3.0 ORAL CAVITY: INTRODUCTION
The areas in the oral cavity can be divided in the following regions:
3.2 - images: Oral orifice, Lip/Palate
The oral orifice is covered by a mucosa and comprising the lips, cheeks, hard and soft palate, and uvula. The outer zone of the lip has a skin-like structure with keratinized epithelium, hairs, sebaceous glands and eccrine sweat gland ducts all covering the lamina propria and the circular skeletal muscle fibers (musculus 0rbicularis) .
In the transitional zone (vermilion, pinkish-red appaearance) the squamous epithelium is only slightly keratinized, transparant and devoid of pigment.
The lamina propria is strongly folded into papillae and well vascularized (red transparancy). The inner zone of the lip, the cheeks and the soft palate are not-keratinized and contain both salivary glands (buccal glands).
Towards the nasal surface the epithelium turns into ciliated columnar epithelium.
See: Lip: POJA-L94+10 and POJA-L94+102+103+104
3.3 - images: Tongue , a mobile three-dimensional muscular organ (skeletal) covered with specialized mucosa with circumvallate papillae, filiform papillae, fungiform papillae and taste buds for acid, sweet, bitter and salty. The ventral surface of the tongue is covered by thin non-keratinizing stratified squamous epithelium identical to the floor of the mouth. The dorsal site, however, is lined by a thick keratinizing stratified epithelium. The circumvallate papillae with numerous taste buds in the epithelium detect bitter taste, the fungiform types detect sweet taste or salty taste. The filliform papillae (most numerous) are devoid of taste buds. Taste buds consist of spindle like receptor cells arranged as onion and are associated with afferent nerve endings. At the surface site they have an opening called taste pore.
See: POJA-L87A+97A+37+38+36 and POJA-L23+26+72+87A+87B.
See: POJA-L87B; POJA-L87BC; POJA-L97A.
3.4 - images: Salivary glands Parotis (serous); submandibularis (seromucous); sublingualis (muco-serous).
Salivary glands inside and outside the mouth contain mucus-secreting cells, serous cells and both. Generally, secretory acini empty into intercalated ducts (cuboidal epithelium) and continue into intralobular ducts (tall columnar epithelium) or striated ducts that are involved in concentrating and modifying the passing salivary. Intralobular ducts fuse into (non-striated) interlobular ducts and subsequently into major ducts. Myoepithelial cells around the acini and ductular cells are involved in squeezing out the salivary.
There are several smaller groups of salivary gland tissue located in and below the tongue (lingual and sublingual glands), in the lips (labial glands), in the soft and hard palatine, nearby the tonsils and in in the submucosa of the cheeks.
3.5 - images: Dental tissue: Development
3.6 - images: Dental tissues: Adult
Structure and development. Teeth develop from both ectoderm and mesoderm in the oral cavity. The enamel originates from the unkeratinizing oral squamous epithelium, initially as a tooth bud that develops from a cap stage to a early and late bell stage. Apposed to the epithelial tooth bud condensed mesenchym develops into the dental papilla within the concavity of the enamel organ. The cells of the epithelial tooth bud further differentiate into external and internal enamel epithelium. The internal enamel epithelium differentiates into columnar ameloblasts. A row of odontoblasts develops from the papil as a layer apposed to the odontoblasts, and separated from them by a membrane. The odontoblasts produce predentine, and thisinduces the production of enamel by the ameloblasts. The dental papil becomes dental papil upon further enclosing by dentine.
See: POJA-L101A; POJA-L102-nr2; POJA-L89AB
3.7 - images: Deviant processes
Sample of pulp stone: See: 3.7 - POJA-L110+101A
Sample of epithelial rests of Malassez: See: POJA-L126+117+116
Sample of damaged dentine: See: POJA-L129+130
Tonsils (Tonsilla lingualis, tonsilla palatina, tonsilla pharyngea, tonsilla tubaria). The Waldeyer's ring of pharyngeal lymphoid tissue have deep tonsillar crypts lined by stratified squamous epithelium and surrounded by lymphoid cells organized as follicles with a germinal center with B cells and surrounded / invaded by T cells, antigen presenting dendritic cells (APC's), all functioning in the immunological defence of the oral cavity.
See: Section 2 Lymphatic organs
3.2 - images: Oral orifice, Lip/Palate
The oral orifice is covered by a mucosa and comprising the lips, cheeks, hard and soft palate, and uvula. The outer zone of the lip has a skin-like structure with keratinized epithelium, hairs, sebaceous glands and eccrine sweat gland ducts all covering the lamina propria and the circular skeletal muscle fibers (musculus 0rbicularis) .
In the transitional zone (vermilion, pinkish-red appaearance) the squamous epithelium is only slightly keratinized, transparant and devoid of pigment.
The lamina propria is strongly folded into papillae and well vascularized (red transparancy). The inner zone of the lip, the cheeks and the soft palate are not-keratinized and contain both salivary glands (buccal glands).
Towards the nasal surface the epithelium turns into ciliated columnar epithelium.
See: Lip: POJA-L94+10 and POJA-L94+102+103+104
3.3 - images: Tongue , a mobile three-dimensional muscular organ (skeletal) covered with specialized mucosa with circumvallate papillae, filiform papillae, fungiform papillae and taste buds for acid, sweet, bitter and salty. The ventral surface of the tongue is covered by thin non-keratinizing stratified squamous epithelium identical to the floor of the mouth. The dorsal site, however, is lined by a thick keratinizing stratified epithelium. The circumvallate papillae with numerous taste buds in the epithelium detect bitter taste, the fungiform types detect sweet taste or salty taste. The filliform papillae (most numerous) are devoid of taste buds. Taste buds consist of spindle like receptor cells arranged as onion and are associated with afferent nerve endings. At the surface site they have an opening called taste pore.
See: POJA-L87A+97A+37+38+36 and POJA-L23+26+72+87A+87B.
See: POJA-L87B; POJA-L87BC; POJA-L97A.
3.4 - images: Salivary glands Parotis (serous); submandibularis (seromucous); sublingualis (muco-serous).
Salivary glands inside and outside the mouth contain mucus-secreting cells, serous cells and both. Generally, secretory acini empty into intercalated ducts (cuboidal epithelium) and continue into intralobular ducts (tall columnar epithelium) or striated ducts that are involved in concentrating and modifying the passing salivary. Intralobular ducts fuse into (non-striated) interlobular ducts and subsequently into major ducts. Myoepithelial cells around the acini and ductular cells are involved in squeezing out the salivary.
There are several smaller groups of salivary gland tissue located in and below the tongue (lingual and sublingual glands), in the lips (labial glands), in the soft and hard palatine, nearby the tonsils and in in the submucosa of the cheeks.
3.5 - images: Dental tissue: Development
3.6 - images: Dental tissues: Adult
Structure and development. Teeth develop from both ectoderm and mesoderm in the oral cavity. The enamel originates from the unkeratinizing oral squamous epithelium, initially as a tooth bud that develops from a cap stage to a early and late bell stage. Apposed to the epithelial tooth bud condensed mesenchym develops into the dental papilla within the concavity of the enamel organ. The cells of the epithelial tooth bud further differentiate into external and internal enamel epithelium. The internal enamel epithelium differentiates into columnar ameloblasts. A row of odontoblasts develops from the papil as a layer apposed to the odontoblasts, and separated from them by a membrane. The odontoblasts produce predentine, and thisinduces the production of enamel by the ameloblasts. The dental papil becomes dental papil upon further enclosing by dentine.
See: POJA-L101A; POJA-L102-nr2; POJA-L89AB
3.7 - images: Deviant processes
Sample of pulp stone: See: 3.7 - POJA-L110+101A
Sample of epithelial rests of Malassez: See: POJA-L126+117+116
Sample of damaged dentine: See: POJA-L129+130
Tonsils (Tonsilla lingualis, tonsilla palatina, tonsilla pharyngea, tonsilla tubaria). The Waldeyer's ring of pharyngeal lymphoid tissue have deep tonsillar crypts lined by stratified squamous epithelium and surrounded by lymphoid cells organized as follicles with a germinal center with B cells and surrounded / invaded by T cells, antigen presenting dendritic cells (APC's), all functioning in the immunological defence of the oral cavity.
See: Section 2 Lymphatic organs
COPYRIGHTS
All rights reserves worldwide for the POJA collection are hold by L.G. Poels and P.H.K. Jap and Radboud University Medical Center (Radboud UMC Nijmegen). No one may modify, copy, distribute, transmit, display, or publish any materials contained in the POJA collection without prior written permission of the authors Poels and Jap or the UMC St Radboud. Any commercial use of the POJA collection is forbidden. POJA images are partly deposited in the Health Education Assets Library (HEAL database) as well as in the MedEdPortal/AAMC database).
All rights reserves worldwide for the POJA collection are hold by L.G. Poels and P.H.K. Jap and Radboud University Medical Center (Radboud UMC Nijmegen). No one may modify, copy, distribute, transmit, display, or publish any materials contained in the POJA collection without prior written permission of the authors Poels and Jap or the UMC St Radboud. Any commercial use of the POJA collection is forbidden. POJA images are partly deposited in the Health Education Assets Library (HEAL database) as well as in the MedEdPortal/AAMC database).