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Tomes's Process
Tomes's processes (also called Tomes processes) are a histology, histologic landmark identified on an ameloblast, cells involved in the production of tooth enamel. During the synthesis of enamel, the ameloblast moves away from the Tooth enamel, enamel, forming a projection surrounded by the developing enamel. Tomes's processes are those projections and give the ameloblast a "picket-fence" appearance under a microscope. They are located on the secretory, basal, end of the ameloblast. Terminal bar apparatuses connect the Tomes's processes. Tonofilaments separate the developing enamel from the enamel organ. Gap junctions synchronize cell activation. The body of the cell between the processes first deposits enamel, which will become the periphery of the enamel prisms, then the Tomes's process will infill the main body of the enamel prism. More than one ameloblast contributes to a single prism. Tomes's processes are distinctly different from Tomes's fibers, which are odontoblastic pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histology
Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures visible without a microscope. Although one may divide microscopic anatomy into ''organology'', the study of organs, ''histology'', the study of tissues, and ''cytology'', the study of cells, modern usage places all of these topics under the field of histology. In medicine, histopathology is the branch of histology that includes the microscopic identification and study of diseased tissue. In the field of paleontology, the term paleohistology refers to the histology of fossil organisms. Biological tissues Animal tissue classification There are four basic types of animal tissues: muscle tissue, nervous tissue, connective tissue, and epithelial tissue. All animal tissues are considered to be subtypes of these four principal tissue types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ameloblast
Ameloblasts are cells present only during tooth development that deposit tooth enamel, which is the hard outermost layer of the tooth forming the surface of the crown. Structure Each ameloblast is a columnar cell approximately 4 micrometers in diameter, 40 micrometers in length and is hexagonal in cross section. The secretory end of the ameloblast ends in a six-sided pyramid-like projection known as the Tomes' process. The angulation of the Tomes' process is significant in the orientation of enamel rods, the basic unit of tooth enamel. Distal terminal bars are junctional complexes that separate the Tomes' processes from ameloblast proper. Development Ameloblasts are derived from oral epithelium tissue of ectodermal origin. Their differentiation from preameloblasts (whose origin is from inner enamel epithelium) is a result of signaling from the ectomesenchymal cells of the dental papilla. Initially the preameloblasts will differentiate into presecretory ameloblasts and then into s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth Enamel
Tooth enamel is one of the four major Tissue (biology), tissues that make up the tooth in humans and many other animals, including some species of fish. It makes up the normally visible part of the tooth, covering the Crown (tooth), crown. The other major tissues are dentin, cementum, and Pulp (tooth), dental pulp. It is a very hard, white to off-white, highly mineralised substance that acts as a barrier to protect the tooth but can become susceptible to degradation, especially by acids from food and drink. Calcium hardens the tooth enamel. In rare circumstances enamel fails to form, leaving the underlying dentin exposed on the surface. Features Enamel is the hardest substance in the human body and contains the highest percentage of minerals (at 96%),Ross ''et al.'', p. 485 with water and organic material composing the rest.Ten Cate's Oral Histology, Nancy, Elsevier, pp. 70–94 The primary mineral is hydroxyapatite, which is a crystalline calcium phosphate. Enamel is formed o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth Enamel
Tooth enamel is one of the four major Tissue (biology), tissues that make up the tooth in humans and many other animals, including some species of fish. It makes up the normally visible part of the tooth, covering the Crown (tooth), crown. The other major tissues are dentin, cementum, and Pulp (tooth), dental pulp. It is a very hard, white to off-white, highly mineralised substance that acts as a barrier to protect the tooth but can become susceptible to degradation, especially by acids from food and drink. Calcium hardens the tooth enamel. In rare circumstances enamel fails to form, leaving the underlying dentin exposed on the surface. Features Enamel is the hardest substance in the human body and contains the highest percentage of minerals (at 96%),Ross ''et al.'', p. 485 with water and organic material composing the rest.Ten Cate's Oral Histology, Nancy, Elsevier, pp. 70–94 The primary mineral is hydroxyapatite, which is a crystalline calcium phosphate. Enamel is formed o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microscope
A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisible to the eye unless aided by a microscope. There are many types of microscopes, and they may be grouped in different ways. One way is to describe the method an instrument uses to interact with a sample and produce images, either by sending a beam of light or electrons through a sample in its optical path, by detecting photon emissions from a sample, or by scanning across and a short distance from the surface of a sample using a probe. The most common microscope (and the first to be invented) is the optical microscope, which uses lenses to refract visible light that passed through a thinly sectioned sample to produce an observable image. Other major types of microscopes are the fluorescence microscope, electron microscope (both the transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomes's Fibers
An odontoblast process (also called Tomes's fibers or Tomes fibers, or by a dated term Tomes's fibrils) is an extension of a cell called an odontoblast, which forms dentin in a tooth. The odontoblast process is located in dentinal tubules. It forms during dentinogenesis and results from a part of the odontoblast staying in its location as the main body of the odontoblast moves toward the center of the tooth's pulp. The odontoblast process causes the secretion of hydroxyapatite crystals and mineralization of the matrix secreted by the odontoblasts. References * See also *Tomes's process Tomes's processes (also called Tomes processes) are a histology, histologic landmark identified on an ameloblast, cells involved in the production of tooth enamel. During the synthesis of enamel, the ameloblast moves away from the Tooth enamel, ena ... * John Tomes Tooth development {{dentistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartilaginous fish, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Tomes
Sir John Tomes (21 March 1815 – 29 July 1895) was an English dental surgeon. Life The eldest son of John Tomes and Sarah, his wife, daughter of William Baylies of Welford-on-Avon, then in Gloucestershire, he was born at Weston-on-Avon in Gloucestershire on 21 March 1815. He was articled in 1831 to Thomas Furley Smith, a medical practitioner in Evesham, and in 1836 he entered the medical schools of King's College, London and the Middlesex Hospital, at that time united. He was house surgeon to the Middlesex Hospital during 1839–40. Research with Madder on histology of bone and teeth brought Tomes to the notice of Sir Thomas Watson and James Moncrieff Arnott, who advised him to concentrate on dental surgery. He was admitted a member of the College of Surgeons of England on 21 March 1839, and in 1840 he went into practice at 41 Mortimer Street (now Cavendish Place). He was also preoccupied with the question of general anæsthesia, shortly after the introduction of ether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
