The Oral Cavity

Question 1

What are the functions of the oral cavity

Answer 1

-entry of air and food
-chewing
-swallowing
-sensation (taste and general)
-speech- modification of sound
-facial expression
-extra hand

Question 2

What is the arrangement of the oral cavity

Answer 2

• extends from oral fissure (gap between two lips) to pharynx
• roof- hard and soft palate (roof of the oral cavity and floor of the nasal cavity)
• wall-cheeks and lips
• floor- muscle
  -lined with stratified squamous epithelium for protection

Question 3

What is the oral cavity lined with

Answer 3

Stratified squamous epithelium for protection

Question 4

How is the oral cavity divided

Answer 4

Teeth into the vestibule and the oral cavity proper

Question 5

Roof of the oral cavity

Answer 5

-hard palate- formed by bone covered with keratinised stratified squamous epithelium
-palatine process of maxilla
-horizontal process of palatine bone
-soft palate- muscle covered with non keratinised stratified squamous epithelium
-sensory innervation- maxillary division of trigeminal nerve

Question 6

What is the floor of the oral cavity made of

Answer 6

Muscle covered with non keratinised stratified squamous epithelium innervated by mandibular division of trigeminal nerve.

Question 7

what do muscles on the floor of the oral cavity do

Answer 7

Allow change in the shape for vocal resonance and swallowing

Question 8

What is the tongue

Answer 8

-bag of muscle covered with mucosa
-fills most of the oral cavity proper
-has a dorsal surface and a ventral surface

Question 9

What is the dorsal surface of the tongue

Answer 9

Covered with para keratinised stratified squamous epithelium- rough and quite dry (surface you can see)

Question 10

Ventral surface of the tongue

Answer 10

Covered with non keratinised stratified squamous epithelium, moist and shiny (bottom part of the tongue you cant see)

Question 11

Functions of the tongue

Answer 11

-sensation (taste and general sensation- pressure, temperature, pain)
-articulation
-swallowing
-chewing

Question 12

Describe the surface of the tongue

Answer 12

-papilla on the dorsal surface of tongue to grip bolus and manipulate in oral cavity
-behind sulcus terminals, there are no papilla and marks the posterior third of dorsal surface
-Lingua frenulum attatched to ventral surface of tongue to deep surface of mandible
-the sublingual papilla releases excess saliva for mastificaion

Question 13

How is the epiglottis attached to the tongue

Answer 13

-three folds
-medial and lateral glossoepiglottic
-the gaps between these are called vallecullae

Question 14

What are the two muscles of the tongue and what do they do

Answer 14

-intrinsic muscles
Originate and insert within the tongue
Alter the shape of the tongue
-extrinsic muscles
Originate outside and insert within the tongue
Alter the position of the tongue
When they contract they pull the tongue back to its origin point

Question 15

What are the extrinsic muscles of the tongue

Answer 15

• styloglossus
  -Palatoglossu
  -Hyoglossus
  -genioglossu

Question 16

How is the tongue innervated

Answer 16

-anterior two thirds of the tongue
Special sensation- facial nerve 7
General sensation- trigeminal nerve 5
-posterior third of tongue
Special and general - CN IX glossopharyngeal
-motor- hypoglossal

Question 17

How is taste transmitted

Answer 17

-taste buds on fungi form and circumvallate papillae
-then go to glossopharyngeal nerve
-to the nucleus solitarius in brainstem
-ventral posterior nucleus of the thalamus
-taste cortex

Question 18

What is the Hypoglossal nerve (CNXII)

Answer 18

• provides motor innervation to the muscles of the tongue
• innervates all intrinsic muscles in tongue

Question 19

What are the 3 pairs of salivary glands

Answer 19

Parotid
Submandibular
Sublingual

Question 20

Salivary glands produce a seromucous fluid. What does it contain ?

Answer 20

• water- wash oral cavity
• mucins- lubrication
• amylase- carbohydrate digestion
• lysozyme- antibacterial
• Imunoglobulin A-defence
• bicarbonate- neutralise acid and prevent tooth decay

Question 21

Parotid salivary glands

Answer 21

-behind the cheek
-only produces serous saliva
-PNS innervation: glossopharyngeal

Question 22

Submandibular salivary glands

Answer 22

-mixed seromucous saliva (3:2)
-PNS innervation: facial nerve VII

Question 23

Sublingual salivary glands

Answer 23

-mixed seromucous saliva (1:3)
-PNS innervation: facial nerve (VII)

Question 24

The fauces

Answer 24

• leads from the back of the oral cavity into the pharynx
• has the uvula, palatonphrayngeal fold, palatine tonsil, palatoglossal fold (covered in mucus)

Question 25

What is the trigeminal nerve (cranial nerve 5)

Answer 25

-sensory innervation to the oral cavity supplied by trigeminal nerve
-arise in the pons
-trigeminal nerve converts general sensory fibres form the oral cavity
-trigeminal nuclei located in the pons and the medulla
-cell bodies of the sensory neurones are located in the trigeminal ganglion

Question 26

What are the three divisons of the trigeminal nerve

Answer 26

-ophthalmic v1
-maxillary v2
-mandibular v3

Question 27

What is the ophthalmic v1

Answer 27

-enters the skull at the superior orbital fissure
-sensory to:
-orbit
-nasal cavity
-forehead
-cornea
-upper eyelids

Question 28

What is the maxillary v2

Answer 28

-enters the skull at the foramen rotundum
Sensory to:
-upper lips
-lower eyelids
-maxillary teeth
-maxillary gingiva
-hard and soft palate
-cheek
-nose
-parts of pharynx

Question 29

What is the mandibular v3

Answer 29

-enters the skull at the foramen ovale
Sensory to:
-lower lips
-mandibular teeth
-mandibular gingiva(gums)
-anterior 2/3 tongue
-chin
Motor to:
-muscles of mastication
-anterior belly of digastric
-Mylohyoid muscle
-tensor veil palatini muscle
-tensor tympani muscle

Question 30

Styloglossus (extrinsic muscles)

Answer 30

-extends from styloïde process of temporal bone to the posterolateral aspect of the tongue

Question 31

Palatoglossus (extrinsic muscle)

Answer 31

Extends from the palatine aponeurosis to the posterolateral aspect of the tongue

Question 32

Hyoglossus (extrinsic muscles)

Answer 32

Extends from the hyoid bone to the posterior aspect of the tongue

Question 33

Genioglossus (extrinsic muscles)

Answer 33

Extends from the mandible to tip and body of the tongue