NEET-PG 2012 - Anatomy Practice Questions

Q: Which of the following is not a neural plate inducer?

High BMP. High BMP - **Bone Morphogenetic Proteins (BMPs)** are primarily involved in promoting epidermal differentiation in the ectoderm, and actively **inhibiting neural differentiation**. - Therefore, high levels of BMP would **prevent neural plate formation**, rather than induce it. *FGF upregulation* - **Fibroblast Growth Factors (FGFs)** are crucial in the early development of the nervous system. - They play a key role in **inducing neural plate formation** and maintaining its identity. *Prechordal mesoderm* - The **prechordal mesoderm**, located anterior to the notochord, is an important signalling center during early embryonic development. - It contributes to the **induction of the forebrain** and plays a role in patterning the anterior neural plate. *Notochord appearance* - The **notochord**, a transient rod-like structure, is a primary inducer of the neural plate. - It secretes factors like **Sonic Hedgehog (Shh)** which induce the overlying ectoderm to differentiate into neuroectoderm, forming the neural plate.

Q: Unilateral lacrimal gland destruction may be caused by?

Fracture of roof of orbit. ***Fracture of roof of orbit*** - The **lacrimal gland** is situated in the **lacrimal fossa** on the anterior-lateral part of the **orbital roof**. A fracture in this specific area can directly damage the gland. - Trauma to the **orbital roof** can lead to laceration, avulsion, or compression of the lacrimal gland, resulting in its destruction and impairing tear production. *Inferior orbital fissure fracture* - The **inferior orbital fissure** transmits nerves and vessels to the orbit but is located inferior to the lacrimal gland, making direct injury unlikely. - Fractures here are more associated with **infraorbital nerve damage** or disruption of orbital contents into the maxillary sinus, not lacrimal gland destruction. *Fracture of lateral wall* - The **lateral wall of the orbit** forms the outer boundary and protects structures deeper within the orbit, but the lacrimal gland is situated superiorly and anteriorly. - While significant trauma to the lateral wall can impact orbital contents, it is less likely to directly cause unilateral lacrimal gland destruction compared to a direct roof fracture. *Fracture of sphenoid* - Fractures of the **sphenoid bone** are typically more posterior and central, affecting structures like the **optic canal** or **cavernous sinus**. - While it can indirectly affect orbital function, it is not a direct cause of isolated lacrimal gland destruction due to its anatomical location.

Q: Which of the following extraocular muscle has the longest tendon?

Superior oblique. ***Superior oblique*** - The superior oblique muscle has the **longest tendon** and overall length of all extraocular muscles because it passes through the **trochlea**, a cartilaginous pulley. - Its long course allows it to have a complex action, primarily **intorsion, depression, and abduction** of the eye [1]. *Superior rectus* - The superior rectus is one of the **straight muscles** (recti) and is not the longest. - Its primary actions are **elevation, adduction, and intorsion** of the eyeball [1]. *Medial rectus* - The medial rectus is another **straight muscle** and is generally considered the **strongest** but not the longest extraocular muscle. - Its main action is **adduction** (moving the eye inward) [1]. *Inferior oblique* - The inferior oblique is the **shortest** of all the extraocular muscles. - Its primary actions are **extorsion, elevation, and abduction** of the eyeball [1].

Q: After trauma, a person cannot move their eye outward beyond the midpoint. Which nerve is injured?

6th. ***6th*** - The **abducens nerve (CN VI)** innervates the **lateral rectus muscle**, which is responsible for moving the eye **outward (abduction)** [1]. - Injury to the abducens nerve would result in an inability to move the eye laterally, causing an **esotropia** (eye turned inward at rest) [1]. *2nd* - The **optic nerve (CN II)** is responsible for **vision**, not eye movement [2]. - Damage to this nerve would cause **visual field defects** or **blindness** [3]. *3rd* - The **oculomotor nerve (CN III)** controls most extraocular muscles, including the **medial, superior, and inferior rectus** and **inferior oblique muscles**, as well as the **levator palpebrae superioris** and **pupillary constriction** [2]. - Injury to CN III would lead to a **down and out deviation of the eye**, **ptosis**, and a **dilated pupil** [2]. *4th* - The **trochlear nerve (CN IV)** innervates the **superior oblique muscle**, which primarily causes **intorsion** (rotation downward and inward) [1]. - Damage to this nerve results in **vertical diplopia**, especially when looking down and in, and a characteristic **head tilt** to compensate [3].

Q: In the case of a penile injury, which of the following structures prevents the extravasation of blood?

Buck's fascia. ***Buck's fascia*** - **Buck's fascia** is a strong, fibrous sheath that surrounds the **corpora cavernosa** and **corpus spongiosum**, acting as a confining layer. - In cases of **penile injury**, such as a penile fracture, rupture of the tunica albuginea leads to bleeding [1]. Buck's fascia contains this extravasated blood, preventing its spread beyond the penis and resulting in a characteristic **"eggplant" deformity** [1]. *Fascia of Camper* - The **fascia of Camper** is the superficial fatty layer of the anterior abdominal wall's superficial fascia. - It is continuous with the superficial perineal fascia but does not directly cover the erectile tissues of the penis. *Fascia transversalis* - The **fascia transversalis** is a deep fascia lining the inner aspect of the anterior abdominal wall, beneath the transversus abdominis muscle. - It plays a role in forming the posterior wall of the inguinal canal and is not directly involved in containing blood within the penis after an injury. *None of the options* - This option is incorrect because Buck's fascia specifically fulfills the function described, isolating blood within the penile shaft.

Q: A person inhaled a peanut two days ago and is now unable to cough it out. Where is the possible location?

Right lower lobe. ***Right lower lobe*** - Due to the **angle** of the right main bronchus, which is less acute than the left, aspirated foreign bodies, like a peanut, tend to preferentially enter the **right bronchial tree**. - Within the right lung, foreign bodies are most commonly found in the **right lower lobe** because its **bronchus is the most direct continuation** of the right main bronchus, especially in an upright position. *Right superior lobe* - While material can go into the right lung, the **right upper lobe bronchus** branches off at a more acute angle, making aspiration into this lobe less common than into the lower lobes when a person is in an upright or semi-recumbent position. - Aspiration into the superior lobes is more common with specific body positions or in cases of massive aspiration. *Right middle lobe* - The **right middle lobe bronchus** is smaller and branches off at an angle that is less favorable for direct aspiration compared to the right lower lobe. - Aspiration to this lobe is less frequent than to the lower lobes. *Left lower lobe* - The **left main bronchus** is narrower and branches off at a much more acute angle from the trachea compared to the right main bronchus. - This anatomical difference makes aspiration into the left lung, including the **left lower lobe**, significantly less common than into the right lung.

Q: The commonest site of aspiration of a foreign body in the supine position is into the:

Right lower lobe superior segment. ***Right lower lobe superior segment*** - When an individual is in the **supine position**, the most dependent portion of the lung (where gravity would pull aspirated material) is the **superior segment of the right lower lobe**. - This anatomical orientation, combined with the **wider and more vertical right main bronchus**, increases the likelihood of aspirated foreign bodies entering and settling in this specific segment. - The superior segment of the right lower lobe is **posteriorly located** and becomes the most dependent when lying supine. *Right upper lobe apical* - While the right upper lobe is on the favored side for aspiration due to the anatomy of the main bronchi, the **apical segment** is not the most dependent in the supine position. - Aspiration into the apical segment is generally less common than into more dependent segments when lying flat. *Left basal* - The **left main bronchus** is narrower and takes a more acute angle compared to the right, making aspiration into the left lung less common. - Even if aspiration were to occur in the left lung, the **basal segments** are not the most dependent in the supine position. *Right middle lobe medial segment* - The medial segment of the middle lobe is **not as posteriorly positioned** as the superior segment of the right lower lobe in the supine position. - While aspiration can occur into the middle lobe, it is **less common** than into the superior segment of the right lower lobe when supine due to the anatomical positioning and gravity effects.

Q: Identify the type of connective tissue present in the image.

Dense irregular. ***Dense irregular*** - The image shows **densely packed collagen fibers** arranged in an **irregular, haphazard fashion**, characteristic of dense irregular connective tissue. - This type of tissue provides **strength** and resistance to stress from multiple directions, found in the **dermis of the skin** and organ capsules. *Loose and irregular* - **Loose connective tissue** would show more ground substance and fewer, loosely arranged fibers, whereas this image displays high fiber density. - While it is "irregular" in fiber arrangement, the density of fibers rules out the "loose" classification. *Specialized* - **Specialized connective tissues** include cartilage, bone, blood, and adipose tissue, which have distinct cellular and extracellular matrix components not seen here. - This tissue lacks the specific cellular and matrix characteristics that would classify it as specialized (e.g., chondrocytes in lacunae, osteocytes, blood cells). *Dense regular* - **Dense regular connective tissue** features collagen fibers arranged in parallel bundles, providing strength in one direction. - Examples include **tendons and ligaments**, which are structurally organized in an orderly, aligned manner, unlike the displayed irregular arrangement.

Q: Which arteries supply the talus?

All of the options. ***All of the options*** - The **talus** has a tenuous blood supply due to its limited muscular attachments, receiving contributions from multiple surrounding arteries to ensure adequate perfusion. - The **anterior tibial artery**, **posterior tibial artery**, and **peroneal artery** all contribute branches that form an anastomotic network around the talus. *Anterior tibial artery* - The **anterior tibial artery** contributes blood supply to the talus primarily through its **dorsal pedis branch** and ascending branches that supply the neck and head of the talus. - Its major role is in supplying the **anterior and superior talar surfaces**. *Posterior tibial artery* - The **posterior tibial artery** is a significant source of blood supply, particularly to the body and posterior aspect of the talus, via branches like the **artery of the tarsal canal** and the **deltoid branch**. - Its branches contribute to the **posterior talar artery network** which is crucial for the central part of the talus. *Peroneal artery* - The **peroneal artery** provides blood supply to the lateral and posterior parts of the talus through its **communicating branch** and perforating branches. - It contributes to the **tarsal artery network**, ensuring collateral circulation to the talus.

Question 1

Which of the following is not a neural plate inducer?

Accepted Answer

High BMP

Answer

FGF upregulation

Answer

Prechordal mesoderm

Answer

Notochord appearance

Question 2

Unilateral lacrimal gland destruction may be caused by?

Accepted Answer

Fracture of roof of orbit

Answer

Inferior orbital fissure fracture

Answer

Fracture of lateral wall

Answer

Fracture of sphenoid

Question 3

Which of the following extraocular muscle has the longest tendon?

Accepted Answer

Superior oblique

Answer

Medial rectus

Answer

Superior rectus

Answer

Inferior oblique

Question 4

After trauma, a person cannot move their eye outward beyond the midpoint. Which nerve is injured?

Accepted Answer

6th

Answer

3rd

Answer

4th

Answer

2nd

Question 5

In the case of a penile injury, which of the following structures prevents the extravasation of blood?

Accepted Answer

Buck's fascia

Answer

Fascia of camper

Answer

Fascia transversalis

Answer

None of the options

Question 6

A person inhaled a peanut two days ago and is now unable to cough it out. Where is the possible location?

Accepted Answer

Right lower lobe

Answer

Right superior lobe

Answer

Left lower lobe

Answer

Right middle lobe

Question 7

In axillary nerve paralysis, which of the following statements is false?

Accepted Answer

Extension of shoulder with arm abducted to 90 degrees is impossible

Answer

Deltoid muscle is wasted

Answer

Small area of numbness is present over the shoulder region

Answer

Patient cannot initiate abduction

Question 8

The commonest site of aspiration of a foreign body in the supine position is into the:

Accepted Answer

Right lower lobe superior segment

Answer

Right upper lobe apical

Answer

Left basal

Answer

Right middle lobe medial segment

Question 9

Identify the type of connective tissue present in the image.

Accepted Answer

Dense irregular

Answer

Loose and irregular

Answer

Specialized

Answer

Dense regular

Question 10

Which arteries supply the talus?

Accepted Answer

All of the options

Answer

Peroneal artery

Answer

Posterior tibial artery

Answer

Anterior tibial artery

NEET-PG 2012 — Anatomy