Lecture 8: Oral cavity and submandibular gland

Question 1

Underside of the tongue?

Answer 1

Question 2

Back of the oral cavity?

Answer 2

Can’t always see the palatine tonsil so we use the two landmarks to pinpoint its location

Question 3

Surface of the tongue?

Answer 3

remember: the foramen cecum is where the thyroid develops before descending down the thryoglossal duct.

Question 4

Boundaries of the oral cavity?

Answer 4

Roof = hard and soft palate (palatine process of maxilla, palatine and sphenoid)

Floor = muscular diaphragm and tongue

lateral walls = oral mucosa, fascia and buccinator muscle (attached to pterigomandible raphae)

anterior = oral fissure

posterior = oropharyngeal isthmus

Question 5

Floor of the oral cavity specifics?

Answer 5

Most superficial is the mylohyoid (V3) from the hyoid bone to the mylohoid line with a free posterior lateral edge. Deep to this is the geniohyoid (C1) from the hyoid bone to the inferior mental spines of the mandible.

The triangular apeture is formed by the superior and middle constrictor muscle as well as the lateral posterior boarder of the mylohyoid muscle.

Question 6

Muscles of the tongue?

Answer 6

Intrinsic muscles - O and I lies within the tongue

• superior longitudinal
• vertical
• transverse
• inferor longitudunal

Extrinsic muscles have an attachment outside the tongue and allow movement = talking - all Hypoglossal (CN XII) except palatoglossus (CN X)

• palatoglossus
• styloglossus (from the styloid process)
• hyoglossus (from the hyoid bone)
• genioglossus (from superior mental spines)

Question 7

Muscles deep to the mylohyoid? potential spaces?

Answer 7

Directly below is the geniohyoid

deep to this is the genioglossus (from the superior mental spine to body of the tongue)

The hyloglossus forms two potential spaces between itself and the mylohyoid and lateral to itself between itself and the genioglossus.

Question 8

Contents of the potential spaces?

Answer 8

Superficial space contains:

• chorda tympani (from VII)
• lingual nerve (branch of V3 - same space but higher up)
• hypoglossal (XII) - runs lateral to ext and int carotid
• deep lingual vein (one you see looking at bas of tongue)

Deep space contains:

• glossopharyngeal (IX) -runs between ext and int carotid
• lingual artery
• dorsal lingual vein

Question 9

Sensory and motor of the oral cavity?

Answer 9

Anterior 2/3 sensation

general sensation = mandibular nerve V3 via the Lingual n.

Special sensation = Facial nerve VII via the Corda Tympani

Posterior 1/3

General and special = via glossopharyngeal (IX)

Motor

intrinsic muscles, genioglossus, hyoglossus and styloglossus all by the hypoglossal XII

Palatoglossus by the vagus X

Question 10

overview of the roof of the oral cavity?

Answer 10

Question 11

Muscles of the soft palate?

Answer 11

Levator veli palatini - elevates the soft palate

palatopharyngeus

(palatine tonsils)

Palatoglossus

musculus uvulae (from nasal spine to uvula itself)

• lesser palatine artery makes it a highly vascularised area
• Pharyngeal plexus of vagus (X) innervates via greater and lesser palatine nerves traveling through the palatine foramen

Question 12

can you answer these?

Answer 12

yes you can