NEET-PG 2015 Practice Questions

Q: Largest cranial nerve is:

Trigeminal. ***Trigeminal*** - The **trigeminal nerve (CN V)** is the largest cranial nerve, both in terms of its overall diameter and the number of fibers it contains. - It has three major divisions: **ophthalmic, maxillary, and mandibular**, providing extensive sensory innervation to the face and motor innervation to the muscles of mastication. *Trochlear* - The **trochlear nerve (CN IV)** is the smallest cranial nerve in terms of diameter and number of axons. - It primarily innervates a single muscle, the **superior oblique muscle** of the eye. *Oculomotor* - The **oculomotor nerve (CN III)** is responsible for innervating several extrinsic eye muscles and plays a role in pupil constriction. - While significant, it is not the largest cranial nerve. *Vagus* - The **vagus nerve (CN X)** has the longest anatomical course among all cranial nerves, extending into the abdomen, but it is not the largest in terms of overall size or fiber count. - It carries extensive **parasympathetic fibers** and has broad effects on visceral organs.

Q: The nasopharynx is primarily lined by which type of epithelium?

Ciliated columnar. ***Ciliated columnar*** - The **nasopharynx** is lined by **pseudostratified ciliated columnar epithelium** with goblet cells, also known as respiratory epithelium [2]. - This specialized epithelium is crucial for **warming**, **humidifying**, and **filtering** inhaled air before it reaches the lungs [1]. *Stratified squamous nonkeratinized* - This type of epithelium is found in areas subject to **abrasion** and needing protection, such as the **oral cavity**, pharynx (oropharynx and laryngopharynx), and esophagus. - It is not primary in the nasopharynx, which requires ciliary action for particle removal. *Stratified squamous keratinized* - This robust epithelium is characteristic of areas that require significant **protection against friction** and **drying**, such as the **epidermis of the skin**. - It is not found in the nasopharynx due to its lack of flexibility and ciliary function. *Cuboidal* - **Cuboidal epithelium** is typically found in glands and kidney tubules, where its function includes **secretion** and **absorption**. - It lacks the specialized cilia and goblet cells necessary for the respiratory function of the nasopharynx [2].

Q: From which structure is the greater petrosal nerve formed?

Geniculate ganglion. ***Geniculate ganglion*** - The **greater petrosal nerve** arises directly from the **geniculate ganglion** of the **facial nerve (cranial nerve VII)**. - This nerve carries **preganglionic parasympathetic fibers** destined for the lacrimal gland and mucous glands of the nose, palate, and pharynx, as well as **taste fibers** from the palate. *Plexus around ICA* - The **plexus around the internal carotid artery (ICA)** typically carries **postganglionic sympathetic fibers**, primarily for structures in the head, including the dilator pupillae muscle. - It does not give rise to the greater petrosal nerve, which is predominantly parasympathetic and sensory. *Plexus around middle meningeal artery* - The **plexus around the middle meningeal artery** consists mainly of **sympathetic fibers** that supply the artery itself and surrounding structures. - It has no direct connection or contribution to the formation of the greater petrosal nerve. *None of the options* - This option is incorrect because the **greater petrosal nerve** does indeed arise from the **geniculate ganglion**.

Q: The third ventricle is a cavity located in which part of the brain?

Diencephalon. ***Diencephalon*** - The **third ventricle** is a narrow, median cavity situated within the **diencephalon** of the brain. - It connects the lateral ventricles via the **interventricular foramen (of Monro)** and with the fourth ventricle via the **cerebral aqueduct (of Sylvius)** [2]. *Mesencephalon* - The **mesencephalon (midbrain)** contains the **cerebral aqueduct**, but not the third ventricle itself [1]. - It is located superior to the pons and inferior to the diencephalon. *Rhombencephalon* - The **rhombencephalon (hindbrain)** contains the **fourth ventricle**, which is situated posterior to the pons and medulla oblongata [2]. - It develops into the pons, cerebellum, and medulla oblongata. *Telencephalon* - The **telencephalon (cerebrum)** contains the **lateral ventricles**, which are paired cavities, one in each cerebral hemisphere [2]. - The telencephalon is the most anterior part of the brain and develops into the cerebral cortex, basal ganglia, and limbic system.

Q: Oculomotor nucleus is located in -

Midbrain. ***Midbrain*** - The **oculomotor nucleus** (cranial nerve III) and the Edinger-Westphal nucleus (parasympathetic component) are both located in the **ventral gray matter** near the cerebral aqueduct in the **midbrain** [1]. - This position allows the oculomotor nerve to exit from the interpeduncular fossa of the midbrain [1]. *Forebrain* - The **forebrain** primarily contains structures like the cerebral hemispheres, thalamus, and hypothalamus, which are involved in higher cognitive functions and sensory processing. - No cranial nerve nuclei are located within the forebrain itself; they are largely concentrated in the brainstem. *Pons* - The **pons** contains nuclei for cranial nerves V (trigeminal), VI (abducens), VII (facial), and VIII (vestibulocochlear), but not the oculomotor nucleus. - It is located inferior to the midbrain and superior to the medulla. *Medulla* - The **medulla oblongata** houses nuclei for cranial nerves IX (glossopharyngeal), X (vagus), XI (accessory), and XII (hypoglossal). - It is the most caudal part of the brainstem, inferior to the pons, and is not where the oculomotor nucleus is found.

Q: Which of the following is pure sensory nerve?

Olfactory. ***Olfactory*** - The **olfactory nerve (Cranial Nerve I)** is exclusively responsible for the sense of **smell**, making it a pure **sensory nerve** [1]. - It transmits impulses from the **olfactory receptors** in the nasal cavity to the brain. *Trigeminal* - The **trigeminal nerve (Cranial Nerve V)** is a **mixed nerve**. - It has both **sensory functions** (face sensation) and **motor functions** (mastication). *Abducent* - The **abducent nerve (Cranial Nerve VI)** is a **motor nerve**. - It innervates the **lateral rectus muscle**, responsible for moving the eye laterally. *Trochlear* - The **trochlear nerve (Cranial Nerve IV)** is primarily a **motor nerve**. - It innervates the **superior oblique muscle**, which depresses and intorts the eyeball.

Q: The Great cerebral vein of Galen drains into which structure?

Straight sinus. ***Straight sinus*** - The **Great cerebral vein of Galen** is a major venous channel that collects blood from the deep cerebral veins, including the internal cerebral veins. - It empties directly into the **straight sinus**, which then joins the confluence of sinuses. *Cavernous sinus* - The **cavernous sinus** drains blood from the orbit, face, and temporal lobe, and it receives input from superficial cerebral veins, not the deep system of Galen. - It is located on either side of the **sella turcica** and is distinct from the drainage pathway of the Great cerebral vein. *Basal vein of Rosenthal* - The **basal vein of Rosenthal** is a tributary that drains into the Great cerebral vein of Galen, not a structure that Galen drains into. - It courses around the midbrain and receives blood from various deep structures, eventually contributing to the formation of the Great cerebral vein. *Internal cerebral vein* - The **internal cerebral veins** are tributaries that merge to form the Great cerebral vein of Galen; therefore, Galen does not drain into them. - These veins run within the tela choroidea of the third ventricle and collect blood from the thalamus, basal ganglia, and internal capsule.

Q: Superficial middle cerebral vein drains into -

Cavernous sinus. **Cavernous sinus** - The **superficial middle cerebral vein** runs along the **lateral sulcus** and is a major drainage pathway, typically emptying into the **cavernous sinus**. - Its drainage into the **cavernous sinus** then allows blood to eventually reach the superior and inferior petrosal sinuses [1]. *Internal cerebral vein* - This vein is part of the **deep venous system** of the brain [1] and primarily drains structures like the **basal ganglia** and **thalamus**. - It does not receive direct drainage from the **superficial middle cerebral vein**. *Great cerebral vein of Galen* - The **great cerebral vein of Galen** is formed by the union of the **internal cerebral veins** and is a major collector of **deep venous blood**. - It drains into the **straight sinus** and is not the primary drainage site for the superficial middle cerebral vein. *Straight sinus* - The **straight sinus** is a large dural venous sinus that receives blood from the **great cerebral vein of Galen** and the **inferior sagittal sinus**. - It primarily drains deeper structures of the brain and does not directly receive the **superficial middle cerebral vein** [1].

Q: Which artery is the major supply of the medial surface of the cerebral hemisphere?

Anterior cerebral artery. ***Anterior cerebral artery*** - The **anterior cerebral artery (ACA)** is a primary branch of the internal carotid artery and is responsible for supplying blood to the **medial surface** of the frontal and parietal lobes of the cerebral hemispheres [1]. - It also supplies the **corpus callosum**, the superior aspect of the frontal and parietal lobes, and parts of the basal ganglia [1]. *Posterior cerebral artery* - The **posterior cerebral artery (PCA)** primarily supplies the **occipital lobe** and the inferior part of the **temporal lobe** [1]. - It also provides blood to parts of the midbrain and the **thalamus** [1]. *Middle cerebral artery* - The **middle cerebral artery (MCA)** is the largest cerebral artery and supplies most of the **lateral surface** of the cerebral hemispheres [1]. - It is crucial for the blood supply to the **motor and sensory cortices** for the face and upper limb, as well as language areas (Broca's and Wernicke's). *Posterior inferior cerebellar artery* - The **posterior inferior cerebellar artery (PICA)** is a branch of the **vertebral artery** and exclusively supplies the **cerebellum** and the lateral medulla. - It is not involved in the blood supply to the cerebral hemispheres.

Q: Ligament which prevents the spleen from falling in left iliac fossa -

Phrenicocolic ligament. ***Phrenicocolic ligament*** - The **phrenicocolic ligament** is a fold of peritoneum that extends from the left colic flexure to the diaphragm, under the spleen. - It forms a shelf that **supports the spleen** and prevents it from descending into the left iliac fossa. *Lienorenal ligament* - The **lienorenal (splenorenal) ligament** connects the hilum of the spleen to the posterior abdominal wall (specifically over the left kidney) [1]. - While it helps to anchor the spleen, its primary role is not preventing caudal displacement, but rather containing the **splenic artery and vein** and the tail of the pancreas [1]. *Upper pole of right kidney* - The **right kidney** is located on the opposite side of the abdominal cavity from the spleen. - It plays no role in supporting the spleen or preventing its descent. *Sigmoid colon* - The **sigmoid colon** is a part of the large intestine located in the left lower quadrant of the abdomen and pelvis. - It is situated far below the spleen and has no direct anatomical connection or supporting role for the spleen.

Question 1

Largest cranial nerve is:

Accepted Answer

Trigeminal

Answer

Trochlear

Answer

Oculomotor

Answer

Vagus

Question 2

The nasopharynx is primarily lined by which type of epithelium?

Accepted Answer

Ciliated columnar

Answer

Stratified squamous keratinized

Answer

Cuboidal

Answer

Stratified squamous nonkeratinized

Question 3

From which structure is the greater petrosal nerve formed?

Accepted Answer

Geniculate ganglion

Answer

Plexus around ICA

Answer

Plexus around middle meningeal artery

Answer

None of the options

Question 4

The third ventricle is a cavity located in which part of the brain?

Accepted Answer

Diencephalon

Answer

Mesencephalon

Answer

Rhombencephalon

Answer

Telencephalon

Question 5

Oculomotor nucleus is located in -

Accepted Answer

Midbrain

Answer

Forebrain

Answer

Pons

Answer

Medulla

Question 6

Which of the following is pure sensory nerve?

Accepted Answer

Olfactory

Answer

Trigeminal

Answer

Abducent

Answer

Trochlear

Question 7

The Great cerebral vein of Galen drains into which structure?

Accepted Answer

Straight sinus

Answer

Cavernous sinus

Answer

Basal vein of Rosenthal

Answer

Internal cerebral vein

Question 8

Superficial middle cerebral vein drains into -

Accepted Answer

Cavernous sinus

Answer

Internal cerebral vein

Answer

Great cerebral vein of Galen

Answer

Straight sinus

Question 9

Which artery is the major supply of the medial surface of the cerebral hemisphere?

Accepted Answer

Anterior cerebral artery

Answer

Posterior cerebral artery

Answer

Middle cerebral artery

Answer

Posterior inferior cerebellar artery

Question 10

Ligament which prevents the spleen from falling in left iliac fossa -

Accepted Answer

Phrenicocolic ligament

Answer

Lienorenal ligament

Answer

Upper pole of right kidney

Answer

Sigmoid colon

NEET-PG 2015

Anatomy