Head & Neck Practice Questions

Q: Impaired gag reflex is seen due to a lesion in which cranial nerves?

CN IX & X. ***Correct: CN IX & X*** The **gag reflex (pharyngeal reflex)** is a protective reflex involving two cranial nerves: - **Afferent limb**: **CN IX (Glossopharyngeal nerve)** provides sensory innervation to the posterior third of the tongue, oropharynx, and pharyngeal walls - **Efferent limb**: **CN X (Vagus nerve)** provides motor innervation to the pharyngeal muscles (via the pharyngeal plexus) that contract during the reflex **Clinical correlation**: Testing the gag reflex helps assess brainstem function and the integrity of CN IX and X. Impairment suggests lesions affecting these nerves or their nuclei in the medulla. *Incorrect: CN V & VI* - CN V (Trigeminal) provides facial sensation and motor to muscles of mastication, not involved in gag reflex - CN VI (Abducens) controls lateral rectus muscle for eye abduction *Incorrect: CN X & XI* - While CN X is involved, CN XI (Accessory nerve) innervates sternocleidomastoid and trapezius muscles, not pharyngeal muscles *Incorrect: CN VII & VIII* - CN VII (Facial) controls facial expression and taste from anterior 2/3 of tongue - CN VIII (Vestibulocochlear) is involved in hearing and balance, not the gag reflex *Incorrect: CN XI & XII* - CN XI (Accessory) innervates SCM and trapezius - CN XII (Hypoglossal) provides motor to intrinsic and extrinsic tongue muscles, not pharyngeal muscles involved in gag reflex

Q: Which tongue papillae do not have taste buds?

Filiform. ***Filiform*** - **Filiform papillae** are the most abundant type of papillae on the tongue and are responsible for the **mechanical action of gripping food**, due to their cone-shaped, abrasive structure of keratinized epithelium. - Unlike other papillae, they **lack taste buds** and thus do not play a role in taste sensation. *Fungiform* - **Fungiform papillae** are mushroom-shaped and are scattered among the filiform papillae, primarily on the tip and sides of the tongue. - These papillae **contain taste buds** on their superior surface and are involved in sensing taste stimuli. *Circumvallate* - **Circumvallate papillae** are large, dome-shaped structures arranged in a V-shape at the back of the tongue. - They are surrounded by a trench into which salivary glands empty, and their walls contain a **large number of taste buds**. *Foliate* - **Foliate papillae** are leaf-like folds located on the lateral margins of the posterior tongue. - They are **well-developed in young children** and contain taste buds, though they tend to degenerate with age. *Conical* - **Conical** is not a recognized classification of tongue papillae. While filiform papillae have a conical (cone-shaped) structure, "conical papillae" is not an anatomical term used to describe a distinct type of papilla.

Q: The nerve passing through the arrow-marked region in the provided image has been lesioned. Which of the following is the most likely clinical presentation?

Loss of sensation in the maxillary area of the face. ***Loss of sensation in the maxillary area of the face*** - The arrow points to the **foramen rotundum**, which transmits the **maxillary nerve (V2)**, a branch of the trigeminal nerve. - Lesion of the maxillary nerve (V2) leads to sensory loss in the **maxillary region of the face**, including the cheek, upper lip, upper teeth, and palate. *Loss of sensation in the jaw area* - Sensation in the jaw area, including the lower teeth and chin, is primarily supplied by the **mandibular nerve (V3)**, which exits through the foramen ovale. - A lesion at the foramen rotundum would not directly affect V3. *Loss of sensation on the scalp and nose* - Sensation to the scalp (anterior part) and nose is primarily supplied by the **ophthalmic nerve (V1)**, which exits the skull through the superior orbital fissure. - The foramen rotundum is not involved in the passage of the ophthalmic nerve. *Loss of sensation in the mucosa of nasopharynx* - While parts of the nasopharynx mucosa receive innervation from V2, this is a very specific and limited area, and the primary and most prominent sensory loss from a V2 lesion would be in the **maxillary facial region**. - Other nerves like the glossopharyngeal nerve also contribute to nasopharyngeal sensation. *Loss of motor function to muscles of facial expression* - Motor function to muscles of facial expression is supplied by the **facial nerve (CN VII)**, not the maxillary nerve (V2). - The maxillary nerve is a purely **sensory** branch of the trigeminal nerve and has no motor function. - The facial nerve exits the skull through the stylomastoid foramen, not the foramen rotundum.

Q: A patient was admitted with skull base trauma. The doctor was testing the marked structure in the pharyngeal region. Which of the following nerves was being tested?

Glossopharyngeal nerve. ***Glossopharyngeal nerve*** - The image shows a probe stimulating the posterior part of the **pharynx**, which elicits the **gag reflex**. - The afferent limb of the **gag reflex** is mediated primarily by the **glossopharyngeal nerve (CN IX)**, which detects sensation from the posterior tongue and pharynx. *Trigeminal nerve* - The **trigeminal nerve (CN V)** primarily mediates sensation from the face, teeth, and anterior two-thirds of the tongue, and motor control of the **muscles of mastication**. - It does not have a primary role in the sensation or reflex of the posterior pharyngeal wall. *Facial nerve* - The **facial nerve (CN VII)** is responsible for the **muscles of facial expression**, taste from the anterior two-thirds of the tongue, and parasympathetic innervation to several glands. - While it contributes to some aspects of swallowing, it is not the main sensory nerve for the gag reflex from the posterior pharynx. *Vagus* - The **vagus nerve (CN X)** provides the efferent limb of the gag reflex, causing pharyngeal muscle contraction. - However, the sensory input from the posterior pharynx (the afferent limb being tested by the probe) is primarily carried by the **glossopharyngeal nerve**. *Hypoglossal nerve* - The **hypoglossal nerve (CN XII)** provides motor innervation to the intrinsic and extrinsic muscles of the tongue. - While it is relevant in skull base trauma, it does not mediate sensation from the pharynx or the gag reflex being tested in the image.

Q: Which nerve is responsible for gag reflex

9th Cranial Nerve. ***9th Cranial Nerve*** - The **glossopharyngeal nerve (CN IX)** is primarily responsible for the **afferent (sensory)** limb of the gag reflex, detecting touch in the posterior pharynx. - It transmits sensory information to the **brainstem**, initiating the efferent response via the vagus nerve. - CN IX is considered the nerve "responsible for" the gag reflex as it **detects and initiates** the protective response. *10th Cranial Nerve* - The **vagus nerve (CN X)** provides the **efferent (motor)** limb of the gag reflex, causing pharyngeal muscle contraction. - While essential for the motor response, CN IX is the primary sensory trigger that initiates the reflex. - Both nerves work together, but CN IX is the **detection nerve** that starts the reflex arc. *11th Cranial Nerve* - The **spinal accessory nerve (CN XI)** primarily innervates the **sternocleidomastoid** and **trapezius muscles**, controlling head and shoulder movements. - It has no direct role in the **gag reflex**. *6th Cranial Nerve* - The **abducens nerve (CN VI)** is responsible for the **lateral rectus muscle** of the eye, controlling **abduction of the eyeball**. - It does not participate in the complex **sensory or motor pathways** of the gag reflex. *7th Cranial Nerve* - The **facial nerve (CN VII)** controls **facial expressions**, taste from the anterior two-thirds of the tongue, and some glandular secretions. - While it has some role in taste and salivation, it is not the primary nerve for the **gag reflex**.

Q: A 57-year-old man comes to the physician for a follow-up examination. During the last 6 months, he has had recurring pneumonia after undergoing a surgical operation. He reports that, when food has gone down his windpipe, he has not automatically coughed. Examination shows normal voluntary coughing, but an impaired cough reflex. The nerve responsible for this patient's symptoms is most likely damaged at which of the following anatomical sites?

Piriform recess. ***Piriform recess*** - Damage to the sensory fibers of the **internal laryngeal nerve (a branch of the superior laryngeal nerve, which comes from the vagus nerve)** in the piriform recess impairs the afferent limb of the cough reflex, specifically from the larynx above the vocal folds. - This results in the inability to automatically cough when food enters the windpipe (aspiration), explaining the recurrent pneumonia. *Foramen magnum* - Damage at the foramen magnum would typically affect structures like the **medulla oblongata** or proximal cervical spinal cord, leading to more widespread neurological deficits such as respiratory failure, severe motor and sensory deficits, or cranial nerve palsies. - Such extensive involvement is not indicated by isolated impairment of the cough reflex with normal voluntary coughing. *Aortic arch* - The **left recurrent laryngeal nerve** loops around the aortic arch, but damage here would primarily cause **hoarseness** due to vocal cord paralysis, which is not described. - While the recurrent laryngeal nerves innervate the intrinsic muscles of the larynx and provide some sensation below the vocal folds, impairment here is less likely to cause the specific symptom of absent cough reflex upon aspiration without hoarseness. *Parotid gland* - The parotid gland houses the **facial nerve (CN VII)**, which innervates muscles of facial expression, and the **auriculotemporal nerve** (a branch of CN V3) provides sensation. - Damage here would cause **facial paralysis** or sensory deficits, neither of which are consistent with an impaired cough reflex. *Infratemporal fossa* - The infratemporal fossa contains structures like the **mandibular nerve (CN V3)**, **otic ganglion**, and the **chorda tympani** (a branch of CN VII). - Damage here would typically affect mastication, sensation to the lower face, or taste, none of which explain the patient's specific symptoms related to coughing and aspiration.

Question 1

Impaired gag reflex is seen due to a lesion in which cranial nerves?

Accepted Answer

CN IX & X

Answer

CN V&VI

Answer

CN X & XI

Answer

CN VII & VIII

Answer

CN XI & XII

Question 2

Which tongue papillae do not have taste buds?

Accepted Answer

Filiform

Answer

Fungiform

Answer

Circumvallate

Answer

Foliate

Answer

Conical

Question 3

Match the following nerves to their respective areas of supply to the auricle

Accepted Answer

A - Auriculotemporal, B - Greater auricular, C - Vagus, D - Lesser occipital

Answer

A - Greater auricular, B - Auriculotemporal, C - Lesser occipital, D - Vagus

Answer

A - Auriculotemporal, B - Lesser occipital, C - Greater auricular, D - Vagus

Answer

A - Auriculotemporal, B - Lesser occipital, C - Vagus, D - Greater auricular

Answer

A - Vagus, B - Greater auricular, C - Auriculotemporal, D - Lesser occipital

Question 4

The nerve passing through the arrow-marked region in the provided image has been lesioned. Which of the following is the most likely clinical presentation?

Accepted Answer

Loss of sensation in the maxillary area of the face

Answer

Loss of sensation in the jaw area

Answer

Loss of sensation on the scalp and nose

Answer

Loss of sensation in the mucosa of nasopharynx

Answer

Loss of motor function to muscles of facial expression

Question 5

An absent gag reflex can result from injury to which of the following nerves?

Accepted Answer

Cranial Nerve IX (Glossopharyngeal) and Cranial Nerve X (Vagus)

Answer

Cranial Nerve VII (Facial) and Cranial Nerve V (Trigeminal)

Answer

Cranial Nerve V (Trigeminal) and Cranial Nerve IX (Glossopharyngeal)

Answer

Cranial Nerve X (Vagus) and Cranial Nerve VII (Facial)

Answer

Cranial Nerve XII (Hypoglossal) and Cranial Nerve X (Vagus)

Question 6

Which of the following statements is true regarding the structure shown in the image?

Accepted Answer

Lingual nerve

Answer

Hypoglossal nerve

Answer

Nerve to mylohyoid

Answer

Inferior alveolar nerve

Answer

Glossopharyngeal nerve

Question 7

A patient was admitted with skull base trauma. The doctor was testing the marked structure in the pharyngeal region. Which of the following nerves was being tested?

Accepted Answer

Glossopharyngeal nerve

Answer

Trigeminal nerve

Answer

Facial nerve

Answer

Vagus

Answer

Hypoglossal nerve

Question 8

Which nerve is responsible for gag reflex

Accepted Answer

9th Cranial Nerve

Answer

11th cranial nerve

Answer

6th Cranial Nerve

Answer

7th Cranial Nerve

Answer

10th Cranial Nerve

Question 9

A 32-year-old man presents to the emergency department with a severe headache. He says that the pain has been getting progressively worse over the last 24 hours and is located primarily in his left forehead and eye. The headaches have woken him up from sleep and it is not relieved by over-the-counter medications. He has been recovering from a sinus infection that started 1 week ago. His past medical history is significant for type 1 diabetes and he has a 10 pack-year history of smoking. Imaging shows thrombosis of a sinus above the sella turcica. Which of the following findings would most likely also be seen in this patient?

Accepted Answer

Ophthalmoplegia

Answer

Anosmia

Answer

Mandibular pain

Answer

Vertigo

Answer

Vision loss

Question 10

A 57-year-old man comes to the physician for a follow-up examination. During the last 6 months, he has had recurring pneumonia after undergoing a surgical operation. He reports that, when food has gone down his windpipe, he has not automatically coughed. Examination shows normal voluntary coughing, but an impaired cough reflex. The nerve responsible for this patient's symptoms is most likely damaged at which of the following anatomical sites?

Accepted Answer

Piriform recess

Answer

Foramen magnum

Answer

Aortic arch

Answer

Parotid gland

Answer

Infratemporal fossa

Head & Neck — MCQs

Head & Neck — MCQs

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