NEET-PG 2013 Practice Questions

Q: Which nucleus is primarily involved in the Papez circuit?

Anterior nucleus of the thalamus. ***Anterior nucleus of the thalamus*** - The **anterior nucleus of the thalamus** is a key relay station in the Papez circuit [1], receiving input from the mamillary bodies and projecting to the cingulate gyrus. - This circuit is crucial for **memory formation** [2] and emotional processing. *Pulvinar nucleus* - The pulvinar nucleus is primarily involved in **visual processing**, attention, and eye movements. - It does not form a direct part of the classic Papez circuit for emotion and memory. *Intralaminar nucleus* - The intralaminar nuclei are involved in **arousal**, attention, and pain perception, with widespread projections to the cerebral cortex [1]. - They are not considered a primary component of the Papez circuit. *Ventral posterolateral (VPL) nucleus* - The VPL nucleus is a major **somatosensory relay** in the thalamus, transmitting touch, proprioception, and vibration information from the body to the cortex. - It has no direct role in the Papez circuit or limbic functions.

Q: Which of the following is the major glycosaminoglycan of synovial fluid?

Hyaluronic acid. ***Hyaluronic acid*** - **Hyaluronic acid** is the primary glycosaminoglycan in **synovial fluid**, providing its characteristic **viscosity** and **lubricating properties**. - It plays a crucial role in maintaining **joint health** by reducing friction and acting as a shock absorber. *Chondroitin sulfate* - **Chondroitin sulfate** is abundant in **cartilage**, contributing to its **compressive strength**. - While present in connective tissues, it is not the major glycosaminoglycan of synovial fluid. *Dermatan sulfate* - **Dermatan sulfate** is primarily found in **skin**, **blood vessels**, and **heart valves**. - Its main roles involve tissue structure and repair, not lubrication of synovial fluid. *Heparan sulfate* - **Heparan sulfate** is found on **cell surfaces** and in the **extracellular matrix**, especially in the **basement membranes**. - It regulates cell growth, adhesion, and signaling, and is not a major component of synovial fluid viscosity.

Q: Which of the following is NOT a feature of Peutz-Jeghers syndrome?

Autosomal recessive inheritance. ***High risk of malignancy*** - Peutz-Jeghers syndrome is primarily associated with **benign hamartomatous polyps**, not a **high risk of malignancy**, which distinguishes it from other syndromes. - Although patients may develop cancers [1], the syndrome itself does not inherently denote a high malignancy risk like other syndromes such as familial adenomatous polyposis. *Autosomal dominant* - This syndrome is indeed **autosomal dominant**, caused by mutations in the STK11 gene. - Families with this condition typically show **vertical transmission**, characteristic of autosomal dominant inheritance. *Hamartomatous polyp* - Individuals with Peutz-Jeghers syndrome develop **hamartomatous polyps**, which are a hallmark feature of the condition [1]. - These polyps can occur in the gastrointestinal tract and are benign lesions rather than adenomatous type seen in other syndromes [1]. *Mucocutaneous pigmentation* - Mucocutaneous pigmentation, such as **freckling around the lips and buccal mucosa**, is a key clinical feature of Peutz-Jeghers syndrome. - This pigmentation usually appears in childhood and is often a distinguishing sign of the syndrome.

Q: Which of the following is not an obstructive lung disease?

Interstitial fibrosis. ***Interstitial fibrosis*** - **Interstitial fibrosis** is a **restrictive lung disease**, characterized by **reduced lung elasticity** and lung volumes, rather than airway obstruction [1]. - In this condition, the **lung tissue becomes scarred and stiff**, making it difficult to expand fully during inspiration [1]. *Emphysema* - **Emphysema** is a classic **obstructive lung disease** caused by the destruction of the **alveolar walls**, leading to enlarged air spaces and loss of elastic recoil [3]. - This destruction results in **airflow limitation**, particularly during exhalation, as airways collapse prematurely. *Asthma* - **Asthma** is an **obstructive lung disease** characterized by **reversible airway inflammation**, bronchoconstriction, and increased mucus production [2]. - These factors lead to **episodic airflow obstruction**, making it difficult to breathe, especially during exacerbations [2]. *Bronchitis* - **Bronchitis**, particularly **chronic bronchitis**, is an **obstructive lung disease** defined by chronic inflammation of the bronchi. - This inflammation causes **mucus hypersecretion** and narrowing of the airways, leading to persistent cough and airflow limitation.

Q: In which condition are Pseudo-Pelger-Huët cells typically seen?

Myelodysplastic syndrome. ***Mylodysplastic syndrome*** - Pseudo-Pelger-Huet cells are characteristic and often observed in myelodysplastic syndromes, indicating an ineffective hematopoiesis [1]. - These cells appear as **hyposegmented neutrophils** and are associated with dysplastic changes in the bone marrow [1]. *Hairy cell leukemia* - Typically presents with **hairy cells** in peripheral blood and often involves splenomegaly; pseudo-Pelger-Huet cells are not usual in this condition. - Associated with **PANCYTOPENIA** and reticulin fibrosis, differing from myelodysplastic syndrome. *Hodgkin's lymphoma* - Characterized by the presence of **Reed-Sternberg cells** and typically involves lymphadenopathy. - Peripheral blood findings generally do not include pseudo-Pelger-Huet cells; the focus is on lymphatic tissue. *Multiple myeloma* - Commonly presents with **plasma cells** and related symptoms like bone pain and renal failure, not associated with pseudo-Pelger-Huet cells. - It primarily causes an increase in monoclonal proteins rather than dysplastic changes seen in myelodysplastic syndrome. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 613-614.

Q: Cell bodies of orexigenic neurons are present in?

Lateral hypothalamic area. ***Lateral hypothalamic area*** - The **lateral hypothalamic area** (LHA) contains neurons that produce **orexin (hypocretin)**, a neuropeptide critical for promoting appetite and wakefulness. - Stimulation of the LHA leads to increased food seeking and consumption, earning it the moniker "**feeding center**." *Dorsal raphe* - The **dorsal raphe nucleus** is a key source of **serotonin** in the brain, involved in mood, sleep-wake cycles, and appetite regulation (often promoting satiety). - It does not primarily house orexigenic neurons that directly stimulate appetite. *Locus coerulus* - The **locus coeruleus** is the primary source of **norepinephrine** in the brain, playing a significant role in arousal, attention, and stress response. - While it modulates appetitive behaviors indirectly, its neurons are not the primary orexigenic cell bodies. *Hippocampus* - The **hippocampus** is crucial for **learning, memory formation**, and spatial navigation. - It is not directly involved in the primary neural circuits that control hunger and satiety through orexigenic neuropeptides.

Q: Which of the following does not have sympathetic noradrenergic fibers?

Sweat gland. ***Sweat gland*** - While sweat glands are innervated by the **sympathetic nervous system**, their postganglionic fibers are **cholinergic**, releasing **acetylcholine** rather than noradrenaline. - This is an important exception where sympathetic stimulation leads to acetylcholine release, causing sweating. *Blood vessels* - Most blood vessels, particularly resistance vessels such as **arterioles**, receive substantial **sympathetic noradrenergic innervation** that causes vasoconstriction. - This sympathetic tone is crucial for regulating **blood pressure** and distributing blood flow. *Heart* - The heart is richly innervated by **sympathetic noradrenergic fibers** that increase **heart rate**, **contractility**, and **conduction velocity** via beta-1 adrenergic receptors. - This makes noradrenaline a key neurotransmitter in the sympathetic regulation of cardiac function. *Eye* - The eye receives sympathetic noradrenergic innervation primarily to the **dilator pupillae muscle**, causing **mydriasis** (pupil dilation) upon activation. - These fibers also contribute to the sympathetic control of the **tarsal muscle** (Müller's muscle) in the eyelid.

Q: In which of the following conditions is protein catabolism MOST increased?

Burns. ***Burns*** - Severe burns lead to a profound **hypermetabolic state** with the highest increase in **protein catabolism** among all the options listed. - The extensive tissue damage triggers massive breakdown of muscle protein to provide amino acids for **wound healing**, **acute phase protein synthesis**, and **immune response**. - Burns can increase metabolic rate by **100-200%**, with protein catabolism far exceeding that of other stress conditions. *Starvation* - While starvation initially increases protein catabolism, the body adapts within days by shifting towards **ketone body utilization** to spare protein. - After adaptation, protein breakdown decreases to **20-30 grams per day** to preserve lean body mass. - The goal is survival through metabolic adaptation, not tissue repair. *Surgery* - Major surgery induces a **stress response** that increases protein catabolism, but it is typically less severe and shorter-lived than burns. - The degree of catabolism is proportional to the **magnitude of surgical trauma** and usually resolves within days. - Protein catabolism increases by **50-75%** in major surgery compared to **100-200%** in severe burns. *Fever* - Fever increases basal metabolic rate by approximately **13% per degree Celsius** rise in body temperature. - While metabolism is elevated, protein catabolism is **modest** compared to the massive tissue destruction and repair demands of severe burns. - The increase is primarily in energy expenditure, not protein breakdown.

Question 1

Which nucleus is primarily involved in the Papez circuit?

Accepted Answer

Anterior nucleus of the thalamus

Answer

Pulvinar nucleus

Answer

Intralaminar nucleus

Answer

Ventral posterolateral (VPL) nucleus

Question 2

Which of the following statements about hemoglobin is true?

Accepted Answer

Hemoglobin consists of two alpha and two beta subunits, each capable of binding one O2 molecule.

Answer

Each hemoglobin molecule can bind up to six O2 molecules.

Answer

Each hemoglobin subunit contains two heme groups, which bind oxygen.

Answer

Each hemoglobin molecule is made of 6 polypeptide chains.

Question 3

Which of the following is the major glycosaminoglycan of synovial fluid?

Accepted Answer

Hyaluronic acid

Answer

Chondroitin sulfate

Answer

Dermatan sulfate

Answer

Heparan sulfate

Question 4

Which of the following is NOT a feature of Peutz-Jeghers syndrome?

Accepted Answer

Autosomal recessive inheritance

Answer

Mucocutaneous pigmentation

Answer

Autosomal dominant

Answer

Hamartomatous polyp

Question 5

Which of the following is not an obstructive lung disease?

Accepted Answer

Interstitial fibrosis

Answer

Emphysema

Answer

Asthma

Answer

Bronchitis

Question 6

In which condition are Pseudo-Pelger-Huët cells typically seen?

Accepted Answer

Myelodysplastic syndrome

Answer

Hairy cell leukemia

Answer

Multiple myeloma

Answer

Hodgkin's lymphoma

Question 7

What is the sequence of events in acute inflammation?

Accepted Answer

Transient vasoconstriction - Vasodilatation - Increased permeability - Stasis

Answer

Transient vasoconstriction - Stasis - Vasodilatation - Increased permeability

Answer

Transient vasoconstriction - Vasodilatation - Stasis - Increased permeability

Answer

Vasodilatation - Stasis - Transient vasoconstriction - Increased permeability

Question 8

Cell bodies of orexigenic neurons are present in?

Accepted Answer

Lateral hypothalamic area

Answer

Dorsal raphe

Answer

Locus coeruleus

Answer

Hippocampus

Question 9

Which of the following does not have sympathetic noradrenergic fibers?

Accepted Answer

Sweat gland

Answer

Heart

Answer

Eye

Answer

Blood vessels

Question 10

In which of the following conditions is protein catabolism MOST increased?

Accepted Answer

Burns

Answer

Surgery

Answer

Starvation

Answer

Fever

NEET-PG 2013

Anatomy

Biochemistry

Internal Medicine

Pathology

Physiology

Surgery