Anatomy
6 questionsWhich statement accurately describes a characteristic of synovial joints?
Which structures are located anterior to the transverse sinus?
The thoracic duct crosses from the right to the left at the level of
Anal valve is found in which part of anal canal?
What are the main types of cells found in the cerebellar cortex?
Inferior parathyroid develops from which pharyngeal pouch?
NEET-PG 2012 - Anatomy NEET-PG Practice Questions and MCQs
Question 391: Which statement accurately describes a characteristic of synovial joints?
- A. Hyaline cartilage covers the articular surfaces of synovial joints. (Correct Answer)
- B. The metacarpo-phalangeal joint is a condyloid joint.
- C. Cartilage can sometimes divide the joint into two cavities.
- D. Stability is inversely proportional to mobility in synovial joints.
Explanation: ***Hyaline cartilage covers the articular surfaces of synovial joints.*** - The articular surfaces of bones within a **synovial joint** are covered by a thin layer of **hyaline cartilage**, providing a smooth, low-friction surface for movement [1]. - This **articular cartilage** absorbs shock and protects the underlying bone from wear and tear [1]. - This is a **universal structural characteristic** of all synovial joints, making it the most accurate answer. *The metacarpo-phalangeal joint is a condyloid joint.* - While this statement is factually true (MCP joints are indeed **condyloid/ellipsoid joints** allowing movement in two planes), it describes a **specific type** of synovial joint, not a general characteristic of all synovial joints. - The question asks for a characteristic that describes synovial joints as a category, not an example of one specific joint classification. - This makes it incorrect as the best answer to this question. *Cartilage can sometimes divide the joint into two cavities.* - This statement refers to an **articular disc** or **meniscus**, which is a fibrocartilaginous structure that can partially or completely divide a synovial joint cavity. - This feature is present in **some** synovial joints (like the knee or temporomandibular joint) but is **not universal**. - Since it's not a characteristic of all synovial joints, it's not the best answer. *Stability is inversely proportional to mobility in synovial joints.* - Generally, there is an **inverse relationship** between **stability** and **mobility** in joints; joints designed for great mobility (e.g., shoulder) tend to be less stable, and vice-versa (e.g., hip). - However, this describes a **functional principle** or trade-off rather than a **structural characteristic** that defines synovial joints. - While true, it's not the defining characteristic being asked for in this question.
Question 392: Which structures are located anterior to the transverse sinus?
- A. Right atrium
- B. Left atrium
- C. Right pulmonary artery
- D. Aorta (Correct Answer)
Explanation: ***Aorta*** - The **transverse sinus of the pericardium** is a passage within the pericardial cavity that separates the great arteries (aorta and pulmonary trunk) anteriorly from the atria and great veins posteriorly. - The **ascending aorta** and **pulmonary trunk** are both located anterior to the transverse sinus. - This anatomical relationship is clinically important during cardiac surgery, as the transverse sinus can be used to pass ligatures around the great vessels. *Right atrium* - The **right atrium** is located posterior to the transverse sinus. - It forms part of the posterior wall of the pericardial cavity and receives the superior and inferior venae cavae. - The transverse sinus separates the atria from the anteriorly positioned great arteries. *Left atrium* - The **left atrium** is also positioned posterior to the transverse sinus. - It forms the base of the heart and receives the pulmonary veins. - Like the right atrium, it lies behind the plane of the transverse sinus. *Right pulmonary artery* - The **right pulmonary artery** is a branch of the pulmonary trunk that passes to the right lung. - While the **pulmonary trunk** itself is anterior to the transverse sinus, the **right pulmonary artery** branch courses laterally and posteriorly, passing behind the ascending aorta and superior vena cava. - Therefore, the right pulmonary artery is NOT considered anterior to the transverse sinus in the same way the main great vessels (aorta and pulmonary trunk) are.
Question 393: The thoracic duct crosses from the right to the left at the level of
- A. T12 vertebra
- B. T2 vertebra
- C. T4-T5 vertebra (Correct Answer)
- D. T6 vertebra
Explanation: ***T4-T5 vertebra*** - The **thoracic duct** crosses from the right to the left side of the vertebral column at the level of the **T4-T5 vertebrae**, specifically just above the root of the left lung. - This crossover is an important anatomical landmark as it signifies the duct's ascent towards the neck to drain into the left subclavian vein. *T12 vertebra* - The **thoracic duct** originates from the **cisterna chyli** at the level of the L1 or L2 vertebra and ascends into the thorax at or below the T12 vertebra, it does not cross over at this level. - This level primarily marks its entry into the thoracic cavity, not its main crossover point. *T6 vertebra* - While the **thoracic duct** is present in the thorax at this level, it does not undergo its characteristic crossover from right to left at the T6 vertebra. - The duct continues its ascent along the right side of the vertebral column before moving across. *T2 vertebra* - By the level of the T2 vertebra, the **thoracic duct** has already crossed to the left side of the vertebral column and is ascending towards its termination in the neck. - The crossover event occurs more inferiorly, at the T4-T5 level.
Question 394: Anal valve is found in which part of anal canal?
- A. Lower
- B. At anus
- C. Middle (Correct Answer)
- D. Upper
Explanation: ***Middle*** - The **anal valves** are crescentic folds located at the level of the **pectinate (dentate) line** in the middle portion of the anal canal. - They mark the inferior limit of the **anal columns** and form small recesses called **anal sinuses**. *Lower* - The lower part of the anal canal, below the pectinate line, is lined by **anoderm** and lacks anal valves. - This region is sensitive to pain due to somatic innervation. *At anus* - The anus refers to the external opening and perianal skin, which does not contain anal valves. - The anal canal transitions into the perianal skin at the anocutaneous line. *Upper* - The upper part of the anal canal, above the pectinate line, contains the **anal columns (columns of Morgagni)** but not the anal valves themselves, which are located at the base of these columns. - This region is lined by columnar epithelium and is relatively insensitive to pain.
Question 395: What are the main types of cells found in the cerebellar cortex?
- A. Purkinje cells, granule cells, and molecular layer interneurons (Correct Answer)
- B. Glomus cells
- C. Principal cells
- D. Intercalated cells
Explanation: **Purkinje cells, granule cells, and molecular layer interneurons** - The **cerebellar cortex** is characterized by distinct layers housing these cell types: **Purkinje cells** (large, inhibitory neurons), **granule cells** (small, excitatory neurons), and **molecular layer interneurons** (stellate and basket cells, inhibitory) [1]. - These cells work in concert to process motor information, with Purkinje cells serving as the sole output of the cerebellar cortex [1]. *Glomus cells* - **Glomus cells** are primarily found in the **carotid and aortic bodies**, where they act as chemoreceptors sensing changes in blood oxygen, carbon dioxide, and pH. - They are not a characteristic cell type of the cerebellar cortex. *Principal cells* - **Principal cells** is a general term often used to describe the main excitatory neurons of a brain region, such as **pyramidal cells in the cerebral cortex** or CA3 neurons in the hippocampus [2]. - While granule cells are excitatory in the cerebellum, "principal cells" is not a specific or exclusive term for cerebellar cortical cell types. *Intercalated cells* - **Intercalated cells** are specialized cells found in various locations, such as the **collecting ducts of the kidney** where they regulate acid-base balance, or in the **amygdala** as a type of inhibitory interneuron. - They do not represent a primary cell type of the cerebellar cortex.
Question 396: Inferior parathyroid develops from which pharyngeal pouch?
- A. 1st
- B. 2nd
- C. 3rd (Correct Answer)
- D. 4th
Explanation: The inferior parathyroid glands develop from the dorsal wing of the third pharyngeal pouch. Due to their origin, they often migrate further caudally than the superior parathyroid glands, sometimes even locating within the thymus which also develops from the third pouch. *1st* - The first pharyngeal pouch contributes to the formation of the eustachian tube, tympanic cavity, and mastoid air cells. - It has no role in the development of the parathyroid glands. *2nd* - The second pharyngeal pouch mainly gives rise to the palatine tonsils and their crypts. - It is not involved in the development of parathyroid tissue. *4th* - The fourth pharyngeal pouch gives rise to the superior parathyroid glands and the parafollicular cells (C cells) of the thyroid, which produce calcitonin. - While it forms parathyroid tissue, it is for the superior glands, not the inferior ones.
Internal Medicine
1 questionsRenal vein thrombosis is associated with all of the following conditions except:
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 391: Renal vein thrombosis is associated with all of the following conditions except:
- A. Nephrotic syndrome
- B. Dehydration
- C. Sickle cell anemia
- D. Trauma (Correct Answer)
Explanation: **Trauma** - While trauma to the abdomen can cause **renal injury** and other vascular issues, isolated **renal vein thrombosis** is not a common direct association or complication [1]. - Renal vein thrombosis typically results from conditions that lead to a **hypercoagulable state** or local vascular stasis. *Sickle cell anemia* - Individuals with **sickle cell anemia** are prone to **vaso-occlusive crises** from sickled red blood cells obstructing blood flow [2]. - This can lead to **renal medullary ischemia** and infarction, making them highly susceptible to **renal vein thrombosis**. *Nephrotic syndrome* - **Nephrotic syndrome** is a significant risk factor for **renal vein thrombosis** due to the urinary loss of **antithrombin III**, a natural anticoagulant. - This loss creates a **hypercoagulable state**, increasing the likelihood of thrombus formation in renal veins. *Dehydration* - Severe **dehydration** leads to **hemoconcentration** (increased blood viscosity) and reduced blood flow. - These factors promote a **hypercoagulable state**, increasing the risk of thrombotic events, including **renal vein thrombosis**, especially in vulnerable populations like infants or the elderly.
Physiology
3 questionsWhich type of carbohydrate is absorbed most efficiently from the gastrointestinal tract?
Motilin secretion is decreased in which of the following states?
What is the average progressive velocity of human sperm under standard laboratory conditions?
NEET-PG 2012 - Physiology NEET-PG Practice Questions and MCQs
Question 391: Which type of carbohydrate is absorbed most efficiently from the gastrointestinal tract?
- A. Disaccharides
- B. Polysaccharides
- C. Monosaccharides (Correct Answer)
- D. 5-carbon sugars
Explanation: ***Monosaccharides*** - **Monosaccharides**, like glucose and fructose, are the simplest forms of carbohydrates and do not require further digestion. - They are directly absorbed into the bloodstream from the intestinal lumen via specific **transporters** on the enterocyte membrane. *Disaccharides* - **Disaccharides**, such as sucrose and lactose, must first be broken down into their constituent monosaccharides by **brush border enzymes** (e.g., lactase, sucrase) before absorption can occur. - This additional enzymatic step makes their absorption less efficient than that of monosaccharides. *Polysaccharides* - **Polysaccharides**, including starch and glycogen, are complex carbohydrates requiring extensive digestion by enzymes like **amylase** in the mouth and small intestine. - This multi-step breakdown into monosaccharides is the least efficient process and takes the longest time. *5-carbon sugars* - While 5-carbon sugars (**pentoses**) like ribose and deoxyribose are monosaccharides and can be absorbed, they are not a primary energy source in the diet and are not absorbed as efficiently or in as large quantities as the metabolically more significant 6-carbon monosaccharides (hexoses like glucose). - The question asks which *type* of carbohydrate is most efficiently absorbed, and **monosaccharides** as a general category (including 6-carbon sugars) are the most efficient.
Question 392: Motilin secretion is decreased in which of the following states?
- A. Thirsty
- B. Starving
- C. Ingested meal (Correct Answer)
- D. Interdigestive state
Explanation: ***Ingested meal*** - Motilin secretion is **decreased after a meal** due to the presence of food in the small intestine, which stimulates other gastrointestinal hormones and neuronal reflexes that inhibit motilin release. - The primary role of motilin is to stimulate **gastric and intestinal motility** during fasting, clearing residual food and preventing bacterial overgrowth, making its activity counterproductive during digestion. *Thirsty* - **Thirst** is primarily regulated by antidiuretic hormone (ADH) and the renin-angiotensin-aldosterone system, and it does not directly impact motilin secretion. - Motilin's main function is related to gut motility, largely independent of the body's hydration status. *Starving* - Motilin levels tend to be **higher during fasting or starvation**, as it plays a crucial role in initiating the **migrating motor complex (MMC)**, which sweeps undigested material through the gastrointestinal tract. - This activity prevents bacterial overgrowth and prepares the gut for the next meal; thus, its secretion is increased, not decreased. *Interdigestive state* - The **interdigestive state** refers to the period between meals, which is synonymous with a fasting or starving state. - During this period, motilin secretion is **increased** to stimulate the **migrating motor complex (MMC)**, which is essential for gut cleansing.
Question 393: What is the average progressive velocity of human sperm under standard laboratory conditions?
- A. 1-3 mm/min (Correct Answer)
- B. 4-6 mm/min
- C. 6-9 mm/min
- D. 10-13 mm/min
Explanation: ***1-3 mm/min*** - The typical average progressive velocity of human sperm, categorized as **Grade A (rapid progressive)** motility, ranges from **25 micrometers/second or faster**, which translates to approximately 1-3 mm/minute. - This velocity is crucial for sperm to traverse the female reproductive tract and reach the ovum for fertilization. *4-6 mm/min* - This velocity range is significantly faster than the **average progressive velocity** observed in viable human sperm under standard laboratory conditions. - While some individual sperm may achieve higher speeds, this range is not representative of the **average progressive motility** of a healthy sperm population. *6-9 mm/min* - This progressive velocity is exceptionally high and not typically observed as the average for human sperm, even for highly motile sperm. - Such a high velocity would indicate an **abnormally fast movement** not compatible with biological norms for average progressive motility. *10-13 mm/min* - This range represents an extremely rapid progressive velocity for human sperm, well beyond physiological averages. - It does not align with the standard measurements for **progressive motility**, which are generally much lower.