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Esophageal Submucosal Glands
The esophageal glands are glands that are part of the digestive system of various animals, including humans. In humans In humans the glands are known as the esophageal submucosal glands and are a part of the human digestive system. They are a small compound racemose exocrine glands of the mucous type. There are two types: * Esophageal submucosal glands are compound tubulo-alveolar glands. Some serous cells are present. These glands are more numerous in the upper third of the esophagus. They secrete acid mucin for lubrication. * Esophageal cardiac glands- mucous glands located near the cardiac orifice (esophago-gastric junction) in the lamina propria mucosae. They secrete neutral mucin that protects the esophagus from acidic gastric juices. They are simple tubular or branched tubular glands. * There are also mucous glands present at the pharyngo-esophageal junction in the lamina propria mucosae. These are simple tubular or branched tubular glands. Each opens upon the surface b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucosa
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] |
Striated Muscular Fibers
Striated muscle tissue is a muscle tissue that features repeating functional units called sarcomeres. Under the microscope, sarcomeres are visible along muscle fibers, giving a striated appearance to the tissue. The two types of striated muscle are skeletal muscle and cardiac muscle. Structure Striated muscle tissue contains T-tubules which enables the release of calcium ions from the sarcoplasmic reticulum. Skeletal muscle Skeletal muscle includes skeletal muscle fibers, blood vessels, nerve fibers, and connective tissue. Skeletal muscle is wrapped in epimysium, allowing structural integrity of the muscle despite contractions. The perimysium organizes the muscle fibers, which are encased in collagen and endomysium, into fascicles. Each muscle fiber contains sarcolemma, sarcoplasm, and sarcoplasmic reticulum. The functional unit of a muscle fiber is called a sarcomere. Each muscle cell contains myofibrils composed of actin and myosin myofilaments repeated as a sarcomere. Many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neomphalina
Neomphaloidea is a superfamily of deep-sea snails or limpets, marine gastropod mollusks. Neomphaloidea is the only superfamily in the order Neomphalida. The order Neomphalida has the largest ''in situ'' radiation in hydrothermal vent habitats. Neomphalida is a major taxonomic grouping of sea snails, vent-endemic marine gastropod mollusks that form a very ancient lineage, going back to the Palaeozoic era. 2005 taxonomy The superfamily Neomphaloidea was regarded for a long time as belonging within the clade Vetigastropoda. Superfamily Neomphaloidea was also classified in the clade Vetigastropoda according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005. 2010 taxonomy Molecular phylogeny showed that Neomphaloidea belongs in its own order, the Neomphalida, and that this clade is basal to the Vetigastropoda. The Neomphalina is, based on optimal phylogenetic analysis, a monophyletic clade, with uncertain relations among the gastropods. Description The anatomical cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neritimorpha
Neritimorpha is a clade of gastropod molluscs that contains around 2,000 extant species of sea snails, limpets, freshwater snails, land snails and slugs. This clade used to be known as the superorder Neritopsina. Etymology The clade’s name, Neritimorpha, is from the Ancient Greek νηρίτης (nērī́tēs 'Nerite') and μορφή (morphḗ 'form'). Description Despite their relatively low diversity, with only around 2,000 species, neritomorphs have achieved a remarkable diversity of forms, resembling a smaller-scale version of the diversity achieved by Gastropoda as a whole. Terrestrial lifestyles have evolved at least three separate occasions in neritimorphs: the extinct Dawsonellidae and the extant taxon, extant Helicinidae and Hydrocenidae. Neritimorphs also include the shellless, slug-like ''Titiscania''. In all modern neritomorphs except neritopsids, the inner walls of the protoconch are resorbed. Unlike most other gastropods, neritomorphs typically have calcifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocculiniformia
The Cocculinoidea is a superfamily of deepwater limpets (marine gastropods), the only superfamily in the order Cocculinida, one of the main orders of gastropods according to the taxonomy as set up by ( Bouchet & Rocroi, 2005). The clade Cocculiniformia used to be designated as a superorder. Taxonomy The Cocculinoidea (Cocculinacea Dall, 1882) are combined with the Lepetelliodea (Lepetellacea Dall, 1882) in Cocculinoformia Haszprunar, 1987, referred to as a clade in Bouchet & Rocroi, 2005 although it used to be designated a superorder by Ponder & Lindberg, 1997. Bouchet & Rocroi (2005) leave the Cocculiniformia to consist only of the Cocculinoidea, having moved the Lepetelloidea to the Vetigastropoda. (Note that before the stipulation by the ICZN, the majority of invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vetigastropoda
Vetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically the Vetigastropoda are sometimes treated as an order, although they are treated as an unranked clade in Bouchet and Rocroi, 2005. Vetigastropods are considered to be among the most primitive living gastropods, and are widely distributed in all oceans of the world. Their habitats range from the deep sea to intertidal zones. Many have shells with slits or other secondary openings. One of their main characteristics is the presence of intersected crossed platy shell structure. Most vetigastropods have some bilateral asymmetry of their organ systems. Description Vetigastropods range in size from approximately 0.08 in (2 mm) long in the case of Scissurelloidea or Skeneoidea, to more than 11.8 in (300 mm) in length, as with the Haliotoidea. External colours and patterns are typically drab, but such groups as the Tricolioidea and some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patelloidea
Patelloidea is a taxonomic superfamily of sea snails or true limpets, marine gastropod molluscs in the subclass Patellogastropoda.WoRMS (2020). Patelloidea Rafinesque, 1815. Accessed at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=156481 on 2020-07-31 Genera Families within the superfamily Patelloidea include: * Nacellidae Thiele, 1891 * Patellidae Patellidae is a taxonomic family of true limpets, marine gastropod molluscs in the superfamily Patelloidea. (The superfamily Patelloidea should not be confused with the similar-sounding genus of true limpets '' Patelloida'' which is in the ... Rafinesque, 1815 References * Bouchet, P., Rocroi, J.-P. (2005). Classification and nomenclator of gastropod families. Malacologia. 47(1-2): 1-397 . {{Taxonbar, from=Q606711 Patellogastropoda Taxa named by Constantine Samuel Rafinesque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digestive System Of Gastropods
The digestive system of gastropods has evolved to suit almost every kind of diet and feeding behavior. Gastropods (snails and slugs) as the largest taxonomic class of the mollusca are very diverse: the group includes carnivores, herbivores, scavengers, filter feeders, and even parasites. In particular, the radula is often highly adapted to the specific diet of the various group of gastropods. Another distinctive feature of the digestive tract is that, along with the rest of the visceral mass, it has undergone torsion (gastropod), torsion, twisting around through 180 degrees during the larval stage, so that the anus of the animal is located above its head. A number of species have developed special adaptations to feeding, such as the "drill" of some limpets, or the harpoon of the Neogastropoda, neogastropod genus ''Conus''. Filter feeders use the gills, mantle lining, or nets of mucus to trap their prey, which they then pull into the mouth with the radula. The highly modified para ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoplacophora
Shell of Monoplacophora Monoplacophora , meaning "bearing one plate", is a polyphyletic class of molluscs with a cap-like shell, inhabiting deep sea environments. Extant representatives were not recognized as such until 1952; previously they were known only from the fossil record, and were thought to have become extinct 375 million years ago. Although the shell of many monoplacophorans is limpet-like in shape, they are not gastropods, nor do they have any close relation to gastropods. Definition Discussion about monoplacophorans is made difficult by the slippery definition of the taxon; some authors take it to refer to all non-gastropod molluscs with a single shell, or all single-shelled molluscs with serially repeated units; whereas other workers restrict the definition to cap-shaped forms, excluding spiral and other shapes of shell. The inclusion of the gastropod-like Bellerophontoidea within the group is also contentious. One attempt to resolve this confusion was to separ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duct (anatomy)
In anatomy and physiology, a duct is a circumscribed channel leading from an exocrine gland or organ. Types of ducts Examples include: Duct system As ducts travel from the acinus which generates the fluid to the target, the ducts become larger and the epithelium becomes thicker. The parts of the system are classified as follows: Some sources consider "lobar" ducts to be the same as "interlobar ducts", while others consider lobar ducts to be larger and more distal from the acinus. For sources that make the distinction, the interlobar ducts are more likely to classified with simple columnar epithelium (or pseudostratified epithelium), reserving the stratified columnar for the lobar ducts. File:Gray1025.png, Section of submaxillary gland of kitten. Duct semidiagrammatic. X 200. File:Gray1173.png, Section of portion of mamma. Intercalated duct The intercalated duct, also called intercalary duct (ducts of Boll), is the portion of an exocrine gland leading directly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiac Orifice
The stomach is a muscular, hollow organ in the upper gastrointestinal tract of humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical terms related to the stomach. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach is involved in the gastric phase of digestion, following the cephalic phase in which the sight and smell of food and the act of chewing are stimuli. In the stomach a chemical breakdown of food takes place by means of secreted digestive enzymes and gastric acid. It also plays a role in regulating gut microbiota, influencing digestion and overall health. The stomach is located between the esophagus and the small intestine. The pyloric sphincter controls the passage of partially digested food (chyme) from the stomach into the duodenum, the first and shortest part of the small intestine, where peristalsis takes over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucus
Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and mucous cells. It is a viscous colloid containing inorganic ions, inorganic salts, antimicrobial enzymes (such as lysozymes), Antibody, immunoglobulins (especially Immunoglobulin A, IgA), and glycoproteins such as lactoferrin and mucins, which are produced by goblet cells in the mucous membranes and submucosal glands. Mucus covers the Epithelium, epithelial cells that interact with outside environment, serves to protect the linings of the respiratory system, respiratory, Digestion#Digestive system, digestive, and Genitourinary system, urogenital systems, and structures in the Visual system, visual and auditory systems from pathogenic Fungus, fungi, bacteria and viruses. Most of the mucus in the body is produced in the gastrointestinal tract. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
