NEET-PG 2017 Practice Questions

Q: Identify the structure:

Tonsil. ***Tonsil*** - The image displays multiple **crypts** lined by **stratified squamous epithelium** and filled with abundant **lymphoid follicles**, which are characteristic features of a tonsil. - Tonsils are secondary lymphoid organs located in the oropharynx, specialized for immune surveillance of ingested and inhaled antigens. *Lymph node* - Lymph nodes are typically encapsulated and show distinct cortical and medullary regions, lacking the deep crypts seen in the image. - They contain lymphoid follicles but are surrounded by a capsule and have afferent and efferent lymphatic vessels. *Spleen* - The spleen is characterized by red pulp (involved in filtering blood) and white pulp (containing lymphoid follicles around arterioles). - Its histological structure does not include epithelial-lined crypts. *Thymus* - The thymus is distinctively lobulated and features a cortex rich in thymocytes and a medulla containing **Hassall's corpuscles**. - It lacks the prominent lymphoid follicles and crypts observed in the image, as its primary role is T-cell maturation.

Q: Which type of salivary glands is shown in the image?

Mixed. ***Mixed*** - The image displays both **serous acini** (darkly stained, uniform cells forming spherical structures) and **mucous tubules** (larger, lighter-stained cells often forming more tubular or crescent structures), characteristic of a mixed salivary gland. - The presence of **serous demilunes** capping some mucous tubules further confirms the mixed nature, although not clearly visible at this magnification, it's inferred by the blend of cell types. *Serous* - Serous glands would show almost exclusively **darkly stained, granular acini** producing watery secretions, like the parotid gland. - The image clearly contains lighter-stained, more translucent structures in addition to the dark acini, ruling out a purely serous gland. *Mucous* - Mucous glands would primarily consist of **pale-staining, vacuolated cells** forming tubules, responsible for viscous secretions. - While mucous components are present, significant numbers of darkly stained serous acini are also visible. *Papillary* - "Papillary" refers to a **growth pattern** characterized by finger-like projections, not a type of secretory cell or gland. - This term is typically used in the context of tumors or certain glandular epithelia but not for classifying conventional salivary gland types.

Q: Which type of salivary glands is shown in the image?

Mucous. ***Mucous*** - The image predominantly displays **mucous acini**, characterized by their **pale-staining cytoplasm** and **flat, basally located nuclei**. - These cells produce **viscous, carbohydrate-rich mucus** for lubrication and protection. *Serous* - **Serous acini** typically show **darker, basophilic cytoplasm** due to abundant rough endoplasmic reticulum and **round, centrally located nuclei**. - They secrete **watery fluid rich in enzymes**, which is not the primary feature seen here. *Mixed* - **Mixed glands** contain both **serous and mucous acini**, often with **serous demilunes** capping the mucous acini. - While some ducts are visible, the overwhelming majority of secretory units are clearly mucous, not a balance of both or prominent serous demilunes. *Papillary* - **Papillary structures** are typically associated with ducts or cyst linings, forming finger-like projections. - This term does not describe a primary type of salivary gland secretory unit based on its cellular composition or secretory product.

Q: The testis reaches the point marked $X$ at which month of gestation? (Recent NEET Pattern 2016-17)

7th month. ***7th month*** - The diagram shows the **testis** descending through the **inguinal canal** into the scrotum. - Testicular descent typically occurs during the **seventh month** of gestation, guided by the **gubernaculum**. *5th month* - By the fifth month, the testes have typically descended to the **deep inguinal ring** but have not yet entered the inguinal canal. - This stage precedes the point marked X, indicating an earlier phase of descent. *6th month* - During the sixth month, the testes are usually found within the **inguinal canal**, but not yet nearing its exit into the scrotum. - The point X represents the testis having passed through the inguinal canal, which occurs later. *8th month* - By the eighth month, the testes are typically **fully descended into the scrotum**. - The image depicts the testis at the exit of the inguinal canal, signifying the completion of descent rather than full scrotal positioning.

Q: All are true about the ganglion ' $X$ ' shown in the image except:

Located at external genu near facial canal. ***Located at external genu near facial canal*** - The ganglion labeled 'X' is the **trigeminal ganglion** (also known as the **Gasserian ganglion**). - The **geniculate ganglion** is located at the external genu of the facial nerve (cranial nerve VII) near the facial canal, not the trigeminal ganglion. - This statement is **incorrect** for the trigeminal ganglion, making it the correct answer to this EXCEPT question. *Semilunar in shape* - The **trigeminal ganglion** (ganglion 'X' in the image) is indeed flat and **semilunar or crescent-shaped**. - This characteristic shape allows it to conform to the contours of the temporal bone within the cranial cavity. *Housed in Meckel's cave* - The **trigeminal ganglion** is specifically located within a dura mater pouch known as **Meckel's cave** (also called the trigeminal cave or cavum trigeminale). - This cave is situated in the middle cranial fossa, near the apex of the petrous part of the temporal bone. *Corresponds to posterior root ganglion of spinal nerve* - The **trigeminal ganglion** is homologous to the **posterior root ganglia** (also known as dorsal root ganglia) of spinal nerves. - Both types of ganglia contain the cell bodies of **sensory neurons** (pseudounipolar neurons) that transmit sensory information to the central nervous system.

Q: The pathway of light reflex is shown. Lesion of which of the following areas results in development of Argyll Robertson pupil?

Periaqueductal gray matter. ***Periaqueductal gray matter in the midbrain*** - This region is crucial for the **light reflex pathway**, as it contains interneurons that connect the pretectal nucleus (after optic afferents synapse) to the Edinger-Westphal nuclei. - A lesion here interrupts the pupillary light reflex while sparing the accommodation reflex, leading to the classic **"light-near dissociation"** seen in Argyll Robertson pupils. - Classically associated with **neurosyphilis**, though can also occur in diabetes mellitus. *Optic nerve* - Damage to the optic nerve causes a **loss of consensual and direct light reflexes** in the affected eye, resulting in a **relative afferent pupillary defect (RAPD)**. - While it affects pupillary response to light, it does not produce the light-near dissociation characteristic of Argyll Robertson pupils. *Lateral geniculate body (LGB)* - The LGB is primarily involved in **visual processing**, receiving input from the optic tracts and projecting to the visual cortex. - Lesions here would cause **visual field defects** but would not affect the pupillary light reflex, as the light reflex pathway projects to the pretectal nucleus, bypassing the LGB. *Edinger-Westphal (E-W) nuclei* - These nuclei are the **preganglionic parasympathetic component** of the oculomotor nerve, controlling pupillary constriction. - Bilateral damage to the E-W nuclei would result in **fixed, dilated pupils** (mydriasis) that do not react to light *or* accommodation, unlike the Argyll Robertson pupil which preserves the accommodation reflex.

Q: Identify the nerve passing through the Triangle of Doom:

Femoral branch of genitofemoral nerve. ***Femoral branch of genitofemoral nerve*** - The **Triangle of Doom** is an inverted triangle located inferior to the deep inguinal ring, bounded by the **vas deferens medially** and the **gonadal vessels laterally**. - The **femoral branch of genitofemoral nerve** courses along the **external iliac artery** and passes through or immediately adjacent to the Triangle of Doom. - This nerve is at significant risk during laparoscopic inguinal hernia repair when dissecting within this triangle, making it a critical landmark. - Injury can result in sensory loss over the anterior thigh. *Lateral femoral cutaneous nerve* - The **lateral femoral cutaneous nerve** runs **lateral to the Triangle of Doom**, passing under the lateral aspect of the inguinal ligament near the anterior superior iliac spine. - It does NOT pass through the Triangle of Doom itself. - It provides sensation to the lateral thigh and can be injured during lateral dissection, but is not within the triangle's boundaries. *Genital branch of genitofemoral nerve* - The **genital branch of genitofemoral nerve** courses through the **inguinal canal** alongside the spermatic cord. - It innervates the cremaster muscle and scrotal skin. - It lies more anterior and medial, within the inguinal canal rather than in the Triangle of Doom. *Ilio-inguinal nerve* - The **ilio-inguinal nerve** runs within the inguinal canal parallel to the spermatic cord. - It provides sensation to the groin, perineum, and inner thigh. - It is located superficial to the deep inguinal ring and anterior to the Triangle of Doom structures.

Q: Identify the tissue:

Thymus. ***Thymus*** - The presence of a **cortex** and **medulla**, along with **Hassall's corpuscles** (epithelial reticular cells arranged concentrically), is characteristic of the thymus [1]. - The thymus is responsible for **T-cell maturation** and selection [1]. *Lymph node* - Lymph nodes typically show a distinct **cortex** with lymphoid follicles (B-cell areas) and a **paracortex** (T-cell area), but lack Hassall's corpuscles. - They function in **filtering lymph** and initiating immune responses. *Tonsil* - Tonsils are characterized by **crypts** lined by stratified squamous epithelium and prominent **lymphoid follicles** beneath the epithelium, which are not the primary features here. - They are part of the **Waldeyer's ring** and serve as a first line of defense against inhaled and ingested pathogens. *Spleen* - The spleen has distinct **red pulp** (involved in filtering blood and removing old red blood cells) and **white pulp** (lymphoid areas with periarteriolar lymphoid sheaths and follicles), but does not contain Hassall's corpuscles. - It is a major site for **immune surveillance** and blood filtration. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, p. 634.

Q: The blood vessel marked as $X$ in the CT angiography image is:

P2 PCA. ***P2 PCA*** - The image displays a CT angiography of the **Circle of Willis**. The vessel marked 'X' is a segment of the **posterior cerebral artery** (PCA). - The PCA is conventionally divided into four segments: P1 (pre-communicating), P2 (peduncular), P3 (quadrigeminal), and P4 (cortical). The 'X' points to the segment of the PCA that is distal to the posterior communicating artery, indicating the **P2 segment**. *P1 PCA* - The **P1 segment** of the PCA is the initial part, located between the basilar artery bifurcation and the posterior communicating artery. - The vessel marked 'X' is clearly **distal to the connection point** where the posterior communicating artery would typically join, thus it is not the P1 segment. *Internal carotid artery* - The **internal carotid arteries** typically ascend higher and give rise to the anterior and middle cerebral arteries, forming the anterior circulation. - The vessel marked 'X' is part of the **posterior circulation**, originating from the basilar artery system, not the internal carotid artery. *M1, Middle cerebral artery* - The **M1 (main trunk) segment of the middle cerebral artery** extends laterally from the internal carotid artery. - The vessel marked 'X' is situated more posteriorly and medially, clearly identifying it as part of the **posterior cerebral artery**, and not the middle cerebral artery.

Q: Name the structure marked as $X$ in the CT abdomen shown below: (Recent NEET Pattern 2016-17)

Inferior vena cava. ***Inferior vena cava*** - The structure marked as X is located to the **right of the aorta** and is typically seen as a large, relatively **thin-walled vessel**. - Its position anterior and to the right of the vertebral body, draining into the heart, is consistent with the **inferior vena cava (IVC)**. *Pancreas* - The pancreas is typically located more anteriorly and superiorly in this cross-section, usually nestled between the duodenum and spleen. - It would appear as a **glandular organ** with a different texture and position on a CT scan. *Aorta* - The aorta is typically the **larger, thick-walled, pulsatile vessel** located to the **left of the vertebral body** and to the left of the structure marked X. - It usually appears circular in cross-section and is often seen with higher attenuation due to arterial contrast. *Left renal vein* - The left renal vein typically arises from the left kidney and crosses the midline to drain into the IVC, passing **anterior to the aorta**. - The structure marked X is the IVC itself, which receives the left renal vein, rather than the left renal vein.

Question 1

Identify the structure:

Accepted Answer

Tonsil

Answer

Lymph node

Answer

Spleen

Answer

Thymus

Question 2

Which type of salivary glands is shown in the image?

Accepted Answer

Mixed

Answer

Serous

Answer

Mucous

Answer

Papillary

Question 3

Which type of salivary glands is shown in the image?

Accepted Answer

Mucous

Answer

Serous

Answer

Mixed

Answer

Papillary

Question 4

The testis reaches the point marked $X$ at which month of gestation? (Recent NEET Pattern 2016-17)

Accepted Answer

7th month

Answer

5th month

Answer

6th month

Answer

8th month

Question 5

All are true about the ganglion ' $X$ ' shown in the image except:

Accepted Answer

Located at external genu near facial canal

Answer

Semilunar in shape

Answer

Housed in Meckel's cave

Answer

Corresponds to posterior root ganglion of spinal nerve

Question 6

The pathway of light reflex is shown. Lesion of which of the following areas results in development of Argyll Robertson pupil?

Accepted Answer

Periaqueductal gray matter

Answer

Lateral geniculate body

Answer

Edinger-Westphal nuclei

Answer

Optic nerve

Question 7

Identify the nerve passing through the Triangle of Doom:

Accepted Answer

Femoral branch of genitofemoral nerve

Answer

Genital branch of genitofemoral nerve

Answer

Ilio-inguinal nerve

Answer

Lateral femoral cutaneous nerve

Question 8

Identify the tissue:

Accepted Answer

Thymus

Answer

Lymph node

Answer

Tonsil

Answer

Spleen

Answer

Bone marrow

Question 9

The blood vessel marked as $X$ in the CT angiography image is:

Accepted Answer

P2 PCA

Answer

P1 PCA

Answer

Internal carotid artery

Answer

M1, Middle cerebral artery

Question 10

Name the structure marked as $X$ in the CT abdomen shown below: (Recent NEET Pattern 2016-17)

Accepted Answer

Inferior vena cava

Answer

Pancreas

Answer

Aorta

Answer

Left renal vein

NEET-PG 2017

Anatomy

Pathology

Radiology