Subject: Oral Biology Chapter: Oral Topic: Subdivisions of ; Non-Keratinized Areas Teacher: Dr. Munawar Aziz Khattak LECTURE VII

2 Learning Objective

• At the end of this lecture, the students will be able to know about the;  Oral Mucous Membrane  Subdivisions of Oral Mucosa  Non-keratinized Areas

3 NON-KERATINIZED AREAS LINING MUCOSA

• , , Vestibular fornix, Alveolar mucosa, Floor of the , Ventral surface of the , Soft • A relatively thick nonkeratinized • A thin • Variation ----- Structure of  Loosely textured and of considerable volume – reflecting mucosa  Fixed to the epimysium or fascia and is highly elastic – lining mucosa  The mucosa of the is intermediate between the two Lining Mucosa Cont’d… LIP AND CHEEK Lining Mucosa Cont’d… Lining Mucosa Cont’d… Lining Mucosa Cont’d…

• Epithelium is stratified squamous nonkeratinized epithelium • Lamina propria consists of dense connective and has short, irregular papillae • Submucosa connects the lamina propria to the thin fascia of the muscles  Consists of strands of densely grouped fibers  Limit the mobility of the mucous membrane  Holding mucous membrane to the musculature  Preventing elevation of mucous membrane into folds Lining Mucosa Cont’d…

 Loose containing fat and small mixed glands is present between these strands  The mixed minor salivary glands of the  In the cheek the glands are larger and are  Usually found between the bundles of the buccinator muscle and sometimes on its outer surface  Fordyce spots VESTIBULAR FORNIX AND ALVEOLAR MUCOSA Lining Mucosa Cont’d… • In the fornix the mucosa is loosely connected to the underlying structures • The alveolar mucosa is thin and loosely attached to the periosteum  Continuous with the gingiva • The epithelium is thin and nonkeratinized  The epithelial ridges and papillae are low and often entirely missing • The median and lateral labial frenula • A well-defined submucous layer of  Contain small mixed glands INFERIOR SURFACE OF TONGUE AND FLOOR OF ORAL CAVITY Lining Mucosa Cont’d…

• The mucous membrane of the inferior surface of the tongue is smooth and relatively thin • The epithelium is nonkeratinized • The papillae of the connective tissue are numerous but short • The submucosa cannot be identified as a separate layer  It binds the mucous membrane tightly to the connective tissue surrounding the bundles of the muscles of the tongue Lining Mucosa Cont’d… Lining Mucosa Cont’d…

• The mucous membrane on the floor of the oral cavity is thin and loosely attached to the underlying structures • The epithelium is nonkeratinized • The papillae of the lamina propria are short • The submucosa contains  The sublingual glands lie close to the covering mucosa in the sublingual fold • The sublingual mucosa and the lingual gingiva have a junction • The sublingual mucosa continues as the ventrolingual mucosa SOFT PALATE Lining Mucosa Cont’d…

• Highly vascularized • Reddish in color • The stratified squamous epithelium is nonkeratinized • The lamina propria shows a distinct layer of elastic fibers separating it from the submucosa  The papillae of the connective tissue are few and short • The submucosa is relatively loose  contains an almost continuous layer of mucous glands  Also contains taste buds For Questions & Queries: [email protected]

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