Head and Neck Anatomy: Case Scenarios

Note: The following is a detailed explanation for each case scenario related to head and neck anatomy. Correct answers are marked (C) in parentheses after each question.

1. Lateral Pterygoid Muscle (C)

Damage to the articular disc of the temporomandibular joint would hinder the movement of which of the following muscles?

• Masseter: The masseter muscle plays a major role in closing the jaw and is not directly related to the articular disc.
• Temporalis: The temporalis muscle participates in closing the jaw and moving it laterally. Articular disc damage can affect this muscle.
• Medial Pterygoid: The medial pterygoid muscle participates in moving the jaw laterally. Articular disc damage can affect this muscle.
• Lateral Pterygoid (C): The lateral pterygoid muscle is primarily responsible for protracting the jaw (opening the mouth). Damage to the articular disc would hinder the movement of this muscle.

2. Lateral Pterygoid Muscle (C)

A patient is unable to open their mouth due to muscle paralysis.

• Medial Pterygoid: This muscle is not involved in opening the mouth.
• Masseter: The masseter muscle participates in closing the jaw and is not involved in opening the mouth.
• Temporalis: The temporalis muscle participates in closing the jaw and moving it laterally, not primarily in opening the mouth.
• Lateral Pterygoid (C): The lateral pterygoid muscle is the primary muscle for protracting the jaw (opening the mouth). Paralysis of this muscle would result in the inability to open the mouth.

3. Stylohyoid Muscle (C)

Which of the following muscles is a landmark for the hypoglossal nerve in the neck?

• Inferior constrictor muscle: This muscle is located in the anterior neck and is not related to the hypoglossal nerve.
• Stylohyoid (C): The stylohyoid muscle is located in the posterior neck, close to the hypoglossal nerve. It serves as a landmark for identifying the hypoglossal nerve in the neck.
• Posterior belly of the digastric: This muscle is located in the posterior neck but is not a landmark for the hypoglossal nerve.
• Longus colli: This muscle is located in the anterior neck and is not related to the hypoglossal nerve.

4. Tensing the Vocal Cords (C)

Damage to the external laryngeal nerve during thyroid surgery could make it impossible for a patient to

• Relax the vocal cords: The external laryngeal nerve controls the cricothyroid muscle, not involved in relaxing the vocal cords.
• Rotate the cricoid cartilage: The external laryngeal nerve doesn’t control the cricoid cartilage.
• Tensing the vocal cords (C): The external laryngeal nerve controls the cricothyroid muscle, which tenses the vocal cords. Damage to this nerve would result in the patient being unable to tense the vocal cords.
• Widening the glottis: The external laryngeal nerve is not involved in widening the glottis.

5. Transverse Cervical Nerve (C)

A patient complains of numbness in the anterior cervical triangle. Which of the following nerves could be damaged?

• Great auricular nerve: The great auricular nerve provides sensation to the ear area, not related to the anterior cervical triangle.
• Transverse Cervical Nerve (C): The transverse cervical nerve provides sensation to the anterior cervical triangle. Damage to this nerve could cause numbness in this area.
• Superior root of the ansa cervicalis: The superior root of the ansa cervicalis provides sensation to the skin behind the ear, not related to the anterior cervical triangle.
• Inferior root of the ansa cervicalis: The inferior root of the ansa cervicalis provides sensation to the skin of the shoulder and chest, not related to the anterior cervical triangle.

6. Superior border of the thyroid cartilage (C)

If a benign tumor were located at the bifurcation of the common carotid artery, it would be at the level of the

• Isthmus of the thyroid gland: The isthmus of the thyroid gland is located lower than the bifurcation of the common carotid artery.
• Cricoid cartilage: The cricoid cartilage is located lower than the bifurcation of the common carotid artery.
• Angle of the mandible: The angle of the mandible is located higher than the bifurcation of the common carotid artery.
• Superior border of the thyroid cartilage (C): The superior border of the thyroid cartilage is at the level of the bifurcation of the common carotid artery.

7. Loss of parotid gland secretion (C)

Which of the following conditions could arise from damage to the parasympathetic fibers in the glossopharyngeal nerve?

• Loss of lacrimal gland secretion: The parasympathetic fibers in the glossopharyngeal nerve don’t control the lacrimal gland.
• Loss of submandibular gland secretion: The parasympathetic fibers in the glossopharyngeal nerve don’t control the submandibular gland.
• Loss of parotid gland secretion (C): The parasympathetic fibers in the glossopharyngeal nerve control the parotid gland. Damage to these fibers would lead to loss of parotid gland secretion.
• Constriction of the pupil: The parasympathetic fibers in the glossopharyngeal nerve don’t control the pupil.

8. Upwards and backwards (C)

To get a clear view of the tympanic membrane, the physician needs to pull the pinna

• Upwards and backwards (C): Pulling the pinna upwards and backwards will give the physician a clear view of the tympanic membrane.
• Upwards and forwards: Pulling the pinna in this direction is not conducive to observing the tympanic membrane.
• Forwards: Pulling the pinna forwards is not conducive to observing the tympanic membrane.
• Downwards: Pulling the pinna downwards is not conducive to observing the tympanic membrane.

9. Internal laryngeal nerve (C)

During superior laryngeal artery ligation, care must be taken to avoid damage to which of the following nerves?

• External laryngeal nerve: The external laryngeal nerve is located outside of the superior laryngeal artery, not affected during ligation.
• Internal laryngeal nerve (C): The internal laryngeal nerve is located inside the superior laryngeal artery and requires careful attention to avoid damage during ligation.
• Superior laryngeal nerve: The superior laryngeal nerve is located above the superior laryngeal artery, not affected during ligation.
• Hypoglossal nerve: The hypoglossal nerve is not related to the superior laryngeal artery.

10. Medial strabismus (C)

Which of the following conditions arises due to a severed abducens nerve?

• Ptosis: Ptosis is due to damage to the superior tarsal muscle.
• Lateral strabismus (exotropia): Lateral strabismus is caused by damage to the medial rectus muscle.
• Medial strabismus (C): Medial strabismus is caused by damage to the abducens nerve, which weakens the lateral rectus muscle, leading to the eye being pulled inwards.
• Inability to dilate the pupil: Inability to dilate the pupil is due to damage to the optic nerve.

11. Vagus Nerve (C)

Death could be a consequence of bilateral severance of which of the following nerves?

• Trigeminal: The trigeminal nerve controls facial sensation and mastication; severance of this nerve is not fatal.
• Facial: The facial nerve controls facial expression; severance of this nerve is not fatal.
• Vagus (C): The vagus nerve controls heart rate, breathing, and digestion. Bilateral severance of the vagus nerve could be fatal.
• Accessory: The accessory nerve controls head rotation; severance of this nerve is not fatal.

12. Epidural Space (C)

When the middle meningeal artery is ruptured but the dura mater remains intact, blood will collect in the

• Subarachnoid space: Blood cannot enter the subarachnoid space if the dura mater remains intact.
• Subdural space: Blood cannot enter the subdural space if the dura mater remains intact.
• Epidural Space (C): When the middle meningeal artery is ruptured but the dura mater remains intact, blood will collect in the epidural space, causing an epidural hematoma.
• Dural sinuses: Dural sinuses are located inside the dura mater and are not related to this scenario.

13. Trigeminal Nerve (C)

After a tongue tumor excision, a patient loses general sensation in the anterior two-thirds of the tongue. This condition is likely due to damage to the branches of which of the following nerves?

• Trigeminal Nerve (C): The trigeminal nerve provides general sensation to the anterior two-thirds of the tongue. Damage to the trigeminal nerve could cause loss of sensation in this area.
• Facial nerve: The facial nerve controls facial expression, not related to tongue sensation.
• Hypoglossal nerve: The hypoglossal nerve controls general sensation of the posterior one-third of the tongue, not related to the anterior two-thirds.
• Vagus nerve: The vagus nerve controls digestive function, not related to tongue sensation.

14. Internal Carotid Artery Ligation (C)

All the anastomoses of the subclavian artery with other arteries will be effective in the following situations, except

• Stenosis of the aorta (immediately after the origin of the left subclavian artery): Anastomoses of the subclavian artery can help blood circulate to the organs if the aorta is stenosed.
• Ligation of the axillary artery: Anastomoses of the subclavian artery can help blood circulate to the organs if the axillary artery is ligated.
• Ligation of the common carotid artery: Anastomoses of the subclavian artery can help blood circulate to the organs if the common carotid artery is ligated.
• Internal Carotid Artery Ligation (C): The internal carotid artery is the main branch of the subclavian artery, supplying blood to the brain. If the internal carotid artery is ligated, other anastomoses cannot replace its function.

15. Sphenoid Sinus (C)

In a patient with swelling of the nasal mucosa of the middle meatus, all openings of the posterior ethmoid sinuses are blocked, except

• Maxillary sinus: The maxillary sinus communicates with the middle meatus through the maxillary sinus opening.
• Sphenoid Sinus (C): The sphenoid sinus communicates with the superior meatus through the sphenoid sinus opening.
• Anterior ethmoid sinuses: The anterior ethmoid sinuses communicate with the middle meatus through the anterior ethmoid sinus openings.
• Frontal sinus: The frontal sinus communicates with the superior meatus through the frontal sinus opening.

16. Deep Petrosal Nerve (C)

Chronic dryness of the nasal cavity due to lack of secretion from the mucous glands indicates damage to all of the following structures, except

• Pterygopalatine ganglion: The pterygopalatine ganglion plays a role in secreting fluid that moisturizes the nasal mucosa.
• Facial nerve: The facial nerve has branches that control the lacrimal gland, which helps to moisten the nasal mucosa.
• Greater petrosal nerve: The greater petrosal nerve has branches that control the lacrimal gland, which helps to moisten the nasal mucosa.
• Deep Petrosal Nerve (C): The deep petrosal nerve is a branch of the greater petrosal nerve and is not involved in secreting fluid to moisten the nasal mucosa.

17. External Carotid Arteries (C)

A transverse cut across the neck that severs the inferior thyroid artery will also sever all of the following structures, except:

• Recurrent laryngeal nerves: The recurrent laryngeal nerves are located close to the inferior thyroid artery and may be severed during ligation of this artery.
• External Carotid Arteries (C): The external carotid arteries are located in the anterior neck and are not severed during ligation of the inferior thyroid artery.
• Internal jugular veins: The internal jugular veins are located close to the inferior thyroid artery and may be severed during ligation of this artery.
• Vagus nerves: The vagus nerves are located in the posterior neck and are not severed during ligation of the inferior thyroid artery.

18. Sympathetic Nervous System (C)

Infection in the carotid sheath could damage all of the following structures, except:

• Vagus nerve: The vagus nerve is located in the carotid sheath and could be damaged by infection.
• Common carotid artery: The common carotid artery is located in the carotid sheath and could be damaged by infection.
• Sympathetic Nervous System (C): The sympathetic nervous system is the autonomic nervous system, not located in the carotid sheath and is not affected by infection in the carotid sheath.
• Internal jugular vein: The internal jugular vein is located in the carotid sheath and could be damaged by infection.

19. Tensor Tympani Muscle (C)

Severance of the main trunk of the facial nerve during parotid gland tumor surgery would lead to paralysis of all of the following muscles, except:

• Stapedius: The stapedius muscle is a muscle of the outer ear and is controlled by the facial nerve.
• Tensor veli palatini: The tensor veli palatini is a muscle of the mouth and is controlled by the facial nerve.
• Tensor Tympani Muscle (C): The tensor tympani muscle is a muscle of the middle ear and is controlled by the greater petrosal nerve, not affected by facial nerve damage.
• Zygomaticus major: The zygomaticus major is a facial muscle and is controlled by the facial nerve.

20. Scalenus Medius (C)

A low tracheostomy below the isthmus of the thyroid gland could encounter all of the following blood vessels, except

• Inferior thyroid artery or its branches: The inferior thyroid artery is located in this region and could be encountered during tracheostomy.
• Arch of the aorta: The arch of the aorta is located in this region and could be encountered during tracheostomy.
• Scalenus Medius (C): The scalenus medius muscle is located higher in the neck and is not encountered during a low tracheostomy.
• Thyroid ima artery: The thyroid ima artery is located in this region and could be encountered during tracheostomy.

21. It is divided into two triangles by the superior belly of the omohyoid muscle

Before excising a benign tumor in the neck of a patient, a surgeon examines the posterior cervical triangle. All of the following descriptions about this triangle are correct, except:

• Its posterior border is the anterior border of the trapezius muscle: The anterior border of the trapezius muscle is the posterior border of the posterior cervical triangle.
• It is divided into two triangles by the superior belly of the omohyoid muscle: The posterior cervical triangle is divided into the supraclavicular triangle and the occipital triangle, not by the superior belly of the omohyoid muscle.
• It contains the suprascapular artery, a branch of the thyrocervical trunk: The suprascapular artery is located in the posterior cervical triangle.
• It contains the XI (accessory) nerve: The accessory nerve is located in the posterior cervical triangle.

22. Hypoglossal nerve (C)

An invasive injury at the carotid foramen could damage all of the following structures, except:

• Vagus nerve: The vagus nerve passes through the carotid foramen and could be damaged.
• Accessory nerve: The accessory nerve passes through the carotid foramen and could be damaged.
• Internal carotid artery: The internal carotid artery passes through the carotid foramen and could be damaged.
• Hypoglossal nerve (C): The hypoglossal nerve does not pass through the carotid foramen and is not damaged in this scenario.

23. Decreased parotid gland secretion (C)

Severance of the greater petrosal nerve will result in all of the following conditions, except:

• Decreased lacrimal gland secretion: The greater petrosal nerve has branches that control the lacrimal gland, and severance of this nerve will cause decreased lacrimal gland secretion.
• Dryness of the nasal cavity and palate: The greater petrosal nerve has branches that control the mucous glands of the nasal cavity and palate, and severance of this nerve will cause dryness of these areas.
• Decreased parotid gland secretion (C): The greater petrosal nerve does not control the parotid gland, and severance of this nerve will not cause decreased parotid gland secretion.
• Loss of general sensation in the roof of the mouth: The greater petrosal nerve has branches that control general sensation in the roof of the mouth, and severance of this nerve will cause loss of sensation in this area.

24. Long ciliary nerve (C)

It is possible to abolish the pupillary light reflex by cutting all of the following nerves, except:

• Short ciliary nerves: The short ciliary nerves control the levator palpebrae superioris muscle, not related to the pupillary light reflex.
• Long ciliary nerve (C): The long ciliary nerve controls the dilator pupillae muscle, not related to the pupillary light reflex.
• Oculomotor nerve: The oculomotor nerve controls the eye muscles, not related to the pupillary light reflex.
• Optic nerve: The optic nerve controls vision, and severance of this nerve will cause loss of vision and abolish the pupillary light reflex.

25. Loss of lacrimal gland secretion

Severance of the oculomotor nerve could cause all of the following conditions, except:

• Ptosis: Severance of the oculomotor nerve could cause ptosis.
• The anterior part of the eyeball is pulled outwards: Severance of the oculomotor nerve could cause this.
• Pupil dilation: Severance of the oculomotor nerve could cause pupil dilation.
• Loss of lacrimal gland secretion: Severance of the oculomotor nerve does not cause loss of lacrimal gland secretion.

26. Glossopharyngeal nerve (C)

Dryness of the cornea due to a lack of moisturizing fluid could be a sign of damage to all of the following nerves, except:

• The terminal branch of the lacrimal nerve: The terminal branch of the lacrimal nerve controls the lacrimal gland, which helps to moisten the cornea.
• The zygomatic branch of the maxillary nerve: The zygomatic branch of the maxillary nerve controls the lacrimal gland, which helps to moisten the cornea.
• Glossopharyngeal nerve (C): The glossopharyngeal nerve controls the parotid gland, not related to moistening the cornea.
• Greater petrosal nerve: The greater petrosal nerve has branches that control the lacrimal gland, which helps to moisten the cornea.

27. Accessory nerve (C)

The act of swallowing requires all of the following nerves, except:

• Hypoglossal nerve: The hypoglossal nerve controls the tongue muscles, involved in swallowing.
• Accessory nerve (C): The accessory nerve controls the shoulder and neck muscles, not involved in swallowing.
• Vagus nerve: The vagus nerve controls the smooth muscle of the esophagus, involved in swallowing.
• Facial nerve: The facial nerve controls the muscles of the mouth, involved in swallowing.

Note:

• These case scenarios are just examples of the knowledge related to head and neck anatomy.
• For a more detailed understanding of anatomical structures and their functions, you should consult additional anatomical textbooks.
• Always remember that knowledge of anatomy is crucial for diagnosing and treating pathologies related to the head and neck.

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