanation: ***Glycoprotein*** - Carcinoembryonic Antigen (CEA) is classified as a **glycoprotein** due to its structure, which consists of both **carbohydrate** and **protein** components. - This glycosylation is crucial for its function as a cell adhesion molecule and its recognition in diagnostic assays. *Lipoprotein* - **Lipoproteins** are complexes of lipids and proteins that function primarily in **lipid transport** in the blood. - CEA's primary role and structure are not related to lipid transport or being predominantly lipid-based. *Phosphoprotein* - A **phosphoprotein** is a protein that has been **covalently modified by the addition of a phosphate group**, a process crucial for cell signaling. - While proteins can be phosphorylated, the defining characteristic and major classification of CEA is its extensive glycosylation rather than phosphorylation state. *Nucleoprotein* - **Nucleoproteins** are proteins that are **structurally associated with nucleic acids** (DNA or RNA), such as histones or ribosomal proteins. - CEA does not have a structural or functional association with nucleic acids.
Community Medicine
1 questionsThe strongest occupational risk factor for hematological carcinoma is
NEET-PG 2015 - Community Medicine NEET-PG Practice Questions and MCQs
Question 421: The strongest occupational risk factor for hematological carcinoma is
- A. Benzene (Correct Answer)
- B. Lithium
- C. Radiation exposure
- D. Cigarette smoke
Explanation: ***Benzene*** - Benzene exposure is recognized as a potent **carcinogen** linked to various hematological malignancies, including **leukemia** [1]. - It affects the **bone marrow**, leading to dysplastic changes and ultimately malignancy. *Nicotine* - Although nicotine is associated with **smoking-related cancers**, it is not directly linked to **hematological carcinomas**. - Its primary role is in causing **lung cancer**, rather than blood cancers. *Lithium* - Lithium is primarily used for **bipolar disorder** and does not have a known link to causing hematological malignancies. - Side effects are more related to **nephrotoxicity** rather than carcinogenic effects. *Alcohol* - Alcohol consumption is primarily associated with **liver cancers** and not specifically linked to hematological carcinomas [2]. - It can contribute to general malignancy development but is not a direct cause of blood cancers. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Neoplasia, p. 286. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 217-218.
Forensic Medicine
2 questionsWhat is the most specific sign of antemortem burns?
Which of the following statements best describes a key characteristic of fingerprint development?
NEET-PG 2015 - Forensic Medicine NEET-PG Practice Questions and MCQs
Question 421: What is the most specific sign of antemortem burns?
- A. Cyanosis of the fingernails
- B. Pugilistic attitude
- C. Heat ruptures
- D. Presence of soot in the respiratory passage (Correct Answer)
Explanation: ***Presence of soot in the respiratory passage*** - The presence of **soot** in the **trachea, bronchi, and lungs** is a definitive sign of **inhalation during a fire**, indicating the person was alive and breathing when exposed to the fire. - This finding demonstrates **vital reaction** to the fire and is crucial forensic evidence of **antemortem burns** or smoke inhalation. *Cyanosis of the fingernails* - **Cyanosis** indicates **hypoxia** or **poor oxygenation**, which can occur antemortem during a fire but is not specific to burns. - It can also be seen in other conditions leading to death, and its presence does not solely indicate vital reaction to fire. *Pugilistic attitude* - This refers to the **flexion of the limbs** and clenching of fists due to **heat-induced muscle contraction** and protein denaturation. - While common in fire deaths, it is a **postmortem phenomenon** resulting from heat acting on the body, not a sign of life during the fire. *Heat ruptures* - **Heat ruptures** (or heat fractures) are **skin tears** or bone fractures caused by intense heat, often mimicking traumatic injuries. - These are **postmortem artifacts** resulting from tissue expansion and cracking due to heat, and do not indicate vital reaction.
Question 422: Which of the following statements best describes a key characteristic of fingerprint development?
- A. Fingerprints are fully formed before birth. (Correct Answer)
- B. DNA analysis is the most specific method of identification.
- C. The most common type of fingerprint is loops.
- D. None of the options are true.
Explanation: ***Fingerprints are fully formed before birth.*** - Fingerprints begin to develop during the **fetal stage**, specifically between the 10th and 17th weeks of gestation. - Once formed, their unique ridge patterns remain **unchanged throughout life**, except for changes due to injury or disease. *DNA analysis is the most specific method of identification.* - While **DNA analysis** is a highly specific method of identification, the statement refers to its specificity generally, not as a characteristic of fingerprint development itself. - Fingerprints are a distinct form of identification based on unique **dermal ridge patterns**, independent of genetic material. *The most common type of fingerprint is loops.* - It is true that **loops** are indeed the most common type of fingerprint pattern, occurring in about 60-70% of the population. - However, this statement describes a characteristic of fingerprint patterns, not a key characteristic of their **development** or formation. *None of the options are true.* - This option is incorrect because the statement that **fingerprints are fully formed before birth** is a key characteristic of fingerprint development. - This option would only be correct if all other statements were false.
Pathology
3 questionsLines of Zahn are LEAST likely to be seen in -
Which of the following is a type of small vessel vasculitis?
Which protein is defective in dilated cardiomyopathy?
NEET-PG 2015 - Pathology NEET-PG Practice Questions and MCQs
Question 421: Lines of Zahn are LEAST likely to be seen in -
- A. Liver
- B. Kidney
- C. Heart
- D. Lung (Correct Answer)
Explanation: ***Lung*** - **Lines of Zahn are LEAST likely in the lungs** because most pulmonary thrombi are actually **emboli that formed elsewhere** (typically in deep leg veins) and then **lodged in pulmonary vessels**. - These pre-formed thrombi developed in **low-flow venous environments** and therefore **lack the characteristic layered appearance** of Lines of Zahn. - Even when thrombi form in situ in pulmonary vessels, the vascular bed characteristics make Lines of Zahn formation less common compared to other sites. *Heart* - **Mural thrombi** in heart chambers (especially post-MI in left ventricle or in atrial fibrillation) commonly show **Lines of Zahn**. - The **high-flow, turbulent environment** with continuous cardiac contractions creates ideal conditions for alternating platelet-fibrin and RBC layer deposition. - These are classic examples of antemortem thrombi with visible Lines of Zahn. *Liver* - **Portal vein thrombosis** and **hepatic vein thrombosis** (Budd-Chiari syndrome) can exhibit **Lines of Zahn**. - Despite being venous, these vessels have **sufficient flow velocity and turbulence** to allow layered thrombus formation. - Lines of Zahn indicate the thrombus formed during life with flowing blood. *Kidney* - **Renal artery thrombosis** and **renal vein thrombosis** frequently show **Lines of Zahn**. - Both arterial and venous renal circulation have adequate flow dynamics for layered thrombus formation. - These represent antemortem thrombi formed in vessels with active blood flow.
Question 422: Which of the following is a type of small vessel vasculitis?
- A. Classical PAN
- B. Giant cell arteritis
- C. Granulomatosis with polyangiitis (GPA) (Correct Answer)
- D. None of the options
Explanation: ***Granulomatosis with polyangiitis (GPA)*** - GPA is a prototypic **ANCA-associated small vessel vasculitis** characterized by necrotizing granulomas and vasculitis [1], [2]. - It commonly involves the **upper and lower respiratory tracts** and the **kidneys** with necrotizing granulomatous inflammation [1], [2]. - Classified as small vessel vasculitis according to the **Chapel Hill Consensus Conference** classification. *Classical PAN* - This refers to **Polyarteritis Nodosa (PAN)**, which is a **medium-sized vessel vasculitis**. - PAN is characterized by multifocal inflammatory and necrotizing lesions of medium-sized muscular arteries, **not small vessels**. *Giant cell arteritis* - **Giant cell arteritis (GCA)** is a **large vessel vasculitis** that primarily affects the aorta and its major branches, particularly the temporal artery [3]. - Symptoms include headache, jaw claudication, and visual disturbances, reflecting the involvement of larger blood vessels [3]. *None of the options* - This option is incorrect because Granulomatosis with polyangiitis (GPA) is a clear example of a small vessel vasculitis. - There is a correct answer among the provided choices. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 519-520. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 536-537. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 515-516.
Question 423: Which protein is defective in dilated cardiomyopathy?
- A. Tropomyosin
- B. Myosin
- C. Troponin
- D. Dystrophin (Correct Answer)
Explanation: ***Dystrophin*** - **Dystrophin** is a crucial protein in the **muscle cell membrane** that anchors the cytoskeleton to the extracellular matrix. - Defects in dystrophin lead to sarcolemmal fragility, causing muscle damage and can result in **dilated cardiomyopathy**, especially in conditions like **Duchenne muscular dystrophy** [1]. *Myosin* - **Myosin** is a fundamental **motor protein** involved in muscle contraction, forming the thick filaments. - While mutations in myosin can cause various cardiac conditions, like hypertrophic cardiomyopathy, direct primary defects in myosin are not typically identified as the cause of dilated cardiomyopathy [2]. *Troponin* - **Troponin** is a protein complex that regulates muscle contraction by controlling the interaction between actin and myosin, particularly in response to calcium. - Although troponins are vital for cardiac function and are released during myocardial injury, their primary defect is not typically implicated in the etiology of dilated cardiomyopathy [2]. *Tropomyosin* - **Tropomyosin** is a protein that winds around actin filaments and, along with troponin, regulates the binding of myosin to actin. - While essential for muscle contraction, direct defects in tropomyosin are not a common genetic cause of dilated cardiomyopathy. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Peripheral Nerves and Skeletal Muscles, pp. 1244-1245. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 574.
Psychiatry
1 questionsWhich hormone is primarily responsible for maintaining the luteal phase of the menstrual cycle?
NEET-PG 2015 - Psychiatry NEET-PG Practice Questions and MCQs
Question 421: Which hormone is primarily responsible for maintaining the luteal phase of the menstrual cycle?
- A. Estrogen
- B. Progesterone (Correct Answer)
- C. Follicle-stimulating hormone (FSH)
- D. Luteinizing hormone (LH)
Explanation: ***Progesterone*** - **Progesterone**, secreted by the **corpus luteum** after ovulation, is crucial for maintaining the luteal phase by preparing the **endometrium** for implantation. - It causes the endometrial lining to thicken and become more vascularized, creating a suitable environment for a fertilized egg. *Estrogen* - While **estrogen** is important throughout the menstrual cycle for endometrial proliferation, its primary role is in the **follicular phase**, not the maintenance of the luteal phase. - Estrogen levels are higher during the follicular phase, promoting the growth of the dominant follicle. *Follicle-stimulating hormone (FSH)* - **FSH** is primarily responsible for stimulating the growth and development of **ovarian follicles** during the follicular phase. - Its levels decrease significantly after ovulation, and it does not play a direct role in maintaining the luteal phase. *Luteinizing hormone (LH)* - **LH** triggers **ovulation** and the formation of the **corpus luteum** from the ruptured follicle. - While essential for initiating the luteal phase, its levels decline afterward, and it's not the primary hormone for *maintaining* the corpus luteum's function.