1 General Anatomy, Embryology, Radiology

Question 1

Describe the landmarks used to find the facial nerve during parotid surgery.

Answer 1

The typical landmarks used to find the facial nerve during parotid surgery are the

1. tragal pointer- refers to the tragus cartilage, which “points” to the location of the nerve one centimeter anterior, inferior, and deep to the cartilage.
2. tympanomastoid suture line- another method of identification is to follow the tympanomastoid suture line inferiorly to its drop-off point. Six to eight millimeters medial to this point, the facial nerve can be found passing through the stylomastoid foramen
3. posterior digastric muscle- the nerve can be located just medial to the insertion of the posterior belly of the digastric on the mastoid.

Question 2

Name the eight branches of the external carotid artery in the neck.

Answer 2

From proximal to distal, the branches are:

1. superior thyroid
2. ascending pharyngeal
3. lingual
4. facial
5. occipital
6. posterior auricular
7. maxillary
8. superficial temporal arteries.

Question 3

Name each of the major salivary glands and describe the types of saliva produced by each.

Answer 3

There are three paired major salivary glands: the parotid, submandibular, and sublingual glands. Each gland has acinar cells that produce either serous or mucinous solution.

• Parotid glands produce mostly serous saliva.
• Submandibular glands produce a mixture of the two
• Sublingual glands produce mostly mucinous saliva

Question 4

Describe the lymph node levels of the neck used for staging head and neck cancer.

Answer 4

The neck is divided into six areas for the purposes of staging head and neck cancer. The location of the primary tumor determines the likelihood of spread to each particular area.

• Level I includes the submandibular and submental triangles.
• Levels II through IV lie along the carotid sheath superiorly to inferiorly.
• The boundary between levels II and III is the hyoid bone.
• The boundary between levels III and IV is the cricoid cartilage.
• Level V encompasses the posterior triangle, while level VI is the central compartment

Question 5

Name the 12 cranial nerves and their functions.

Answer 5

I: Olfactory—olfaction

II: Optic—vision

III: Oculomotor—motor to all eye muscles except superior oblique and lateral rectus muscles; parasympathetic to ciliary muscle (accommodation) and sphincter pupillae muscle (pupil constriction)

IV: Trochlear—motor to superior oblique muscle

V: Trigeminal—sensation* from the face; *motor to muscles of mastication, tensor tympani, tensor veli palatine, mylohyoid, and anterior digastric muscles

VI: Abducens—motor to lateral rectus muscle

VII: Facial—motor* to the muscles of facial expression, stapedial, stylohyoid, and posterior digastric muscles; *parasympathetics* to lacrimal gland (lacrimation), submandibular and sublingual glands (salivation); *taste* to anterior two thirds of the tongue; *sensation from the concha, postauricular skin, wall of the EAC, and part of the tympanic membrane

VIII: Vestibulocochlear—balance and hearing

IX: Glossopharyngeal—taste*; *motor* to stylopharyngeus muscle; *sensation* from the posterior one third of the tongue, tympanic membrane, and external auditory canal; *visceral sensation* from the carotid body; *parasympathetics to parotid gland (salivation)

X: Vagus—motor* to the pharyngeal muscles (except stylopharyngeal), levator veli palatini, uvulae, palatopharyngeus, palatoglossus, salpingopharyngeus, cricothyroid and pharyngeal constrictors (via superior laryngeal nerve), and all intrinsic muscles of the larynx (via the recurrent laryngeal nerve) except cricothyroid; *parasympathetic* innervation to and sensation from the thoracic and abdominal viscera; *sensation from the laryngeal mucosa, postauricular skin, external auditory canal, tympanic membrane, and pharynx

XI: Spinal accessory—motor to the sternocleidomastoid and trapezius muscles

XII: Hypoglossal—motor to the tongue except palatoglossus muscle

Question 6

What muscle is the only vocal fold abductor?

Answer 6

Posterior cricoarytenoid is the only ABductor of the larynx.

Question 7

Name the layers of the vocal fold, from superficial to deep.

Answer 7

1. Squamous epithelium
2. Lamina propria (three layers: superficial, intermediate, and deep)
3. Thyroarytenoid muscle and vocalis muscle (vocal fold body)

Question 8

Which layers of the vocal fold form the cover? Which form the ligament?

Answer 8

The cover is formed by the epithelium and superficial lamina propria. The intermediate and deep lamina propria form the vocal ligament.

Question 9

What is the best type of imaging to evaluate the cerebellopontine angle?

Answer 9

MRI, with its superior ability to show soft tissue contrast, is best for evaluating tumors and lesions of the cerebellopontine angle. MRI of the internal auditory canals is usually done with contrast.

Question 10

What is the best type of imaging to evaluate the thyroid?

Answer 10

The best type of initial imaging for evaluation of the thyroid is ultrasound.

Question 11

If you suspect a peritonsillar abscess is present, do you need to obtain imaging?

Answer 11

No imaging is needed to diagnose a peritonsillar abscess, since this is usually a clinical diagnosis.

If an abscess is suspected in the retropharyngeal or parapharyngeal space, imaging can be helpful for establishing a diagnosis.

Question 12

What changes to the appearance of a lymph node make it suspicious for malignancy on a CT scan with contrast?

Answer 12

1. Lymph nodes that are greater than one centimeter (1.5 centimeters in the jugulodigastric area)
2. Necrotic center
3. Ill-defined margins
4. Round (instead of the usual oval shape) are suspicious for malignancy.

Lymph nodes with these characteristics should undergo either needle or excisional biopsy depending on the rest of the clinical history