9. Anatomy of oral cavity

Question 1

where does the oral cavity lie?

Answer 1

inferior to the nasal cavity

Question 2

what does the oral cavity consist of?

Answer 2

2 lateral walls, a floor and a roof

Question 3

what forms the lateral walls of the oral cavity?

Answer 3

buccinators (cheek muscle)

Question 4

what do the buccinators act with and what are their function?

Answer 4

buccinators act with tongue to keep food between teeth when chewing

Question 5

what forms the roof of the oral cavity?

Answer 5

hard and soft palate

Question 6

what forms the floor of the oral cavity?

Answer 6

muscular diaphragm and the tongue

with other soft tissues

Question 7

where does the oral cavity begin anteriorly?

Answer 7

oral fissure (bounded by the lips)

Question 8

where does the oral cavity extend posteriorly?

Answer 8

to the oropharyngeal isthmus

connection between oral cavity and pharynx

Question 9

what is the isthmus?

Answer 9

an ‘arch’ formed by the soft palate above

and the upper surface of the tongue below

Question 10

what forms the sides of the oropharyngeal isthmus?

Answer 10

anterior and posterior pillars of the fauces

Question 11

what forms the pillars / arches (of fauces)?

Answer 11

palatoglossal muscle (anterior)
palatopharyngeal muscle (posterior)

Question 12

where do the palatoglossal and palatopharyngeal muscles run from?

Answer 12

from the soft palate of the tongue and pharynx

Question 13

when do the palatoglossal and palatopharyngeal muscles contract?

Answer 13

contract during chewing to pull the soft palate down towards the back of tongue, closing the oropharyngeal isthmus

Question 14

why do the palatoglossal and palatopharyngeal muscles contract?

Answer 14

ensure the food remains in the oral cavity while chewing

Question 15

what lies between the pillars (of fauces)?

Answer 15

tonsillar fossa

Question 16

what is within the tonsillar fossa?

Answer 16

palatine tonsil

one of annularly arranged lymphoid tissues of Waldeyer’s ring

Question 17

when are palatine tonsils seen?

Answer 17

often easily visible and readily noticed when swollen due to inflammation e.g. tonsillitis

Question 18

what does the oropharyngeal isthmus continue posterior into?

Answer 18

the oropharynx

Question 19

what does the oral cavity plan an important role in?

Answer 19

function of the digestive system

Question 20

function of oral cavity in digestive system?

Answer 20

entry of food to digestive tract

mastication –> bolus ready for swallow

Question 21

what is digestive function of oral cavity aided by?

Answer 21

salivary gland secretions, lubricate food

contains enzymes to start chemical digestion e.g. amylase

Question 22

what are the salivary glands?

Answer 22

parotid
submandibular
sublingual

Question 23

what can form in ducts draining salivary glands? leading to?

Answer 23

stones can form in ducts draining the glands, causing significant pain and swelling in the salivary glands
(symptoms fluctuate in relation to eating)

Question 24

which salivary gland is most commonly affected by having ducts draining it blocked?

Answer 24

submandibular gland

Question 25

what type of tissue is the tongue and what is it covered entirely by?

Answer 25

an entirely muscular tissue covered in mucous membrane

Question 26

what is the tongue capable of?

Answer 26

different shapes, positions and movements

Question 27

what are the muscles creating the tongue classified into?

Answer 27

intrinsic and extrinsic

Question 28

how many intrinsic muscles are there lying entirely within the tongue?

Answer 28

4 intrinsic muscles | run longitudinally, vertically, transversely

Question 29

what are the intrinsic muscles of the tongue named according to?

Answer 29

the direction in which they travel and act to alter the shape of the tongue

Question 30

what are the intrinsic muscles of the tongue attached to?

Answer 30

not attached to any bones, but blend in with the extrinsic muscles

Question 31

how many extrinsic muscles are there? function?

Answer 31

4 extrinsic muscles, act to: 1. change the position of the tongue 2. anchor it to the surrounding structures

Question 32

which structures do the extrinsic muscles of the tongue anchor the tongue to?

Answer 32

below: hyoid bone and mandible above: styloid process and soft palate

Question 33

what are all the muscles of the tongue innervated by?

Answer 33

the hypoglossal nerve (CN XII) | EXCEPT palatoglossus

Question 34

which nerve innervates the palatoglossus muscle of the tongue?

Answer 34

CN X (vagus)

Question 35

where does the tongue receive innervation from?

Answer 35

receives afferent innervation from a number of cranial nerves

Question 36

why does the tongue receive its afferent innervation from a number of cranial nerves?

Answer 36

because of its embryological origins | pharyngeal arch 1,3,4