NEET-PG 2013 Practice Questions

Q: Attachment of the vitreous is strongest at?

Across ora serrata. ***Across ora serrata*** - The **vitreous base** is a 3-4 mm wide circumferential band extending approximately 2 mm anterior and 2 mm posterior to the **ora serrata**, where the vitreous firmly adheres to the **non-pigmented ciliary epithelium** and the **peripheral retina**. - This strong adhesion makes the **vitreous base** the primary point of vitreous attachment, often remaining attached even during significant vitreous detachments. *Foveal region* - While there is some attachment, the vitreous is typically **less firmly adherent** to the foveal region compared to the vitreous base. - Vitreous detachment from the fovea is a common event, rarely leading to significant tearing or strong adherence. *Back of lens* - The vitreous has a weak attachment to the posterior capsule of the lens, known as the **Wieger's ligament** or **hyaloideocapsular ligament**. - This attachment typically **loses strength with age** and is not the strongest overall point of attachment. *Margin of optic disc* - The vitreous attaches to the margin of the optic disc, forming a circular adhesion called the **peripapillary ring**. - This attachment is **less strong** than the vitreous base and is often the first region from which the vitreous detaches during a **posterior vitreous detachment (PVD)**.

Q: Number of ATP molecules formed per turn of the citric acid cycle is

10. ***10*** - Each turn of the citric acid cycle directly produces **1 GTP** molecule (which is equivalent to 1 ATP). - Additionally, it generates **3 NADH** and **1 FADH2**, which upon oxidative phosphorylation yield approximately **2.5 ATP per NADH** and **1.5 ATP per FADH2**. - Total calculation: (3 × 2.5) + (1 × 1.5) + 1 (from GTP) = 7.5 + 1.5 + 1 = **10 ATP equivalents** per turn. *5* - This number is **too low** and does not account for the significant energy yield from the **NADH** and **FADH2** molecules produced during the cycle. - It likely only considers a partial or incorrect calculation of the ATP equivalents generated. *7* - This value is **insufficient** as it underestimates the total ATP generated when considering the contributions from both **direct substrate-level phosphorylation (GTP)** and the **electron transport chain**. - It may arise from an incomplete understanding of the ATP yield from NADH and FADH2. *15* - This number is **too high** for the ATP equivalents produced per turn of the citric acid cycle. - Such a value would imply a higher energy yield from the electron carriers or direct ATP production than is biologically accurate.

Q: In forensic pathology, what term describes neck compression injuries caused by forearm pressure?

Mugging. ***Mugging*** - This is the **standard forensic pathology term** for neck compression injuries caused by **forearm or arm pressure**, typically applied in a "chokehold" or "arm-hold" position. - Also known as **"bansdola"** in Indian forensic literature, this mechanism involves **circumferential or lateral neck compression** by the forearm/arm, often seen in assault or robbery scenarios. - The injury pattern shows **broad, diffuse bruising** without the linear marks of ligature or discrete fingerprint marks of manual strangulation. - Distinguished by the **absence of a ligature mark** and the presence of **deep soft tissue hemorrhages** in the neck structures. *Garrotting with a stick* - This involves **ligature strangulation** where a **ligature is tightened using a stick** or similar implement as a tourniquet. - The injuries show **specific patterned marks** consistent with the ligature and the **twisting mechanism**. - This differs from mugging, which uses direct arm/forearm pressure without any ligature. *Strangulation with rope* - This refers to **ligature strangulation** using a **rope**, resulting in a **distinct linear mark** consistent with the rope's texture and diameter. - The ligature mark is typically **oblique, ascending** in hanging or **horizontal/variable** in strangulation. - The mechanism involves external compression by a **specific ligature object**, not the human forearm. *Manual strangulation with hands* - This involves **direct neck compression** by the **hands, fingers, or thumbs** of an assailant. - Injuries typically include **fingernail abrasions**, **fingertip bruises**, and **crescent-shaped marks** corresponding to individual digits. - These discrete marks are distinct from the **broad pressure pattern** seen in mugging with forearm compression.

Q: The culture medium used for Entamoeba histolytica is

TYI-S-33 medium. ***TYI-S-33 medium*** - **TYI-S-33 (Trypticase-Yeast extract-Iron-Serum) medium** is the most commonly used axenic culture medium for *Entamoeba histolytica*, meaning it supports the growth of the amoeba in the absence of other microorganisms. - This medium provides the necessary nutrients, including **trypticase**, **yeast extract**, **iron**, and **serum**, for the proliferation and maintenance of *E. histolytica* cultures in vitro. - It is the gold standard for axenic cultivation in research and diagnostic laboratories. *Robinson's medium* - **Robinson's medium** is a diphasic medium, meaning it has both solid and liquid phases, and is used for culturing *Entamoeba histolytica* but it is a **xenic** culture medium, meaning it requires the presence of other microorganisms (bacterial flora). - This medium was historically important but is less commonly used for routine culture and has been largely replaced by axenic media like TYI-S-33 for research and diagnostic purposes. *CLED medium* - The **Cystine-Lactose-Electrolyte-Deficient (CLED) medium** is a differential culture medium primarily used for the isolation and enumeration of urinary pathogens. - It is designed to prevent **swarming of Proteus species** and to differentiate lactose fermenters from non-fermenters, but it is not suitable for growing *Entamoeba histolytica*. *Blood agar* - **Blood agar** is a general-purpose enriched agar medium used for the isolation and cultivation of a wide variety of fastidious and non-fastidious bacteria. - It is particularly useful for demonstrating **hemolytic reactions** of bacteria, which are important for bacterial identification, but it does not support the growth of parasitic protozoa like *Entamoeba histolytica*.

Q: True about proximal fragment in subtrochanteric fracture is?

All of the options. ***All of the options*** - In a subtrochanteric fracture, the **proximal fragment** is under the influence of several strong muscle groups, leading to a characteristic displacement. - The **iliopsoas muscle** causes **flexion**, the **gluteus medius and minimus** cause **abduction**, and the **short external rotators** cause **external rotation**. *Flexion* - The powerful **iliopsoas muscle** inserts on the lesser trochanter and acts to flex the hip. - This muscle pulls the proximal fragment anteriorly and superiorly, resulting in a **flexion deformity**. *Abduction* - The **gluteus medius and minimus muscles** attach to the greater trochanter and exert a strong abducting force. - This action pulls the proximal fragment away from the midline, causing **abduction**. *External rotation* - The **short external rotators** (e.g., piriformis, obturators, gemelli) insert around the greater trochanter. - These muscles collectively cause the proximal fragment to rotate outwards, resulting in **external rotation**.

Q: Which of the following is not a myeloproliferative disorder?

Acute myeloid leukemia. ***Acute myeloid leukemia*** - *Acute myeloid leukemia (AML)* is a **myeloid neoplasm** characterized by the rapid proliferation of myeloid cells and is classified as an acute leukemia, not a myeloproliferative disorder. - It involves **highly abnormal cells** that impede normal blood cell production, contrasting with chronic myeloproliferative disorders which have a more gradual progression. *Essential thrombocytosis* - This is a true **myeloproliferative disorder** characterized by an **increase in platelet count** and is due to the increased production of megakaryocytes in the bone marrow [1]. - Patients can present with thrombotic or hemorrhagic complications, supporting its classification as a myeloproliferative neoplasm. *Chronic myeloid leukemia* - Chronic myeloid leukemia (CML) is another type of **myeloproliferative disorder**, arising from a genetic mutation leading to excessive production of myeloid cells. - It is associated with the **Philadelphia chromosome** and typically presents in a chronic phase with variable leukocytosis. *Polycythemia vera* - Polycythemia vera is a **myeloproliferative neoplasm** characterized by hyperproduction of red blood cells, often accompanied by leukocytosis and thrombocytosis [1]. - It is associated with mutations in the **JAK2 gene**, leading to increased erythropoiesis and elevation of hemoglobin levels, confirming its classification [1]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 614-615.

Q: Which immunohistochemical marker is primarily associated with glomus tumors?

CD-34. ***CD-34*** (Marked answer, but controversial) - **IMPORTANT NOTE:** This association is **contested** in modern pathology literature. - Glomus tumors are derived from modified smooth muscle cells of the glomus body and typically show **smooth muscle actin (SMA)** and **vimentin positivity**. - **CD34** is an endothelial marker; while glomus tumors have prominent vascularity, the **neoplastic glomus cells themselves** are generally **CD34-negative**. - The correct positive markers are **SMA, vimentin, and caldesmon** - none of which are options here. - Among the given options, CD-34 may show positivity in the **vascular endothelium** within the tumor, but this does not represent the tumor cells. *CD-57* - **CD57** (HNK-1) is associated with neural differentiation, particularly in peripheral nerve sheath tumors like **schwannoma** or **neurofibroma**. - Glomus tumors lack neural differentiation and are **CD57-negative**. *Cytokeratin* - **Cytokeratin** is a marker for epithelial cells and carcinomas. - Glomus tumors are mesenchymal smooth muscle tumors and are **cytokeratin-negative**. *S-100* - **S-100** protein marks neural crest-derived cells, melanomas, and schwannomas. - Glomus tumors originate from modified smooth muscle cells, not neural crest, and are typically **S-100-negative** (though rare cases may show focal weak positivity).

Q: Which one of the following stains is specific for amyloid?

Congo red. ***Congo red*** - Congo red is a **specific stain for amyloid** that exhibits a characteristic **apple-green birefringence** under polarized light [1]. - It is widely used in **histopathology** to confirm the diagnosis of amyloidosis by staining amyloid deposits [1]. *Periodic Acid schiff (PAS)* - While PAS stain reveals **glycogen** and is useful in identifying certain infections, it is **not specific** for amyloid. - It may also stain various other cellular components like **glucose** and can lead to false positives in different conditions. *Von - Kossa* - This stain is primarily used to detect **calcium deposits**, particularly in cases of **mineralization** in tissues. - It is not applicable to amyloid deposits and does not provide diagnostic information about amyloidosis. *Alzerian red* - Alzerian red cannot be found in literature as a recognized stain; likely a misspelling of a similar term. - It fails to serve any staining purpose related to amyloid or established histological diagnostics. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of the Immune System, pp. 264-269.

Q: Doppelganger is a term used to describe which medical phenomenon?

Feeling of double of oneself. ***Feeling of double of oneself*** - **Doppelganger** (also called **autoscopy** or **heautoscopy**) refers to the experience of seeing or sensing one's own double or duplicate - This is the **correct definition** of the term doppelganger in medical terminology - Associated with **neurological conditions** (temporal lobe epilepsy, brain lesions, migraine) and **psychiatric conditions** (schizophrenia, dissociative states) - The person perceives their duplicate as a separate entity, which may appear visually or be sensed as a presence *Shadow following person* - This is not a recognized medical or psychiatric phenomenon - Does not describe the autoscopic experience of seeing one's own double - Not related to the definition of doppelganger *Identification of stranger as familiar* - This more closely describes **Fregoli delusion**, where a person believes that different people are actually a single person in disguise - Could also relate to other delusional misidentification syndromes - **Not doppelganger**, which specifically involves seeing one's own double, not misidentifying others - Note: **Capgras syndrome** is the opposite—believing a familiar person has been replaced by an imposter *None of the options* - Incorrect because "Feeling of double of oneself" accurately describes the doppelganger phenomenon

Q: What deficiency may contribute to relapse in a patient who has experienced remission with selective serotonin reuptake inhibitors (SSRIs) or tricyclic antidepressants (TCAs)?

Folate. ***Folate*** - **Folate (vitamin B9) deficiency** is strongly linked to depression and is a well-established cause of relapse in patients treated with antidepressants. - Folate plays a crucial role in the **one-carbon metabolism pathway**, which is essential for the synthesis of monoamine neurotransmitters including **serotonin, norepinephrine, and dopamine**. - Studies show that **low folate levels** are associated with poor response to SSRIs and TCAs, and folate supplementation can improve antidepressant efficacy. - Approximately **30% of depressed patients** have folate deficiency, making it a clinically significant factor in treatment resistance and relapse. *Cobalamin* - **Cobalamin (vitamin B12)** deficiency can cause neuropsychiatric symptoms including depression and cognitive impairment. - While B12 is important for myelin formation and neurotransmitter synthesis, it is less specifically implicated in antidepressant relapse compared to folate. - B12 deficiency more commonly presents with **cognitive and neurological symptoms** rather than pure mood symptoms. *Pyridoxine* - **Pyridoxine (vitamin B6)** is a cofactor in neurotransmitter synthesis, including serotonin and dopamine. - While B6 deficiency can contribute to mood disturbances, it is not commonly implicated as a primary cause of relapse in antidepressant-treated depression. *Ascorbate* - **Ascorbate (vitamin C)** is an antioxidant with some role in neurotransmitter metabolism. - Severe vitamin C deficiency (scurvy) can have psychiatric manifestations, but it is not typically associated with relapse in patients treated with SSRIs or TCAs.

Question 1

Attachment of the vitreous is strongest at?

Accepted Answer

Across ora serrata

Answer

Foveal region

Answer

Back of lens

Answer

Margin of optic disc

Question 2

Number of ATP molecules formed per turn of the citric acid cycle is

Accepted Answer

10

Answer

5

Answer

7

Answer

15

Question 3

In forensic pathology, what term describes neck compression injuries caused by forearm pressure?

Accepted Answer

Mugging

Answer

Garrotting with a stick

Answer

Strangulation with rope

Answer

Manual strangulation with hands

Question 4

The culture medium used for Entamoeba histolytica is

Accepted Answer

TYI-S-33 medium

Answer

Robinson's medium

Answer

CLED medium

Answer

Blood agar

Question 5

True about proximal fragment in subtrochanteric fracture is?

Accepted Answer

All of the options

Answer

Flexion

Answer

Abduction

Answer

External rotation

Question 6

Which of the following is not a myeloproliferative disorder?

Accepted Answer

Acute myeloid leukemia

Answer

Chronic myeloid leukemia

Answer

Essential thrombocytosis

Answer

Polycythemia vera

Question 7

Which immunohistochemical marker is primarily associated with glomus tumors?

Accepted Answer

CD-34

Answer

Cytokeratin

Answer

S-100

Answer

CD-57

Question 8

Which one of the following stains is specific for amyloid?

Accepted Answer

Congo red

Answer

Von - Kossa

Answer

Alizarin red

Answer

Periodic Acid Schiff (PAS)

Question 9

Doppelganger is a term used to describe which medical phenomenon?

Accepted Answer

Feeling of double of oneself

Answer

Shadow following person

Answer

Identification of stranger as familiar

Answer

None of the options

Question 10

What deficiency may contribute to relapse in a patient who has experienced remission with selective serotonin reuptake inhibitors (SSRIs) or tricyclic antidepressants (TCAs)?

Accepted Answer

Folate

Answer

Pyridoxine

Answer

Cobalamin

Answer

Ascorbate

NEET-PG 2013

Anatomy

Biochemistry

Forensic Medicine

Microbiology

Orthopaedics

Pathology

Psychiatry