Oral Mucosa III Flashcards
What is the Palate divided into?
- Hard Palate
2. Soft Palate
What are the characteristics of the Hard Palate?
- Masticatory mucosa
- Keratinised epithelium (sometime Parakeratinised)
- Central region = NO SUBMUCOSA - the dense Lamina Propria binds directly to the underlying bone
- Where Palate joins the alveolus, a submucosa is present and contains the main NEUROVASCULAR BUNDLE
- Minor salivary glands posteriorly (lateral sides)
- Adipose tissue anteriorly
What changes in tissue composition occur at the nasal surface of the hard palate?
- Lined by a respiratory mucosa
- Respiratory mucosa consists of ciliated columnar epithelial cells + lots of goblet cells
- Beneath this there is a vascular submucosa containing minor salivary glands (mucous & serous)
What are the characteristics of the Soft Palate?
- Non-keratinised lining mucosa
- CT papillae are short and broad
Lamina Propria contains lots of elastic fibres and thin collagen fibre bundles
- Broad submucosa with lots of salivary glands
- Submucosa bound to underlying palatal muscles
What is it like at the junction between the hard and soft palate?
- An abrupt shift in the epithelium
What are the characteristics of the Floor of the Mouth?
- Lining mucosa
- Little wear and tear but requires considerable mobility
- Thin, non-keratinised epithelium with short papillae
- Extensive submucosa at the floor of the mouth with a highly vascular lamina propria = ideal for drug delivery
What are the characteristics of the Tongue?
- Ventral surface covered in Lining mucosa
- Anterior 2/3 are divided from the posterior 1/3 by the SULCUS TERMINALIS
- Anterior 2/3 of the tongue are covered with PAPILLAE
- Posterior 1/3 has lots of lymphatic nodules
What are the 4 main types of papillae covering the DORSAL surface of the tongue?
- Filiform Papillae (most abundant)
- Fungiform Papillae (appears likes mushroom-oid papillae between Filiform)
- Folite Papillae
- Circumvallate Papilla
What’s Filiform Papillae?
- Largely covers the anterior 2/3 of the dorsum of the tongue
- Keratinised (Ortho or Para)
- Forms hair-like tufts - areas between the tufts tend to be non-keratinised
- Central core of Lamin Propria with secondary papillae branching from it
- Mechanical function as they are HIGHLY ABRASIVE during mastication
What’s Fungiform Papillae?
- Found as isolated, elevated mushroom-shaped papillae scattered between Filiform Papillae
- Covered in thin epithelium. Keratinised OR non-keratinised
- Vascular core of Lamina Propria
- Taste buds found on the surface
What’s Foliate Papillae?
- Present as 1 or 2 longitudinal clefts at the side of the posterior part of the tongue
- Non-keratinised epithelium
- Taste buds may be found within their epithelium
What’s Circumvallate Papillae?
- Large and rounded
- Surrounded by trench-like feature but don’t project beyond the surface of the tongue
- Non-keratinised epithelium
- Taste buds on the internal wall of the trenches
- At the bottom of the trenches, small serous minor salivary glands empty
Taste Buds: What are they?
- Specialised chemoreceptive organs responsible for taste
- Located within the epithelium particularly around the walls of Circumvallate papillae
- Also present on upper surface of Fungiform pap
- Lateral walls of foliate pap
- In the mucosa of the soft palate and in the epiglottis
- A small pore opens from the surface into the bud
What are the 2 main types of cells?
- Taste cells
2. Supporting cells
What are the taste buds 4 distinct cell types?
- Type 1 = cells appear dark
- Type 2 = cells appear light
- Type 3 = cells appear light
- Type 4 = undifferentiated, lay basally and possess intermediate filaments
- Type I and III form synapses with the intrageminal nerves
- The taste bud is separated from the underlying CT by a basal lamina
