Oral cavity

Question 1

What are the boundaries of the oral cavity?

Answer 1

Roof is made out of hard palate (covered by mucoperiosteum over palatine glands)

• perforated anteriorly by incisive foramina at junction of premaxillae and maxillae
• soft palate is continuation of hard palat that ends with uvula

Question 2

Whats the function of uvula?

Answer 2

hangs at the back edge of oral cavity but functions in pharynx
-functions as flap valve to separate nasopharynx during swallowing

Question 3

What are the walls of oral cavity formed by?

Answer 3

Oral vestibule (only in mammals with cheeks) between cheeks (buccinator) and labial surface of the gums and teeth.

• Fenula is the median fold of mucousa attaching lips to gum
• Parotid opens in vestibule opposite M2

Question 4

What are teeth derived from?

Answer 4

Derived from dermal scales.

Question 5

What is the floor of the oral cavity formed by?

Answer 5

By anterior 2/3 of tongue

• Sublingual region
• -Frenulum linguae median fold attaching tongue to floor of mouth
• -Deep lingual veins-visible on each side of frenulum
• -submandibular ducts- openings on each side of frenulum @ caruncles
• -pilica sublingualis (sublingual fold)-several ducts from sublingual glands open along this ridge raised by the submandibular duct

Question 6

What are the function of salivary glands?

Answer 6

Lubricate dry food, moisten for taste.

Question 7

What are the salivary glands?

Answer 7

• Parotid (Open in estibule)
• Sublingual glands
• Submandibular

Question 8

What is the sulcus terminalis?

Answer 8

Demarcates anterior 2/3 from posterior 1/3

-foramen caecum in the center of the sulcus (Just behind row of large papillae

Question 9

What does the tongue develop from and what are the implications of that?

Answer 9

The tongue develops from occipital myotomes and migrates anteriorly.

• All muscles of (Intirnsinc and extrinsic) save palatoglossus are supplied nu CN XII
• picks up different sensory nerves on the way anterior 2/3 carry taste via CN VII and sensation via lingual CN V3
• posterior 1/3 extends trhough territories of CN X and CN IX both general and special

Question 10

Extrinsic tongue muscles:

Answer 10

• Styloglossal: retract and elevate
  
  • the anterior surface of styloid to tongue
• Platoglossus -elevates when soft palate elevated. Palate to tongue
• Hypoglossus
• Genioglossus: protrude and depress. attaches from genial tubercle to tongue.

Question 11

What is the hyoglossus muscle?

Answer 11

retract and depress. attached from hyoid to tongue crossed by hypoglossal and lingual nn.
-lingual a passes deep to it

Question 12

What are the intrinsic muscles of the tongue?

Answer 12

• Superior longtitudinal
• transverse
• vertical
• inferior longtitudinal

Question 13

What are the functions to of the intrinsinc muscles of the tongue?

Answer 13

• major site for taste via widley distributed taste buds
• manipulates food
• articulation
• drives food down the pharynx

Question 14

What is the supply to the intirinsinc tongue muscles?

Answer 14

From external carotid artery.

• Lingual artery which passes between hyoglossus and genioglossus to supply mm of tongue and floor of mouth
• Facial- minor contribution via tonsillar branches

Question 15

What is the blood supply to the oral cavity?`

Answer 15

Maxillary artery:

• nasopalatines
• lateral nasal
• palatinse
• alveolars
• facial artery- supplies cheeks and lips and more
• lingual artery:supply mm of tongue and floor of mouth

Question 16

What are the sensory nerves of the oral cavity?

Answer 16

General sensory are:

• CN V2 from upper jaw
• CN V3 from lower jaw

Question 17

What supplies special sense innervation tot he tongue?

Answer 17

Special sense:

-CN VII transmits taste from anterior 2/3 tongue and from palate

Question 18

What supplies motor innervation to the oral cavity?

Answer 18

• Visceral: CN V3 to muscles of lower jaw
• Secretomotor:
• CN VII provides parasympathetic to upper and lower jaws
• CN IX provides parasympathetic to parotid.