Salivary-Thyroid

Question 1

Which vein can be ligated and retracted superiorly during submandibular gland excision to protect the marginal mandibular branch of the facial nerve?

Answer 1

Anterior facial vein.

Question 2

What muscle does Stenson’s duct pierce?

Answer 2

Buccinator.

Question 3

What is the secretory potential?

Answer 3

Hyperpolarization of acinar cells upon stimulation by the autonomic nervous system.

Question 4

Which lymph nodes drain tumors from the parotid gland?

Answer 4

Nodes just inferior to the gland adjacent to the sternocleidomastoid muscle and the external jugular vein.

Question 5

What is the major venous drainage of the parotid gland?

Answer 5

Posterior facial vein.

Question 6

What membrane separates the parotid gland from the submandibular gland?

Answer 6

Stylomandibular membrane.

Question 7

Which salivary glands contribute the highest % of resting/unstimulated saliva output?

Answer 7

Submandibular glands.

Question 8

What is unique about the lymphatic drainage of the parotid gland?

Answer 8

The lymph nodes are contained within the gland, and it is the only salivary gland with two layers of lymph nodes.

Question 9

True/False: Only muscarinic acetylcholine receptors are involved in salivary gland stimulation.

Answer 9

True.

Question 10

Where does Stenson’s duct arise from in relation to the zygoma?

Answer 10

1.5cm inferior to the zygoma.

Question 11

What branch of the facial nerve travels with Stenson’s duct?

Answer 11

Buccal.

Question 12

What is the role of salivary peroxidase?

Answer 12

Helps breakdown salivary thiocyanate into products that interfere with bacterial cell metabolism.

Question 13

Where do the hypoglossal nerve and lingual nerve lie in relation to Wharton’s duct as it exits the submandibular gland?

Answer 13

Hypoglossal nerve lies inferiorly and lingual nerve lies superiorly.

Question 14

Where does the retromandibular vein lie in relation to the facial nerve?

Answer 14

In most people, it courses deep to both trunks of the facial nerve. In up to 10% of people, the vein crosses either trunk laterally.

Question 15

What happens to the composition of saliva as it moves from the acinar cell (primary secretion) through the duct?

Answer 15

It loses sodium, acquires potassium, and becomes increasingly hypotonic. The degree of modification depends on the salivary flow rate, with higher rates producing saliva closer in composition to the primary secretion.

Question 16

Where does Stenson’s duct open intraorally?

Answer 16

Just opposite the 2nd upper molar.

Question 17

With what other organs do the salivary glands share the same embryologic origin?

Answer 17

Liver, gallbladder, and pancreas (all come from mesodermal buds of the foregut).

Question 18

What component of saliva agglutinates bacteria and activates autolysins?

Answer 18

Lysozyme.

Question 19

What muscle separates the submandibular gland into a superficial and deep lobe?

Answer 19

Mylohyoid.

Question 20

Which salivary glands contribute the highest % of stimulated saliva output?

Answer 20

Parotid glands.

Question 21

Describe the pathway of parasympathetic innervation to the parotid gland.

Answer 21

Preganglionic parasympathetic fibers leave the inferior salivatory nucleus via the glossopharyngeal nerve, pass through the jugular foramen, travel through the middle ear (as Jacobson’s nerve), and then travel along the floor of the middle cranial fossa (as the lesser petrosal nerve) to the otic ganglion; postganglionic parasympathetic fibers leave the otic ganglion via the auriculotemporal branch of V3 and travel to the parotid gland.

Question 22

Which layer of lymph nodes has the most nodes (superficial or deep)?

Answer 22

Superficial.

Question 23

What are the boundaries of the parotid compartment?

Answer 23

Superiorly, the zygoma; posteriorly, the external auditory canal; anteriorly, the masseter muscle; inferiorly, the styloid process, carotid artery, jugular vessels, and styloid muscles.

Question 24

How does the saliva produced from the parotid gland differ from that of the sublingual gland?

Answer 24

The saliva from the parotid gland is serous, high in enzymes, and low in mucin; that from the sublingual gland is primarily composed of mucin.

Question 25

When does the parotid gland encase the facial nerve?

Answer 25

Third month gestation.

Question 26

What is the blood supply to the parotid gland?

Answer 26

Transverse facial artery, a branch of the superficial temporal artery.

Question 27

What duct(s) drain the sublingual gland?

Answer 27

Typically there are about 10 ducts of Rivinus that drain the gland but occasionally several of these small ducts may join to form a larger sublingual/Bartholin's duct.

Question 28

What percent of the population has more than four parathyroid glands?

Answer 28

10%.

Question 29

What percent of parathyroid glands are located in the mediastinum?

Answer 29

2%.

Question 30

What percent of a parathyroid gland is composed of fat?

Answer 30

20-30%.

Question 31

What percent of the population has only three parathyroid glands?

Answer 31

3%.

Question 32

What is the NIS?

Answer 32

A Na-I-Symporter that serves to concentrate I- into cells. It is found in the thyroid gland, salivary glands, gastric mucosa, placenta, ciliary body of the eye, the choroids plexus, the mammary glands, and certain cancers. Except for the thyroid gland, the NIS in these tissues does not respond to TSH.

Question 33

What are the three plasma proteins that bind thyroid hormonse?

Answer 33

Albumin, transthyretin, and thyroxine-binding globulin (TBG).

Question 34

increases reabsorption of calcium and magnesium and the excretion of phosphorus

Answer 34

and bicarbonate in the kidney; enhances intestinal absorption of calcium by stimulating the activation of vitamin Din the kidney.

Question 35

What are the three types of cells comprising the parathyroid glands?

Answer 35

Chief cells, clear cells, and oxyphil cells.

Question 36

Which cells produce PTH?

Answer 36

Chief cells.

Question 37

Where are the inferior parathyroids typically located?

Answer 37

Inferior and anterior to the inferior thyroid artery.

Question 38

What is the function ofpendrin?

Answer 38

Mediates exchange of iodide from the thyrocyte to the colloid, which is one of the first steps of thyroid hormone synthesis.

Question 39

Which terminal of PTH is active?

Answer 39

N-terminal.

Question 40

What are the functions of parathyroid hormone (PTH)?

Answer 40

Stimulates osteolysis and release of calcium and phosphorus from the bone;

Question 41

What is the arterial blood supply to the thyroid gland?

Answer 41

Superior thyroid branch of the external carotid artery and the inferior thyroid branch of the thyrocervical trunk.

Question 42

What is the venous drainage of the thyroid gland?

Answer 42

Superior and middle thyroid veins, which drain into the anterior facial and internal jugular veins, and the inferior thyroid and thyroid ima veins which drain into the innominate veins.

Question 43

Where are the superior parathyroids typically located?

Answer 43

Superior and posterior to the inferior thyroid artery and more likely to extend posteriorly and inferiorly or be found retroesophageally.

Question 44

What is the embryologic origin of the thyroid gland?

Answer 44

The median downgrowth of the first and second pharyngeal pouches in the area of the foramen cecum.

Question 45

What is the primary blood supply of the parathyroid glands?

Answer 45

The superior and inferior parathyroid arteries, which are usually branches of the inferior thyroid artery.

Question 46

From which pharyngeal pouches are the inferior parathyroid glands derived?

Answer 46

Third.

Question 47

What is the predominant glycoprotein found in colloid?

Answer 47

Thyroglobulin.

Question 48

True/False: The inferior glands vary more in location than the superior glands.

Answer 48

True.