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Brodmann Area 18
Human Brodmann area 18, or BA18, is part of the occipital cortex in the human brain. It accounts for the bulk of the volume of the occipital lobe. It is known as a "Visual Association Area" or V2 and is a first stage in processing or feature extraction of retinotopic images from V1. This area is also known as parastriate area 18. It is a subdivision of the cytoarchitecturally defined occipital region of cerebral cortex. In the human it is located in parts of the cuneus, the lingual gyrus and the lateral occipital gyrus (H) of the occipital lobe. It is bounded on one side by the Brodmann area 17, from which it is distinguished by absence of a band of Gennari, and on the other by the peristriate area 19 (Brodmann-1909). Guenon Brodmann area 18 is a subdivision of the cerebral cortex of the guenon defined on the basis of cytoarchitecture. It is topographically and cytoarchitecturally homologous to parastriate area 18 of the human (Brodmann-1909). Distinctive features (Brodmann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occipital Lobe
The occipital lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The name derives from its position at the back of the head, from the Latin ''ob'', "behind", and ''caput'', "head". The occipital lobe is the visual processing center of the mammalian brain containing most of the anatomical region of the visual cortex. The primary visual cortex is Brodmann area 17, commonly called V1 (visual one). Human V1 is located on the medial side of the occipital lobe within the calcarine sulcus; the full extent of V1 often continues onto the occipital pole. V1 is often also called striate cortex because it can be identified by a large stripe of myelin, the Stria of Gennari. Visually driven regions outside V1 are called extrastriate cortex. There are many extrastriate regions, and these are specialized for different visual tasks, such as visuospatial processing, color differentiation, and motion perception. Bilateral lesions of the occipital lobe can lead ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homology (biology)
In biology, homology is similarity due to shared ancestry between a pair of structures or genes in different taxa. A common example of homologous structures is the forelimbs of vertebrates, where the wings of bats and birds, the arms of primates, the front flippers of whales and the forelegs of four-legged vertebrates like dogs and crocodiles are all derived from the same ancestral tetrapod structure. Evolutionary biology explains homologous structures adapted to different purposes as the result of descent with modification from a common ancestor. The term was first applied to biology in a non-evolutionary context by the anatomist Richard Owen in 1843. Homology was later explained by Charles Darwin's theory of evolution in 1859, but had been observed before this, from Aristotle onwards, and it was explicitly analysed by Pierre Belon in 1555. In developmental biology, organs that developed in the embryo in the same manner and from similar origins, such as from matching p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Regions In The Human Brain
The human brain anatomical regions are ordered following standard neuroanatomy hierarchies. Functional, connective, and developmental regions are listed in parentheses where appropriate. Hindbrain (rhombencephalon) Myelencephalon * Medulla oblongata **Medullary pyramids **Arcuate nucleus **Olivary body ***Inferior olivary nucleus **Rostral ventrolateral medulla **Caudal ventrolateral medulla **Solitary nucleus (Nucleus of the solitary tract) **Respiratory center- Respiratory groups ***Dorsal respiratory group ***Ventral respiratory group or Apneustic centre ****Pre-Bötzinger complex ****Botzinger complex ****Retrotrapezoid nucleus ****Nucleus retrofacialis ****Nucleus retroambiguus ****Nucleus para-ambiguus **Paramedian reticular nucleus **Gigantocellular reticular nucleus **Parafacial zone **Cuneate nucleus ** Gracile nucleus ** Perihypoglossal nuclei *** Intercalated nucleus *** Prepositus nucleus *** Sublingual nucleus **Area postrema **Medullary cranial nerve nucl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brodmann Area
A Brodmann area is a region of the cerebral cortex, in the human or other primate brain, defined by its cytoarchitecture, or histological structure and organization of cells. History Brodmann areas were originally defined and numbered by the German anatomist Korbinian Brodmann based on the cytoarchitectural organization of neurons he observed in the cerebral cortex using the Nissl method of cell staining. Brodmann published his maps of cortical areas in humans, monkeys, and other species in 1909, along with many other findings and observations regarding the general cell types and laminar organization of the mammalian cortex. The same Brodmann area number in different species does not necessarily indicate homologous areas. A similar, but more detailed cortical map was published by Constantin von Economo and Georg N. Koskinas in 1925. Present importance Brodmann areas have been discussed, debated, refined, and renamed exhaustively for nearly a century and remain the most wid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granule Cell
A granule is a large particle or grain. It can refer to: * Granule (cell biology), any of several submicroscopic structures, some with explicable origins, others noted only as cell type-specific features of unknown function ** Azurophilic granule, a structure characteristic of the azurophil eukaryotic cell type ** Chromaffin granule, a structure characteristic of the chromophil eukaryotic cell type. * Astrophysics and geology: ** Granule (solar physics), a visible structure in the photosphere of the Sun arising from activity in the Sun's convective zone ** Martian spherules, spherical granules of material found on the surface of the planet Mars ** Granule (geology), a specified particle size of 2–4 millimetres (-1 to -2 on the φ scale) * Granule, in pharmaceutical terms, small particles gathered into a larger, permanent aggregate in which the original particles can still be identified * Granule (Oracle DBMS), a unit of contiguously allocated virtual memory * Granular synthesis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area 17 Of Brodmann
The visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus and then reaches the visual cortex. The area of the visual cortex that receives the sensory input from the lateral geniculate nucleus is the primary visual cortex, also known as visual area 1 ( V1), Brodmann area 17, or the striate cortex. The extrastriate areas consist of visual areas 2, 3, 4, and 5 (also known as V2, V3, V4, and V5, or Brodmann area 18 and all Brodmann area 19). Both hemispheres of the brain include a visual cortex; the visual cortex in the left hemisphere receives signals from the right visual field, and the visual cortex in the right hemisphere receives signals from the left visual field. Introduction The primary visual cortex (V1) is located in and around the calcarine fissure in the occipital lobe. Each hemisphere's V1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Matter
White matter refers to areas of the central nervous system (CNS) that are mainly made up of myelinated axons, also called tracts. Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distribution of action potentials, acting as a relay and coordinating communication between different brain regions. White matter is named for its relatively light appearance resulting from the lipid content of myelin. However, the tissue of the freshly cut brain appears pinkish-white to the naked eye because myelin is composed largely of lipid tissue veined with capillaries. Its white color in prepared specimens is due to its usual preservation in formaldehyde. Structure White matter White matter is composed of bundles, which connect various grey matter areas (the locations of nerve cell bodies) of the brain to each other, and carry nerve impulses between neurons. Myelin acts as an insulator, which allows electrical signals to jump, rather than c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymorphic Cell
Polymorphism, polymorphic, polymorph, polymorphous, or polymorphy may refer to: Computing * Polymorphism (computer science), the ability in programming to present the same programming interface for differing underlying forms * Ad hoc polymorphism, applying polymorphic functions to arguments of different types * Parametric polymorphism, abstracts types, so that multiple can be used with a single implementation ** Bounded quantification, restricts type parameters to a range of subtypes * Subtyping, different classes related by some common superclass can be used in place of that superclass * Row polymorphism, uses structural subtyping to allow polymorphism over records * Polymorphic code, self-modifying program code designed to defeat anti-virus programs or reverse engineering Science Biology * Chromosomal polymorphism, a condition where one species contains members with varying chromosome counts or shapes * Cell polymorphism, variability in size of cells or nuclei * Gene polymorph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiform Layer
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of allocortex. It is separated into two cortices, by the longitudinal fissure that divides the cerebrum into the left and right cerebral hemispheres. The two hemispheres are joined beneath the cortex by the corpus callosum. The cerebral cortex is the largest site of neural integration in the central nervous system. It plays a key role in attention, perception, awareness, thought, memory, language, and consciousness. The cerebral cortex is part of the brain responsible for cognition. In most mammals, apart from small mammals that have small brains, the cerebral cortex is folded, providing a greater surface area in the confined volume of the cranium. Apart from minimising brain and cranial volume, cortical folding is crucial for the brai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganglion
A ganglion is a group of neuron cell bodies in the peripheral nervous system. In the somatic nervous system this includes dorsal root ganglia and trigeminal ganglia among a few others. In the autonomic nervous system there are both sympathetic and parasympathetic ganglia which contain the cell bodies of postganglionic sympathetic and parasympathetic neurons respectively. A pseudoganglion looks like a ganglion, but only has nerve fibers and has no nerve cell bodies. Structure Ganglia are primarily made up of somata and dendritic structures which are bundled or connected. Ganglia often interconnect with other ganglia to form a complex system of ganglia known as a plexus. Ganglia provide relay points and intermediary connections between different neurological structures in the body, such as the peripheral and central nervous systems. Among vertebrates there are three major groups of ganglia: *Dorsal root ganglia (also known as the spinal ganglia) contain the cell bodies of se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyramidal Layer
A pyramid (from el, πυραμίς ') is a structure whose outer surfaces are triangular and converge to a single step at the top, making the shape roughly a pyramid in the geometric sense. The base of a pyramid can be trilateral, quadrilateral, or of any polygon shape. As such, a pyramid has at least three outer triangular surfaces (at least four faces including the base). The square pyramid, with a square base and four triangular outer surfaces, is a common version. A pyramid's design, with the majority of the weight closer to the ground and with the pyramidion at the apex, means that less material higher up on the pyramid will be pushing down from above. This distribution of weight allowed early civilizations to create stable monumental structures. Civilizations in many parts of the world have built pyramids. The largest pyramid by volume is the Great Pyramid of Cholula, in the Mexican state of Puebla. For thousands of years, the largest structures on Earth were pyrami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyramidal Cell
Pyramidal cells, or pyramidal neurons, are a type of multipolar neuron found in areas of the brain including the cerebral cortex, the hippocampus, and the amygdala. Pyramidal neurons are the primary excitation units of the mammalian prefrontal cortex and the corticospinal tract. Pyramidal neurons are also one of two cell types where the characteristic sign, Negri bodies, are found in post-mortem rabies infection. Pyramidal neurons were first discovered and studied by Santiago Ramón y Cajal. Since then, studies on pyramidal neurons have focused on topics ranging from neuroplasticity to cognition. Structure File:GFPneuron.png, Pyramidal neuron visualized by green fluorescent protein (gfp) File:Hippocampal-pyramidal-cell.png, A hippocampal pyramidal cell One of the main structural features of the pyramidal neuron is the conic shaped soma, or cell body, after which the neuron is named. Other key structural features of the pyramidal cell are a single axon, a large apical dendrite, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
