L29 – The Oral Cavity, Submandibular, Sublingual Glands Flashcards
3 bones that form the oral cavity?
- Palatine bone
- Maxilla
- Mandible
Define the roof, floor and side walls of the oral cavity?
Roof = hard palate (soft palate is in pharynx, not in oral cavity)
Floor = mylohyoid muscle (thin, inserts to hyoid bone)
Side walls = buccinator muscle (wraps around mouth)
Precise origin and attachment of Buccinator muscle?
Origin:
- Maxilla (parallel to alveolar cavitis)
- Pterygomaxillary ligament»_space; extend from maxillary tuberosity to hamulus»_space; form Pterygomandibular raphe
Insertion:
1. Pterygomandibular raphe ends at Buccinator Crest»_space; Continue to external oblique line of mandible, up to first lower molar
Anterior and posterior opening of the oral cavity?
Anterior: • Opens into oral fissure
Posterior: • Opens into oropharynx
What separates oral cavity from the oropharynx?
Fauces:
- Anterior pillar of the fauces = palatoglossal arch
- Posterior pillar = palatopharyngeal arch
2 pillars surround the palatine tonsils
Define the 2 spaces of the oral cavity?
• Oral cavity proper: space medial or posterior to teeth
• Vestibule: space between teeth/gum and cheek
Contains Opening of parotid duct (salivary gland) opposite second upper molar
Describe the sensory nerve supply of the oral cavity? Floor, cheek, upper and lower teeth, gum?
All by trigeminal nerve:
V2 (maxillary), V3 (mandibular):
- Roof: Anterior palatine [V2], nasopalatine nerves [V2]
- Floor: lingual nerve [V3]
- Cheek: buccal nerve [V3]
- Upper Teeth = Ant-, Middle-, Post- Superior alveolar nerve [V2]
- Lower teeth = Inferior alveolar nerve [V3]
- Upper gum = Nasopalatine and Anterior palatine nerve [V2]
- Lower gum = Lingual, Buccal, Inf. Alvoelar nerve [V3]
Define the bony components of the hard palate?
Anterior = maxilla (palatal processes)
Posterior = palatine bone: horizontal plates
Anterior and posterior parts divided by Palatomaxillary fissure
Premaxilla: cleft palate rarely separates the 2 halves of premaxilla
List the foramina in the oral cavity?
Incisive foramen in the Premaxilla
Greater and Lesser palatine foramen in the palatine region (posterior)
List the structures that go through the foramina in the oral cavity?
Incisive foramen = Nasopalatine nerve [V2] + sphenopalatine artery
Greater palatine foramen:
- For greater palatine artery and anterior palatine nerve
Several lesser palatine foramina:
- Perforate palatine bone itself
- For middle, posterior palatine nerves
Name the arterial supply of the hard palate.
Greater palatine artery= branch of the descending palatine artery (a terminal branch of the maxillary artery)
Tract of greater palatine artery?
maxillary artery
> accompanies greater palatine nerve
> down greater palatine canal
> emerges from greater palatine foramen
> passes around palate
> enters incisive foramen
> passes up into the nose
Name of arterial supply to soft palate?
Lesser palatine artery
Nerve supply of the hard palate?
- anterior palatine nerve (from pterygopalatine ganglion), From greater palatine foramen up to incisive foramen
- nasopalatine nerve (from pterygopalatine ganglion), crosses nasal roof, descend on nasal septum, through incisive foramen, supplies hard palate anterior to incisive foramen
What forms the soft palate?
An aponeurosis of tensor veli palatini
acted upon by 5 pairs of muscles
List the muscles that act on the soft palate?
- Tensor veli palatini
- Levator veli palatini
- Palatopharyngeus muscle
- Palatoglossus muscle
- Musculus uvulae
Origin and attachment of the tensor veli palatini?
Origin = outside the pharynx: basicranium and lateral cartilaginous part of eustachian tube
Insertion = Fibers converge to base of pterygoid hamulus, turns flat and hooks around the hamulus to get inside pharynx»_space; turns into aponeurosis (soft palate)
Action of tensor veli palatini? Nerve supply?
- tenses up the aponeurosis so that other muscles can act on it
- pulls open the cartilaginous part of Eustachian tube
- mandibular nerve (CNV3), via nerve to medial pterygoid
Origin and attachment of Levator veli palatini?
Origin = Inside pharyngobasilar fascia (medial cartilaginous part of eustachian tube + quadrate area on petrous part of temporal bone)
> > form V-shape sling
Insertion = nasal surface of the palatine aponeurosis
Action of levator veli palatini? Nerve supply?
pull soft palate backwards and upwards, shutting nasopharynx from oropharynx (i.e. swallowing)
pharyngeal plexus (CNX)
Origin and attachment of palatopharyngeus muscle?
Origin: arises by 2 heads from the horizontal plate of palatine bone + back of palatine aponeurosis
Arches over the lateral margin of palatine aponeurosis, forms posterior pillar of fauces (PALATOPHARYNGEAL ARCH)
Insert: posterior border of thyroid cartilage and cornua
Action and attachment of palatopharyngeus muscle? Nerve supply?
Actions: • elevates larynx and pharynx • depresses soft palate
Nerve supply: pharyngeal plexus (CNX)
Origin and insertion of palatoglossus muscle?
Origin = undersurface of palatine aponeurosis
Insertion: Interdigitate with styloglossus »_space; forms anterior pillar of fauces (Palatoglossal arch)
Action and nerve supply of palatoglossus muscle?
Actions:
• sphincteric at oropharyngeal isthmus
• raises tongue
Nerve supply: pharyngeal plexus (CNX)
Origin and insertion of musculus uvulae?
Origin = Posterior nasal spine + palatine aponeurosis
Insertion = Mucous membrane of uvula
Action and nerve supply of musculus uvulae?
Actions:
• shape the uvula
• draws up the uvula ipsilateral side
Nerve supply: pharyngeal plexus (CNX)
Proportions of tongue in the oral cavity and oropharynx?
- anterior 2/3: in oral cavity
* posterior 1/3: in oropharynx
How are tongue papillae formed? List the papillae in the anterior and posterior tongue?
Mucous membrane projections
Anterior 2/3:
Filliform
Fungiform
Foliate
Boundary between anterior and posterior = Vallate papillae (V-shape) + Sulcus terminalis
Posterior 1/3:
No papilla
What structures divide the anterior and posterior tongue?
Sulcus terminalis
Vallate papillae
no papilla posterior to the vallate papillae
Explain the nodular appearance of posterior tongue?
Rough due to:
Mucous, serous glands
Aggregation of lymphatic tissue (lingual tonsil = part of Waldeyer’s ring)
Compare the functions of the anterior and posterior tongue?
Anterior = Prehensile (can grasp), for mastication (e.g. dig out food from vestibule)
Posterior = Smooth for swallowing, not mastication
Location and embryonic origin of the foramen caecum?
- behind the apex of vallate papillae
* remnant of thyroglossal duct
Glands exist in both the anterior and posterior portions of the tongue. T or F?
False
No glands on the dorsum in the anterior portion, only in posterior
Compare the shape and function of the tongue papillae?
- filiform (conical), furry appearance, NO taste buds, somatosensory
- fungiform (mushroomshaped), visible as red dots, contains taste buds
- foliate, on posterolateral border of the tongue, bear serous glands and taste buds
- vallate, 8-12 in number, anterior to foramen cecum and sulcus terminalis, contains taste buds
Innervation of the vallate papillae?
Glassopharyngeal nerve (even though it exists in the anterior portion of tongue)
Divide the tongue muscles into groups.
4 intrinsic:
- Superior longitudinal fibers
- Inferior longitudinal f.
- Transverse f.
- Vertical f.
4 extrinsic:
- Genioglossus
- Hyoglossus
- Styloglossus
- Palatoglossus
Describe the organization of intrinsic tongue muscles?
Wholly within the tongue
Not attached to bones
Fibres in 3 planes perpendicular to each other
Describe the location of inferior longitudinal fibers in relation to extrinsic muscles of tongue?
alongside genioglossus, medial to hyoglossus
Describe the location of transverse fibers in the tongue?
originate from midline fibrous septum, inserts onto the sides
Describe the location of the vertical fibers in the tongue?
originate from mucous membrane of dorsum, insert onto the sides of lower part
Nerve supply of 4 extrinsic muscles of the tongue?
All supplied by hypoglossal (XII),
except palatoglossus (by pharyngeal plexus [CN X]; forms anterior pillar of fauces)
Extrinsic tongue muscles and their direction of attachment in the oral cavity?
- front: to mandible (genioglossus)
- down: to hyoid bone (hyoglossus)
- back: to styloid process of temporal bone (styloglossus)
- up: to soft palate (anterior pillar of fauces) (palatoglossus)
Origin, insertion and nerve supply of Genioglossus muscle?
Origin: • superior genial tubercle
Fibres radiate widely
Insertion: • the mucous membrane of dorsum of the tongue, lowest fibres go to hyoid (not to confuse with the geniohyoid muscle)
Nerve supply: • CNXII
Origin, insertion and nerve supply of Hyoglossus muscle?
Origin:
• body and the length of greater horn of hyoid
Extends as a quadrilateral sheet on the side of the tongue
Insertion:
• Interdigitate with styloglossus, and attaches to side of tongue
Nerve supply: • CNXII
Origin, insertion and nerve supply of palatoglossus muscle?
• from surface of palatal aponeurosis to side of tongue»_space; anterior pillar of fauces
CN X, pharyngeal plexus
Origin, insertion and nerve supply of styloglossus muscle?
- from styloid process to side of tongue
* CNXII
Compare the overall action of the intrinsic and extrinsic muscles of the tongue?
Shape = altered by intrinsic muscles
Position = altered by extrinsic muscles
Action of genioglossus, styloglossus and hyoglossus muscles on the tongue?
- Genioglossus = protrude tongue
- Styloglossus = Retract
Hyoglossus = Draw sides downwards
Intrinsic muscles involved in narrowing and convex the dorsum of tongue?
Transverse fibers
Intrinsic muscles involved in flattening and elongating the dorsum of tongue?
transverse + vertical fibers
Intrinsic and extrinsic muscles involved in protruding the dorsum of tongue?
transverse + vertical + genioglossus (lowest fibres)
Direction of tongue deviation is the hypoglossal nerve is damaged? Deviation of uvula if the vagus nerve is damaged?
Hypoglossal nerve palsy: tongue deviates to weaker/ injured side: injured side muscle weakness cannot oppose normal side
Uvula deviation to contralateral side: i.e. right vagus cut = only left side is contracted/ shortened
What is the frenulum of tongue? Location, attachment?
Mucous membrane fold extending from the floor of the mouth to the midline of the inferior aspect of the tongue
Describe the sequence of muscle contraction in swallowing?
1) Food is masticated in oral cavity
2) Conscious decision is made to swallow: Tongue pulled up, back = pushes food bolus into back of oral cavity
3) Swallowing reflex takes over:
- Bolus of food enters pharynx, receptors in pharynx trigger reflex
- raise soft palate to temporarily close off nasopharynx from oropharynx
- pharyngeal muscles constrict in sequence
- push bolus into esophagus
- esophageal muscles drive bolus down by peristalsis
Arterial supply of tongue?
Lingual artery
- a branch from the anterior surface of external carotid artery
- passes deep to hyoglossus towards the tip
Venous drainage of tongue?
- ranine veins: on undersurface of tongue, to common facial vein»_space; Internal jugular vein
- lingual vein: to internal jugular vein
Summarize all the nerve supplies to the anterior and posterior tongue?
1) Anterior 2/3:
Sensation: lingual nerve (V3)
Taste + secretomotor: chorda tympani via lingual nerve (CN VII)
2) Posterior 1/3: sensation + taste + secretomotor: glossopharyngeal nerve (IX)
Motor: all intrinsic, extrinsic by hypoglossal nerve (except palatoglossus)
Origin, insertion and innervation of mylohyoid muscle at floor of mouth?
- Origin: mylohyoid line (mandible)
- Insertion: midline raphe, hyoid bone (posterior fibres)
- Innervation: CNV3
2 muscles that form the floor of mouth?
Geniohyoid + Mylohyoid
Origin, insertion and innervation of geniohyoid muscle at floor of mouth?
- Origin: inferior genial tubercle
- Insertion: upper border of hyoid bone
- Lies above mylohyoid, below genioglossus
- Innervation: C1 via CNXII
Location of hyoid bone?
Slung between mandible and styloid process by geniohyoid and stylohyoid
Position determined by tonic contraction of diff. muscles
List muscles that elevate and depress hyoid?
Elevate hyoid:
• geniohyoid, stylohyoid, mylohyoid
Depress hyoid:
• thyrohyoid, omohyoid, sternohyoid, (sternothyroid)
List 4 structures Lateral/ superficial to hyoglossus?
LHSS LGS
Lingual nerve (V3)
Hypoglossal nerve (CN12)
Submandibular duct
Stylohyoid muscle
List 3 structures deep to hyoglossus?
LHSS LGS
Lingual artery*
Glossopharyngeal nerve (CN9)
Stylohyoid ligament
Location of superficial part of submandibular gland?
- lies in submandibular fossa
- superficial to (below) mylohyoid, covered by deep cervical fascia
- curves around posterior border of mylohyoid
Location of deep part of submandibular gland?
- lies in floor of mouth
* between mandible and side of the tongue
Tract of submandibular duct?
- leaves the gland at anterior end of deep part
- runs between sublingual gland and genioglossus
- opens at sublingual papilla: at sublingual caruncles on either side of frenulum of tongue
3 structures that crosses the submandibular gland?
- facial artery: grooves the gland, before turning around inferior border of mandible
- common facial vein: grooves the gland
- mandibular branch of facial nerve: crosses the gland
Location of sublingual gland?
- lies in front of anterior border of hyoglossus, between mylohyoid and genioglossus
- lies below the termination/opening of submandibular duct
Drainage of sublingual gland?
about 15 ducts, half open into submandular duct,
half open directly on sublingual fold and papilla
List the permanent teeth number and types?
Permanent teeth: total 32 • central and lateral incisors • canine • 2 premolars • 3 molars
Nerve supply of teeth? (Upper and lower)
Upper: • maxillary nerve CNV2
Lower: • mandibular nerve CNV3
Submandibular gland nerve supply?
secretomotor fibres from chorda tympani
Synapse at submandibular ganglion
Along maxillary artery, then lingual artery
(Sympathetic fibers hitchhike across lingual artery)
Nerve supply of sublingual gland?
same as submandibular gland (secretomotor fibres from chorda tympani synapse at submandibular ganglion)
