NEET-PG 2013 Practice Questions

Q: Pubic symphysis is which type of joint?

Secondary cartilaginous. ***Secondary cartilaginous*** - The **pubic symphysis** is a classic example of a **secondary cartilaginous joint**, also known as a **symphysis**. - These joints are characterized by a plate of **fibrocartilage** sandwiched between two layers of hyaline cartilage, uniting two bones and allowing for limited movement. *Gomphosis* - A **gomphosis** is a type of **fibrous joint** where a peg-like process fits into a socket, primarily found in the attachment of teeth to their sockets in the jaw. - It is distinct from the cartilaginous structure of the pubic symphysis. *Fibrous joint* - While fibrous joints are characterized by fibrous connective tissue connecting bones, this category is too broad, and doesn't specify the unique cartilaginous nature of the pubic symphysis. - Examples include sutures in the skull, syndesmoses, and gomphoses, none of which fit the structure of the pubic symphysis. *Primary cartilaginous* - A **primary cartilaginous joint**, or **synchondrosis**, involves bones united by **hyaline cartilage**, like the epiphyseal plates of growing bones. - These joints are typically temporary and eventually ossify, or they allow for very restricted movement, unlike the fibrocartilage and slight movement of the pubic symphysis.

Q: Collecting part of kidney develops from ?

Ureteric bud. ***Ureteric bud*** - The **ureteric bud** (also known as the metanephric diverticulum) is an outgrowth of the **mesonephric duct** that develops into the collecting system of the kidney. - It gives rise to the **ureter**, **renal pelvis**, major and minor calyces, and all collecting ducts. *Pronephros* - **Pronephros** is the earliest, most rudimentary, and transient excretory structure that appears in human embryos. - It is non-functional in humans and **degenerates completely** by the fourth week of gestation. *Mesonephros* - The **mesonephros** develops after the pronephros and functions as a temporary kidney during the early fetal period (weeks 4-8). - Its tubules primarily contribute to the **male reproductive system** (e.g., epididymis, ductus deferens) and **degenerate** in females. *Metanephros* - The **metanephros** is the definitive kidney in mammals and gives rise to the **nephrons** (glomeruli, Bowman's capsule, proximal and distal convoluted tubules, loop of Henle). - While it's crucial for kidney development, the **collecting part** specifically originates from the ureteric bud, which interacts with the metanephric mesenchyme.

Q: Arch of Aorta develops from which aortic arch artery?

Left 4th. ***Left 4th*** - The **arch of the aorta** develops from the **fourth left aortic arch artery**. [1] - This artery connects the **aortic sac** to the **dorsal aorta** on the left side during embryonic development. *Right Truncus arteriosus* - The **truncus arteriosus** gives rise to the **ascending aorta** and the **pulmonary artery**, not the arch of the aorta. - The term "right truncus arteriosus" is not standard in describing normal aortic arch development. *Right 3rd* - The **third aortic arch arteries** primarily contribute to the development of the **common carotid arteries** and the proximal part of the **internal carotid arteries**. - The right third aortic arch forms the proximal part of the right common carotid artery. *Left 3rd* - The **left third aortic arch artery** forms the proximal part of the **left common carotid artery** and the proximal part of the left internal carotid artery. - It does not directly form the arch of the aorta itself.

Q: At which level do the somites initially form?

Cervical level. Cervical level - Somites, which are segmented blocks of paraxial mesoderm, initially appear in the **occipital/cranial cervical region** of the developing embryo around day 20 of development. - The first somite pair forms at the **occipital level**, and subsequent somites develop in a **cranio-caudal sequence**. - Development proceeds both cranially (forming occipital somites) and caudally (forming cervical, thoracic, lumbar, and sacral somites) from this initial formation. - By the end of the 5th week, approximately **42-44 somite pairs** are present. *Thoracic level* - Thoracic somites form subsequent to the initial occipital/cervical somites, as the segmentation process extends caudally. - The formation of somites is a sequential process along the **cranio-caudal axis**. *Lumbar level* - Lumbar somites develop later in the embryological timeline, after the cervical and thoracic regions have undergone somite formation. - The **caudal regions** receive somites progressively as development continues. *Sacral level* - Sacral somites are among the last to form, representing the caudal extent of somite development. - Their formation follows the cranio-caudal progression of somite appearance.

Q: The cardiac jelly formed around the heart tube during early development contributes to the formation of:

Endocardium. Endocardium (Endocardial Cushions/Valves/Septa) - The **cardiac jelly** is an acellular, gelatinous matrix rich in **hyaluronic acid** that lies between the endocardium and the primordial myocardium during early heart development. - It undergoes **endothelial-to-mesenchymal transformation (EMT)** to form the **endocardial cushions** [1]. - These cushions are critical for forming: - **Atrioventricular (AV) valves** (mitral and tricuspid) [1] - **Semilunar valves** (aortic and pulmonary) [1] - **Cardiac septa** (portions of atrial, ventricular, and AV septa) [1] - While cardiac jelly doesn't form the endocardial lining itself (which is already present as endothelium), it forms the endocardial cushions that are essential endocardial derivatives. *Pericardium* - The **pericardium** develops from the **pleuropericardial folds** and **somatic and splanchnic mesoderm**, forming the fibrous and serous outer coverings of the heart. - It is completely distinct from cardiac jelly, which is an intra-cardiac structure. *Mesocardium* - The **dorsal mesocardium** is a transient mesentery that temporarily connects the developing heart tube to the dorsal wall of the pericardial cavity. - It rapidly degenerates by **day 22-23** to form the **transverse pericardial sinus**. - It does not contribute to cardiac jelly or any heart wall structures. *Myocardium* - The **myocardium** differentiates directly from the **splanchnic mesoderm** surrounding the endocardial tube. - It forms the muscular contractile layer of the heart wall. - Cardiac jelly lies between the endocardium and myocardium but does not form myocardial tissue.

Q: What is the Chandler's Index for Hookworm that indicates a significant health problem?

> 50. ***> 50*** - A Chandler's Index of **> 50** indicates a significant public health problem due to **hookworm infection**. - **Chandler's Index** is calculated as the **average egg count per person in a community** (total hookworm eggs counted ÷ number of persons examined), used to assess the population-level burden of hookworm infection. - A value **> 50** suggests that the community has a significant hookworm problem requiring public health intervention. *> 300* - This value is significantly higher than the threshold for a significant public health problem and would indicate an **extremely severe burden of infection**. - While this represents a very high Chandler's Index, it's not the standard cut-off for defining a "significant" health problem (which is the lower threshold of >50). *> 200* - A Chandler's Index of **> 200** would denote a very high intensity of hookworm infection in the community. - However, this is not the standard threshold used to define when hookworm becomes a "significant" public health issue - the threshold is lower at >50. *> 100* - A Chandler's Index of **> 100** represents a substantial level of hookworm infection within a population. - However, the widely recognized cutoff for a "significant health problem" is **> 50**, indicating public health concern even at this moderate level of community infection burden.

Q: What is the first permanent tooth to erupt?

First molar. ***First molar*** - The **first molars** are typically the first permanent teeth to erupt, usually around **6 years of age**. - They erupt distal to the primary second molars and are not preceded by primary teeth, making them crucial for establishing the **occlusion**. *First premolar* - **First premolars** typically erupt later, between **10 and 11 years of age**, replacing the primary first molars. - Their eruption is part of the **exchange of primary teeth** for permanent successors. *Second premolar* - The **second premolars** erupt even later, usually between **11 and 12 years of age**, replacing the primary second molars. - They are also involved in the **replacement of primary teeth**, not the initial permanent eruption. *Second molar* - **Second molars** erupt much later than the first molars, typically between **11 and 13 years of age**, distal to the first molars. - They are part of the **later stages of permanent dentition development**.

Q: Migraine is due to

Cortical spreading depression. ***Cortical spreading depression*** - The current understanding is that **cortical spreading depression (CSD)** is the initiating event in migraine with aura, characterized by a wave of neuronal and glial depolarization that spreads across the cerebral cortex, leading to a temporary shutdown of neuronal activity [1]. - CSD is thought to activate the **trigeminal nerve**, subsequently causing the release of inflammatory neuropeptides and contributing to the pain phase [1]. *Dilatation of cranial blood vessels* - While **vasodilation of intracranial and extracranial blood vessels** does occur during the headache phase of migraine, it is now considered a *consequence* of the initial neurological events rather than the primary cause [1]. - This vasodilation contributes to the throbbing sensation of migraine pain but does not explain the aura or the initiation of the attack. *Constriction of cranial blood vessels* - **Vasoconstriction** was previously thought to be the cause of the migraine aura, but this theory has largely been disproven. - While some temporary constriction may precede CSD, it is not the primary mechanism behind the migraine attack. *Inflammation of the meninges* - While **neurogenic inflammation** of the meninges, involving the release of inflammatory mediators like **calcitonin gene-related peptide (CGRP)**, does play a role in sensitizing the trigeminal system and contributing to migraine pain, it is a downstream effect. - It is not the initial trigger for a migraine attack but rather part of the pain pathway activated by events like CSD.

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: Muttering delirium is seen with: NEET 13

Datura. ***Datura*** - **Datura poisoning** is characterized by an **anticholinergic toxidrome**, which includes central nervous system effects like **muttering delirium, hallucinations**, and disorientation. - The patient exhibits features like **dilated pupils, dry mouth, flushed skin**, and **tachycardia** due to the blockage of muscarinic acetylcholine receptors. *Castor oil plant* - The **castor oil plant** contains **ricin**, a potent toxin that causes **gastrointestinal symptoms** (nausea, vomiting, abdominal pain, bloody diarrhea) and eventually multi-organ failure. - It does not typically cause the central nervous system effects like **muttering delirium** seen with Datura poisoning. *Cocaine (stimulant)* - **Cocaine** is a central nervous system stimulant that causes **euphoria, agitation, paranoia, dilated pupils**, and **tachycardia**. - While it can cause psychosis, the specific **muttering delirium** is not its hallmark presentation; instead, it is associated with a hyperadrenergic state. *Monkshood (Aconitum)* - **Monkshood** contains **aconitine**, a neurotoxin that primarily affects cardiac and neurological function, causing **paresthesias, muscle weakness, bradycardia**, and potentially fatal arrhythmias. - It does not typically cause the **muttering delirium** with features of an anticholinergic syndrome.

Question 1

Pubic symphysis is which type of joint?

Accepted Answer

Secondary cartilaginous

Answer

Gomphosis

Answer

Fibrous joint

Answer

Primary cartilaginous

Question 2

Collecting part of kidney develops from ?

Accepted Answer

Ureteric bud

Answer

Mesonephros

Answer

Metanephros

Answer

Pronephros

Question 3

Arch of Aorta develops from which aortic arch artery?

Accepted Answer

Left 4th

Answer

Right 3rd

Answer

Left 3rd

Answer

Right Truncus arteriosus

Question 4

At which level do the somites initially form?

Accepted Answer

Cervical level

Answer

Lumbar level

Answer

Sacral level

Answer

Thoracic level

Question 5

The cardiac jelly formed around the heart tube during early development contributes to the formation of:

Accepted Answer

Endocardium

Answer

Pericardium

Answer

Mesocardium

Answer

Myocardium

Question 6

What is the Chandler's Index for Hookworm that indicates a significant health problem?

Accepted Answer

> 50

Answer

> 200

Answer

> 100

Answer

> 300

Question 7

What is the first permanent tooth to erupt?

Accepted Answer

First molar

Answer

First premolar

Answer

Second premolar

Answer

Second molar

Question 8

Migraine is due to

Accepted Answer

Cortical spreading depression

Answer

Dilatation of cranial blood vessels

Answer

Constriction of cranial blood vessels

Answer

Inflammation of the meninges

Question 9

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 10

Muttering delirium is seen with: NEET 13

Accepted Answer

Datura

Answer

Castor oil plant

Answer

Cocaine (stimulant)

Answer

Monkshood (Aconitum)

NEET-PG 2013

Anatomy

Community Medicine

Dental

Internal Medicine

Physiology

Psychiatry