Oral Cavity Flashcards
what is the oral cavity?
start of the alimentary canal
function of the oral cavity?
digestion
communication
breathing
role of oral cavity in digestion?
receives food, preparing it for digestion in the stomach and small intestine
role of oral cavity in communication?
modifies the sound produced in the larynx to create a range of sounds
role of oral cavity in breathing?
acts as an air inlet in addition to the nasal cavity
where does the oral cavity span?
between the oral fissure (anteriorly – the opening between the lips), and the oropharyngeal isthmus (posteriorly – the opening of the oropharynx)
what is the oral cavity divided into?
two parts by the upper and lower dental arches (formed by the teeth and their bony scaffolding)
what are the 2 divisions of the oral cavity?
the vestibule, and the mouth cavity proper
where is the vestibule located?
The horseshoe-shaped vestibule is situated anteriorly.
It is the space between the lips/cheeks, and the gums/teeth
what does the vestibule communicate with?
The vestibule communicates with the mouth proper via the space behind the third molar tooth, and with the exterior through the oral fissure
what controls the diameter of the oral fissure?
controlled by the muscles of facial expression – principally the orbicularis oris
what is located opposite to the upper 2nd molar tooth?
the duct of the parotid gland opens out into the vestibule, secreting salivatory juices
where does the mouth proper lie?
The mouth proper lies posteriorly to the vestibule
what is the mouth proper bordered by?
a roof, a floor, and the cheeks
what fills a large proportion of the cavity of the mouth proper?
the tongue
roof of mouth proper?
consists of the hard and soft palates
where is the hard palate found?
anteriorly
function of the hard palate?
a bony plate that separates the nasal cavity from the oral cavity
what is the hard palate covered superiorly by?
respiratory mucosa (ciliated pseudostratified columnar epithelium)
what is the hard palate covered inferiorly by?
oral mucosa (stratified squamous epithelium)
what is the soft palate?
a posterior continuation of the hard palate. In contrast to the hard palate, it is a muscular structure
function of soft palate?
acts as a valve that can lower to close the oropharyngeal isthmus, and elevate to separate the nasopharynx from the oropharynx
floor of the oral cavity?
Muscular diaphragm
Geniohyoid muscles
Tongue
Salivary glands and ducts
what does the muscular diaphragm (floor of oral cavity) comprise of?
the bilateral mylohyoid muscles
function of the muscular diaphragm?
provides structural support to the floor of the mouth, and pulls the larynx forward during swallowing
function of the geniohyoid muscles? (floor)
pull the larynx forward during swallowing
what is the tongue connected to the floor of the oral cavity by?
by the frenulum of the tongue, a fold of oral mucosa
what are the cheeks formed by?
the buccinator muscle
what is the buccinator muscle lined internally by?
oral mucous membrane (stratified squamous)
function of the buccinator muscle?
contracts to keep food between the teeth when chewing
innervation of buccinator muscle?
buccal branch of the facial nerve (CN VII) - motor
sensory innervation of the oral cavity?
supplied by the branches of the trigeminal nerve (CN V)
hard and soft palates innervation?
the greater palatine and nasopalatine nerves
both derived from the maxillary branch (V2) of the trigeminal nerve
innervation to floor of oral cavity?
receives sensory innervation from the lingual nerve – a branch of the mandibular (V3) division of the trigeminal nerve
innervation of tongue?
innervated by special sensory fibres for taste from the chorda tympani, a branch of the facial nerve (CN VII)
(anterior 2/3rd)
innervation of cheeks?
buccal nerve
branch of the mandibular division of the trigeminal nerve - sensory
