Oral Cavity: Tongue And Floor Of The Mouth

Question 1

What are the boundaries of the oral cavity?

Answer 1

Roof = hard + soft palate

Floor = soft tissues inc. tongue

Lateral walls = cheeks

Anterior = oral fissure, created by lips

Posterior = oropharynx, accessed via oropharyngeal isthmus

Question 2

What is the oral vestibule? Note some features present.

Answer 2

Gap between teeth and the lips/cheeks when closed

Labial frenulum, buccal frenulum

Question 3

How is the floor of the oral cavity composed?

Answer 3

Floor is formed of paired mylohyoid muscles connecting the hyoid bone to the mylohyoid line of mandible.

Above the mylohyoid are paired geniohyoid muscles attaching from mental spine of mandible to the body of the hyoid.

Superior to both of these is the tongue

Question 4

Describe the superior surface of the tongue

Answer 4

Posterior 1/3 forms the anterior wall of oropharynx

Superior surface covered by papillae - grip food + tastebuds

Fungiform are mushroom tastebuds

Foliate = fold of mucosa lining posteriorly and laterally on superior tongue

Vallate = largest, in V shape anterior to terminal sulcus

Filiform = no tastebuds

Question 5

Describe the inferior surface of the tongue

Answer 5

No papillae

Midline marked by the frenulum

Lingual vein can be seen either side as well as sub-lingual folds

Question 6

What are the muscles of the tongue and their function?

Answer 6

Intrinsic - change size + shape

They are…
- superior longitudinal
- vertical
- transverse
- inferior longitudinal

Extrinsic - originate outside tongue and protrude, retract, elevate and depress

They are..
- palatoglossus
- hyoglossus
- styloglossus
- genioglossus

Question 7

Describe the location and function of the genioglossus

Answer 7

Sit superiorly to geniohyoid

Protrudes the tongue

Question 8

Describe the location and function of the hyoglossus

Answer 8

Lateral to genioglossus and blends with intrinsic fibres on lateral edges of tongue

Depresses sides of tongue

bold Lingual artery enters tongue between hyoglossus and genioglossus

bold hypoglossal and lingual nerves enter tongue on external surface of hyoglossus

Question 9

Describe the location and function of the styloglossus

Answer 9

Originates from styloid process, elevates and retracts the tongue

Question 10

Give the location and function of the palatoglossus

Answer 10

Muscle of tongue and soft palate

Origin is palatine aponeurosis

Fibres pass inferiorly and blend with intrinsic on lateral surface

Question 11

Describe motor innervation to tongue

Answer 11

All by hypoglossal nerve

minus palatoglossus = vagus

Question 12

Describe sensory innervation to tongue

Answer 12

General (pressure, pain, temperature)

• anterior 2/3 = mandibular nerve - lingual
• posterior 1/3 = Glossopharyngeal

Special (taste)

• anterior 2/3 = facial nerve via chordate tympani
• posterior 1/3 = Glossopharyngeal

Question 13

Describe the blood supply and venous drainage to the tongue

Answer 13

Lingual artery via external carotid

Deep lingual and dorsal lingual veins drain the tongue - to internal jugular vein