Oral Cavity and Pharynx Flashcards
Where is the hard palate?
Where is the soft palate?
Formed by the palatine bones and the maxilla. Anterior 2/3 is hard and posterior 1/3 is soft and muscular
Uvula
Extends from the posterior part of the soft palate and elevates to close off the opening of the nasopharynx when swallowing (so food doesn’t get in there)
Fauces are …
Opening between the oral cavity and the oropharynx
Anterior fold: Glossopalatine arch
Posterior fold: Pharyngopalatine arch
Tongue
Accessory organ formed by muscle and covered in keratinized squamous epithelium
Manipulates and mixes ingested materials during chewing and turns food into bolus
Features of the tongue
Inferior surface attaches to the floor of the oral cavity via the lingual frenulum (thin vertical mucous membrane)
Superior surface is covered by small projections (papillae)
Posterior surface contains the lingual tonsils
Tongue innervation:
Anterior 2/3
Posterior 1/3
Lingual N. and Chorda tympani
Glossopharyngeal N.
Salivary glands
Produce saliva which assists in initial activities of digestion
3 pairs of parotid glands, submandibular glands and sublingual glands
Lymph from theroot of the tonguedrains
bilaterally into thesuperior deep cervical lymph nodes.
Lymph from themedial part of the bodydrains
bilaterally and directly to theinferior deep cervical lymph nodes.
Lymph from the right and leftlateral parts of bodydrains
to the submandibularlymph nodes on the ipsilateral side.
Theapex and frenulumdrain
All lymph from the tongue ultimately drains
to thesubmental lymph nodes, the medial portion draining bilaterally.
to the deep cervical nodes
Parotid glands
Largest of the salivary glands
Located anterior and inferior to ear, partially over the masseter muscle
Saliva secreted through the parotid duct to the oral cavity > oral vestibule next to second upper molar
Submandibular glands:
Located inferior to body of the mandible and produce most of the saliva
Saliva is secreted through a duct from each gland to the papilla in the floor of the mouth lateral to the lingual frenulum of the tongue
Sublingual glands
Located inferior to the tongue and internal to the oral cavity mucosa
Sublingual duct extends from each gland and into the inferior surface of the oral cavity behind the submandibular duct papilla
Features and functions of saiiva
99% water and slightly acidic. Contains antibodies and lysozymes which inhibit bacterial growth in oral cavity.
Dissolves food molecules to get to the taste receptors and moistens ingested food to form the bolus that is swallowed
Teeth
Responsible for ingestion and mastication
Crown is exposed, neck is constricted and roots are anchored in the jaw. Roots fit into the dental alveoli on the alveolar process of maxilla and mandible
Joint of the teeth
Gomphosis joint. Formed by the roots, dental alveoli and periodontal ligament connecting to the alveolar process
Deciduous teeth
Appear between 6 - 30 months after birth (anterior teeth first then posterior)
Eventually replaced by 32 permanent teeth
Wisdom teeth:
Final teeth to erupt in adulthood, aka 3rd molars. Jaw often lacks space to accommodate these molars so they grow at an angle or become impacted, and are unable to properly erupt
What nerve should you target if you wanna anesthetize the inferior teeth/jaw?
Inferior alveolar nerve (as in inferior alveolar block)
Inject laterally to the Pterygomandibular raphe
What nerve should you target if you wanna anesthesize the anterior/superior (maxillary) portion of the teeth?
Incisors and Canines:
Premolars?
Molars?
(Infraorbital) Superior Alveolar Nerve block (which particular nerve depends on location of the teeth)
Anterior superior alveolar N.
Middle Superior Alveolar N.
Posterior Superior Alveolar N.
Three phases of swallowing
Voluntary
Pharyngeal (involuntary)
Esophageal (involuntary)
Identify the pharyngeal muscles:
Refer to your drawings
Relationship of the buccinator M. and the superior pharyngeal constrictor?
Align with each other (Buccinator is anterior to the SC muscle and both attach to the pterygomandibular raphe)
In general, what do the constrictors do?
Push food down the throat, involuntary
Waldeyer’s lymphatic ring
Composed of the palatine, pharyngeal and lingual tonsils
Drains to the deep cervical lymph nodes
Action and innervation of the Tensor veli palatini:
Tenses soft palate and acts on the pharyngotympanic tube for depressurizing the the middle ear
CN V, V3
Action and innervation of Levator Veli palatini
Elevates the tensed plate, acts on the pharyngotympanic tube CN X (via pharyngeal n.)
*If the tensor and levator veli palatinis are paralyzed, what occurs?
Reflux of oral contents into the nasal cavity and pharyngotympanic tube dysfunction
Voluntary phase of swallowing (phase 1):
Bolus is compressed against the palate and pushed from mouth to oropharynx, mainly by movements of the tongue muscles and soft palate
Phase 2 of swallowing:
Involuntary and rapid. Soft palate is elevated, seals nasopharynx from oropharynx and laryngeopharynx. Pharynx widens and shortens to receive bolus. Suprahyoid and pharyngeal muscles contract and elevate the larynx in the process
Phase 3 of swallowing:
Involuntary: Sequential contraction of all three pharyngeal muscles forces the bolus into the esophagus
Pharyngeal plexus:
Provides sensory innervation of the oropharynx and laryngeopharynx from CN IX and X respectively.
Nasopharynx is innervated by CN v2
Main motor control of the pharyngeal muscles is ….
CN X (except for stylopharyngeus, which is innervated by the glossopharyngeal n.). So upper gag reflex (cough reflex) is via IX while lower (gag reflex) is CN X.
Upper Deciduous teeth eruption times: Upper medial incisor Upper lateral incisor Upper canine Upper 1st molar Upper 2nd molar
- 7-9 months
- 9-11 months
- 18-20 months
- 14-16 months
- 24-30 months
Lower Deciduous teeth eruption times: Lower medial incisor Lower lateral incisor Lower canine Lower 1st molar Lower 2nd molar
- 6-8 months
- 7-9 months
- 16-18 months
- 12-14 months
- 20 - 22 months
Upper Permanent teeth eruption times: Upper medial incisor Upper lateral incisor Canine 1st premolar 2nd premolar 1st molar 2nd molar 3rd molar
- 7-8 years
- 8-9 years
- 11-12 years
- 10-11 years
- 10-12 years
- 6-7 years
- 12-13 years
- 17-25 years
Lower Permanent teeth eruption times: Lower Medial Incisor Lower Lateral Incisor Lower Canine Lower 1st premolar Lower 2nd premolar Lower 1st molar Lower 2nd molar Lower 3rd molar
6-7 years 7-8 years 9-10 years 10-12 years 11-12 years 6-7 years 11-13 years 17-25 years
