Oral Cavity Flashcards
The soft palate is primarily composed of what?
Skeletal muscle
What do the soft palate and uvula do when swallowing?
Elevate to close off the opening of the nasopharynx
What do fauces of the palate represent?
The opening between the oral cavity and the oropharynx
What are fauces bounded by?
Paired muscular folds including the glossopalatine arch (anterior fold) and pharyngopalatine arch (posterior gold)
Where are the palatine tonsils located?
Between the glossopalatine and pharyngopalatine arches
What is Waldeyer’s lymphatic ring composed of?
Palatine, pharyngeal and lingual tonsils
Drains to deep cervical LNs
The tongue is an accessory digestive organ that is formed from what?
Skeletal muscle (which moves it) and covered with lightly keratinized stratified squamous epithelium
What are the functions of the tongue?
Manipulates and mixes ingested materials during chewing
Helps compress the partially digested materials against the palate to turn these materials into a bolus
Performs important functions in swallowing
What attaches the inferior surface of the tongue to the floor of the oral cavity?
The lingual frenulum
What covers the superior (dorsal) surface of the tongue?
Numerous small projections known as papillae
What does the posterior surface of the tongue contain?
Lingual tonsils
When is saliva produced?
Most is produced during mealtime
Smaller amounts are produced continuously to ensure the oral cavity remains moist
What makes up 99% of saliva?
Water
What are the three pairs of large multicellular salivary glands?
Parotid, submandibular and sublingual
What stimulates parotid salivary gland secretion?
Parasympathetic axons in CN IX
What stimulates submandibular and sublingual salivary gland secretions?
Parasympathetic axons in CN VII
Describe the parotid gland
Largest salivary gland
Located anterior and inferior to the ear partially overlying the masseter muscle
Produces about 25-30% of the saliva
Describe saliva secretion from the parotid gland
Saliva production is conducted through the parotid duct to the oral cavity
Parotid duct opens into the oral vestibule next to the 2nd upper molar
Which gland produces most of the saliva in our bodies?
Submandibular glands
A duct opens from each submandibular gland through what?
A papilla in the floor of the mouth on the lateral sides of the lingual frenulum
Each sublingual gland extends multiple tiny sublingual ducts that open onto what?
The inferior surface of the oral cavity, posterior to the submandibular duct papilla
What are the functions of saliva?
Moistens ingested food and helps turn it into a semisolid bolus that is more easily swallowed
Moistens and cleanse oral cavity structures
Functions as a watery medium into which food molecules are dissolved so taste receptors can be stimulated
What is the first step in chemical digestion?
Occurs when amylase in saliva begins to breakdown carbs
What does saliva contain?
Abs and an antibacterial element called lysozyme that helps inhibit bacterial growth in the oral cavity
What are teeth responsible for?
Ingestion and mastication, the first part of the mechanical digestion process
A tooth has which structures?
An exposed crown, a constricted neck and one or more roots that anchor it to the jaw
Roots of the teeth fit tightly into what?
Dental alveoli which are sockets within the alveolar processes of both the maxillae and mandible
Collectively, the roots, dental alveoli, and periodontal ligaments that bind the roots of teeth to the alveolar processes form what type of joint?
Gomphosis joint
How many sets of teeth develop and erupt during a normal lifetime?
Two sets
Explain the formation of teeth at different ages
In an infant 20 deciduous teeth (milk teeth) erupt b/w 6 months and 30 months after birth
These teeth are eventually lost and replaced by 32 permanent teeth
More anteriorly placed permanent teeth tend to appear first followed by the posteriorly placed teeth
What are the last teeth to erupt?
Third molars (often called wisdom teeth) in the late teens or early 20s Often the jaw lacks space to accommodate these final molars and may either emerge only partially or grow at an angle and become impacted
