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Oral Mucosa
The oral mucosa is the mucous membrane lining the inside of the mouth. It comprises stratified squamous epithelium, termed "oral epithelium", and an underlying connective tissue termed '' lamina propria''. The oral cavity has sometimes been described as a mirror that reflects the health of the individual. Changes indicative of disease are seen as alterations in the oral mucosa lining the mouth, which can reveal systemic conditions, such as diabetes or vitamin deficiency, or the local effects of chronic tobacco or alcohol use. The oral mucosa tends to heal faster and with less scar formation compared to the skin. The underlying mechanism remains unknown, but research suggests that extracellular vesicles might be involved. Classification Oral mucosa can be divided into three main categories based on function and histology: * ''Lining mucosa'', nonkeratinized stratified squamous epithelium, found almost everywhere else in the oral cavity, including the: ** ''Alveolar mucosa'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucous Membrane
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is mostly of endodermal origin and is continuous with the skin at body openings such as the eyes, eyelids, ears, inside the nose, inside the mouth, lips, the genital areas, the urethral opening and the anus. Some mucous membranes secrete mucus, a thick protective fluid. The function of the membrane is to stop pathogens and dirt from entering the body and to prevent bodily tissues from becoming dehydrated. Structure The mucosa is composed of one or more layers of epithelial cells that secrete mucus, and an underlying lamina propria of loose connective tissue. The type of cells and type of mucus secreted vary from organ to organ and each can differ along a given tract. Mucous membranes line the digestive, respiratory and rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lingual Papillae
Lingual papillae (: papilla, ) are small structures on the upper surface of the tongue that give it its characteristic rough texture. The four types of papillae on the human tongue have different structures and are accordingly classified as circumvallate (or vallate), fungiform, filiform, and foliate. All except the filiform papillae are associated with taste buds. Structure In living subjects, lingual papillae are more readily seen when the tongue is dry. There are four types of papillae present on the tongue in humans: Filiform papillae Filiform papillae () are the most numerous of the lingual papillae. They are fine, small, cone-shaped papillae found on the anterior surface of the tongue. They are responsible for giving the tongue its texture and are responsible for the sensation of touch. Unlike the other kinds of papillae, filiform papillae do not contain taste buds. They cover most of the front two-thirds of the tongue's surface. They appear as very small, conical or cyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinic Stomatitis
Stomatitis nicotina is a diffuse white patch on the hard palate, usually caused by tobacco smoking, usually pipe or cigar smoking. It is painless, and it is caused by a response of the palatal oral mucosa to chronic heat. A more pronounced appearance can occur with reverse smoking, sometimes distinguished from stomatitis nicotina by the term reverse smoker's stomatitis. While stomatitis nicotina that is caused by heat is not a premalignant condition (i.e. it does not carry an increased risk of transformation to oral cancer), the condition that is caused by reverse smoking is premalignant. Signs and symptoms The palate may appear gray or white and contain many papules or nodules that are slightly elevated with red dots in their center. These red dots represent the ducts of minor salivary glands which have become inflamed by heat. The condition is painless. If a denture is normally worn while smoking, then the mucosa underneath the denture appears unaffected by the condition. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, an interventional radiologist, or an interventional cardiology, interventional cardiologist. The process involves the extraction of sampling (medicine), sample Cell (biology), cells or Biological tissue, tissues for examination to determine the presence or extent of a disease. The tissue is then Histopathology, fixed, dehydrated, embedded, sectioned, stained and mounted before it is generally examined under a microscope by a pathologist; it may also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruxism
Bruxism is excessive teeth grinding or jaw clenching. It is an oral Parafunctional habit, parafunctional activity; i.e., it is unrelated to normal function such as eating or talking. Bruxism is a common behavior; the global prevalence of bruxism (both sleep and awake) is 22.22%. Several symptoms are commonly associated with bruxism, including aching jaw muscles, headaches, hypersensitive teeth, tooth wear, and damage to dental restorations (e.g. crowns and fillings). Symptoms may be minimal, without patient awareness of the condition. If nothing is done, after a while many teeth start wearing down until the whole tooth is gone. There are two main types of bruxism: one occurs during sleep (nocturnal bruxism) and one during wakefulness (awake bruxism). Dental damage may be similar in both types, but the symptoms of sleep bruxism tend to be worse on waking and improve during the course of the day, and the symptoms of awake bruxism may not be present at all on waking, and then wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linea Alba (cheek)
In dentistry, the linea alba () is a horizontal streak on the buccal mucosa (inner surface of the cheek), level with the occlusion (biting plane). It usually extends from the commissure to the posterior teeth, and can extend to the inner lip mucosa and corners of the mouth. The linea alba is a common finding and most likely associated with pressure, frictional irritation, or sucking trauma from the facial surfaces of the teeth. It may be mistaken for a lesion requiring treatment and may be found in individuals who chew tobacco. Clinical considerations *The linea alba is usually present bilaterally *It is restricted to dentulous areas (i.e., in areas where there are missing teeth the line will be absent - unless a denture is worn) *It presents an asymptomatic, linear elevation, with a whitish colour, at the level of the occlusal line of the teeth Treatment Treatment is not required. See also * Crenated tongue * Morsicatio buccarum * Linea alba (abdomen) References Extern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progenitor Cell
A progenitor cell is a biological cell that can differentiate into a specific cell type. Stem cells and progenitor cells have this ability in common. However, stem cells are less specified than progenitor cells. Progenitor cells can only differentiate into their "target" cell type. The most important difference between stem cells and progenitor cells is that stem cells can replicate indefinitely, whereas progenitor cells can divide only a limited number of times. Controversy about the exact definition remains and the concept is still evolving. The terms "progenitor cell" and "stem cell" are sometimes equated. Properties Most progenitors are identified as oligopotent. In this point of view, they can compare to adult stem cells, but progenitors are said to be in a further stage of cell differentiation. They are "midway" between stem cells and fully differentiated cells. The kind of potency they have depends on the type of their "parent" stem cell and also on their niche. Some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratinocyte
Keratinocytes are the primary type of cell found in the epidermis, the outermost layer of the skin. In humans, they constitute 90% of epidermal skin cells. Basal cells in the basal layer (''stratum basale'') of the skin are sometimes referred to as basal keratinocytes. Keratinocytes form a barrier against environmental damage by heat, UV radiation, water loss, pathogenic bacteria, fungi, parasites, and viruses. A number of structural proteins, enzymes, lipids, and antimicrobial peptides contribute to maintain the important barrier function of the skin. Keratinocytes differentiate from epidermal stem cells in the lower part of the epidermis and migrate towards the surface, finally becoming corneocytes and eventually being shed, which happens every 40 to 56 days in humans. Function The primary function of keratinocytes is the formation of a barrier against environmental damage by heat, UV radiation, dehydration, pathogenic bacteria, fungi, parasites, and viruses. Pathoge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Differentiation
Cellular differentiation is the process in which a stem cell changes from one type to a differentiated one. Usually, the cell changes to a more specialized type. Differentiation happens multiple times during the development of a multicellular organism as it changes from a simple zygote to a complex system of Tissue (biology), tissues and cell types. Differentiation continues in adulthood as adult stem cells divide and create fully differentiated Cell division, daughter cells during tissue repair and during normal cell turnover. Some differentiation occurs in response to antigen exposure. Differentiation dramatically changes a cell's size, shape, membrane potential, metabolism, metabolic activity, and responsiveness to signals. These changes are largely due to highly controlled modifications in gene expression and are the study of epigenetics. With a few exceptions, cellular differentiation almost never involves a change in the DNA sequence itself. Metabolic composition, however ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soft Palate
The soft palate (also known as the velum, palatal velum, or muscular palate) is, in mammals, the soft biological tissue, tissue constituting the back of the roof of the mouth. The soft palate is part of the palate of the mouth; the other part is the hard palate. The soft palate is distinguished from the hard palate at the front of the mouth in that it does not contain bone. Structure Muscles The five muscles of the soft palate play important roles in swallowing and breathing. The muscles are: # Tensor veli palatini, which is involved in swallowing # Palatoglossus, involved in swallowing # Palatopharyngeus, involved in breathing # Levator veli palatini, involved in swallowing # Musculus uvulae, which moves the palatine uvula, uvula These muscles are innervated by the pharyngeal plexus of vagus nerve, pharyngeal plexus via the vagus nerve, with the exception of the tensor veli palatini. The tensor veli palatini is innervated by the mandibular division of the trigeminal nerve (V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratum Corneum
The stratum corneum (Latin language, Latin for 'horny layer') is the outermost layer of the epidermis (skin), epidermis. Consisting of dead tissue, it protects underlying tissue from infection, dehydration, chemicals and mechanical stress. It is composed of 15–20 layers of flattened cells with no nuclei and cell organelles. Among its properties are mechanical shear, impact resistance, water flux and hydration regulation, microbial proliferation and invasion regulation, initiation of inflammation through cytokine activation and dendritic cell activity, and selective permeability to exclude toxins, irritants, and allergens. The cytoplasm of its cells shows filamentous keratin. These corneocytes are embedded in a lipid matrix composed of ceramides, cholesterol, and fatty acids. Desquamation is the process of cell shedding from the surface of the stratum corneum, balancing proliferating keratinocytes that form in the stratum basale. These cells migrate through the epidermis tow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratum Granulosum
The stratum granulosum (or granular layer) is a thin layer of cells in the epidermis lying above the stratum spinosum and below the stratum corneum ( stratum lucidum on the soles and palms).James, William; Berger, Timothy; Elston, Dirk (2005) ''Andrews' Diseases of the Skin: Clinical Dermatology'' (10th ed.). Saunders. Page 2. . Keratinocytes migrating from the underlying stratum spinosum become known as granular cells in this layer. These cells contain keratohyalin granules, which are filled with histidine- and cysteine-rich proteins that appear to bind the keratin filaments together. Therefore, the main function of keratohyalin granules is to bind intermediate keratin filaments together.Marks, James G; Miller, Jeffery (2006). ''Lookingbill and Marks' Principles of Dermatology'' (4th ed.). Elsevier Inc. Page 7. . At the transition between this layer and the stratum corneum, cells secrete lamellar bodies (containing lipids and proteins) into the extracellular space. This results ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
