NEET-PG 2013 - Anatomy Practice Questions

Q: Which of the following does not contribute to the formation of the nasal septum?

Nasal bone. ***Nasal bone*** - The **nasal bones** form the bridge of the nose and are part of the external nasal skeleton, not the internal nasal septum. - They articulate with the frontal bone superiorly and the maxilla laterally, forming the **roof of the nasal cavity** anteriorly. *Septal cartilage* - The **septal cartilage**, or quadrangular cartilage, forms the anterior and inferior parts of the cartilaginous nasal septum. - It provides flexibility and support to the anterior nasal cavity. *Vomer* - The **vomer** is a thin, plowshare-shaped bone that forms the posteroinferior part of the bony nasal septum. - It articulates with the sphenoid, ethmoid, palatine, and maxillary bones. *Ethmoid* - The **perpendicular plate of the ethmoid bone** forms the superior part of the bony nasal septum. - It extends downward from the cribriform plate to meet the vomer and septal cartilage.

Q: Inlet of larynx is formed by:

Aryepiglottic fold. ***Aryepiglottic fold*** - The **inlet of the larynx** is the opening into the laryngeal cavity from the pharynx. - It is bordered anteriorly by the **epiglottis**, laterally by the **aryepiglottic folds**, and posteriorly by the **arytenoid cartilages** and **interarytenoid notch**. *False vocal cord* - The **false vocal cords** (ventricular folds) are located within the laryngeal cavity, inferior to the inlet. - They play a protective role but do not form the boundaries of the laryngeal inlet itself. *Folds from the base of the tongue to the epiglottis* - These folds, including the **glossoepiglottic folds**, connect the tongue to the epiglottis. - They are superior to the laryngeal inlet and are part of the oropharynx, not direct borders of the inlet. *Vocal cord* - The **true vocal cords** are responsible for voice production and are located deeper within the larynx, inferior to the false vocal cords. - They do not form any part of the laryngeal inlet.

Q: In Articular cartilage, most active chondrocytes are seen in ?

Zone 2. ***Zone 2*** - This is the **transitional (or middle) zone**, where chondrocytes are numerous and more metabolically active, responsible for synthesizing major components of the extracellular matrix. - Chondrocytes here are typically **ovoid or round**, arranged somewhat randomly, and are involved in maintaining the cartilage structure. *Zone 1* - This is the **superficial (or tangential) zone**, where chondrocytes are **flattened** and oriented parallel to the articular surface. - Their primary role is to resist shear forces, and they are generally less metabolically active compared to those in the transitional zone. *Zone 3* - This is the **deep (or radial) zone**, characterized by **columnar arrangements** of chondrocytes. [1] - While these chondrocytes are metabolically active and synthesize matrix components, they are generally less active than those in the transitional zone and are more involved in resisting compressive forces. *Zone 4* - This is the **calcified zone**, directly adjacent to subchondral bone, where chondrocytes are **sparse** and often hypertrophic prior to eventual calcification. - This zone acts as an interface between cartilage and bone, and its chondrocytes have significantly reduced metabolic activity once calcification occurs. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, p. 1184.

Q: Which are the second order neurons in the optic pathway?

Bipolar cells. ***Bipolar cells*** - **Photoreceptors** (rods and cones) are first-order neurons, sensing light. [1] - **Bipolar cells** receive input from photoreceptors and transmit signals to retinal ganglion cells, acting as second-order neurons. [1] *Ganglionic cells* - **Ganglion cells** are third-order neurons in the visual pathway. [1] - Their axons form the **optic nerve**, which carries visual information to the brain. [2] *Cells of lateral geniculate body* - The **lateral geniculate nucleus (LGN)** of the thalamus contains fourth-order neurons. [1] - These cells project to the primary visual cortex. [2] *Astrocytes* - **Astrocytes** are a type of glial cell that provides support and protection to neurons in the central nervous system. - They are **not directly involved** in the transmission of visual information in the optic pathway.

Q: Lymphatic drainage of oropharynx is mainly through?

Jugulodigastric node. ***Jugulodigastric node*** - The **jugulodigastric node** (also known as the principal node of Küttner) is the primary drainage site for infections and malignancies of the posterior third of the tongue and tonsils, which are key components of the oropharynx. - It is a prominent node within the **deep cervical lymph node** chain, specifically located in the superior deep cervical group. *Superficial cervical lymph nodes* - These nodes primarily drain the superficial structures of the neck, scalp, and ear, and are **not the main drainage pathway** for the oropharynx. - They form a chain along the external jugular vein. *Submandibular nodes* - The **submandibular nodes** mainly drain the anterior two-thirds of the tongue, gums, floor of the mouth, and anterior face. - While part of the oral cavity, they are **not the primary drainage** for the oropharynx itself. *Jugulo-omohyoid nodes* - The **jugulo-omohyoid node** is located lower in the deep cervical chain, near the intermediate tendon of the omohyoid muscle. - It is a key drainage node for the **anterior tongue**, but not the primary or main drainage for the entire oropharynx.

Q: Which structure prevents spread of infection from middle ear to brain?

Tegmen tympani. ***Tegmen tympani*** - The **tegmen tympani** is a thin plate of bone forming the roof of the middle ear cavity, separating it from the **middle cranial fossa** and the brain. - Its primary function is to act as a **bony barrier**, preventing upward spread of infection from the middle ear space into the intracranial cavity. *Cribriform plate* - The **cribriform plate** is part of the ethmoid bone, located in the anterior cranial fossa, and is perforated by the **olfactory nerves**. - It does not form a boundary to the middle ear cavity and is not involved in preventing infection spread from the middle ear. *Fundus tympani* - This term is not a standard anatomical landmark. The **floor of the tympanic cavity**, or **fundus tympani**, separates the middle ear from the **internal jugular vein**. - It does not prevent the spread of infection to the brain but rather to structures below the middle ear. *Petrous apex* - The **petrous apex** is the very tip of the petrous part of the temporal bone, which houses the cochlea and vestibule. - While part of the temporal bone, it is not the direct barrier between the middle ear cavity and the brain; its involvement in infection spread is typically due to **petrous apexitis**, a distinct complication.

Q: Which of the following nerves is commonly damaged during McBurney's incision?

Iliohypogastric nerve. ***Iliohypogastric nerve*** - The **iliohypogastric nerve** is most commonly injured during **McBurney's incision** due to its superficial position and transverse course at the level of the incision. - Damage can lead to **numbness** or altered sensation in the suprapubic region, and sometimes **weakness of the lower abdominal wall**. *Subcostal nerve* - The **subcostal nerve** (T12) runs inferior to the 12th rib and is generally superior to the typical site of a McBurney's incision. - Injury to this nerve is less common during this procedure compared to the iliohypogastric and ilioinguinal nerves. *10th thoracic nerve* - The **10th thoracic nerve** (T10) provides sensation around the umbilicus. - While it contributes to innervation of the abdominal wall, its location is typically well above the area of a standard McBurney's incision, making injury unlikely. *11th thoracic nerve* - The **11th thoracic nerve** (T11) innervates the abdominal wall and is located superior to the typical incision site for appendectomy. - Injury to T11 during a McBurney's incision is uncommon as the nerve's course lies cephalad to the surgical field.

Q: Which of the following statements is true regarding the anatomy of the external nose?

The lower one-third is primarily cartilaginous.. ***The lower one-third is primarily cartilaginous.*** - The **lower one-third** of the external nose, including the nasal tip and alae, is predominantly supported by **alar cartilages** (lower lateral cartilages) and other minor cartilages, giving it flexibility. - This cartilaginous structure allows for movement and shaping of the nostrils. - This statement is **anatomically accurate and complete**. *The upper two-thirds is entirely bony.* - This is **incorrect**. - The **upper one-third** is bony (nasal bones and frontal process of maxilla). - The **middle one-third** is primarily **cartilaginous** (upper lateral cartilages). - Therefore, the upper two-thirds consists of **both bone and cartilage**, not entirely bone. *The lateral aspect has only a single cartilage.* - This is **incorrect**. - The lateral aspect contains **multiple cartilages**: upper lateral cartilages, lower lateral (alar) cartilages, and accessory cartilages. - The presence of multiple cartilages provides structural support and flexibility. *The external nose is supported by two nasal bones.* - This is **incomplete and misleading**. - While two **nasal bones** do form the superior bony bridge (upper one-third), the external nose is also supported by: - Frontal process of the maxilla - Upper and lower lateral cartilages - Septal cartilage - Stating only the nasal bones ignores the majority of nasal support structures.

Q: Which muscles are responsible for the elevation of the eye?

SR and IO. ***SR and IO*** - The **superior rectus (SR)** muscle primarily elevates the eye, especially when the eye is **abducted** [1]. - The **inferior oblique (IO)** muscle also contributes to elevation, particularly when the eye is **adducted** [1]. *IO and SO* - While the **inferior oblique (IO)** elevates the eye, the **superior oblique (SO)** muscle is responsible for **depression** and **intorsion**, not elevation [1]. - Therefore, this combination does not exclusively perform elevation. *IR and SR* - The **superior rectus (SR)** muscle elevates the eye, but the **inferior rectus (IR)** muscle is responsible for **depression** of the eye, not elevation [1]. - This pair has opposing primary actions in vertical movement. *SO and IR* - Both the **superior oblique (SO)** and **inferior rectus (IR)** muscles are primarily involved in **depression** of the eye [1]. - The superior oblique also causes **intorsion**, and the inferior rectus causes **extorsion** [1].

Q: Which nerve does NOT carry referred ear pain?

Abducens nerve. ***Abducens nerve*** - The **abducens nerve (CN VI)** primarily controls the **lateral rectus muscle** of the eye, responsible for **abduction of the eyeball**. - It has **no sensory function** and, therefore, cannot carry referred pain from any region, including the ear. *Trigeminal nerve* - The **trigeminal nerve (CN V)**, particularly its **auriculotemporal branch**, provides sensory innervation to part of the external ear and temporomandibular joint, making it a common pathway for **referred otalgia** from dental or TMJ issues. - Pain from conditions like **trigeminal neuralgia**, **TMJ disorders**, or **dental caries** can be referred to the ear via this nerve. *Glossopharyngeal nerve* - The **glossopharyngeal nerve (CN IX)** supplies sensory innervation to the **middle ear**, pharynx, and posterior tongue. - Conditions affecting these areas, such as **glossopharyngeal neuralgia**, **tonsillitis**, or **pharyngitis**, can cause **referred ear pain**. *Vagus nerve* - The **vagus nerve (CN X)**, specifically the **auricular branch (Arnold's nerve)**, provides sensory innervation to a portion of the external auditory canal and concha. - Irritation of this nerve from conditions in the **larynx**, **pharynx**, **esophagus**, or **heart** can lead to referred ear pain.

Question 1

Which of the following does not contribute to the formation of the nasal septum?

Accepted Answer

Nasal bone

Answer

Vomer

Answer

Ethmoid

Answer

Septal cartilage

Question 2

Inlet of larynx is formed by:

Accepted Answer

Aryepiglottic fold

Answer

Vocal cord

Answer

False vocal cord

Answer

Folds from the base of the tongue to the epiglottis

Question 3

In Articular cartilage, most active chondrocytes are seen in ?

Accepted Answer

Zone 2

Answer

Zone 1

Answer

Zone 4

Answer

Zone 3

Question 4

Which are the second order neurons in the optic pathway?

Accepted Answer

Bipolar cells

Answer

Ganglionic cells

Answer

Cells of lateral geniculate body

Answer

Astrocytes

Question 5

Lymphatic drainage of oropharynx is mainly through?

Accepted Answer

Jugulodigastric node

Answer

Superficial cervical lymph nodes

Answer

Submandibular nodes

Answer

Jugulo-omohyoid nodes

Question 6

Which structure prevents spread of infection from middle ear to brain?

Accepted Answer

Tegmen tympani

Answer

Cribriform plate

Answer

Fundus tympani

Answer

Petrous apex

Question 7

Which of the following nerves is commonly damaged during McBurney's incision?

Accepted Answer

Iliohypogastric nerve

Answer

Subcostal nerve

Answer

11th thoracic nerve

Answer

10th thoracic nerve

Question 8

Which of the following statements is true regarding the anatomy of the external nose?

Accepted Answer

The lower one-third is primarily cartilaginous.

Answer

The upper two-thirds is entirely bony.

Answer

The lateral aspect has only a single cartilage.

Answer

The external nose is supported by two nasal bones.

Question 9

Which muscles are responsible for the elevation of the eye?

Accepted Answer

SR and IO

Answer

IO and SO

Answer

IR and SR

Answer

SO and IR

Question 10

Which nerve does NOT carry referred ear pain?

Accepted Answer

Abducens nerve

Answer

Glossopharyngeal nerve

Answer

Vagus nerve

Answer

Trigeminal nerve

NEET-PG 2013 — Anatomy