23.2 Anat: Oral cavity and oropharynx

Question 1

What is the roof of the mouth formed by?

Answer 1

Hard palate: maxilla (palatine bone projecting backwards)

Soft palate ending in the uvula

Question 2

What are the (3) muscles making up the floor of the mouth?

Answer 2

Mylohyoid muscle, digastric muscle (ant. inf. view)

Geniohyoid muscle (sup view)

Question 3

What is the name of the groove that separates the anterior 2/3rds of the tongue from the post third?

Answer 3

Sulcus terminalis

Question 4

What is at the apex of the sulcus terminalis? What is the developmental significance of this?

Answer 4

Foramen caecum- thyroid gland develops and descends into neck

Question 5

What are the lymphoid nodules on the posterior third of the tongue?

Answer 5

Lingual tonsil

Question 6

What are the four types of papillae on the tongue?

What do they contain?

Answer 6

Valate (circular, line ant. sulcus terminalis)
Fungiform (red dots)
Foliate (lateral sides of ST)
[Filiform, can’t see on humans but rough on cats)

Contain the tastebuds

Question 7

What are the 4 extrinsic muscles of the tongue and their actions on contraction?

Answer 7

Hyoglossus (depresses)
Palatoglossus (elevates)

Styloglossus (retracts)
Genioglossus (pulls tongue forward)

Question 8

What is the nerve supply to the extrinsic tongue muscles?

Answer 8

XII except palatoglossus (pharyngeal branch, X)

Question 9

What do the intrinsic muscles of the tongue do? What are they innervated by?

Answer 9

Alter the shape of the tongue

NS: XII

Question 10

What is the innervation for taste?

Answer 10

Ant 2/3rds: Chorda tympani (VII, hitchhikes with lingual nerve)

Post 1/3rd: IX

Question 11

What do the different types of teeth do?

Answer 11

Incisors: cutting
Canines: anchoring
Premolars, molars: grinding

Question 12

What are the teeth innervated by?

What is the blood supply?

Answer 12

Upper: V (maxillary–>superior alveolar nerve)

Lower: V (mandibular–> inferior alveolar nerve)

BS: branches of external carotid

Question 13

What are the salivary glands and their openings?

Answer 13

Parotid gland (duct onto upper second molar)

Submandibular gland (sublingual papillae)

Sublingual gland

Question 14

What is the clinical significance of the vessels under the tongue?

Answer 14

Lingual arteries/veins run close to the surface (good for drug absorption)

Question 15

What forms the oropharynx? (Roof, floor, walls)

Answer 15

Roof: soft palate, uvula

Floor: post. tongue, epiglottis

Wall: palatine tonsils (‘the tonsils’) etc

Question 16

What are the arches in the oropharynx?

Answer 16

Palatopharyngeal arch (formed by palatopharyngeus)

Palatoglossal arch (formed by palatoglossus)

(fauces is the arched opening at the back of the mouth

Question 17

What does the soft palate do?

What connects hard/soft palate?

Answer 17

Seals nasal cavity/oral cavity during actions such as breathing, eating etc.

Question 18

What are the 5 muscles of the soft palate?

What are they innervated by?

Answer 18

Tensor veli palatini (auditory tube)
Levator veli palatini (auditory tube)
Musculus uvulae
Palatoglossus
Palatopharyngeus

All by X except tensor veli (V)

Question 19

What is the name of the incomplete ring of lymphoid tissue?

Answer 19

Waldeyer’s ring