Head — MCQs

Head Indian Medical PG Practice Questions and MCQs

Question 1041: What is the primary function of the inferior longitudinal muscle of the tongue?

A. Shortens the tongue and makes the dorsum concave.
B. Shortens the tongue and makes the dorsum convex. (Correct Answer)
C. Narrows and elongates the tongue.
D. None of the above.

Explanation: The tongue's intrinsic muscles are responsible for altering its shape. The **inferior longitudinal muscle** is a narrow band located on the undersurface of the tongue, situated between the genioglossus and hyoglossus muscles. ### **Explanation of the Correct Answer** **Option B** is correct because the inferior longitudinal muscle fibers run from the base to the apex along the ventral surface. When these fibers contract, they pull the tip of the tongue downward, effectively **shortening** the tongue and making the **dorsum (superior surface) convex**. ### **Analysis of Incorrect Options** * **Option A:** Making the dorsum **concave** is the function of the **superior longitudinal muscle**. Since it lies just beneath the mucous membrane of the dorsum, its contraction curls the tip and sides upward, creating a hollow or concave shape. * **Option C:** **Narrowing and elongating** the tongue is the function of the **transverse and vertical muscles** acting together. Transverse muscles narrow the tongue, while vertical muscles flatten it; their combined action results in protrusion and elongation. ### **NEET-PG High-Yield Pearls** * **Innervation:** All intrinsic and extrinsic muscles of the tongue are supplied by the **Hypoglossal nerve (CN XII)**, except for the **Palatoglossus**, which is supplied by the Archer accessory nerve via the Pharyngeal plexus. * **Development:** The muscles of the tongue are derived from **occipital myotomes**. * **Clinical Sign:** In a lower motor neuron lesion of CN XII, the tongue deviates **toward the side of the lesion** upon protrusion due to the unopposed action of the contralateral genioglossus.

Question 1042: A patient is unable to look downward. Which muscle may be paralyzed?

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

Explanation: The correct answer is **Superior Oblique**. To understand this, one must distinguish between the anatomical action and the clinical testing of extraocular muscles. **1. Why Superior Oblique is correct:** The Superior Oblique (SO) muscle originates from the body of the sphenoid and passes through the trochlea, inserting onto the posterosuperior-lateral aspect of the globe. Its primary anatomical action is **intorsion**, but its secondary and tertiary actions are **depression** and **abduction** [1]. * **Clinical Concept:** When the eye is adducted (turned toward the nose), the visual axis aligns with the pull of the SO tendon, making it the **sole depressor** of the eye in this position. Therefore, a patient with SO paralysis (Trochlear nerve palsy) typically presents with diplopia when looking downward and inward (e.g., while reading or walking down stairs). **2. Why other options are incorrect:** * **Superior Rectus:** Its primary action is **elevation** [1]. Paralysis would result in an inability to look upward. * **Inferior Oblique:** Its primary action is **extorsion**, and its secondary action is **elevation** [1]. It helps the eye look upward and inward. * **Lateral Rectus:** Supplied by the Abducens nerve (CN VI), its sole action is **abduction** (moving the eye outward) [1]. **3. NEET-PG High-Yield Pearls:** * **Mnemonic for Nerve Supply:** **LR6SO4EE3** (Lateral Rectus-6; Superior Oblique-4; Everyone Else-3). * **Trochlear Nerve (CN IV) Unique Facts:** It is the thinnest cranial nerve, has the longest intracranial course, and is the only cranial nerve to emerge from the **dorsal aspect** of the brainstem. * **Clinical Sign:** Patients with SO palsy often tilt their head to the opposite side to compensate for the loss of intorsion (Bielschowsky head tilt test) [2].

Question 1043: A radio-opaque mass continuous with the cementoenamel junction attached to the distal surface of the first premolar is:

A. Hyperkeratosis
B. Calculus (Correct Answer)
C. Food debris
D. Epithelial attachment

Explanation: **Explanation:** The correct answer is **Calculus**. **Why Calculus is correct:** Dental calculus (tartar) is mineralized dental plaque. It primarily consists of calcium phosphate salts, which make it **radio-opaque** (white/light) on dental radiographs. Calculus typically forms and adheres strongly to the tooth surface, often starting at or just apical to the **cementoenamel junction (CEJ)**. Its density and mineral content allow it to appear as a distinct, hard mass continuous with the tooth structure on an X-ray, commonly seen on the proximal surfaces. **Why the other options are incorrect:** * **Hyperkeratosis:** This is a histological term referring to the thickening of the stratum corneum of the epithelium (soft tissue). It is not a mineralized mass and would not appear as a radio-opaque projection on a radiograph. * **Food debris:** While food can get lodged interdentally, it is generally not mineralized or "attached" to the CEJ. Most food particles are radiolucent or only faintly opaque and can be easily displaced, unlike the permanent attachment of calculus. * **Epithelial attachment:** This refers to the biological mechanism (junctional epithelium) that attaches the gingiva to the tooth. It is a soft tissue structure and is radiolucent; it cannot be seen as a radio-opaque mass. **High-Yield Clinical Pearls for NEET-PG:** * **Radiographic Appearance:** Calculus often appears as "spurs" or "lumps" on the mesial or distal surfaces of teeth in bitewing or periapical X-rays. * **Location:** Subgingival calculus is often harder and more pigmented than supragingival calculus. * **Composition:** Calculus is approximately 70-80% inorganic material, which is why its radiodensity is similar to cementum but less than enamel.

Question 1044: The duct of the parotid gland pierces all the following structures except?

A. Buccal pad of fat
B. Buccinator muscle
C. Buccopharyngeal fascia
D. Masseter muscle (Correct Answer)

Explanation: The **Parotid duct (Stensen’s duct)** is a 5 cm long structure that emerges from the anterior border of the parotid gland. It runs horizontally across the **masseter muscle**, approximately a fingerbreadth below the zygomatic arch. At the anterior border of the masseter, the duct makes a sharp medial turn (nearly 90 degrees) to reach the oral cavity. During this course, it must penetrate several layers of the cheek. **Why Option D is correct:** The parotid duct **runs superficial to the masseter muscle**, not through it. It only pierces the structures medial to the masseter to enter the vestibule of the mouth. **Why the other options are incorrect:** After turning medially at the edge of the masseter, the duct sequentially pierces: 1. **Buccal pad of fat (Option A):** A collection of adipose tissue between the masseter and buccinator. 2. **Buccopharyngeal fascia (Option C):** The external covering of the buccinator muscle. 3. **Buccinator muscle (Option B):** The duct pierces this muscle at the level of the third molar. 4. **Buccal mucous membrane:** The final layer before opening into the vestibule. **Clinical Pearls for NEET-PG:** * **Opening:** The duct opens into the vestibule of the mouth opposite the **crown of the upper second molar tooth**. * **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. * **Oblique Course:** The duct runs obliquely between the buccinator and the mucous membrane before opening; this acts as a **valve-like mechanism** to prevent air from entering the duct during coughing or blowing (preventing "pneumoparotitis").

Question 1045: Which of the following is a WRONG pair regarding features of cranial nerves?

A. Most commonly involved in basal skull fracture: Facial nerve
B. Most commonly involved in raised intracranial tension: Abducent nerve
C. Most commonly affected in spinal anaesthesia: Abducent nerve
D. Most commonly involved in intracranial aneurysm: Optic Nerve (Correct Answer)

Explanation: **Explanation:** This question tests your knowledge of clinical correlations and the vulnerability of specific cranial nerves (CN) to various pathologies. **1. Why Option D is the Correct (Wrong Pair):** The **Oculomotor nerve (CN III)**, not the Optic nerve, is the most commonly involved nerve in intracranial aneurysms. Specifically, an aneurysm at the junction of the **Posterior Communicating Artery (PCOM)** and the Internal Carotid Artery frequently compresses CN III. This presents as "surgical third nerve palsy" (dilated pupil with "down and out" eye position) because the pupilloconstrictor fibers are superficial and easily compressed. **2. Analysis of Other Options:** * **Option A (Facial Nerve):** Correct pair. The Facial nerve (CN VII) is the most frequently injured cranial nerve in fractures of the **petrous temporal bone** (basal skull fracture) due to its long course through the bony canal. * **Option B (Abducent Nerve):** Correct pair. CN VI has the longest **intracranial (subarachnoid) course**. In raised intracranial pressure (ICT), the brainstem shifts downward, stretching the nerve against the sharp border of the petrous temporal bone. It is often called a "false localizing sign." * **Option C (Abducent Nerve):** Correct pair. CN VI is the most common nerve affected following spinal anesthesia. This occurs due to a CSF leak (low pressure), causing the "brain to sag" and stretching the nerve. **Clinical Pearls for NEET-PG:** * **Longest Intracranial Course:** Abducent Nerve (CN VI). * **Longest Intracanalicular Course:** Facial Nerve (CN VII). * **Smallest/Slenderest CN:** Trochlear Nerve (CN IV). * **Only CN to emerge posteriorly:** Trochlear Nerve (CN IV). * **Most common CN involved in Cavernous Sinus Thrombosis:** Abducent Nerve (CN VI).

Question 1046: The middle ear cavity is connected anteriorly to which of the following structures?

A. Nasal cavity
B. Nasopharynx (Correct Answer)
C. Mastoid antrum
D. Mastoid air cells

Explanation: **Explanation:** The middle ear cavity (tympanic cavity) is a narrow, air-filled space located within the petrous part of the temporal bone [1]. Its connectivity is a high-yield topic for NEET-PG. **1. Why Nasopharynx is correct:** The **anterior wall** of the middle ear contains the opening of the **Eustachian tube** (auditory tube). This tube runs anteromedially and downwards to connect the middle ear cavity directly to the **nasopharynx** [1]. Its primary function is to equalize air pressure on both sides of the tympanic membrane [1]. **2. Analysis of Incorrect Options:** * **Nasal cavity (A):** While the nasopharynx is continuous with the nasal cavity, the Eustachian tube specifically opens into the lateral wall of the nasopharynx, posterior to the inferior nasal concha. * **Mastoid antrum (C) & Mastoid air cells (D):** These are located **posteriorly**. The posterior wall of the middle ear has an opening called the *aditus ad antrum*, which leads to the mastoid antrum and subsequently to the mastoid air cells. **3. Clinical Pearls & High-Yield Facts:** * **Anatomy of the Eustachian Tube:** In infants, the tube is shorter, wider, and more horizontal, which explains the higher incidence of middle ear infections (Otitis Media) following upper respiratory tract infections. * **Muscles involved:** The *Tensor veli palatini* [1] is the main muscle responsible for opening the Eustachian tube during swallowing or yawning [1]. * **Boundaries:** Remember the "Rule of Walls": * **Anterior:** Eustachian tube & Carotid canal. * **Posterior:** Aditus to mastoid antrum & Facial nerve. * **Medial:** Promontory (basal turn of cochlea). * **Lateral:** Tympanic membrane.

Question 1047: Which of the following is NOT a branch of the cervical part of the facial artery?

A. Ascending palatine artery
B. Ascending pharyngeal artery (Correct Answer)
C. Tonsillar branch
D. Submental artery

Explanation: The **facial artery** is a major branch of the external carotid artery that arises in the carotid triangle. It is divided into two parts: the **cervical part** (in the neck) and the **facial part** (on the face). ### Why the Correct Answer is Right The **ascending pharyngeal artery** is the correct answer because it is a **direct branch of the External Carotid Artery (ECA)**, not the facial artery. It is the smallest branch of the ECA and arises from its medial aspect, ascending between the internal carotid artery and the pharynx. ### Analysis of Incorrect Options (Branches of the Cervical Facial Artery) The cervical part of the facial artery gives off four distinct branches (Mnemonic: **PATS**): * **Ascending Palatine Artery (Option A):** Arises near the origin of the facial artery; it ascends to supply the soft palate and palatine glands. * **Tonsillar Branch (Option C):** The main arterial supply to the palatine tonsil. It pierces the superior constrictor muscle to reach the tonsillar fossa. * **Submental Artery (Option D):** The largest cervical branch; it runs on the superficial surface of the mylohyoid muscle and supplies the submandibular gland and skin of the chin. * **Glandular branches:** Supply the submandibular salivary gland. ### High-Yield Clinical Pearls for NEET-PG * **Facial Artery Course:** It exhibits a "tortuous" course to allow for movements of the pharynx during swallowing and the mandible during mastication. * **Tonsillectomy:** The **tonsillar branch** of the facial artery is the most common source of primary hemorrhage during tonsillectomy. * **Pulsations:** Facial artery pulsations can be felt at the **anteroinferior angle of the masseter** muscle against the base of the mandible. * **Termination:** The facial artery terminates as the **angular artery** at the medial canthus of the eye, where it anastomoses with the dorsal nasal branch of the ophthalmic artery (a branch of the Internal Carotid Artery).

Question 1048: Which of the following structures does not develop to adult size until after birth?

A. Mastoid antrum
B. Tympanic cavity
C. Orbital cavity (Correct Answer)
D. Ear ossicle

Explanation: **Explanation:** The growth and development of the skull and its associated cavities follow different timelines. The correct answer is the **Orbital cavity**, as it is the only structure among the options that continues to grow significantly after birth. 1. **Orbital Cavity (Correct):** At birth, the orbit is relatively small and more circular than in adults. It reaches its adult dimensions only by the age of **7 years**. The growth of the orbit is closely linked to the development of the eyeball and the expansion of the surrounding paranasal sinuses (especially the ethmoid and maxillary sinuses). 2. **Mastoid Antrum (Incorrect):** This is a large air-filled space within the petrous part of the temporal bone. It is unique because it is **already at adult size at birth**. However, the mastoid *process* and mastoid *air cells* only begin to develop after birth (usually by age 2) as the child begins to hold their head up. 3. **Tympanic Cavity (Incorrect):** The middle ear cavity (tympanic cavity) is **adult-sized at birth**, though its walls are initially thin. This is essential for the immediate functionality of the auditory system. 4. **Ear Ossicles (Incorrect):** The Malleus, Incus, and Stapes are the only bones in the human body that are **fully ossified and at adult size at birth**. They do not grow further during postnatal life. **High-Yield NEET-PG Pearls:** * **Adult size at birth:** Ear ossicles, Mastoid antrum, Tympanic cavity, and the Internal ear (Labyrinth). * **Postnatal growth:** The **Maxillary sinus** is the first sinus to develop but is rudimentary at birth; it reaches adult size only after the eruption of permanent teeth (approx. 12-15 years). * **Clinical Correlation:** Because the mastoid process is absent at birth, the **stylomastoid foramen** (and thus the facial nerve) is very superficial. This makes the facial nerve prone to injury during forceps delivery. During fetal development, most bones are modeled in cartilage and then transformed into bone by ossification, though certain bones of the skull form directly from mesenchymal cells [1].

Question 1049: What is the nerve supply of the tympanic membrane?

A. Auriculotemporal nerve (Correct Answer)
B. Auricular branch of vagus nerve
C. Occipital nerve
D. Great auricular nerve

Explanation: The tympanic membrane (TM) is a trilaminar structure with a complex nerve supply derived from multiple sources. Understanding its innervation is high-yield for NEET-PG, as it involves both cranial and spinal nerves. ### **Explanation of the Correct Answer** The **Auriculotemporal nerve** (a branch of the Mandibular nerve, V3) provides sensory innervation to the **anterosuperior part of the lateral (outer) surface** of the tympanic membrane. Since it covers a significant portion of the external surface, it is a primary nerve supply. ### **Analysis of Options** * **B. Auricular branch of vagus nerve (Arnold’s nerve):** This supplies the **posteroinferior part of the lateral surface**. Irritation of this nerve (e.g., during ear syringing) can trigger a "vagal reflex," leading to coughing, vomiting, or even fainting. * **C. Occipital nerve:** The Lesser Occipital nerve (C2) supplies the skin of the upper part of the cranial surface of the auricle and the scalp behind it; it does **not** supply the tympanic membrane. * **D. Great auricular nerve:** This nerve (C2, C3) supplies the skin over the parotid gland, the lower part of the auricle, and the angle of the jaw, but not the TM itself. ### **High-Yield Clinical Pearls** 1. **Medial (Inner) Surface:** The entire medial surface of the TM is supplied by the **Tympanic plexus**, which is primarily formed by the **Tympanic branch of the Glossopharyngeal nerve (Jacobson’s nerve)**. 2. **Referred Otalgia:** Pain from the tongue or pharynx (Glossopharyngeal nerve) or from the teeth/TMJ (Mandibular nerve) can be referred to the ear due to these shared nerve pathways. 3. **Summary of Lateral Surface:** * Anterosuperior: Auriculotemporal (V3) * Posteroinferior: Auricular branch of Vagus (X) and a small contribution from the Facial nerve (VII).

Question 1050: The parasympathetic supply to the otic ganglion comes from which cranial nerve?

A. 7th cranial nerve
B. 8th cranial nerve
C. 9th cranial nerve (Correct Answer)
D. 3rd cranial nerve

Explanation: ### Explanation The **otic ganglion** is a peripheral parasympathetic ganglion located in the infratemporal fossa, just below the foramen ovale. It serves as the relay station for the secretomotor supply to the **parotid gland**. **Why Option C is Correct:** The preganglionic parasympathetic fibers originate in the **inferior salivatory nucleus** of the **Glossopharyngeal nerve (CN IX)**. These fibers travel via the tympanic nerve (Jacobson’s nerve) to the tympanic plexus and emerge as the **lesser petrosal nerve**, which terminates by synapsing in the otic ganglion. Postganglionic fibers then join the **auriculotemporal nerve** (a branch of CN V3) to reach the parotid gland. **Why Other Options are Incorrect:** * **Option A (7th Cranial Nerve):** The Facial nerve provides parasympathetic supply to the submandibular and sublingual glands (via the submandibular ganglion) and the lacrimal gland (via the pterygopalatine ganglion). * **Option B (8th Cranial Nerve):** The Vestibulocochlear nerve is purely sensory (special somatic afferent) for hearing and balance; it carries no parasympathetic fibers. * **Option D (3rd Cranial Nerve):** The Oculomotor nerve provides parasympathetic supply to the ciliary muscle and sphincter pupillae via the ciliary ganglion. **High-Yield Clinical Pearls for NEET-PG:** * **Frey’s Syndrome:** Occurs due to misdirected regeneration of the auriculotemporal nerve after parotid surgery; secretomotor fibers intended for the parotid gland instead innervate sweat glands, leading to "gustatory sweating." * **Mnemonic for Ganglia:** **C**OP **3**79 (Ciliary-CN 3; Otic-CN 9; Pterygopalatine/Submandibular-CN 7). * The otic ganglion is **topographically** related to the mandibular nerve (CN V3) but **functionally** related to the glossopharyngeal nerve (CN IX).

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?