Anatomy
7 questionsIdentify the structure:
Which type of salivary glands is shown in the image?
Which type of salivary glands is shown in the image?
The testis reaches the point marked $X$ at which month of gestation? (Recent NEET Pattern 2016-17)
All are true about the ganglion ' $X$ ' shown in the image except:
The pathway of light reflex is shown. Lesion of which of the following areas results in development of Argyll Robertson pupil?
Identify the nerve passing through the Triangle of Doom:
NEET-PG 2017 - Anatomy NEET-PG Practice Questions and MCQs
Question 301: Identify the structure:
- A. Lymph node
- B. Tonsil (Correct Answer)
- C. Spleen
- D. Thymus
Explanation: ***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.
Question 302: Which type of salivary glands is shown in the image?
- A. Serous
- B. Mucous
- C. Mixed (Correct Answer)
- D. Papillary
Explanation: ***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.
Question 303: Which type of salivary glands is shown in the image?
- A. Serous
- B. Mucous (Correct Answer)
- C. Mixed
- D. Papillary
Explanation: ***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.
Question 304: The testis reaches the point marked $X$ at which month of gestation? (Recent NEET Pattern 2016-17)
- A. 5th month
- B. 6th month
- C. 7th month (Correct Answer)
- D. 8th month
Explanation: ***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.
Question 305: All are true about the ganglion ' $X$ ' shown in the image except:
- A. Semilunar in shape
- B. Housed in Meckel's cave
- C. Corresponds to posterior root ganglion of spinal nerve
- D. Located at external genu near facial canal (Correct Answer)
Explanation: ***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.
Question 306: The pathway of light reflex is shown. Lesion of which of the following areas results in development of Argyll Robertson pupil?
- A. Lateral geniculate body
- B. Edinger-Westphal nuclei
- C. Periaqueductal gray matter (Correct Answer)
- D. Optic nerve
Explanation: ***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.
Question 307: Identify the nerve passing through the Triangle of Doom:
- A. Genital branch of genitofemoral nerve
- B. Femoral branch of genitofemoral nerve (Correct Answer)
- C. Ilio-inguinal nerve
- D. Lateral femoral cutaneous nerve
Explanation: ***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.
Pathology
1 questionsIdentify the tissue:
NEET-PG 2017 - Pathology NEET-PG Practice Questions and MCQs
Question 301: Identify the tissue:
- A. Lymph node
- B. Tonsil
- C. Spleen
- D. Thymus (Correct Answer)
- E. Bone marrow
Explanation: ***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.
Radiology
2 questionsThe blood vessel marked as $X$ in the CT angiography image is:
Name the structure marked as $X$ in the CT abdomen shown below: (Recent NEET Pattern 2016-17)
NEET-PG 2017 - Radiology NEET-PG Practice Questions and MCQs
Question 301: The blood vessel marked as $X$ in the CT angiography image is:
- A. P1 PCA
- B. P2 PCA (Correct Answer)
- C. Internal carotid artery
- D. M1, Middle cerebral artery
Explanation: ***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.
Question 302: Name the structure marked as $X$ in the CT abdomen shown below: (Recent NEET Pattern 2016-17)
- A. Pancreas
- B. Inferior vena cava (Correct Answer)
- C. Aorta
- D. Left renal vein
Explanation: ***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.