Oral Cavity Flashcards
What are the associated organs of the digestive system?
Salivary glands, liver, gallbladder and pancreas
What are the functions of the the digestive system?>
Ingestion, mastication, deglutition (swallowing), propulsion (peristalsis and segmentation), mechanical digestion, chemical digestion, absorption and defecation
What is the oral cavity made up of and what are its functions?
Oral vestibule and the oral cavity proper. The functions are mastication, initiates swallowing and saliva production
Describe the boarders of the oral vestibule and oral cavity proper?
Oral vestibule - Space between teeth, gums, lips and cheeks.
Cavity proper - Deep to the teeth and is bounded posteriorly by palatoglossal folds
Where is the vermilion border?
It is between the skin of the lips and the mucous membrane. Poorly keratinized skin and is rich in blood vessels.
Describe the different regions of teeth in the oral cavity
There are 4, left, right, maxillary and mandibular. Each region has Incisors (2), Canine (1), premolars (2) and molars (3) = 32
Name the muscles of mastication and their innervation
Medial pterygoid, lateral pterygoid (only muscle that opens mouth), masseter and temporalis. They are supplied by the mandibular division of the trigeminal nerve.
Describe the layers of the buccae (cheek)
Skin, Buccal fat pad, buccopharyngeal fascia, buccinator muscle, buccal glands and mucous membrane.
Where does the buccinator muscle attach?
Maxilla (superiorly), mandible (inferior), pterygomandibular raphe (posterior) and orbicularis oris (anteriorly)
What is the modiolus?
It is a point of cross over of the buccinator muscle fibres just lateral to the angle of the mouth
What is the buccinator muscle innervated by?
Facial nerve (cranial nerve 7)
What is the palatine aponeurosis
Formed by periosteum and tendon of tensor veli palatini which supports the soft palate
Name the two arches which extend from the uvula to the lateral walls? And what lies between the two arches?
Palatoglossal arch anteriorly and the palatopharyngeal arch (made by the muscle covered by mucosal membrane) In-between is a tonsillar fossa which houses the palatine tonsils.
Name the muscles of the soft palate and their function
Palatoglossus and palatopharngeus (pull the palate inferiorly) Levator veli palatini and Tensor veli palatini (elevate the pharynx)
Describe the differences between the anterior (2/3rds) and posterior (1/3rd) parts of the tongue
Anterior = Horizontal, oral cavity, involved in taste (facial nerve) and general sensory (mandibular division of trigeminal nerve) .
Posterior - Vertical, oropharynx, taste and general sensation (glossopharyngeal nerve)
Name the different papillae in the anterior 2/3rds of the tongue and their function
- Folate papillae, vallate papillae and the fungiform papillae (all have taste buds)
- Filiform papillae which are densely packed anteriorly (touch and temp)
How does the tongue sit in the oral cavity? and what are these called?
it is suspended by 4 pairs of skeletal muscles; Genioglossus, hypoglossus, styloglossus (all 3 are hypoglossal nerve) and palatoglossus (vagus).
What is the function of the intrinsic and extrinsic muscles of the toungue?
Extrinsic - Changes the position of the tongue (mastication, swallowing and speech).
Intrinsic - Modify the shape
What does the mylohyoid muscle form and what is its clinical relevance?
Forms muscular diaphragm which extends between mandible and hyoid bone. It has a free boundary which creates a fascial plane = spread of infection)
What are crypts?
Pockets/folds that occur naturally in the tonsils
Name the tonsils that form the waldeyer’s ring
Nasal - Tubal x2 and pharyngeal.
Oral - Palatine x2 and lingual
What are the functions of the salivary glands?
Lubrication and binding of masticated food, solubilization of dry food, digestion of carbs via alpha amylase and oral hygiene. (facial and glossopharyngeal nerve)
Name the different types of salivary glands and where they open into the oral cavity
Parotid gland - serous, opens via the parotid/stensen’s duct opposite 2nd maxillary molar.
Sublingual - Mucous, Opens into the floor of the mouth along the sublingual fold.
Submandibular - mixed mucous and serous. Opens at the sublingual papilla
Name the three regions that the pharynx is divided into?
Nasopharynx, oropharynx and laryngopharynx.
What are the constrictor muscles of the pharynx
Superior pharyngeal, middle pharyngeal and inferior pharyngeal muscles.
What are elevator muscles?
Stylopharyngeus, palatopharyngeus and salpingopharyngeus
Where do all the constrictor pharyngeal muscle insert onto?
The pharyngeal raphe
What encloses the gap between the occipital bone and superior constrictor is closed by?
Pharyngobasilar fascia
What is the sinus of morgagni?
Space between the base of the skull and the upper free boarder of superior constrictor.
What is the clinical relevance of Killian’s dehiscence
It is a weak area when the superior pharyngeal constrictor ends. This can prolapse
What is Passavant’s Ridge?
It is a mucosal ridge caused by superior pharyngeal constrictor. It encircles the lateral and posterior walls of the nasopharynx
What passes through the oropharyngeal triangle?
Stylopharyngeus muscle, glossopharyngeus nerve and stylohyoid ligament
Describe the arterial supply of the pharynx
Upper pharynx is supplied by branches of the external carotid artery eg, ascending pharyngeal artery.
Lower pharynx is supplied by pharyngeal branches of the inferior thyroid artery of thyrocervical trunk of subclavian artery
Describe the venous and lymphatic drainage of the pharynx
Veins - Drained by pterygoid plexus
Lymph - drainage to retropharyngeal, paratracheal and infrahyoid nodes
Where do the palatine tonsils drain too?
Jugulodigastric lymph node when is palpable when inflammed
Describe the motor innervation of the pharynx
Stylopharyngeus is supplied by glossopharyngeal nerve, all other constrictor and elevators are supplied by the vagus
Describe the sensory supply of the pharynx
Nasopharynx - Maxilary branch of trigerminal nerve.
Oropharynx - glossopharyngeus.
Laryngopharynx - Vagus
Describe the process of degluttition (swallowing)
1) Blous pushed to back of oral cavity via mylohyoid and tounge muscles.
2) The palatoglossal and palatopharyngeal arches relax,
3) Tongue tips the bolus through oropharyng isthmus into pharynx via styloglossus.
4) Soft palate stretched and elevated via tensor veli palatini and levator veli palatini
5) Elevated soft palate and passavant’s ridge separate nasopharynx from oropharynx.
6) Pharynx elevated by pharyngeal elevators.
7) Laryngeal inlet is closed (aryepiglottic and thyroepiglottic muscles)
8) Bolus pushed towards oesophagus by pharyngeal constrictors
Describe the infant anatomy of the tongue/pharynx
Omega shaped epiglottis, tongue with central groove, fat pads for generation of intra-oral suction, close proximity of soft palate and epigottis.
