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Lamina
Lamina may refer to: Science and technology * Planar lamina, a two-dimensional planar closed surface with mass and density, in mathematics * Laminar flow, (or streamline flow) occurs when a fluid flows in parallel layers, with no disruption between the layers * Lamina (algae), a structure in seaweeds * Lamina (anatomy), with several meanings * Lamina (leaf), the flat part of a leaf, an organ of a plant * Lamina, the largest petal of a floret in an aster family flowerhead: see * ''Lamina'' (spider), a genus in the family Toxopidae * Lamina (neuropil), the most peripheral neuropil of the insect visual system *Nuclear lamina, another structure of a living cell *Basal lamina, a structure of a living cell *Lamina propria, the connective part of the mucous *Lamina of the vertebral arch *Lamination (geology), a layering structure in sedimentary rocks usually less than 1 cm in thickness * Laminae, a part of the horse hoof * Laminae, another name for the core lamiids, a clade in botany S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laminar Flow
In fluid dynamics, laminar flow is characterized by fluid particles following smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing. At low velocities, the fluid tends to flow without lateral mixing, and adjacent layers slide past one another like playing cards. There are no cross-currents perpendicular to the direction of flow, nor eddies or swirls of fluids. In laminar flow, the motion of the particles of the fluid is very orderly with particles close to a solid surface moving in straight lines parallel to that surface. Laminar flow is a flow regime characterized by high momentum diffusion and low momentum convection. When a fluid is flowing through a closed channel such as a pipe or between two flat plates, either of two types of flow may occur depending on the velocity and viscosity of the fluid: laminar flow or turbulent flow. Laminar flow occurs at lower velocities, below a threshold at which the flow becomes turbulent. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamina (spider)
''Lamina'' is a genus of South Pacific araneomorph spiders in the family Toxopidae, and was first described by Raymond Robert Forster in 1970. Species it contains four species, all found in New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...: *'' Lamina minor'' Forster, 1970 ( type) – New Zealand *'' Lamina montana'' Forster, 1970 – New Zealand *'' Lamina parana'' Forster, 1970 – New Zealand *'' Lamina ulva'' Forster, 1970 – New Zealand References External links * Araneomorphae genera Taxa named by Raymond Robert Forster Toxopidae {{Toxopidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamination (geology)
In geology, lamination () is a small-scale sequence of fine layers (laminae; singular: lamina) that occurs in sedimentary rocks. Laminae are normally smaller and less pronounced than bedding. Lamination is often regarded as planar structures one centimetre or less in thickness, whereas bedding layers are greater than one centimetre. However, structures from several millimetres to many centimetres have been described as laminae. A single sedimentary rock can have both laminae and beds. Description Lamination consists of small differences in the type of sediment that occur throughout the rock. They are caused by cyclic changes in the supply of sediment. These changes can occur in grain size, clay percentage, microfossil content, organic material content or mineral content and often result in pronounced differences in colour between the laminae. Weathering can make the differences even more clear. Lamination can occur as parallel structures (parallel lamination) or in different set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamina Propria
The lamina propria is a thin layer of connective tissue that forms part of the moist linings known as mucous membranes or mucosae, which line various tubes in the body, such as the respiratory tract, the gastrointestinal tract, and the urogenital tract. The lamina propria is a thin layer of loose (areolar) connective tissue, which lies beneath the epithelium, and together with the epithelium and basement membrane constitutes the mucosa. As its Latin name indicates, it is a characteristic component of the mucosa, or the mucosa's "own special layer." Thus, the term mucosa or mucous membrane refers to the combination of the epithelium and the lamina propria. The connective tissue of the lamina propria is loose and rich in cells. The cells of the lamina propria are variable and can include fibroblasts, lymphocytes, plasma cells, macrophages, eosinophilic leukocytes, and mast cells. It provides support and nutrition to the epithelium, as well as the means to bind to the underl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamina (anatomy)
Lamina is a general anatomical term meaning "plate" or "layer". It is used in both gross anatomy and microscopic anatomy to describe structures. Some examples include: * The laminae of the thyroid cartilage: two leaf-like plates of cartilage that make up the walls of the structure. * The vertebral laminae: plates of bone that form the posterior walls of each vertebra, enclosing the spinal cord. * The laminae of the thalamus: the layers of thalamus tissue. * The lamina propria: a connective tissue layer under the epithelium of an organ. * The nuclear lamina: a dense fiber network inside the nucleus of cells. * The lamina affixa: a layer of epithelium growing on the surface of the thalamus The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, .... * Lamina cribrosa with two different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planar Lamina
In mathematics, a planar lamina (or plane lamina) is a figure representing a thin, usually uniform, flat layer of the solid. It serves also as an idealized model of a planar cross section of a solid body in integration. Planar laminas can be used to determine moments of inertia, or center of mass of flat figures, as well as an aid in corresponding calculations for 3D bodies. Definition Basically, a planar lamina is defined as a figure (a closed set) of a finite area in a plane, with some mass . This is useful in calculating moments of inertia or center of mass for a constant density, because the mass of a lamina is proportional to its area. In a case of a variable density, given by some (non-negative) surface density function \rho(x,y), the mass m of the planar lamina is a planar integral of over the figure: :m = \iint_D\rho(x,y)\,dx\,dy Properties The center of mass of the lamina is at the point : \left(\frac,\frac\right) where M_y is the moment of the entire lamina a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Lamina
The basal lamina is a layer of extracellular matrix secreted by the epithelial cells, on which the epithelium sits. It is often incorrectly referred to as the basement membrane, though it does constitute a portion of the basement membrane. The basal lamina is visible only with the electron microscope, where it appears as an electron-dense layer that is 20–100 nm thick (with some exceptions that are thicker, such as basal lamina in lung alveoli and renal glomeruli). Structure The layers of the basal lamina ("BL") and those of the basement membrane ("BM") are described below: Anchoring fibrils composed of type VII collagen extend from the basal lamina into the underlying reticular lamina and loop around collagen bundles. Although found beneath all basal laminae, they are especially numerous in stratified squamous cells of the skin. These layers should not be confused with the lamina propria, which is found outside the basal lamina. Basement membrane The basement membra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Lamina
The nuclear lamina is a dense (~30 to 100 nm thick) fibrillar network inside the nucleus of eukaryote cells. It is composed of intermediate filaments and membrane associated proteins. Besides providing mechanical support, the nuclear lamina regulates important cellular events such as DNA replication and cell division. Additionally, it participates in chromatin organization and it anchors the nuclear pore complexes embedded in the nuclear envelope. The nuclear lamina is associated with the inner face of the inner nuclear membrane of the nuclear envelope, whereas the outer face of the outer nuclear membrane is continuous with the endoplasmic reticulum. The nuclear lamina is similar in structure to the nuclear matrix, that extends throughout the nucleoplasm. Structure and composition The nuclear lamina consists of two components, lamins and nuclear lamin-associated membrane proteins. The lamins are type V intermediate filaments which can be categorized as either A-type (lam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamina Cribrosa (other)
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Lamina cribrosa may refer to: *Cribriform plate of the ethmoid bone (horizontal lamina or lamina cribrosa ossis ethmoidalis) *Lamina cribrosa sclerae, a mesh-like structures which allows nerve fibres of the optic nerve to pass through the sclera See also * Lamina (anatomy) Lamina is a general anatomical term meaning "plate" or "layer". It is used in both gross anatomy and microscopic anatomy to describe structures. Some examples include: * The laminae of the thyroid cartilage: two leaf-like plates of cartilage t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamina (leaf)
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the shoot system. In most leaves, the primary photosynthetic tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf but in some species, including the mature foliage of ''Eucalyptus'', palisade mesophyll is present on both sides and the leaves are said to be isobilateral. Most leaves are flattened and have distinct upper (adaxial) and lower (abaxial) surfaces that differ in color, hairiness, the number of stomata (pores that intake and output gases), the amount and structure of epicuticular wax and other features. Leaves are mostly green in color due to the presence of a compound called chlorophyll that is essential for photosynthesis as it absorbs light en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamia (Basque Mythology)
The or (plural: or ) is a siren or nereid-like creature in Basque mythology. , , or are typically portrayed as living in and around rivers. They are depicted as beautiful, long-haired women with webbed duck feet, usually found at the river shore combing their hair with a golden comb and charming men. Mythology in coastal areas includes , a variety of lamiak who live in the sea and have fish-like tails, similar to a mermaid. Beliefs In Basque mythology, are described as helping those who give them presents by providing them with help at work. For example, if a farmer were to leave food for them at the river shore, they would eat it at night and in exchange finish ploughing his field. In some places, bridges were believed to have been built at night by : Ebrain (Bidarray, Lower Navarre), Azalain (Andoain, Gipuzkoa), Urkulu (Leintz-Gatzaga, Gipuzkoa), Liginaga-Astüe (Labourd). In other myths, must leave if the bridge that they were building at night was left unfinished ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamina (algae)
The lamina or blade in macroscopic algae like seaweed is a generally flattened structure that typically forms the principal bulk of the thallus Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms .... It is often developed into specialised organs such as flotation bladders and reproductive organs. The lamina is typically an expansion of the stipe which in term is attached to the substrate by the holdfast. Brown algae {{Protist structures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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