Oral cavity
Paul Ong, Rachel Skittrall in Gastrointestinal Nursing, 2017
The tongue also provides sensory information regarding taste. The superior surface of the tongue is covered in tiny projections called papillae. The papillae are divided into four groups: filiform, fungiform, foliate and circumvallate papillae (Figure 2.6). Filiform papillae occur as elongated projections over the anterior two thirds of the tongue. They provide an abrasive surface for mastication. The filiform papillae do not contain taste buds.Fungiform papillae are distributed towards the tip and sides of the tongue, dispersed between the filiform papillae. They are mushroom shaped and provide taste sensation via the cranial nerves.Foliate papillae are found bilaterally on the posterior-lateral sides of the tongue. They form furrows which lie near to the molar teeth.The circumvallate papillae form a ‘V’ shape just anterior to the root of the tongue and the sulcus terminalis. There are between 8 and 12 papillae which form a demarcation line between the oral and pharyngeal components of the tongue. Like the fungiform papillae, they provide taste sensation via the cranial nerves.
Introduction
Shayne C. Gad in Toxicology of the Gastrointestinal Tract, 2018
The dorsum (upper surface) and lateral surfaces of the tongue are covered with papillae (projections of the lamina propria covered with keratinized epithelium). Many papillae contain taste buds, the receptors for taste. Fungiform papillae are mushroomlike elevations distributed among the filiform papillae that are more numerous near the tip of the tongue. They appear as red dots on the surface of the tongue, and most of them contain taste buds. Vallate papillae are arranged in an inverted V shape on the posterior surface of the tongue; all of them contain taste buds. Foliate papillae are located in small trenches on the lateral margins of the tongue but most of their taste buds degenerate in early childhood. Filiform papillae are pointed, threadlike projections distributed in parallel rows over the anterior two-thirds of the tongue. Although filiform papillae lack taste buds, they contain receptors for touch and increase friction between the tongue and food, making it easier for the tongue to move food in the oral cavity. Lingual glands in the lamina propria secrete both mucus and a watery serous fluid that contains the enzyme lingual lipase, which acts on triglycerides.
Experimental Stomatology
Samuel Dreizen, Barnet M. Levy in Handbook of Experimental Stomatology, 2020
Microscopically, the filiform papillae in the anterior part of the tongue were small but regular in shape. The epithelium was thin, poorly differentiated, and lacked the usual stratification of cell layers. Basal cell layer was normal, but the stratum spinosum was almost entirely absent. The cells varied in size and evidenced hydropic degeneration. Nuclei were irregular in size and shape. Stratum granulosum was thick in some places but contained only a few keratohyaline granules. There was a complete loss of keratinization with the surface covered by a thick layer of parakeratotic cells. Occasionally, a piling up of cells caused disfigurement of the papillae. Nerves were necrotic and in the process of resorption by multinuclear giant cells. Response to specific vitamin therapy was prompt; normal color and papillation returned within 1 week.
Oral microbial diversity analysis among atrophic glossitis patients and healthy individuals
Published in Journal of Oral Microbiology, 2021
Hong Li, Jing Sun, Xiaoyan Wang, Jing Shi
Atrophic glossitis is known as smooth tongue, tongues with it exhibit a smooth, glossy appearance with a red or pink background. The smooth quality is caused by the atrophy of filiform papillae. Histologically, atrophic glossitis is characterized by epithelial atrophy and varying degrees of chronic inflammation in the sub-epithelial connective tissue. It commonly occurs due to nutritional deficiencies such as vitamin B12, folic acid, iron deficiencies, or celiac disease [1–3]. Other aetiological factors include hyposalivation and candidiasis infection [4–6]. Currently, most studies suggested that Candida albicans was the primary component of the oral microbiota that was relevant to atrophic glossitis. Candida is the easiest genus to separate in the oral cavity and is one of the most common taxa of fungi that contribute to the early formation of in vitro biofilms [7,8]. However, apart from Candida albicans, little is known about other species in the oral microbiota that are correlated with atrophic glossitis. The oral microbiome, including bacteria and fungi, involved in atrophic glossitis should be explored.
Comparative studies on the tongue of the Egyptian fruit bat (Rousettus aegyptiacus) and the common quail (Coturnix coturnix)
Published in Egyptian Journal of Basic and Applied Sciences, 2023
Amany Attaallah, Yousra Fouda, Abd El-Fattah B. M. El-Beltagy, Amira M. B. Saleh
Six subtypes of filiform papillae were identified on the dorsal surface of bat tongue: small, conical, giant, cornflower, leaf-like and rosette filiform papillae. The small filiform papillae appear rounded or triangular and have posterior directed several pointed processes and widely distributed on the tip of lingual apex. Conical filiform papillae are more localized on the two lateral regions of the anterior part of the tongue and showed posteriorly directed multiple pointed processes from all borders of the papillae. Giant filiform papillae are found on the anterior median region of tongue and overlapped on each other. Each papilla has a wide rectangular body, and from which extended posteriorly three fingers like processes called tri-dentates papillae. Cornflower filiform papillae appeared on the lateral regions of middle part (inter-molar tubercle) of the tongue and took the shape of the cornflower. The lateral edges of cornflower filiform papillae appeared bended on the dorsal surface of papillae forming a central rounded groove and ended with posteriorly directed processes. Leaf-like filiform papillae were distributed in the median region of inter-molar tubercle part of tongue. They take characteristic appearance of leaf-like. Each papilla was ended posteriorly with one main process from which extended two fine processes. Rosette-shaped filiform papillae were found densely on the median area of posterior part of tongue take the rosette shape. Each papilla had a rounded base and posteriorly directed apex. The rosette-shaped papilla carries multiple posteriorly directed processes giving it its characteristic basket-like appearance.
Related Knowledge Centers
- Chorda Tympani
- Epithelium
- Facial Nerve
- Histology
- Sweetness
- Taste
- Taste Bud
- Connective Tissue
- Tongue
- Submandibular Ganglion