Oral Cavity Part 1 Flashcards
What are the functions of the digestive system?
- ingestion
- mastication
- deglutition
- propulsion (peristalsis and segmentation)
- mechanical digestion
- chemical digestion
- absorption
- defacation
What makes up the oral cavity?
Oral vestibule:
(Borders)
- internal: teeth and gums
- external: lips and cheek
Oral cavity proper:
(Borders):
- anterior/lateral: teeth
- posterior: palatoglossal folds (found hanging off the uvula)
What are the functions of the oral cavity?
- mastication
- initiate swallowing
- saliva production (for antimicrobial defence, digestions and lubrication of food bolus)
Describe the lips
- externally lined with skin
- has vermillion border (between skin and mucous membrane) of poorly keratinized skin and is rich in blood vessels
- internally lined with oral mucosa with small labial glands that open to oral vestibule
Describe the important anatomical features of the mandible
- sublingual fossa (for sublingual gland)
- mylohyoid line (for mylohyoid muscle)
- submandibular fossa for submandibular gland
- retromolar fossa (for attachment of pteryhomandibular raphe)
- lingula of mandible (for sphenomandibular ligmanet)
- mandibular canal/foramen/mental foramen (for inferior alveolar nerve to mental nerve to mandibular teeth)
Briefly describe teeth
4 regions:
- left/right
- maxillary/mandible
each region has:
- 2 incisors
- 1 canine
- 2 pre-molars
- 3 molars
total of 32 teeth
What are the 4 main muscles of mastication and their supply?
- medial pterygoid
- lateral pterygoid (only one that opens mouth)
- masseter
- temporalis
- all supplied by mandibular division of trigeminal nerve (CN V)
Describe the layers of the cheek from superficial to deep
- skin
- buccal fat pad (enhances sucking ability of infant)
- buccopharyngeal fascia
- buccinator muscle
- buccal glands
- mucus membrane
Describe the attachments and supply of the buccinator muscle
- superior: maxilla
- inferior: mandible
- posterior: pterygomandibular raphe
- anterior: orbicularis orbis
- innervated by facial nerve (CN VII)
Where does the fibres of the buccinator muscle cross-over and what is it called?
it is called modiolus found lateral to the angle of the mouth
Describe the palate briefly
- hard palate anteriorly made of bone
- soft palate posteriorly which is musculomembranous
Palatine foramen
- incisive foramen for nasopalatine nerve
- greater palatine foramen for greater palatine nerve
What are Epstein’s pearls?
clusters of white spots in the midline at the junction of hard and soft palates
Describe the palatine arches
- 2 arches that extend from the uvula to the lateral walls
- anteriorly: palatoglossal arch of the palatoglossal muscle
- posteriorly: palatopharyngeal arch of the palatopharyngeus muscle
- there is a tonsillar fossa between arches where the palatine tonsils are
Name the muscles of the soft palate and their innervation
- palatoglossus
- palatopharyngeus
- levator veli palatini
- tensor veli palatini
- innervated by the vagus nerve (CN X)
What is the tongue and its function?
- a bag of constricted muscles covered in a mucous membrane
- mastication
- deglutition
- taste
- speech
- has furry appearance for gripping food and housing tastebuds
Describe the different parts of the tongue
Posterior 1/3:
- vertical part
- in oropharynx
- taste and general sensation (CN IX)
Anterior 2/3:
- horizontal part
- in oral cavity
- taste (CN VII)
- general sensory (CN V3)
where papillae are found: - foliate papillae - vallate papillae - fungiform papillae (^ taste buds) - filiform papillae (touch, temperature)
- anterior and posterior sections separated by sulcus terminalis
What are the extrinsic muscles of the tongue and their action?
- genioglossus
- hyoglossus
- styloglossus
- palatoglossus
- function to change the position of the tongue during mastication, swallowing and speech
What are the intrinsic muscles of the tongue and their action?
- superior and inferior longitudinal muscle of tongue
- vertical and transverse muscle of the tongue
- modify the shape of the tongue during function
What nerves supply the muscles of the tongue?
- hypoglossal nerve (CN XII)
- except palatoglossal which is vagus nerve (CN X)
What makes up the floor of the mouth?
- muscular diaphragm of mainly mylohyoid muscle between the mandible and the hyoid bone to support the tongue
- where the fascial plane is located (site of spread of infection)
What are the functions of the salivary glands?
- lubrication and binding of masticated food
- solubilization of dry food
- digestion of carbohydrates
- oral hygiene
What nerves supply the salivary glands?
- facial nerve (CN VII)
- glossopharyngeal nerve (CN IX)
