NEET-PG 2013 Practice Questions

Q: Fenestration operation is which type of tympanoplasty?

Type-5. ***Type-5*** - **Fenestration operation** is classified as **Type V tympanoplasty** in Wullstein's classification. - This procedure creates a **new fenestra (window) in the lateral semicircular canal** to bypass a fixed oval window/stapes in cases of **otosclerosis**. - Sound waves are directed to this new window, bypassing the immobile stapes footplate. - Historically important procedure before **stapedectomy** became the standard treatment for otosclerosis. *Type-2* - **Type II tympanoplasty** involves repair with a **partially eroded malleus** where the graft is placed onto the **incus or remaining malleus**. - Requires an intact and mobile stapes, unlike fenestration which bypasses a fixed stapes. - Used for tympanic membrane perforations with minor ossicular damage. *Type-3* - **Type III tympanoplasty** involves placing the graft directly onto the **stapes head** (columella effect). - Performed when malleus and incus are eroded but stapes is intact and mobile. - This is **myringostapediopexy**, not fenestration. *Type-4* - **Type IV tympanoplasty** involves creating a **small middle ear cavity** with the graft placed over the **round window**. - Used when the stapes arch is absent but the footplate is mobile. - Different from fenestration as it utilizes the round window, not a semicircular canal fenestra.

Q: Classification of aortic dissection depends on.

Level of aorta affected. The classification of aortic dissection is primarily based on the **segment of the aorta involved**, typically divided into Stanford and DeBakey classifications [1]. This classification helps determine **management strategies** and prognosis based on the affected aortic region (ascending or descending) [1]. Understanding the classification is crucial for guiding **treatment decisions** and predicting outcomes [1]. The classification is more concerned with **anatomical location** rather than the etiology, such as hypertension or collagen disorders [1].

Q: Which organism is characterized by a Medusa head appearance?

Bacillus anthracis. ***Bacillus anthracis*** - This bacterium is known for forming **non-hemolytic colonies on blood agar** with a characteristic "Medusa head" appearance due to its tenacious, wavy outgrowths. - The "Medusa head" morphology is a key identifier in the laboratory diagnosis of **anthrax**. *Bacillus subtilis* - This organism typically forms **flat, dull, and spreading colonies** on agar, often with a frosted glass appearance, but not the specific "Medusa head" morphology. - It is a common **environmental bacterium** and a frequent laboratory contaminant, rarely pathogenic to humans. *Bacillus stearothermophilus* - This bacterium is a **thermophile**, meaning it grows optimally at high temperatures (around 55°C), and its colony morphology is not described as "Medusa head." - It is often used as a biological indicator for **sterilization processes** due to its heat resistance. *Bacillus cereus* - *Bacillus cereus* colonies are typically **large, feathery, and motile**, often showing **beta-hemolysis** on blood agar. - While it can form large colonies, it does not exhibit the distinctive "Medusa head" morphology observed in *Bacillus anthracis*.

Q: What is the best method to assess endometrial activity?

Endometrial biopsy. ***Biopsy*** - **Endometrial biopsy** provides direct tissue samples, allowing for histological examination of the endometrial glands and stroma to assess their phase (proliferative, secretory) and underlying pathology. - This method is considered the **gold standard** for accurately determining endometrial activity and diagnosing conditions like hyperplasia or carcinoma. *HSG* - **Hysterosalpingography (HSG)** is primarily used to evaluate the patency of the fallopian tubes and the shape of the uterine cavity, not the functional activity of the endometrium itself. - It involves injecting contrast dye and taking X-rays, which helps identify structural abnormalities but does not provide microscopic details of endometrial tissue. *USG* - **Transvaginal ultrasonography (USG)** measures endometrial thickness and identifies gross structural abnormalities like polyps or fibroids. - While it can suggest the endometrial phase based on thickness, it does not offer the definitive cellular-level detail of endometrial activity that a biopsy provides. *Colposcopy* - **Colposcopy** is a procedure used to visualize the cervix and vagina with a magnified view, primarily for detecting and evaluating abnormal cells that may lead to cervical cancer. - It is **not used** for assessing the endometrial lining or its physiological activity.

Q: Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?

Granulomatous uveitis. ***Granulomatous uveitis*** - **Mutton-fat keratic precipitates (KPs)** are large, greasy-appearing white deposits on the corneal endothelium, characteristic of **granulomatous inflammation**. - These KPs are composed of macrophages and epithelioid cells, reflecting a **chronic, cell-mediated immune response** seen in granulomatous conditions. *Hemorrhagic uveitis* - This condition involves significant **intraocular bleeding**, which would manifest as hyphema or vitreous hemorrhage, not mutton-fat KPs. - While inflammation may be present, the defining feature is blood, which obscures vision differently than KPs. *Old healed uveitis* - After uveitis heals, KP morphology can change, often appearing smaller, more pigmented, or forming distinct patterns such as **Arlt's triangle**, but not typically actively large, white mutton-fat KPs. - Healed KPs often reflect a less active or resolved inflammatory process, unlike fresh mutton-fat KPs. *Acute anterior uveitis* - This typically presents with smaller, finer, and more numerous **non-granulomatous KPs** (sometimes called "stellate KPs"), in contrast to the large, greasy mutton-fat KPs. - The inflammation is usually acute and less focally organized compared to granulomatous forms.

Q: What is the primary vascular abnormality associated with intestinal angiodysplasia?

Arteriovenous malformation. ***AV malformation*** - **Intestinal angiodysplasia** is characterized by abnormal **arteriovenous (AV) connections**, leading to vascular lesions in the gut [1]. - These malformations can cause **chronic gastrointestinal bleeding** due to fragility of the blood vessels [1]. *Capillary hemangioma* - This is a **benign vascular tumor** often found in the skin or subcutaneous tissue, not specifically associated with intestinal vascular changes. - **Capillary hemangiomas** typically do not cause significant gastrointestinal bleeding as seen in angiodysplasia. *Malignant tumor* - Intestinal angiodysplasia is a **benign condition** and not a malignant tumor, therefore it does not fit the characteristics of malignancy. - **Malignant tumors** usually present with different symptoms and underlying pathophysiology than angiodysplasia. *Cavernous hemangioma* - This type of hemangioma involves larger vascular channels and is typically more associated with the liver than the intestines. - **Cavernous hemangiomas** do not relate to the intestinal bleeding patterns seen in angiodysplasia.

Q: Conversion of chondrocytes into osteogenic cells is caused by

IGF-1. ***IGF-1*** - **Insulin-like Growth Factor 1 (IGF-1)** is the primary direct mediator in endochondral ossification, stimulating chondrocyte proliferation, differentiation, and hypertrophy in the growth plate. - IGF-1 acts directly on chondrocytes to promote their maturation and the subsequent invasion of osteoprogenitor cells that form bone. - It plays a crucial role in longitudinal bone growth by regulating various cellular processes in the growth plate and promoting the replacement of cartilage with bone tissue. *Insulin* - While insulin has anabolic effects on bone and can interact with IGF-1 receptors due to structural similarity, its primary role is in **glucose metabolism** rather than direct regulation of chondrocyte activity in endochondral ossification. - Insulin may have supportive effects on bone formation but is not the primary hormone driving growth plate chondrocyte function. *Growth hormone* - **Growth hormone (GH)** stimulates the production of IGF-1 both systemically (from the liver) and locally (from chondrocytes and other skeletal tissues). - GH acts upstream by increasing IGF-1 levels, which then directly mediates the effects on chondrocytes. - While GH is essential for normal bone growth, IGF-1 is considered the direct effector molecule on chondrocytes. *Thyroxine* - **Thyroxine (T4)** is essential for normal skeletal development and bone maturation, particularly in regulating the timing of growth plate fusion and overall metabolic support for bone growth. - However, it does not directly regulate chondrocyte proliferation and differentiation in the growth plate during endochondral ossification. - Thyroid hormone deficiency causes growth retardation, but thyroxine is not the primary hormonal driver of chondrocyte activity.

Q: The temperature centre is?

Preoptic nucleus of hypothalamus. **Preoptic nucleus of hypothalamus** - The **preoptic nucleus** within the **hypothalamus** serves as the primary **thermoregulatory center** in the brain. - It contains both **heat-sensitive** and **cold-sensitive neurons** that monitor core body temperature and initiate appropriate responses to maintain homeostasis. *Supraoptic nucleus of hypothalamus* - The **supraoptic nucleus** is primarily involved in the production of **antidiuretic hormone (ADH)**, which regulates water balance. - It plays a crucial role in **fluid and electrolyte balance**, not temperature regulation. *Paraventricular nucleus of hypothalamus* - The **paraventricular nucleus** is multifunctional, producing **oxytocin** and **vasopressin** (ADH), and is involved in stress response and feeding. - While it has broad regulatory roles, it is not the primary center for **temperature control**. *Suprachiasmatic nucleus of hypothalamus* - The **suprachiasmatic nucleus (SCN)** is the body's main **circadian clock**, regulating daily rhythms like the sleep-wake cycle. - Its primary function is to synchronize biological activities with the **24-hour light-dark cycle**, not directly control body temperature.

Q: Which of the following is used in the treatment of well-differentiated thyroid carcinoma?

I131. ***I131*** - **Radioactive iodine (I131)** is specifically absorbed by **well-differentiated thyroid cancer cells** because these cells retain the ability to uptake iodine, unlike other types of cancer cells. - Used for **ablating residual thyroid tissue** after surgery and for treating **metastatic well-differentiated thyroid carcinoma** [1]. *99m Tc* - **Technetium-99m (99m Tc)** is primarily used for **diagnostic imaging** (e.g., thyroid scans, bone scans), not for therapeutic treatment of thyroid cancer. - It has a short half-life and emits gamma rays, making it suitable for imaging but generally not for delivering sustained radiation for therapeutic effect. *32p* - **Phosphorus-32 (32p)** is a beta-emitting radionuclide used in the treatment of certain hematological malignancies, such as **polycythemia vera**, and for palliative treatment of bone metastases. - It is not selectively taken up by thyroid cancer cells and therefore is not used in the treatment of thyroid carcinoma. *MIBG* - **Metaiodobenzylguanidine (MIBG)**, often labeled with I123 (diagnostic) or I131 (therapeutic), is used in the diagnosis and treatment of **neuroendocrine tumors** like **pheochromocytoma** and **neuroblastoma**. - Its uptake mechanism targets cells of neuroectodermal origin, which is distinct from the iodine uptake mechanism of thyroid cells.

Q: Inferior rib notching is seen in which of the following conditions?

Coarctation of the aorta. ***Coarctation of the aorta*** - **Inferior rib notching** is a classic radiographic sign caused by the **enlarged, tortuous intercostal arteries** eroding the inferior margins of the ribs. - This collateral circulation develops to bypass the narrowed aortic segment, increasing blood flow through the intercostal arteries. *Rickets* - Rickets can cause **bowing of long bones**, widened epiphyseal plates, and a **rachitic rosary** (enlargement of costochondral junctions). - It does not typically lead to rib notching; rather, it affects bone mineralization and growth patterns. *ASD* - An **atrial septal defect (ASD)** is a congenital heart defect causing a left-to-right shunt, leading to pulmonary overload and right heart enlargement. - While it can manifest with cardiomegaly and increased pulmonary vascular markings, it does not cause rib notching. *Multiple myeloma* - Multiple myeloma is a plasma cell malignancy that causes **punched-out lytic lesions** in bones, leading to bone pain and pathological fractures. - While it affects bone, the lesions are typically osteolytic and diffuse, not specifically causing inferior rib notching.

Question 1

Fenestration operation is which type of tympanoplasty?

Accepted Answer

Type-5

Answer

Type-3

Answer

Type-2

Answer

Type-4

Question 2

Classification of aortic dissection depends on.

Accepted Answer

Level of aorta affected

Answer

Cause of dissection

Answer

Extent of symptoms

Answer

Percentage of aorta affected

Question 3

Which organism is characterized by a Medusa head appearance?

Accepted Answer

Bacillus anthracis

Answer

Bacillus subtilis

Answer

Bacillus stearothermophilus

Answer

Bacillus cereus

Question 4

What is the best method to assess endometrial activity?

Accepted Answer

Endometrial biopsy

Answer

HSG

Answer

USG

Answer

Colposcopy

Question 5

Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?

Accepted Answer

Granulomatous uveitis

Answer

Hemorrhagic uveitis

Answer

Old healed uveitis

Answer

Acute anterior uveitis

Question 6

What is the primary vascular abnormality associated with intestinal angiodysplasia?

Accepted Answer

Arteriovenous malformation

Answer

Capillary hemangioma (usually superficial)

Answer

Malignant tumor

Answer

Cavernous hemangioma

Question 7

Conversion of chondrocytes into osteogenic cells is caused by

Accepted Answer

IGF-1

Answer

Insulin

Answer

Thyroxine

Answer

Growth hormone

Question 8

The temperature centre is?

Accepted Answer

Preoptic nucleus of hypothalamus

Answer

Supraoptic nucleus of hypothalamus

Answer

Paraventricular nucleus of hypothalamus

Answer

Suprachiasmatic nucleus of hypothalamus

Question 9

Which of the following is used in the treatment of well-differentiated thyroid carcinoma?

Accepted Answer

I131

Answer

99m Tc

Answer

32p

Answer

MIBG

Question 10

Inferior rib notching is seen in which of the following conditions?

Accepted Answer

Coarctation of the aorta

Answer

Rickets

Answer

ASD

Answer

Multiple myeloma

NEET-PG 2013

ENT

Internal Medicine

Microbiology

Obstetrics and Gynecology

Ophthalmology

Pathology

Physiology

Radiology