Oral cavity Flashcards
What are the boundaries of the oral cavity?
- Roof: Palate
- Floor: Mandible and mylohyoid
- Lateral walls (3 layers):
1. Skin
2. Muscle (buccinator)
3. Oral mucosa - Posterior:
1. Palatoglossus
2. Palatophayngeus
What is significant about the 2 muscles of the posterior oral cavity?
- Palatoglossus (anterior) and palatopharyngeus (posterior) make up the palatoglossal and palatopharyngeal arches.
- Bilateral arches make up the anterior and posterior tonsillar pillars.
- Between the arches is the tonsillar fossae in which lie the palatine tonsils.
What are the components of the palate?
- Bony hard palate (anterior)
- Muscular soft palate (posterior)
What are the muscles of the soft palate?
- Tensor veli palatini
- Levator veli palatini
- Palatopharyngeus
- Palatoglossus
- Musculus uvulae
What are the bones of the hard palate?
- Palatine process of maxilla
- Horizontal plate of palatine bone
What is the structure of the tongue?
- The tongue is divided into 2 parts, anterior 2/3 (oral part) and posterior 1/3 (pharyngeal part), by sulcus terminalis.
- The oral part is covered by filiform (most common) or fungiform papillae.
- Anterior to the sulcus terminlais is a row of circumvallate papillae.
- Pharyngeal is nodular as a result of the underlying lingual tonsils.
What are the muscles of the tongue?
- Intrinsic (changes shape of tongue):
1. Longitudinal (superior/inferior)
2. Transverse
3. Vertical - Extrinsic (moves position of tongue):
1. Genioglossus
2. Hyoglossus
3. Styloglossus
4. Palatoglossus
What is the nerve supply to the muscles of the tongue?
All muscles of the tongue are supplied by the hypoglossal nerve [XII] except palatoglossus which is supplied by the vagus nerve [X] via the pharyngeal plexus.
What is the sensory supply to the tongue?
- Somatic sensation to the anterior 2/3 of the tongue is supplied by the lingual nerve (branch of mandibular division of trigeminal) while taste is supplied by the chorda tympani (facial nerve [VII]).
- Somatic sensation and taste to the posterior 1/3 of the tongue is supplied by the glossopharyngeal nerve [IX].
- Small part of tongue above epiglottis is supplied by the internal laryngeal branch of the vagus nerve [X].
What are the salivary glands?
What is the structue of the temporomandibular joint (TMJ)?
- Articulation between the head of the mandible and the articular tuberce/mandibular fossa of the temporal bone.
- Atypical synovial joint divided into superior and inferior parts by fibrocartilage articular disc.
What are the functions of the 2 parts of the joint?
- Upper part: Allows gliding of the head of mandible out of mandibular fossa onto articular tubercle during protrusion/retraction.
- Lower part: Allows hinge-like movement of the mandible in the mandibular fossa during elevation/depression.
What are the ligaments associated with the TMJ?
- Temporomandibular (lateral) ligament: Runs from margin of articular tubercle to neck of mandible.
- Sphenomandibular ligament: Runs from the spine of the sphenoid to the medial side of the mandibular ramus.
- Stylomandibular ligament: Runs from styloid process to angle of the mandible.
What are the movements associated with the mandible?
- Elevation:
Masseter
Temporalis
Medial pterygoid
- Depression:
Protrusion: Lateral pterygoids
Depression: Gravity, digastric, infrahyoids
- Protrusion: Medial/lateral pterygoids
- Retraction: Temporalis
-
Grinding (alternate protrusion/retraction of each side):
1. Medial/lateral pterygoids
2. Temporalis
What are the muscles of mastication?
- Masseter
- Temporalis
- Medial pterygoids
- Lateral pterygoids
What movements are involved in mastication?
- Grinding: Medial/lateral pterygoids
- Elevation: Masseter, temporalis
What is the structure of the mandible?
- Condylar process (head, neck)
- Coronoid process
- Mandibular notch
- Ramus
- Angle
- Body
What are the features of the external surface of the mandible?
- Oblique line
- Mental foramen
What are the features of the internal surface of the mandible?
- Lingula
- Mandibular foramen
- Sublingual fossa
- Submandibular fossa
- Mylohyoid groove
- Mylohyoid line
What is the structure of the pterygomandibular raphe?
- Runs between:
1. Medial pterygoid plate (sphenoid)
2. Mandible (posterior to mylohyoid ridge) - Connects:
1. Buccinator (anterior)
2. Superior pharyngeal constrictor (posterior)
What separates the superficial lobe of the submandibular gland from the parotid glands?
Stylomandibular ligament
Which vessel is closely associated with the submandibular gland?
Facial artery (grooved by it)
What are the contents of the parotid gland?
- Secretory tissue
- Facial nerve
- External carotid artery
- Retromandibular vein
- Lymph nodes
- Auriculotemporal nerve
