Oral cavity and submandibular gland Flashcards
What do you do if a patient has a in their mouth for more than 1 week?
Examine the mouth. Probably a cancer. Send a sample for biopsy.
What is in the oral cavity?
The roof (hard palate and soft palate)
The floor: the muscular diaphragm and the tongue,
The lateral walls: fascia and a layer of skeletal muscles
Anterior: It opens anteriorly to the oral fissure
Posteriorly to the oropharyngeal isthmus.
The parotid duct opening
The sublingual gland openings - there are folds sitting on top of the sublingual glands and that’s all we can see of it (sublingual fold). The sublngual ducts end in sublingual caruncles.
The submandibular glands - only one opening on each side at the bottom of the frenulum.
The lingual vein can be seen under the tongue on either side of the frenulum.
The lingual artery and lingual nerve is also under the tongue (risk from tongue percing).
The lingual nerve is a branch from the mandibula division of the trigeminal nerve and it receives sensory info from the anterior 2/3 of the tongue. It also carries fibres from the facial nerve, which receives taste fromthe anterior 2/3s.
At the back of theoral cavity is the soft palate with the uvula.
Also have the palatine tonsils, which is between two arches, the palatoglossal arch (anterior; formed bythe palatoglossus muscle) and the palatopharyngeal arch (posterior).
Where does the frenulum sit?
It attaches the bottom of the tongue to the base of the oral cavity
What are the parts of the tongue?
V shape of papillae at the back of the tongue called the vallate papillae.
Posterior to that you have the pharyngeal part of the tongue.
In the middle of the tongue you have the foramen cecum. This is where the thyroid develops initially.
Different papillae on the tongue.
What bony structures contribute to the oral cavity?
roof: palatine process of the maxilla and he horizontal plane of the palatine bone
Sphenoid bone contributes to the roof.
Floor: Mandable ramus and body of the mandible.
Lateral walls: buccinator muscle.
This muscle attaches posteriorly to a raphe between the mandible and the pteroygoid plate (pterygoidmandibular raphe).
Floor: mylohyoid (V3) muscles attaching at a raphe. The lateral side has no attachment
Deep to he mylohyoid is the genihyoid (C1).
Some structures get into the oral cavity through a triangle formed posterior to the mylohyoid and inferior to the superior constrictor muscles and some things enter the oral cavity through this gap.
What does the buccinatory muscle attach to posteriorly?
This muscle attaches posteriorly to a raphe between the mandible and the pteroygoid plate (pterygoidmandibular raphe).
What are the muscles of the tongue?
There are intrinsic an extrensic musclses.
Intrensic: superior longitudinal, vertical, transverse, and the inferior longitudinal
Extrinsic musclse: Palatoglossus (from palate) Styloglossus (styloid process) Hyoglossus (hyoid bone) genioglossus (mental process of mandable [superior to where geiohyoid muscle attaches]) - if you cut through the geniohyoid you will see the genioglossus.
What nerves innervate the tongue muscles?
The hypoglossal innervates al excet the palatoglossus, which is innervated by the vagus.
What are the two potential spaces of created by the hyoglossus and what runs in them?
Cranial nerves run in each of these spaces which makes the hyoglossus an essential landmark
Between the mylohyoid and the hypoglossus muscle - the hypoglossal nerve gets here by running through the runs here the triangle formed by the mylohyoid and the superior constrictor muscles.
The lingual nerve runs in the same lateral plane but is superior to the hypoglossal.
The other potential space is between the hyoglossus and the geniglossus (deep to the hypoglosus). The lingual artery runs here deep to the hypoglossal nerve. The glossopharngeal nerve also runs here.
Where does the hypoglossal nerve run?
It goes across the internal and external carotid, the occipital artery hocks around it, it goes over the lingual artery and entersthe triangle gap and enters the foramen between the hyoglussus and the mylohyoid (first potential space). It runs with the deep lingual vein to the base of the tongue.
The lingual artery branches from the extrnal carotid and runs in the second potential space with the dorsal lingual vein
Where does the glossophryngeal nerve run?
It runs between the internal and external carotid through the second potential space deep to the hyoglossus to the posterior 1/3 of the tongue.
Where is the submandbular gland?
It wraps around the mylohyoid (has deep and superficial parts)
The duct exitss at the deep part (deep to the mylohyoid).
If you want to ligate the submandibular duct where do you have to go and what do you have to avoid?
Deep to the mylohyoid muscle in the first potential space. Need to look out for hypoglossal nerve and the lingual nerve, which hooks around the duct. Also look out for the marginal mandibular branch of the facial nerve which go to the lower lip muscles (damage causes the lip to go up).
What do you have to avoid if going into the second potential space?
After going through the the structures of the the first potential space you also need to watch out for the lingual artery and the glossopharngyeal nerve
What provides the sensory and motor function to the tongue?
Sensory anterior 2/3rds: Mandibular nerve (V3) via the lingual nerve. Except to roof of the mouth which comes from V3.
Special sensory anterior 2/3rds: facial nerve via the chorda tympani
Posterior 1/3rd: glosopharyngeal nere
Motor: hypoglossal to all except 1.
Palatoglossus - vagus nerve
