20. Oral Cavity and Pharynges (Wright)

Question 1

Explain the innervation of the tongue.

Answer 1

Posterior ⅓, both sensation AND taste = glossopharyngeal.

Anterior ⅔ taste = facial

Anterior ⅔ sensory = lingual (branch of the mandibular N. [branch of CN V])

Movement for the entire tongue = hypoglossal

Question 2

Parasympathetic axons in what nerve stimulates parotid salivary secretions?

Answer 2

CN IX

Glossopharyngeal

Question 3

Parasympathetic axons in what cranial nerve stimulates salivary secretion in the sublingual and submandibular gland?

Answer 3

Facial N

Question 4

What stimulates mucus secretion from the sublingual gland?

Answer 4

Sympathetic fibers from the cervical ganglia.

Question 5

Answer 5

Question 6

What nerve can be found deep to the palatine tonsil?

Answer 6

The glossopharyngeal N.

Question 7

What three muscles depress the torus tubarius and open the eustachian tube?

Answer 7

Superior pharyngeal constrictor.

Tensor veli palatini.

Levator veli palatini.

Question 8

What happens if the tensor veli palatini or levator veli palatini are paralyzed?

What nerves innervate them?

Answer 8

Oral contents will reflux into the oral cavity or auditory tube dysfunction

Levator veli palatini is the laryngeal branch of the vagus N.

Tensor veli palatini is medial pterygoid (a branch of V3 — off of the trigeminal)

Question 9

Describe neural control of saliva secretions

Answer 9

• parasympathetic axons in CN IX stimulate parotid salivary gland secretions
• parasympathetic axons in CN VII stimulate submandibular and sublingual salivary gland secretions
• Sympathetic stimulation from cervical ganglia stimulates mucus secretions

Question 10

Structure/Location of Parotid

Type of secretion

Percentage of saliva

Answer 10

largest, anteroinferior to ear

only serous

25-30%

Question 11

Structure/location of Submandibular

types of secretion

percentage of saliva

Answer 11

medial to mandibular angle, opens lateral to lingual frenulum

mucous and serous

60-70%

Question 12

Structure and location of salivary glands

types of secretions

percentage of saliva

Answer 12

smallest, inferior to tongue, opens into floor of oral cavity

mucous and serous

3-5% of all saliva

Question 13

What does the periodontal Ligament assist in?

Answer 13

maintaining health of alveolar bone. When tooth is lost, the periodontal L. is lost and leads to bone loss

Question 14

glossopharyngeal nerve does what reflex?

vagal nerve does what reflex?

Answer 14

gag

cough/vomit

Question 15

All pharyngeal constrictors innervated by what?

Answer 15

vagus N.

stylopharyngeus is glossopharyngeal N.

Question 16

What are Waldyer’s Ring?

Answer 16

Waldyer’s lymphatic ring is composed of palatine, pharyngeal and lingual tonsils

Drain to deep cervical lymph nodes

Question 17

the glossopharyngeal nerve is deep to what structure?

Both of these arteries serve which palatine tonsils

Answer 17

palatine tonsil

tonsillar branch of ascending artery

tonsillar branch of facial artery

Question 18

Tensor veli palatini important function?

Answer 18

tenses soft palate and acts on pharyngotympnic tube for depressurizing middle ear (CN V3)

like popping ears on an airplane by swallowing

Question 19

Levator Veli Palatini important function?

Answer 19

elevates the tensed palate and acts on pharyngotympanic tube

CN X, pharyngeal plexus

Question 20

Describe stage one of swallowing

Answer 20

Voluntary

bolus is compressed against palate and pushed from mouth into oropharynx by movement of tongue and soft palate

Question 21

Describe stage 2 of swallowing

Answer 21

• involuntary and rapid
• soft palate is elevated, seals off nasopharynx from oro and laryngopharyx
• pharynx widens and shortens to receive bolus as suprahyoid and pharyngeal muscles contract, elevating larynx

Question 22

describe stage 3 of swallowing

Answer 22

involuntary, contraction of all three pharyngeal constrictor muscles force food inferiorly into esophagus

Question 23

What does the pharyngeal plexus provide innervation for?

Answer 23

sensory innervation of the oropharynx and laryngopharynx from CN IX and X, respectively

nasopharyngeal above the auditory tube and the torus tubarious is innervated by V2

Motor to all of these structures is vagus, except stylopharyngeus