Oral Cavity

Question 1

What are the divisions of the oral cavity?

Answer 1

The oral cavity is divided into the vestibule and the oral cavity

Question 2

What are the boundaries of the oral cavity?

Answer 2

Superior: Hard/Soft palate
Inferior: mylohyoid muscle
Anterior/Lateral: Teeth/gingiva & alveolar processes
Posterior: palatoglossal fold (oropharynx)

Question 3

What are the foramen of the hard palate?

Answer 3

Incisive canal: midline located directly posterior to incisor teeth

Greater Palatine foramen – located in the posterolateral region of the hard palate

Lesser Palatine foramen – located posterior to the greater palatine foramen

Question 4

What passes through the foramen of the hard palate?

Answer 4

Incisive canal: Nasopalatine nerve and terminal branches of the greater palatine artery pass through

Greater Palatine foramen - Greater palatine nerve and artery pass through

Lesser Palatine foramen - Lesser palatine nerve and artery pass through

Question 5

Innervation of the Levator veli palatini (pair)?

Answer 5

Pharyngeal plexus by way of the vagus nerve

Question 6

Action of the Levator veli palatini (pair)?

Answer 6

Elevates palate - prime mover of palate.

Question 7

Innervation of the Tensor veli palatini (pair)?

Answer 7

V3 (mandibular division of trigeminal)

Question 8

Action of the Tensor veli palatini (pair)?

Answer 8

Tenses soft palate and opens auditory tube

Question 9

Innervation of the Palatoglossus (pair)?

Answer 9

Pharyngeal plexus by way of the vagus nerve

Question 10

Action of the Palatoglossus (pair)?

Answer 10

Raises tongue to close off oral cavity from oropharynx during swallowing; depresses the soft palate; forms arch

Question 11

Innervation of the Palatopharyngeus (pair)?

Answer 11

Pharyngeal plexus by way of the vagus nerve

Question 12

Action of the Palatopharyngeus (pair)?

Answer 12

Raises pharynx during swallowing and tenses soft palate.

Question 13

Blood supply of the hard palate?

Answer 13

Greater palatine artery (branch of descending palatine artery) - enters through greater palatine foramen and anastomoses with the septal artery after the greater palatine artery passes through the incisive canal.

Question 14

Blood supply of the soft palate?

Answer 14

Lesser palatine artery - enters through lesser palatine foramen.

Question 15

Blood supply of the upper dentition

Answer 15

Posterior superior alveolar artery (branch of maxillary) – supplies molars, and anastamoses with branches from infraorbital artery.

Middle and Anterior superior alveolar arteries (branches of infraorbital) – middle supplies premolars; anterior supplies canine & incisors; anastamose with posterior superior alveolar artery

Question 16

Sensory innervation of the hard palate?

Answer 16

Greater palatine nerve - via greater palatine foramen.

Nasopalatine nerve - via incisive canal (foramen) to innervate anterior aspect of hard palate.

Question 17

Innervations of the soft palate?

Answer 17

Lesser palatine nerve

CN IX - somatic sensation (gag reflex)

Question 18

Innervation of teeth of upper palate?

Answer 18

Posterior, Middle and Anterior Superior Alveolar nerves (branches of infraorbital nerve – V2) supply the teeth of the upper palate.

Posterior branches typically supply the molars

Middle branches supply the premolars

Anterior branches supply the canine & incisors

Question 19

Innervation of mandibular teeth?

Answer 19

Mandibular teeth are supplied by the Inferior Alveolar nerve (branch of V3) and artery (branch of the maxillary artery)

Question 20

What is the sulcus terminalis?

Answer 20

The oral and pharyngeal parts of the tongue are separated from one another by a V-shaped groove known as the sulcus terminalis

Question 21

What provides motor innervation to the tongue muscles (Genioglossus, Hyoglossus, Styloglossus) ?

Answer 21

CN XII

Question 22

Action of Genioglossus?

Answer 22

Wags the tongue

Question 23

Action of Hyoglossus?

Answer 23

Depresses and retracts tongue

Question 24

Action of Styloglossus?

Answer 24

Moves tongue superiorly and posteriorly

Question 25

What is in the floor of the oral cavity?

Answer 25

Submandibular and sublingual salivary glands

Submandibular duct (Wharton’s duct)

Lingual nerve

Hypoglossal nerve

Question 26

What is the course of the lingual and hypoglossal nerves and the lingual artery relative to the hyoglossus muscle?

Answer 26

Both the lingual and the hypoglossal nerves course lateral to the hyoglossus muscle, whereas the lingual artery runs medial to this muscle

Question 27

Blood supply of the tongue?

Answer 27

Lingual artery.

Question 28

Describe sensory innervation of the tongue.

Answer 28

Anterior two-thirds of the tongue:

1. General sensation - lingual nerve (from V3)
2. Taste - chorda tympani (from CN VII) is carried by the lingual nerve

Posterior one-third of the tongue:
General sensation and taste - glossopharyngeal nerve (CN IX)

Base of Tongue:
Taste – vagus (CN X)

Question 29

Describe parasympathetic supply of the Submandibular & Sublingual Glands.

Answer 29

Submandibular & Sublingual Glands: Innervated by the motor branch of Facial nerve traveling in the Chorda Tympani, which synapses in the Submandibular ganglion. Post-ganglionic fibers continue on in the lingual nerve to tongue and glands. Sympathetic post-ganglionic fibers originate in the Superior cervical ganglion and travel with the blood supply (lingual a.) to reach the glands.

Question 30

Describe parasympathetic innervation of the parotid gland.

Answer 30

Parotid Gland: GLOAP Glossopharyngeal nerve via the Lesser petrosal nerve synapses in the Otic ganglion. Postganglionic fibers follow the Auriculotemporal nerve into the Parotid gland. Sympathetic post-ganglionic fibers originate in the Superior cervical ganglion and travel with the blood supply (maxillary & superficial temporal aa.) to reach the parotid gland.