Head — MCQs

Head Indian Medical PG Practice Questions and MCQs

Question 411: Which of the following muscles is derived from the first pharyngeal arch?

A. Anterior belly of digastric (Correct Answer)
B. Buccinator
C. Platysma
D. Posterior belly of digastric

Explanation: ### Explanation The pharyngeal (branchial) arches are fundamental to head and neck development. Each arch is associated with a specific cranial nerve, which determines the innervation of the muscles derived from that arch. **1. Why the Correct Answer is Right:** The **Anterior belly of digastric** is derived from the **1st Pharyngeal Arch** (Mandibular arch). The nerve of the 1st arch is the **Mandibular nerve (V3)**. Consequently, the anterior belly is supplied by the nerve to the mylohyoid, a branch of the inferior alveolar nerve (from V3). Other 1st arch muscles include the muscles of mastication, mylohyoid, tensor tympani, and tensor veli palatini. **2. Why the Incorrect Options are Wrong:** * **Buccinator & Platysma (Options B & C):** These are muscles of facial expression. All muscles of facial expression are derived from the **2nd Pharyngeal Arch** (Hyoid arch) and are supplied by the **Facial nerve (CN VII)**. * **Posterior belly of digastric (Option D):** Unlike the anterior belly, the posterior belly is derived from the **2nd Pharyngeal Arch**. Therefore, it is supplied by the digastric branch of the Facial nerve. **3. NEET-PG High-Yield Clinical Pearls:** * **The

Question 412: Which muscle is the antagonist to the superior rectus?

A. Inferior oblique
B. Inferior rectus (Correct Answer)
C. Superior oblique
D. Lateral rectus

Explanation: The movement of the eyeball is governed by the coordinated action of six extraocular muscles. To identify an **antagonist**, one must look for the muscle that produces the exact opposite primary action in the same plane of movement. **1. Why Inferior Rectus is Correct:** The **Superior Rectus (SR)** and **Inferior Rectus (IR)** are a functional pair acting along the vertical axis [1]. * The primary action of the Superior Rectus is **elevation** [1]. * The primary action of the Inferior Rectus is **depression** [1]. Since their primary actions are diametrically opposed, the Inferior Rectus is the direct antagonist to the Superior Rectus. **2. Why Other Options are Incorrect:** * **Inferior Oblique (IO):** This muscle is a **synergist** to the Superior Rectus for elevation. Both muscles work together to move the eye upward [1]. * **Superior Oblique (SO):** While it is an "antagonist" in terms of torsion (SR is an intorter, SO is an intorter; however, SO is a depressor), it is not the primary antagonist for the SR’s main vertical action. The SO and IO are functional pairs [1]. * **Lateral Rectus (LR):** This muscle is involved in **abduction** (horizontal movement). Its antagonist is the Medial Rectus [1]. **Clinical Pearls for NEET-PG:** * **Hering’s Law:** States that synergistic muscles (yoke muscles) receive equal and simultaneous innervation (e.g., Right SR and Left IO when looking up and right). * **Sherrington’s Law:** States that when an agonist muscle contracts, its antagonist (e.g., SR and IR) receives an inhibitory signal to relax. * **RAD Rule:** **R**ecti are **AD**ductors (except Lateral Rectus). * **SIN Rule:** **S**uperior muscles are **IN**torters (Superior Rectus and Superior Oblique).

Question 413: A 45-year-old woman presents with numbness over the tip of her nose. Which of the following nerves is most likely damaged?

A. Ophthalmic division of the trigeminal nerve (Correct Answer)
B. Maxillary division of the trigeminal nerve
C. Mandibular division of the trigeminal nerve
D. Facial nerve

Explanation: ### Explanation The sensory innervation of the nose is a high-yield topic for NEET-PG. The correct answer is the **Ophthalmic division of the trigeminal nerve (V1)**. **Why it is correct:** The skin of the nose is supplied by branches of both the Ophthalmic (V1) and Maxillary (V2) nerves. Specifically, the **tip of the nose** is supplied by the **external nasal nerve**, which is the terminal branch of the **anterior ethmoidal nerve**. The anterior ethmoidal nerve is a branch of the nasociliary nerve, which originates from the **Ophthalmic division (V1)**. Therefore, numbness at the tip indicates a lesion involving the V1 pathway. **Why the other options are incorrect:** * **Maxillary division (V2):** While V2 supplies the ala (wings) of the nose and the vestibule via the infraorbital nerve, it does not supply the bridge or the tip. * **Mandibular division (V3):** This nerve provides sensory innervation to the lower face (chin, lower lip) and motor innervation to the muscles of mastication. It has no sensory distribution on the nose. * **Facial nerve (CN VII):** This is primarily a motor nerve for the muscles of facial expression. While it carries some sensory fibers (taste), it does not provide general somatic sensation to the skin of the face. **Clinical Pearls for NEET-PG:** * **Hutchinson’s Sign:** In Herpes Zoster Ophthalmicus, vesicles on the **tip of the nose** indicate that the nasociliary nerve is involved. This is a strong predictor of ocular involvement (corneal ulcers), as the nasociliary nerve also supplies the eyeball. * **Nasal Nerve Supply Rule:** * **Bridge and Tip:** V1 (External nasal nerve). * **Sides/Ala:** V2 (Infraorbital nerve). * **Root of the nose:** Supplied by the infratrochlear nerve (branch of V1).

Question 414: Epidural hemorrhage commonly occurs from tearing of:

A. Maxillary artery
B. Middle meningeal artery (Correct Answer)
C. Bridging veins
D. All of the above

Explanation: **Explanation:** **Epidural Hemorrhage (EDH)** occurs due to the accumulation of blood between the inner table of the skull and the endosteal layer of the dura mater. 1. **Why Middle Meningeal Artery (MMA) is correct:** The MMA is a branch of the first part of the **maxillary artery**. It enters the skull through the **foramen spinosum** and runs along the inner surface of the temporal bone. The most vulnerable point is the **pterion** (the H-shaped junction of the frontal, parietal, temporal, and sphenoid bones), where the bone is thin and the anterior branch of the MMA lies directly underneath. Trauma to the pterion often results in a skull fracture that tears the MMA, leading to rapid arterial bleeding. 2. **Why other options are incorrect:** * **Maxillary artery:** While the MMA is a branch of the maxillary artery, the parent artery itself is located in the infratemporal fossa (extracranial). It is not involved in intracranial hemorrhages. * **Bridging veins:** Tearing of these veins (which drain from the cerebral cortex into the dural venous sinuses) causes **Subdural Hemorrhage (SDH)**, not epidural [1]. SDH is typically seen in elderly patients or infants due to brain atrophy or shaking [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Radiology:** EDH presents as a **biconvex (lentiform/lemon-shaped)** hyperdensity on CT because the blood is limited by cranial sutures where the dura is firmly attached. * **Lucid Interval:** A classic clinical feature where the patient regains consciousness after initial trauma before rapidly deteriorating as the hematoma expands. * **Source of Bleeding:** While 90% are arterial (MMA), EDH can occasionally be venous (dural sinuses), especially in children.

Question 415: Which of the following structures is NOT seen in the norma basalis?

A. Mental foramen (Correct Answer)
B. Foramen magnum
C. Foramen ovale
D. Foramen lacerum

Explanation: **Explanation:** The **Norma Basalis** refers to the view of the skull from the inferior aspect (base of the skull) after the mandible has been removed. **Why Option A is correct:** The **Mental Foramen** is located on the anterolateral surface of the **mandible**, typically below the interval between the two premolar teeth. Since the norma basalis describes the external base of the cranium excluding the mandible, the mental foramen is not a feature of this view. It is instead seen in the *Norma Frontalis* or *Norma Lateralis* when the mandible is articulated. **Why the other options are incorrect:** * **Foramen Magnum (B):** This is the largest foramen of the skull, located in the occipital bone. It is the central landmark of the posterior part of the norma basalis. * **Foramen Ovale (C):** Located in the greater wing of the sphenoid, it is a key feature of the middle part of the norma basalis, transmitting the mandibular nerve (V3). * **Foramen Lacerum (D):** This is an irregular opening at the junction of the sphenoid, occipital, and petrous temporal bones, clearly visible on the external base of the skull. **High-Yield Clinical Pearls for NEET-PG:** * **Structures passing through Foramen Ovale (Mnemonic: MALE):** **M**andibular nerve, **A**ccessory meningeal artery, **L**esser petrosal nerve, and **E**missary veins. * **Foramen Lacerum:** In life, it is filled with fibrocartilage; only the **emissary veins** and the **meningeal branch of the ascending pharyngeal artery** actually traverse it. The internal carotid artery passes *across* its superior aspect but does not go through it. * **Mental Foramen:** It transmits the mental nerve and vessels. Its position changes with age; it is near the lower border in edentulous elderly patients.

Question 416: Which of the following sinuses is related to the middle ear cavity?

A. Ethmoid sinus
B. Cavernous sinus
C. Transverse sinus
D. Sigmoid sinus (Correct Answer)

Explanation: **Explanation:** The **sigmoid sinus** is the correct answer due to its critical anatomical proximity to the middle ear and mastoid apparatus. It lies in a deep groove on the internal surface of the mastoid part of the temporal bone. Specifically, it is separated from the **mastoid antrum** and air cells only by a thin plate of bone. In cases of chronic suppurative otitis media (CSOM), infection can erode this bony plate, leading to **sigmoid sinus thrombosis**. **Analysis of Incorrect Options:** * **Ethmoid sinus:** These are located within the ethmoid bone between the nasal cavity and the orbit, far anterior to the middle ear. * **Cavernous sinus:** Located on either side of the sella turcica (sphenoid bone). While it is related to the internal carotid artery and several cranial nerves, it is medial to the temporal bone and not directly related to the middle ear cavity. * **Transverse sinus:** This sinus runs along the attachment of the tentorium cerebelli in the occipital bone. It becomes the sigmoid sinus only after it reaches the petrous part of the temporal bone. **Clinical Pearls for NEET-PG:** * **Griesinger’s Sign:** Edema over the mastoid process due to thrombosis of the mastoid emissary vein, a classic sign of sigmoid sinus thrombosis. * **The Tegmen Tympani:** A thin plate of bone that forms the roof of the middle ear, separating it from the **middle cranial fossa** (temporal lobe of the brain). * **The Floor of the Middle Ear:** Related to the **superior bulb of the internal jugular vein**.

Question 417: What is the sensory nerve supply to the capsule of the temporomandibular joint (TMJ)?

A. Auriculotemporal nerve (Correct Answer)
B. Masseter nerve
C. Facial nerve
D. All of the above

Explanation: The **Temporomandibular Joint (TMJ)** is a synovial joint of the bicondylar variety. Its sensory innervation follows **Hilton’s Law**, which states that the nerve supplying a joint also supplies the muscles moving that joint and the skin over it. ### 1. Why Auriculotemporal Nerve is Correct The primary sensory supply to the TMJ capsule and the lateral aspect of the joint is the **Auriculotemporal nerve**, a branch of the posterior division of the Mandibular nerve ($V_3$). It carries pain and proprioceptive fibers from the joint. Additionally, the **Masseteric nerve** (a branch of the anterior division of $V_3$) provides sensory fibers to the anterior part of the joint. However, the Auriculotemporal nerve is the **dominant** and most frequently tested supply. ### 2. Why Other Options are Incorrect * **Masseter nerve:** While it does provide some sensory fibers to the anterior capsule, it is not the *primary* supply. In most MCQ formats, if both are listed separately, Auriculotemporal is the best answer. * **Facial nerve (CN VII):** This is a purely motor nerve to the muscles of facial expression in this region. It does not provide sensory innervation to the TMJ capsule. * **All of the above:** Incorrect because the Facial nerve does not contribute to the sensory supply of the joint. ### 3. High-Yield Clinical Pearls for NEET-PG * **Hilton’s Law:** The TMJ is supplied by the Auriculotemporal and Masseteric nerves (both from $V_3$). * **Referred Pain:** TMJ pathology often presents as earache (otalgia) because the Auriculotemporal nerve also supplies the external auditory meatus and the auricle. * **Blood Supply:** Primarily from the **Superficial Temporal** and **Maxillary arteries** (terminal branches of the External Carotid). * **Author’s Note:** The joint capsule receives its sensory supply from cranial nerve V branches. * **Dislocation:** The TMJ usually dislocates **anteriorly** into the infratemporal fossa when the mouth is opened excessively.

Question 418: The parotid duct opens opposite to which tooth?

A. Upper first molar
B. Upper second molar (Correct Answer)
C. Upper second premolar
D. Upper first premolar

Explanation: **Explanation:** The **parotid duct (Stensen’s duct)** is the primary excretory channel of the parotid gland. It measures approximately 5 cm in length. After crossing the masseter muscle and piercing the buccinator muscle, it opens into the vestibule of the mouth on a small papilla. **Why Option B is Correct:** The anatomical landmark for the opening of the parotid duct is the **vestibule of the mouth, opposite the crown of the maxillary (upper) second molar tooth**. This is a classic high-yield anatomical fact frequently tested in postgraduate entrance exams. **Why Other Options are Incorrect:** * **Options A & D (Upper Molars/Premolars):** While the duct travels across the cheek area, it does not open near the first molar or the premolars. These teeth are located too anteriorly relative to the terminal course of the duct. * **Lower Teeth:** The parotid duct specifically opens in the **maxillary** (upper) arch. Openings in the floor of the mouth (sublingual caruncle) are associated with the submandibular (Wharton’s) duct, not the parotid. **NEET-PG High-Yield Pearls:** 1. **Course:** The duct pierces four structures: Buccal fat pad, Buccopharyngeal fascia, **Buccinator muscle**, and finally the Buccal mucous membrane. 2. **Surface Anatomy:** It corresponds to the middle third of a line drawn from the tragus of the ear to the midpoint between the ala of the nose and the red margin of the upper lip. 3. **Clinical Correlation:** In cases of **Mumps** (epidemic parotitis), the opening of the duct may appear red and swollen. Additionally, retrograde cannulation of this opening is performed during **Sialography** to visualize the ductal system for stones (sialolithiasis).

Question 419: The highest nuchal lines give attachment to which structure?

A. Trapezius
B. Ligamentum nuchae
C. Sternocleidomastoid
D. Occipitalis (Correct Answer)

Explanation: The **highest nuchal line** is a faint, curved ridge on the occipital bone located just above the superior nuchal line. It serves as the site of origin for the **occipital belly of the occipitofrontalis muscle (Occipitalis)** and the attachment for the epicranial aponeurosis (galea aponeurotica). **Why the other options are incorrect:** * **Trapezius:** This muscle originates from the medial third of the **superior nuchal line**, the external occipital protuberance, and the ligamentum nuchae—not the highest nuchal line. * **Ligamentum nuchae:** This fibroelastic membrane extends from the **external occipital protuberance** and the external occipital crest down to the spinous process of the C7 vertebra. * **Sternocleidomastoid:** This muscle inserts onto the lateral half of the **superior nuchal line** and the lateral surface of the mastoid process. **NEET-PG High-Yield Pearls:** 1. **Nuchal Line Hierarchy:** * **Highest Nuchal Line:** Occipitalis muscle and Epicranial aponeurosis. * **Superior Nuchal Line:** Trapezius (medial), Sternocleidomastoid (lateral), and Splenius capitis (deep to SCM). * **Inferior Nuchal Line:** Rectus capitis posterior major and minor, and Obliquus capitis superior. 2. The **External Occipital Protuberance** (the most prominent point being the **Inion**) is the landmark for the confluence of dural venous sinuses internally. 3. The area between the superior and inferior nuchal lines provides attachment for the **Semispinalis capitis**.

Question 420: During surgery on the submandibular gland, which of the following anatomical relationships is accurate?

A. Damage to the lingual nerve will cause loss of sensation to the posterior third of the tongue.
B. The submandibular gland is seen to wrap around the posterior border of the mylohyoid muscle. (Correct Answer)
C. The facial artery and vein are usually divided as they course through the deep part of the gland.
D. The hypoglossal nerve is seen to loop under the submandibular duct.

Explanation: The submandibular gland is a "J-shaped" salivary gland divided into superficial and deep lobes by the **mylohyoid muscle**. The correct answer (B) reflects this fundamental anatomy: the gland wraps around the **posterior free border of the mylohyoid**, with the superficial lobe lying in the submandibular triangle and the deep lobe extending into the floor of the mouth. **Analysis of Incorrect Options:** * **Option A:** The **lingual nerve** provides general sensation to the **anterior two-thirds** of the tongue. Sensation to the posterior third is provided by the glossopharyngeal nerve (CN IX). * **Option C:** The **facial artery** grooves the posterior part of the gland, but the **facial vein** remains superficial to it. During surgery, the vein is often ligated and retracted to protect the marginal mandibular nerve, but these vessels are not typically "divided within the deep part" of the gland. * **Option D:** This is a classic "trap" regarding anatomical relationships. It is the **lingual nerve** that loops under the submandibular (Wharton’s) duct (from lateral to medial), not the hypoglossal nerve. **NEET-PG High-Yield Pearls:** * **Nerve at Risk:** The **marginal mandibular branch of the facial nerve** is the most commonly injured nerve during superficial dissection of the submandibular gland. * **The "Triple Relationship Library":** In the submandibular region, from superior to inferior, the structures are: Lingual Nerve → Submandibular Duct → Hypoglossal Nerve. * **Duct Opening:** Wharton’s duct opens at the **sublingual papilla** at the side of the frenulum of the tongue.

Practice by Chapter

Skull and Facial Bones

Practice Questions

Scalp and Facial Muscles

Practice Questions

Dural Venous Sinuses

Practice Questions

Cranial Cavity

Practice Questions

Orbit and Contents

Practice Questions

Temporal and Infratemporal Regions

Practice Questions

Pterygopalatine Fossa

Practice Questions

Oral Cavity

Practice Questions

Paranasal Sinuses

Practice Questions

Applied Anatomy and Clinical Correlations

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Head — MCQs

Head — MCQs

On this page

Practice by Chapter

Want unlimited practice?