310 likes | 1.2k Views
Oral Mucosa. Dr Jamal Naim PhD in Orthodontics. Cont. 3. Taste buds. Taste buds are specialized structures that contain the taste cells, the detectors of tastants. They are located in: All tongue papillae except the filiform ones Soft palate Posterior surface of the epiglottis
E N D
Oral Mucosa Dr Jamal Naim PhD in Orthodontics Cont. 3
Taste buds • Taste buds are specialized structures that contain the taste cells, the detectors of tastants. • They are located in: • All tongue papillae except the filiform ones • Soft palate • Posterior surface of the epiglottis • They are onion-shaped structures, each one containing 50–100 cells.
Taste buds • There are at least four qualities in human taste perception: saltiness, sourness, sweetness, and bitterness. • All qualities can be elicited from all the regions of the tongue that contain taste buds.
bitter sour salt sweet
Taste buds • The bud rests in the basal lamina • Tastants dissolved in saliva contact the taste cells through the pore, interacting with taste receptors (sweet and bitter tastes) or ion channels (salty and sour tastes) on the surface of the cells. The result is a depolarization of the taste cells, leading to the release of neurotransmitters that will, in turn, stimulate afferent nerve fibers connected to the taste cells.
Macroanatomy of the hard palate • The palate is characterized by the presence of: • Palatine rugae • Median palatine raphe • Palatine gingiva • Anterio-lateral fatty zone • Posterio-lateral glandular zone
Hard Palate Macro-anatomy palatine rugae incisive papilla antero-lateral (fatty) zone median palatine raphe posterio-lateral (glandular) zone palatine gingiva soft palate uvula
Mucosa of the hard palate • It is keratinized masticatory mucosa. • It is pink in color which is firmly attached to the underlying structures. • In the region of the median palatine raphe there is no lamina propria (mucoperiosteum)
Mucosa of the soft palate • The epithelium is continuous with that of the hard palate but non-KE, so between them there is a healthy line. • It is highly vascularized and red in color. • Lamina propria is thin with few and short papillae. • The epithelium at the nasal side is pseudostratified columnar ciliated epithelium with goblet cells.
Mucosa of the soft palate • A continuous layer of elastic fibers separating lamina propria from submucosa. • The submucosa contains fat cells and mucous glands. Nasal side Oral side
Mucosa of the cheek • The epithelium is non-keratinized stratified squamous epithelium. • C. T. papillae are short, irregular with few elastic fibers. • In submucosa and between the buccinator muscle bundles small mixed salivary gland are present. • Sometimes isolated sebaceous glands may present in the C.T. lateral to the mouth corner (Fordyce granules or spots)
Mucosa of the cheek • The firm attachment of the cheek mucosa to the muscles prevents its biting especially during mastication. • The submucosa contains fat cells and mucous glands.
Lip epithelium • Formed of three surfaces: • lining mucosa • transitional zone (vermilion) • skin side. • The junction between the skin • and the oral mucosa at the • transitional zone is called • mucocutaneous junction skin side
Lining Mucosa of the lip • Similar to that of cheek except: • The submucosa contains fat cells and mixed salivary gland on the surface of orbecularis oris muscle. • No Fordyce spots. Lip Lining Mucosa
Transitional zone • Lying between lining mucosa and skin side of lip. • Present only in human race and represented as red zone called vermilion zone. • The line separating it from the skin side is the vermilion border • It is covered by stratified squamous epithelium with thin layer of keratin.
Transitional zone • C.T. papillae are numerous, long and densely arranged, these deep papillae carry large capillary loops, so the thin layer of epithelium permits the red color of blood. • few sebaceous glands may be present at the angle of the mouth. • Because of the lack on salivary glands this zone tends to dry out in cold weather.
Transitional zone • Between the vermilion zone and the nonkeratinized labial mucosa is an intermediate zone covered by parakeratinized oral epithelium. • In infants this region is thick and more opalescent, which represents an adaptation to suckling, called the suckling pad.
Transitional zone Transitional zone Lip
Skin side • Consists of two layers: • Epidermis: formed of stratified squamous keratinized epithelium with hair, sweat and sebaceous glands. • The epithelium is similar to that of the keratinized mucosa except that; there is additional layer present between granular cell layer and the keratinized layer called stratum lucidum. • Melanoblasts present in between the basal cell layer • Dermis formed of dense C. T. with few and short papillae
Skin side Skin side Lip