NEET-PG 2015 - Anatomy Practice Questions

Q: Most common site for Cystic Hygroma is -

Lower third of neck. ***Lower third of neck*** - **Cystic hygromas** (also known as **lymphatic malformations**) most commonly occur in the **posterior triangle of the neck**, which is located in the lower lateral aspect of the neck [1]. - Approximately **75-80%** of cystic hygromas are found in the neck region, with the **posterior triangle** being the predominant site. - The **posterior jugular lymph sac** fails to connect properly with the venous system during embryonic development, leading to these cystic malformations in this characteristic location [1]. - The posterior triangle encompasses the lower lateral neck, making "lower third of neck" an acceptable description of this most common site. *Overlying the parotid gland* - While lymphatic malformations can occur in the parotid region, this represents only about **10-15%** of cases. - This is a less common site compared to the posterior triangle of the neck. - Lesions in this area might raise concern for other parotid pathologies like **pleomorphic adenoma** or **hemangioma**. *Along the Zygomatic Prominence* - This is an unusual location for a cystic hygroma, as the lymphatic drainage and embryonic development in this area are not typically associated with these malformations. - Lesions here might suggest different developmental or neoplastic etiologies such as **dermoid cysts** or **vascular malformations**. *Post auricular* - The post-auricular region is not a common site for cystic hygromas. - Swelling in this area could be due to other conditions like **mastoiditis**, **lymphadenopathy**, or **sebaceous cysts**.

Q: Transplanted kidney is relocated to which region in the recipient's body?

Retroperitoneal region. ***Retroperitoneal region*** - The transplanted kidney is typically placed in the **iliac fossa** within the **retroperitoneal space** of the recipient [2]. - This location provides adequate space and a convenient site for connecting the transplant's renal artery and vein to the recipient's **iliac vessels**, and the ureter to the bladder [2]. *Lumbar region* - The native kidneys are located in the lumbar region, but a transplanted kidney is not usually placed there due to the complexity of vascular anastomoses and limited access [1]. - Positioning in the lumbar region would require more extensive surgical dissection and potentially longer vascular connections. *Epigastrium* - The epigastrium is the upper central part of the abdomen, above the navel. - This location is not suitable for kidney transplantation due to anatomical constraints and the lack of readily accessible large blood vessels for connection. *Beside the dysfunctional Kidney* - The dysfunctional native kidneys are usually left in place unless they are causing severe complications like uncontrolled hypertension or infection. - Placing the transplanted kidney directly beside the native dysfunctional kidney is not the standard procedure due to space limitations and to avoid operating near potentially diseased native organs.

Q: Food can commonly get obstructed in the esophagus at all of the following locations except

Crossing of the hemiazygous vein. Food can commonly get obstructed in the esophagus at all of the following locations except ***Crossing of the hemiazygous vein*** - The **hemiazygos vein crosses the vertebral column** at T7-T9 to drain into the azygos vein; however, this anatomical relationship does not typically create a constriction or point of obstruction for the esophagus. - While it is in proximity, its course does not physically compress or narrow the esophageal lumen in a manner that would commonly cause food impaction. *Crossing of left bronchus* - The **left main bronchus crosses anterior to the esophagus** at the level of the carina (T4-T5), causing a natural indentation and narrowing of the esophageal lumen. - This anatomical narrowing, coupled with the rigid structure of the bronchus, makes it a common site for food impaction, especially for larger boluses. *Crossing of arch of aorta* - The **arch of the aorta crosses anterior and to the left of the esophagus** at the level of T3-T4, creating another significant anatomical constriction. - This bending and compression by a large, typically pulsatile vessel forms a natural bottleneck where swallowed food can easily become lodged. *Diaphragmatic aperture* - The **esophageal hiatus of the diaphragm** (T10) is the most distal natural esophageal narrowing, where the esophagus passes through a muscular opening before joining the stomach. - This narrow opening, surrounded by the crura of the diaphragm, is a very common site for food impaction, particularly when the opening is physiologically or pathologically narrowed (e.g., in cases of hiatal hernia or tight diaphragmatic attachments).

Q: Trigone of urinary bladder develops from:

Mesoderm. ***Mesoderm*** - The **trigone** of the urinary bladder develops from the **distal ends of the mesonephric (Wolffian) ducts**, which are **mesodermal in origin**. - These ducts are **absorbed into the posterior wall of the bladder**, forming the smooth triangular area between the two ureteric orifices and the internal urethral orifice [1]. - Although the epithelium of the trigone is later **replaced by endodermal epithelium** from the urogenital sinus, the **structural origin remains mesodermal**. - This is a classic example of **epithelial metaplasia** where endodermal epithelium replaces mesodermal tissue. *Endoderm of urachus* - The **urachus** is the fibrous remnant of the allantois that connects the apex of the bladder to the umbilicus. - It forms the **median umbilical ligament** in adults and does **not contribute to the trigone**. - The **urogenital sinus** (endodermal) forms the majority of the bladder body, but not the trigone. *Ectoderm* - The **ectoderm** forms the nervous system, epidermis, and sensory epithelia. - It does **not contribute** to the development of the urinary bladder or its trigone. - The urinary system is derived from **mesoderm** (kidneys, ureters, trigone) and **endoderm** (bladder body, urethra). *None of the options* - This is incorrect because **mesoderm** is the correct embryological origin of the trigone. - The mesonephric ducts that form the trigone are definitively mesodermal structures.

Q: Foot drop occurs due to the involvement of:

Common peroneal nerve palsy. ***Common peroneal nerve palsy*** - The **common peroneal nerve** (also known as the common fibular nerve) innervates the muscles responsible for **dorsiflexion** and eversion of the foot (tibialis anterior, extensor hallucis longus, extensor digitorum longus, peroneus longus and brevis). - Damage to this nerve leads to weakness or paralysis of these muscles, resulting in **foot drop**, which is the most common neurological cause. - The nerve is vulnerable at the **neck of the fibula** where it is superficial and can be compressed or injured. *Sciatic nerve* - The **sciatic nerve** divides into the tibial and common peroneal nerves. - Proximal sciatic nerve injury can cause foot drop, but it would also cause additional deficits including hamstring weakness, loss of ankle plantarflexion, and sensory loss over a wider distribution. - Isolated foot drop typically indicates **common peroneal nerve** injury, not sciatic nerve injury. *Direct injury to the dorsiflexors* - Direct trauma to the **dorsiflexor muscles** (tibialis anterior, extensor hallucis longus, extensor digitorum longus) can mechanically impair dorsiflexion. - However, the term "foot drop" typically refers to **neurological causes** rather than direct muscle injury, making common peroneal nerve palsy the more specific answer. *Obturator nerve* - The **obturator nerve** innervates the **adductor muscles of the thigh** (adductor longus, adductor brevis, adductor magnus, gracilis). - It does not innervate any muscles responsible for dorsiflexion of the foot and therefore **cannot cause foot drop**.

Q: Submucosal plexus is -

Meissner's plexus. ***Meissner's plexus*** - The **submucosal plexus** is also known as **Meissner's plexus**, located in the submucosal layer of the **gastrointestinal tract** [1]. - It primarily controls local **secretions**, **absorption**, and **blood flow** within the gut [2]. *Myenteric plexus* - The **myenteric plexus** is also known as **Auerbach's plexus**, located between the longitudinal and circular muscle layers of the **gastrointestinal tract** [1]. - It primarily controls **gastrointestinal motility**, not local secretions [1]. *Tympanic plexus* - The **tympanic plexus** is a network of nerves in the **middle ear** that provides sensory innervation to the tympanic cavity. - It is unrelated to the gastrointestinal tract or its intrinsic nervous system. *Auerbach's plexus* - **Auerbach's plexus** is another name for the **myenteric plexus**, which is located between the muscle layers [1]. - It is responsible for gut motility and distinct from the submucosal plexus.

Q: Which of the following extraocular muscles is not supplied by oculomotor nerve?

Lateral rectus. ***Lateral rectus*** - The **lateral rectus muscle** is innervated by the **abducens nerve (CN VI)**, not the oculomotor nerve (CN III). [1] - Its primary action is **abduction** of the eye, moving it laterally away from the midline. [1] *Inferior oblique* - The **inferior oblique muscle** is innervated by the **oculomotor nerve (CN III)**. [1] - Its actions include **extorsion**, elevation, and abduction of the eye. [1] *Medial rectus* - The **medial rectus muscle** is innervated by the **oculomotor nerve (CN III)**. [1] - Its primary action is **adduction** of the eye, moving it medially towards the midline. [1] *Inferior rectus* - The **inferior rectus muscle** is innervated by the **oculomotor nerve (CN III)**. [1] - Its actions include **depression**, extorsion, and adduction of the eye. [1]

Q: Extensor carpi radialis longus is

Extensor and radial deviator of the wrist. ***Extensor and radial deviator of the wrist*** - The **extensor carpi radialis longus (ECRL)** is one of the primary muscles responsible for **extension of the wrist**. [1] - Due to its anatomical position on the radial side of the forearm, it also contributes significantly to **radial deviation** (abduction) of the wrist. [1] *Weak extensor of the wrist* - While it is an extensor, the ECRL is considered a **strong extensor** of the wrist, especially when acting with other extensors like the Extensor Carpi Radialis Brevis (ECRB). [1] - Its strength is crucial for tasks requiring **grip and wrist stabilization**. *Extensor and ulnar deviator of the wrist* - The ECRL performs wrist extension but causes **radial deviation**, not ulnar deviation. [1] - **Ulnar deviation** is primarily performed by the **extensor carpi ulnaris** and **flexor carpi ulnaris**. *Injured in Posterior interosseous nerve injury* - The ECRL is innervated by the **radial nerve** **before** it divides into the superficial and deep (posterior interosseous) branches. [2] - Therefore, ECRL function is typically **spared in isolated posterior interosseous nerve injuries**, which mainly affect muscles in the deep compartment of the posterior forearm. [2]

Question 1

Most common site for Cystic Hygroma is -

Accepted Answer

Lower third of neck

Answer

Overlying the parotid gland

Answer

Along the Zygomatic Prominence

Answer

Post auricular

Question 2

Transplanted kidney is relocated to which region in the recipient's body?

Accepted Answer

Retroperitoneal region

Answer

Lumbar region

Answer

Epigastrium

Answer

Beside the dysfunctional kidney

Question 3

Food can commonly get obstructed in the esophagus at all of the following locations except

Accepted Answer

Crossing of the hemiazygous vein

Answer

Crossing of left bronchus

Answer

Crossing of arch of aorta

Answer

Diaphragmatic aperture

Question 4

Trigone of urinary bladder develops from:

Accepted Answer

Mesoderm

Answer

Ectoderm

Answer

None of the options

Answer

Endoderm of urachus

Question 5

Foot drop occurs due to the involvement of:

Accepted Answer

Common peroneal nerve palsy

Answer

Obturator nerve

Answer

Sciatic nerve

Answer

Direct injury to the dorsiflexors

Question 6

Submucosal plexus is -

Accepted Answer

Meissner's plexus

Answer

Myenteric plexus

Answer

Tympanic plexus

Answer

Auerbach's plexus

Question 7

Which of the following extraocular muscles is not supplied by oculomotor nerve?

Accepted Answer

Lateral rectus

Answer

Inferior oblique

Answer

Medial rectus

Answer

Inferior rectus

Question 8

Extensor carpi radialis longus is

Accepted Answer

Extensor and radial deviator of the wrist

Answer

Weak extensor of the wrist

Answer

Extensor and ulnar deviator of the wrist

Answer

Injured in Posterior interosseous nerve injury

NEET-PG 2015 — Anatomy