Diferencia entre revisiones de «Organo de Esmalte»

Revisión del 07:49 8 may 2011

Anatomy of the Enamel Organ

Histology of Enamel Organ - Copyright RVC 2008

Enamel Organ Layers - Copyright RVC 2008

Thomes' Fibres - Copywright RVC 2008

The main components which form the enamel organ are:

Outer epithelium
Stellate reticulum- star shaped cells lying between the outer and inner epithelial layers. It has the appearance of connective tissue but is of epithelial derivation.
Inner epithelium which becomes the enamel secreting ameloblast layer

Componentes

The enamel organ has many different components. These consist of:

Corona

The crown is covered by enamel. It meets the root at the cemento-enamel junction (CEJ).

The crown of incisors have only one cusp. The crown of molars have up to 4 cusps for the grinding of food.

Root

Teeth may have one or more roots. The furcation angle is the point where roots diverge. The root ends in an apex which is where the nerves, blood vessels and lymphatics travel to the pulp. Hypsodont teeth can have open roots (aradicular) e.g. in rabbits which have continued growth. Hypsodont teeth can have closed roots (radicular) e.g. horse where growth decreases with age. Brachydont teeth have no capacity for growth and so the roots are closed.

Diferencias Entre las Especies

The apex has a single foramen in dogs and cats. It remains open in herbivores. In the horse, the apex closes as the animal ages. Brachiocephalic dogs often have fused roots. Equine incisors have fused roots. In the horse's canines, the size of the root is much larger than the crown.

Alveolar Bone

The alveolar processes of the jaw consists of the alveolar bone, trabecular bone and compact bone.

The densest bone called the cribiform plate lines the alveolus. This appears white on radiographs and is referred to as the lamina dura.

Lamina Dura

The lamina dura lines the alveolar bone. If uninterrupted, it indicates good dental health.

The lamina dura is seen as a white line radiographically.

Enamel

Enamel has an ectodermal origin. It is synthesised by ameloblasts. It is very hard, densly calcified and acellular, therefore cannot regenerate.

Complicated enamel folding occurs in teeth where the crowns are high. Enamel forming secretions pass through processes of apical cytoplasmic extension called Thomes' Fibres.

Dentine

Dentine is a calcified, collagen rich matrix. It is synthesised by odontoblasts.

Secondary dentine is produced throughout life and increases with rate of repair. It is darker in colour than primary dentine.

Cementum

Cementum is synthesised by cementoblasts. It is calcified tissue and lacks regular organisation. Collagen fibres extend from the cementum into the periodontal ligament to fasten the tooth in its socket. Cementum is relatively immune to pressure erosion, therefore the tooth can be be romedelled in its socket.

Pulp

Pulp fills the dental cavity. It is a delicate connective tissue bordering the odontoblast layer. It is highly vascularised and contains a lymphatic plexus.

Pulp allows pain sensation to thermal, mechanical and chemical stimulants. Most of the nervous supply is sensory, with some vasomotor input.

Periodontal Ligament

The collagen fibre bundles are called Sharpey's fibres. The fibres insert into the alveolar bone and cementum of the tooth.

There are 3 categories: gingival, trans-septal and alveolodental. There are evenly distributed blood vessels and nerve fibres transmitting thermal, pain and pressure sensation. Some species can also sense proprioception in the periodontal ligament.

Main Cells

Ameloblast Histology - Copywright RVC 2008

Ameloblasts

Ameloblasts are cells in the enamel organ which forms the tooth. They secrete enamel.

Epithelial cells line the inner surface of the enamel organ. Ameloblasts are derived from epithelium and form a single layer of very long columnar cells that are hexagonal in cross section. They have elongated, basally sited nuclei. They synthesise enamel which forms the crown of each tooth. They maintain connections with the newly synthesised enamel through cellular projections called Thomes' fibres.

Enamel is acellular so once the connection with the ameloblasts via the Thomes' fibres is lost (upon eruption), the enamel matrix cannot be remodelled.

Odontoblasts

The odontoblasts are cells in the enamel organ which forms the tooth. They secrete dentine.

Odontoblasts are derived from mesenchyme and are composed of a single layer of elongated columnar cells. They are at the dental-pulp border. They secrete dentine which is a mineralised matrix of collagen I, dentine and proteins.

The first layer of dentine is formed on the enamel organ. As production increases, the odontoblasts are displaced from the enamel. It is a major part of the tooth structure and is produced continually by the odontoblasts. The rate of dentine synthesis is increased during repair as it is innervated (but still acellular).

Cementoblasts

Cementoblasts are cells in the enamel organ which forms the tooth. They secrete cementum.

Epithelial cells are present near the distal end of the cup. They become follicle cells. Cementoblasts synthesise cementum which mostly contains collagen I.

Cementum surrounds the dentine of the root. Cementum is acellular and not readily absorbed.

Test yourself

Dientes y Gingiva - Flashcards

@@ Línea 1: / Línea 1: @@
-==Anatomía del Organo de Esmalte==
+==Anatomy of the Enamel Organ==
-[[Image:Soft Histology of Enamel Organ.jpg|thumb|right|150px|Histología del Organo de Esmalte - Copyright RVC 2008]]
+[[Image:Soft Histology of Enamel Organ.jpg|thumb|right|150px|Histology of Enamel Organ - Copyright RVC 2008]]
-[[Image:Enamel Organ Layers.jpg|thumb|right|150px|Capas del Organo de Esmalte - Copyright RVC 2008]]
+[[Image:Enamel Organ Layers.jpg|thumb|right|150px|Enamel Organ Layers - Copyright RVC 2008]]
-[[Image:Thomes' Fibres Histology.jpg|thumb|right|150px|Fibras Thomes' - Copywright RVC 2008]]
+[[Image:Thomes' Fibres Histology.jpg|thumb|right|150px|Thomes' Fibres - Copywright RVC 2008]]
-Los componentes principales que forman el órgano del esmalte son:
+The main components which form the enamel organ are:
-*'''Epitelio externo'''
+*'''Outer epithelium'''
-*'''Retículo estrellado'''- células en forma de estrellas que extienden entre las capas epiteliales interior y exterior. Tiene la apariencia del tejido conectivo, pero es de origen epitelial.
+*'''Stellate reticulum'''- star shaped cells lying between the outer and inner epithelial layers. It has the appearance of connective tissue but is of epithelial derivation.
-*'''Epitelio interno''' convierte en la capa de [[Organo de Esmalte#Ameloblastos|ameloblastos]] que secretan esmalte
+*'''Inner epithelium''' which becomes the enamel secreting [[Enamel Organ#Ameloblasts|ameloblast]] layer
 ==Componentes==
-El órgano del esmalte tiene muchos componentes diferentes. Estos consisten de:
+The enamel organ has many different components. These consist of:
 ===Corona===
-La '''corona''' está cubierta por el esmalte. Se reúne a la raíz en la '''unión cemento-esmalte'''.
+The '''crown''' is covered by enamel. It meets the root at the '''cemento-enamel junction''' (CEJ).
-La corona de los incisivos tienen una sola '''cúspide'''. La corona de los molares tienen hasta cuatro cúspides para la trituración de los alimentos.
+The crown of incisors have only one '''cusp'''. The crown of molars have up to 4 cusps for the grinding of food.
+===Root===
+Teeth may have one or more roots. The furcation angle is the point where roots diverge. The root ends in an apex which is where the nerves, blood vessels and lymphatics travel to the [[Enamel Organ#Pulp|pulp]]. '''Hypsodont''' teeth can have open roots (aradicular) e.g. in rabbits which have continued growth. Hypsodont teeth can have closed roots (radicular) e.g. horse where growth decreases with age. '''Brachydont''' teeth have no capacity for growth and so the roots are closed.
-===Raíz===
-Los dientes pueden tener una o más raíces. El ángulo de bifurcación es el punto donde las raíces se separan. La raíz termina en una punta que es donde los nervios, vasos sanguíneos y linfáticos viajar a la [[Organo de Esmalte#Pulpa Dental|pulpa dental]]. Dientes '''hipsodontos''' pueden tener raíces abiertos (aradicular) por ejemplo, en conejos que tienen crecimiento continuoso.Dientes hipsodontos pueden tener tambíen raíces cerradas (radicular) por ejemplo, en caballos cuando el crecimiento disminuye con la edad. Dientes '''brachidontos''' no tienen capacidad de crecimiento y las raíces están cerrados.
 '''Diferencias Entre las Especies'''
-El ápice tiene un único agujero en perros y gatos. Queda abierta en los herbívoros. En el caballo, el ápice se cierra con el envejecimiento del animal. Perros braquiocefálicos a menudo tienen raíces fusionadas. Incisivos equinos tienen las raíces fusionados. En los caninos del caballo, el tamaño de la raíz es mucho más grande que la [[Organo de Esmalte#Corona|corona]].
+The apex has a single foramen in dogs and cats. It remains open in herbivores. In the horse, the apex closes as the animal ages. Brachiocephalic dogs often have fused roots. Equine incisors have fused roots. In the horse's canines, the size of the root is much larger than the [[Enamel Organ#Crown|crown]].
+===Alveolar Bone===
+The alveolar processes of the jaw consists of the '''alveolar bone''', '''trabecular bone''' and '''compact bone'''.
-===Hueso Alveolar===
+The densest bone called the '''cribiform plate''' lines the alveolus. This appears white on radiographs and is referred to as the '''[[Enamel Organ#Lamina Dura|lamina dura]]'''.
-The alveolar processes of the jaw consists of the '''hueso alveolar''', '''trabecular bone''' and '''compact bone'''.
-The densest bone called the '''cribiform plate''' lines the alveolus. This appears white on radiographs and is referred to as the '''[[Organo de Esmalte#Lamina Dura|lamina dura]]'''.
-Los procesos alveolares de los maxilares consiste en el hueso alveolar , hueso trabecular y hueso compacto .
-La más densa del hueso llamada placa cribiforme líneas de los alvéolos. Esto aparece en blanco en las radiografías y se le conoce como la lámina dura .
 ===Lamina Dura===
-La '''lámina dura''' reviste el [[Organo de Esmalte#Hueso Alveolar|hueso alveolar]]. Si esta ininterrumpido, indica una buena salud dental.
+The '''lamina dura''' lines the [[Enamel Organ#Alveolar Bone|alveolar bone]]. If uninterrupted, it indicates good dental health.
-La '''lámina dura''' se ve como una línea blanca radiográficamente.
+The '''lamina dura''' is seen as a white line radiographically.
+===Enamel===
+Enamel has an '''ectodermal''' origin. It is synthesised by [[Enamel Organ#Ameloblasts|ameloblasts]]. It is very hard, densly calcified and '''acellular''', therefore cannot regenerate.
-===Esmalte===
+Complicated enamel folding occurs in teeth where the '''[[Enamel Organ#Crown|crowns]]''' are high. Enamel forming secretions pass through processes of apical cytoplasmic extension called '''Thomes' Fibres'''.
-El esmalte tiene un origen '''ectodérmica'''. Esta sintetizada por [[Organo de Esmalte#Ameloblastos|ameloblastos]]. Esta muy duro, '''acelular''' y densamente calcificado, y por lo tanto no puede regenerarse.
-Un plegamiento complicado del esmalte ocurre en los dientes cuando las '''[[Organo de Esmalte#Corona|coronas]]''' son altos. la formación de Secreciones para formar el esmalte pasan a través de procesos de extensión citoplasmática apical llamado '''Fibras Thomes'''.
+===Dentine===
+'''Dentine''' is a calcified, collagen rich matrix. It is synthesised by '''[[Enamel Organ#Odontoblasts|odontoblasts]]'''.
-===Dentina===
+'''Secondary dentine''' is produced throughout life and increases with rate of repair. It is darker in colour than '''primary dentine'''.
-'''Dentina''' una matriz calcificado rico en colágeno. Esta sintetizada por los '''[[Organo de Esmalte#Odontoblastos|odontoblastos]]'''.
-La '''dentina secundaria''' se produce durante toda la vida y aumenta con la velocidad de reparación. Es de un color más oscuro que la '''dentina primaria'''.
+===Cementum===
+'''Cementum''' is synthesised by '''[[Enamel Organ#Cementoblasts|cementoblasts]]'''. It is calcified tissue and lacks regular organisation. Collagen fibres extend from the cementum into the '''[[Enamel Organ#Periodontal Ligament|periodontal ligament]]''' to fasten the tooth in its socket. '''Cementum''' is relatively immune to pressure erosion, therefore the tooth can be be romedelled in its socket.
-===Cemento===
+===Pulp===
-El '''cemento'' es sintetizado por ''[[Organo de Esmalte#Cementoblastos|cementoblastos]]'''. Es un tejido calcificado y carece de una organización regular. Las fibras de colágeno se extienden desde el cemento al '''[[Organo de Esmalte#Ligamento Periodontal|ligamento periodontal]]''' para fijar el diente en su alvéolo. El '''cemento''' es relativamente inmune a la erosión de la presión, por lo tanto el diente puede ser romedelado en su cavidad.
+Pulp fills the dental cavity. It is a delicate connective tissue bordering the [[Enamel Organ#Odontoblasts|odontoblast]] layer. It is highly vascularised and contains a lymphatic plexus.
-===Pulpa Dental===
+Pulp allows pain sensation to thermal, mechanical and chemical stimulants. Most of the nervous supply is sensory, with some vasomotor input.
-La pulpa dental llena la cavidad dental. Se trata de un tejido delicado que bordea la capa de [[Organo de Esmalte#Odontoblastos|odontoblastos]]. Esta altamente vascularizada y contiene un plexo linfático.
-La pulpa dental permite la sensación de dolor a los estimulantes térmicas, mecánicas y químicas. La mayor parte de la inervación es sensorial, con alguna entrada vasomotores.
+===Periodontal Ligament===
+The collagen fibre bundles are called '''Sharpey's fibres'''. The fibres insert into the [[Enamel Organ#Alveolar Bone|alveolar bone]] and [[Enamel Organ#Cementum|cementum]] of the tooth.
-===Ligamento Periodontal===
+There are 3 categories: gingival, trans-septal and alveolodental. There are evenly distributed blood vessels and nerve fibres transmitting thermal, pain and pressure sensation. Some species can also sense proprioception in the periodontal ligament.
-Los haces de fibras de colágeno se llaman de las '''fibras de Sharpey'''. Las fibras insertan en el [[Organo de Esmalte#Hueso alveolar|hueso alveolar]] y el [[Organo de Esmalte#Cemento|cemento]] del diente.
-Hay 3 categorías: gingival, trans-septal y alveolodental. Hay vasos sanguíneos y fibras nerviosas distribuidos uniformemente que transmiten el dolor y la sensación térmica y de presión. Algunas especies también pueden sentir la propiocepción en el ligamento periodontal.
+==Main Cells==
+[[Image:Ameloblast Histology.jpg|thumb|right|150px|Ameloblast Histology - Copywright RVC 2008]]
+===Ameloblasts===
+'''Ameloblasts''' are cells in the enamel organ which forms the tooth. They secrete '''[[Enamel Organ#Enamel|enamel]]'''.
-==Células==
+Epithelial cells line the inner surface of the enamel organ. '''Ameloblasts''' are derived from epithelium and form a single layer of very long columnar cells that are hexagonal in cross section. They have elongated, basally sited nuclei. They synthesise '''[[Enamel Organ#Enamel|enamel]]''' which forms the '''[[Enamel Organ#Crown|crown]]''' of each tooth. They maintain connections with the newly synthesised '''[[Enamel Organ#Enamel|enamel]]''' through cellular projections called '''Thomes' fibres'''.
-[[Image:Ameloblast Histology.jpg|thumb|right|150px|Histología de Ameloblasto - Copywright RVC 2008]]
-===Ameloblastos===
-'''Ameloblastos''' son las células en el organo del esmalta que forman el diente. Secretan el '''[[Organo de Esmalte#Esmalte|esmalte]]'''.
-Células epiteliales revisten la superficie interna del órgano del esmalte. '''Ameloblastos''' se derivan del epitelio y forman una sola capa de células columnares muy largos que son hexagonales en sección transversal. Tienen núcleos alargados, situado  basales. Sintetizan '''[[Organo de Esmalte#Esmalte|esmalte]]''' que forma la '''[[Organo de Esmalte#Corona|corona]]''' de cada diente. Mantienen conexiones con la nueva síntesis del '''[[Organo de Esmalte#Esmalte|esmalte]]''' a través de proyecciones celulares llamadas '''fibras Thomes'''.
+'''[[Enamel Organ#Enamel|Enamel]]''' is acellular so once the connection with the ameloblasts via the '''Thomes' fibres''' is lost (upon eruption), the [[Enamel Organ#Enamel|enamel]] matrix cannot be remodelled.
-El '''[[Organo de Esmalte#Esmalte|esmalte]]''' es acelular entonces una vez que la conexión con los ameloblastos a través de la '''fibras Thomes''' se pierde (en erupción), el [[Organo de Esmalte#Esmalte|esmalte]] de la matriz no puede ser remodelado.
+===Odontoblasts===
+The '''odontoblasts''' are cells in the '''enamel organ''' which forms the tooth. They secrete '''[[Enamel Organ#Dentine|dentine]]'''.
-===Odontoblastos===
+'''Odontoblasts''' are derived from mesenchyme and are composed of a single layer of elongated columnar cells. They are at the '''dental-pulp border'''. They secrete '''[[Enamel Organ#Dentine|dentine]]''' which is a mineralised matrix of collagen I, [[Enamel Organ#Dentine|dentine]] and proteins.
-Los '''odontoblastos''' son células en el '''órgano del esmalte''', que forma el diente. Segregan la '''[[Organo de Esmalte#Dentina|dentina]]'''.
-'''Odontoblastos''' se derivan del mesénquima y se componen de una sola capa de células columnares alargados. Están en el borde '''pulpa-dental'''. Segregan la '''[[Organo de Esmalte#Dentina|dentina]]''', que es una matriz mineralizada del colágeno I, la '''[[Organo de Esmalte#Dentina|dentina]]''' y las proteínas.
-La primera capa de la [[Organo de Esmalte#Dentina|dentina]] se forma en el órgano del esmalte. A medida que aumenta la producción, los odontoblastos son desplazados del [[Organo de Esmalte#Esmalte|esmalte]]. Es una parte importante de la estructura del diente y produce continuamente por los odontoblastos. La frecuencia de síntesis de [[Organo de Esmalte#Dentina|dentina]] se incrementa durante la reparación, ya que está inervado (pero aún acelular).
+The first layer of [[Enamel Organ#Dentine|dentine]] is formed on the enamel organ. As production increases, the odontoblasts are displaced from the [[Enamel Organ#Enamel|enamel]]. It is a major part of the tooth structure and is produced continually by the odontoblasts. The rate of [[Enamel Organ#Dentine|dentine]] synthesis is increased during repair as it is innervated (but still acellular).
-===Cementoblastos ===
+===Cementoblasts ===
-'''Cementoblastos''' son las células del órgano del '''[[Organo de Esmalte#Esmalte|esmalte]]''' que forma el diente. Segregan '''[[Organo de Esmalte#Cemento|cemento]]'''.
+'''Cementoblasts''' are cells in the '''[[Enamel Organ#Enamel|enamel]]''' organ which forms the tooth. They secrete '''[[Enamel Organ#Cementum|cementum]]'''.
-Las células epiteliales se encuentran cerca del extremo distal de la copa. Se convierten en células foliculares. '''Cementoblastos''' sintetizan [[Organo de Esmalte#Cemento|cemento]] que en su mayoría contiene '''colágeno I'''.
+Epithelial cells are present near the distal end of the cup. They become follicle cells. '''Cementoblasts''' synthesise [[Enamel Organ#Cementum|cementum]] which mostly contains '''collagen I'''.
-El [[Organo de Esmalte#Cemento|cemento]] rodea la '''[[Organo de Esmalte#Dentina|dentina]]''' de la [[Organo de Esmalte#Raíz|raíz]]. El [[Organo de Esmalte#Cemento|cemento]] es acelular y no se absorbe fácilmente.
+[[Enamel Organ#Cementum|Cementum]] surrounds the '''[[Enamel Organ#Dentine|dentine]]''' of the [[Enamel Organ#Root|root]]. [[Enamel Organ#Cementum|Cementum]] is acellular and not readily absorbed.
-==Comprobar tus Conocimientos ==
+==Test yourself ==
-[[Cavidad Oral - Anatomía & Fisiología_-_Flashcards#Dientes y Gingiva_Flashcards|Dientes y Gingiva - Flashcards]]
+[[Cavidad Oral - Anatomía & Fisiología_-_Flashcards#Teeth_&_Gingiva_Flashcards|Dientes y Gingiva - Flashcards]]
 [[Categoría:Dientes - Anatomía & Fisiología]]