NEET-PG 2015

1414 Questions — Page 42 of 142

Anatomy

2 questions

Q411

Where are the stretch receptors located in the left atrium?

Q412

Which organ receives dual blood supply with both sources contributing to its primary metabolic function?

NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs

Question 411: Where are the stretch receptors located in the left atrium?

A. None of the options
B. Atrioventricular septum
C. Septum between the atria
D. Entrance of the pulmonary veins (Correct Answer)

Explanation: ***Entrance of the pulmonary veins*** - **Stretch receptors** are mechanoreceptors that detect changes in pressure and volume. In the left atrium, they are primarily located at the **junction of the pulmonary veins and the left atrium** [1]. - These receptors play a crucial role in the **Bainbridge reflex** and the release of **atrial natriuretic peptide (ANP)** in response to increased blood volume [1]. *Atrioventricular septum* - The **atrioventricular septum** separates the atria from the ventricles and primarily contains components of the **cardiac conduction system**, such as the AV node and bundle of His [2]. - While it has specialized tissues, it is not the primary location for **stretch receptors** involved in volume sensing. *Septum between the atria* - The **interatrial septum** primarily separates the right and left atria. - Although it contains some myocardial cells, it is not the main site for **stretch receptors** responsible for monitoring left atrial volume. *None of the options* - This option is incorrect because the **entrance of the pulmonary veins** is indeed the primary location for stretch receptors in the left atrium [1].

Question 412: Which organ receives dual blood supply with both sources contributing to its primary metabolic function?

A. Heart
B. Liver (Correct Answer)
C. Kidney
D. Lung

Explanation: ***Liver*** - The liver receives blood from two sources: the **hepatic artery** (supplying oxygenated blood, ~25% of blood flow) and the **hepatic portal vein** (supplying nutrient-rich, deoxygenated blood from the gastrointestinal tract, ~75% of blood flow). - Both blood supplies are essential for the liver's primary metabolic functions, detoxification, and nutrient processing [1]. - This is the classic example of dual blood supply in medical education. *Heart* - The heart receives its blood supply primarily from the **coronary arteries**, which branch off the aorta. - While it has an extensive arterial network, it has a single primary source of blood supply. *Kidney* - The kidneys receive their blood supply exclusively from the **renal arteries**, which branch directly from the aorta. - Each kidney typically has a single renal artery supplying it for high-pressure filtration. *Lung* - The lungs do receive blood from two sources: **pulmonary arteries** (deoxygenated blood for gas exchange) and **bronchial arteries** (oxygenated blood for tissue nourishment, <5% of flow). - However, the primary function (gas exchange) is served by pulmonary circulation alone, while bronchial circulation only nourishes lung tissue. - The liver is the standard answer for dual blood supply where both sources serve the organ's primary function.

Forensic Medicine

1 questions

Q411

Which of the following statements best describes a key characteristic of fingerprint development?

Pathology

5 questions

Q411

What is the most common nephropathy associated with malignancy?

Q412

IgA nephropathy is not associated with which of the following?

Q413

Characteristic feature of IgA nephropathy?

Q414

Most common type of renal carcinoma is:

Q415

Which histological type of lung cancer is most commonly associated with metastasis?

NEET-PG 2015 - Pathology NEET-PG Practice Questions and MCQs

Question 411: What is the most common nephropathy associated with malignancy?

A. Focal segmental glomerulosclerosis (FSGS)
B. Minimal change disease
C. IgA nephropathy
D. Membranous glomerulonephritis (Correct Answer)

Explanation: ***Membranous glomerulonephritis*** - **Membranous glomerulonephritis** has the strongest and most frequent association with solid organ malignancies, particularly in older patients. - While other glomerulopathies can be linked to cancer, **membranous nephropathy** is the most common paraneoplastic glomerulopathy in adults. *Focal segmental glomerulosclerosis (FSGS)* - While FSGS can be associated with certain cancers, particularly hematological malignancies and HIV-associated nephropathy, it is **less common** than membranous nephropathy in solid tumors. - The link is often with **HIV-associated nephropathy** or direct tumor effects rather than a paraneoplastic syndrome. *Minimal change disease* - Minimal change disease is predominantly seen in **children** and is less frequently associated with malignancy compared to membranous nephropathy. - When associated with malignancy, it is typically with **lymphoproliferative disorders** like Hodgkin lymphoma. *IgA nephropathy* - **IgA nephropathy** is the most common primary glomerulonephritis worldwide but has a **weak and inconsistent association** with malignancy. - Its presence alongside cancer is often coincidental rather than directly causative.

Question 412: IgA nephropathy is not associated with which of the following?

A. Focal mesangial proliferation
B. Gross hematuria concurrent with upper respiratory infection
C. Immunofluorescence deposits contain IgA and IgG
D. Decreased complement level (Correct Answer)

Explanation: ***Decreased complement level*** - IgA nephropathy is typically associated with **normal serum complement levels** (C3 and C4), which is an important distinguishing feature. - Unlike post-streptococcal glomerulonephritis or lupus nephritis where complement levels are **low/decreased**, IgA nephropathy does not cause systemic complement consumption. - While complement activation does occur locally in the glomerulus (via lectin and alternative pathways), it does not lead to a decrease in serum complement levels. *Focal mesangial proliferation* - This is a **common histological finding** in IgA nephropathy, reflecting the proliferative response to IgA deposition in the mesangium. - The mesangial cells proliferate in an attempt to clear the immune deposits. *Gross hematuria concurrent with upper respiratory infection* - This is a **classic clinical presentation** of IgA nephropathy, often referred to as **synpharyngitic hematuria**. - The episode of gross hematuria typically occurs **within 1-2 days** of the onset of an upper respiratory tract infection, distinguishing it from post-streptococcal glomerulonephritis where hematuria appears 1-3 weeks later. *Immunofluorescence deposits contain IgA and IgG* - The defining feature of IgA nephropathy on immunofluorescence is the **predominant deposition of IgA**, often accompanied by C3. - While IgA is the primary immunoglobulin, **IgG and IgM can also be present** in variable amounts, but IgA must be the dominant or co-dominant immunoglobulin for the diagnosis.

Question 413: Characteristic feature of IgA nephropathy?

A. More common in old age
B. It is a type of membranoproliferative GN
C. Gross hematuria presents after 10 days
D. Serum complement level is normal (Correct Answer)

Explanation: ***Serum complement level is normal*** - In **IgA nephropathy**, serum complement levels remain **normal** as this condition is not associated with complement consumption [1]. - This distinguishes it from other glomerulonephritides like **membranoproliferative GN**, where complement levels may be decreased. *Gross hematuria presents after 10 days* - Gross hematuria in IgA nephropathy often occurs **upon infection** or triggers, but not strictly after a set duration like 10 days [1]. - Typically, hematuria is seen with **episodic** flares rather than presenting consistently after a specific time frame. *More common in old age* - IgA nephropathy is actually more common in **young adults**, particularly males, rather than the elderly. - It is not characterized by age but rather often presents in **teenage years to early adulthood**. *It is a type of membranoproliferative GN* - IgA nephropathy is a **separate entity** and is predominantly characterized by the deposition of IgA in the mesangial regions [1], not classified under membranoproliferative GN. - This condition has distinct **pathological features** and immunological characteristics, differentiating it from membranoproliferative forms. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 928-929.

Question 414: Most common type of renal carcinoma is:

A. Clear cell type (Correct Answer)
B. Chromophobe type
C. Papillary type
D. Collecting duct type

Explanation: ***Clear cell type*** - The **clear cell type** is the most common subtype of renal carcinoma, constituting about **70-80%** of cases [3]. - It is typically associated with **von Hippel-Lindau syndrome** and presents with clear or "foamy" cells due to lipid accumulation [3]. *Chromophobe type* - This type comprises about **5-10%** of renal cell carcinomas and usually has a better prognosis [1]. - Characterized by **pale cells with distinct cell borders** and lacks the common features of clear cell carcinoma [1]. *Tubular type* - The tubular variant is less common and does not represent a major subtype of renal cell carcinoma. - It is often confused with other variants but lacks the distinct characteristics of the clear cell type. *Papillary type* - The papillary type accounts for about **10-15%** of renal carcinomas and is characterized by papillary structures [2]. - This type generally has a distinct chromosomal mutation profile compared to the clear cell type [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, p. 959. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 958-959. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 959-961.

Question 415: Which histological type of lung cancer is most commonly associated with metastasis?

A. Small cell carcinoma (Correct Answer)
B. Squamous cell carcinoma
C. Adenocarcinoma
D. Large cell carcinoma

Explanation: ***Squamous cell CA*** - Known for its **aggressive nature** and propensity to metastasize, particularly in later stages. - Typically arises in the **central part of the lungs**, often associated with smoking and leads to local invasion and distant spread. *Alveolar-carcinoma* - Rarely found and tends to be **less aggressive** compared to squamous cell carcinoma. - Usually has a more localized effect without the same potential for widespread metastasis. *Small cell carcinoma* - Although it is **highly metastatic**, it is less common than squamous cell carcinoma in terms of overall lung cancer incidence. - Characterized by its rapid growth and early metastasis [1], but mostly associated with a specific subtype of lung cancer cases. *Adenocarcinoma* - Generally presents as a **peripheral lung lesion** and has **less propensity for early metastasis** compared to squamous cell carcinoma. - More common in non-smokers and tends to have a less aggressive metastatic pattern. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Respiratory Tract Disease, pp. 337-338.

Physiology

2 questions

Q411

Which of the following statements is true regarding the Bezold-Jarisch reflex?

Q412

Which of the following factors is most commonly targeted therapeutically for blood pressure control?

NEET-PG 2015 - Physiology NEET-PG Practice Questions and MCQs

Question 411: Which of the following statements is true regarding the Bezold-Jarisch reflex?

A. Hypertension
B. Tachycardia
C. Hyperpnea
D. Hypotension (Correct Answer)

Explanation: ***Hypotension*** - The Bezold-Jarisch reflex is a **cardioinhibitory reflex** that is typically activated by strong ventricular contraction or noxious stimuli, leading to a triad of **bradycardia**, **peripheral vasodilation**, and subsequent **hypotension**. - This reflex is thought to be a protective mechanism to prevent excessive cardiac work or to trigger a "fainting" response to remove the body from danger. *Hypertension* - The Bezold-Jarisch reflex primarily causes a **decrease in blood pressure**, making hypertension an incorrect outcome. - Its activation directly opposes the mechanisms that would lead to increased blood pressure. *Tachycardia* - A key component of the Bezold-Jarisch reflex is **bradycardia** (slowing of the heart rate), not tachycardia. - This reflex is mediated by the vagus nerve, which primarily exerts inhibitory control over heart rate. *Hyperpnea* - The Bezold-Jarisch reflex primarily impacts **cardiovascular function** and does not directly cause hyperpnea (increased rate and depth of breathing). - While other reflexes can affect respiration, this particular reflex is not known for its respiratory effects.

Question 412: Which of the following factors is most commonly targeted therapeutically for blood pressure control?

A. Heart rate
B. Peripheral resistance (Correct Answer)
C. Cardiac output
D. Stroke volume

Explanation: ***Peripheral resistance*** - **Peripheral resistance** is primarily determined by the **arteriolar tone**, which can be effectively modulated by various antihypertensive medications. - Medications like **ACE inhibitors**, **ARBs**, **calcium channel blockers**, and **diuretics** all influence peripheral resistance to lower blood pressure. *Heart rate* - While heart rate contributes to **cardiac output** and thus blood pressure, it is not the most common primary target for hypertension management. - **Beta-blockers** reduce heart rate, but they are often used for specific indications beyond essential hypertension, such as angina or post-MI. *Cardiac output* - **Cardiac output** is a product of **heart rate** and **stroke volume**, and while it directly impacts blood pressure, directly targeting cardiac output as a whole is less common than modulating its individual components or peripheral resistance. - Many antihypertensive drugs reduce cardiac output as a secondary effect of reducing blood volume or heart rate, but directly reducing cardiac output is not the primary mechanism for the most common medications. *Stroke volume* - **Stroke volume** is influenced by **preload**, **afterload**, and **contractility**, and while it impacts cardiac output, it is generally less accessible for direct pharmacological manipulation in hypertension management compared to peripheral resistance. - **Diuretics** can indirectly reduce stroke volume by decreasing preload, but this is often considered a mechanism related to volume status rather than a direct myocardial effect.