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Aqueductal Stenosis
Aqueductal stenosis is a narrowing of the aqueduct of Sylvius which blocks the flow of cerebrospinal fluid (CSF) in the ventricular system. Blockage of the aqueduct can lead to hydrocephalus, specifically as a common cause of congenital and/or obstructive hydrocephalus. The aqueduct of Sylvius is the channel which connects the third ventricle to the fourth ventricle and is the narrowest part of the CSF pathway with a mean cross-sectional area of 0.5 mm2 in children and 0.8 mm2 in adults. Because of its small size, the aqueduct is the most likely place for a blockage of CSF in the ventricular system. This blockage causes ventricle volume to increase because the CSF cannot flow out of the ventricles and cannot be effectively absorbed by the surrounding tissue of the ventricles. Increased volume of the ventricles will result in higher pressure within the ventricles, and cause higher pressure in the cerebral cortex, cortex from it being pushed into the skull. A person may hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurosurgery
Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the specialty (medicine), medical specialty that focuses on the surgical treatment or rehabilitation of disorders which affect any portion of the nervous system including the Human brain, brain, spinal cord, peripheral nervous system, and cerebrovascular system. Neurosurgery as a medical specialty also includes non-surgical management of some neurological conditions. Education and context In different countries, there are different requirements for an individual to legally practice neurosurgery, and there are varying methods through which they must be educated. In most countries, neurosurgeon training requires a minimum period of seven years after graduating from medical school. United Kingdom In the United Kingdom, students must gain entry into medical school. The MBBS qualification (Bachelor of Medicine, Bachelor of Surgery) takes four to six years depending on the student's route. The newly qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congenital
A birth defect is an abnormal condition that is present at childbirth, birth, regardless of its cause. Birth defects may result in disability, disabilities that may be physical disability, physical, intellectual disability, intellectual, or developmental disability, developmental. The disabilities can range from mild to severe. Birth defects are divided into two main types: structural disorders in which problems are seen with the shape of a body part and functional disorders in which problems exist with how a body part works. Functional disorders include metabolic disorder, metabolic and degenerative disease, degenerative disorders. Some birth defects include both structural and functional disorders. Birth defects may result from genetic disorder, genetic or chromosome abnormality, chromosomal disorders, exposure to certain medications or chemicals, or certain vertically transmitted infection, infections during pregnancy. Risk factors include folate deficiency, alcohol drink, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shunt (medical)
In medicine, a shunt is a hole or a small passage that moves, or allows movement of, fluid from one part of the body to another. The term may describe either congenital or acquired shunts; acquired shunts (sometimes referred to as iatrogenic shunts) may be either biological or mechanical. __TOC__ Types * Cardiac shunts may be described as right-to-left, left-to-right or bidirectional, or as systemic-to-pulmonary or pulmonary-to-systemic. * Cerebral shunt: In cases of hydrocephalus and other conditions that cause chronic increased intracranial pressure, a one-way valve is used to drain excess cerebrospinal fluid from the brain and carry it to other parts of the body. This valve usually sits outside the skull but beneath the skin, somewhere behind the ear. Cerebral shunts that drain fluid to the peritoneal cavity (located in the upper abdomen) are called ''ventriculoperitoneal'' (''VP'') shunts. * Lumbar-peritoneal shunt (a.k.a. ''lumboperitoneal'', ''LP''): In cases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Computed Tomography
An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ranging from 10 nanometers to 10 picometers, corresponding to frequencies in the range of 30 petahertz to 30 exahertz ( to ) and photon energies in the range of 100 eV to 100 keV, respectively. X-rays were discovered in 1895 by the German scientist Wilhelm Conrad Röntgen, who named it ''X-radiation'' to signify an unknown type of radiation.Novelline, Robert (1997). ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. . X-rays can penetrate many solid substances such as construction materials and living tissue, so X-ray radiography is widely used in medical diagnostics (e.g., checking for broken bones) and materials science (e.g., identification of some chemical elements and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fourth Ventricle Small , or The Fourth of July
{{Disambiguation ...
Fourth or the fourth may refer to: * the ordinal form of the number 4 * ''Fourth'' (album), by Soft Machine, 1971 * Fourth (angle), an ancient astronomical subdivision * Fourth (music), a musical interval * ''The Fourth'', a 1972 Soviet drama See also * * * 1/4 (other) * 4 (other) * The fourth part of the world (other) * Forth (other) * Quarter (other) * Independence Day (United States) Independence Day, known colloquially as the Fourth of July, is a federal holiday in the United States which commemorates the ratification of the Declaration of Independence by the Second Continental Congress on July 4, 1776, establishing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Third Ventricle Small
Third or 3rd may refer to: Numbers * 3rd, the ordinal form of the cardinal number 3 * , a fraction of one third * 1⁄60 of a ''second'', i.e., the third in a series of fractional parts in a sexagesimal number system Places * 3rd Street (other) * Third Avenue (other) * Highway 3 Music Music theory *Interval number of three in a musical interval **Major third, a third spanning four semitones **Minor third, a third encompassing three half steps, or semitones **Neutral third, wider than a minor third but narrower than a major third **Augmented third, an interval of five semitones **Diminished third, produced by narrowing a minor third by a chromatic semitone *Third (chord), chord member a third above the root *Degree (music), three away from tonic **Mediant, third degree of the diatonic scale **Submediant, sixth degree of the diatonic scale – three steps below the tonic ** Chromatic mediant, chromatic relationship by thirds *Ladder of thirds, similar to the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adducted Thumb Syndrome
Adducted thumb syndrome recessive form is a rare disease affecting multiple systems causing malformations of the palate, thumbs, and upper limbs. The name Christian syndrome derives from Joe. C. Christian, the first person to describe the condition. Inheritance is believed to be autosomal recessive, caused by mutation in the CHST14 (carbohydrate sulfotransferase 14) gene. Signs and symptoms This syndrome is characterised by typical facial appearance, slight build, thin and translucent skin, severely adducted thumbs, arachnodactyly, club feet, joint instability, facial clefting and bleeding disorders, as well as heart, kidney or intestinal defects. Severe psychomotor and developmental delay and decreased muscle tone may also be present during infancy. Cognitive development during childhood is normal. Cause Diagnosis The syndrome is associated with microcephaly, arthrogryposis and cleft palate and various craniofacial, respiratory, neurological and limb abnormalities, including ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Adhesion
Cell adhesion is the process by which cells interact and attach to neighbouring cells through specialised molecules of the cell surface. This process can occur either through direct contact between cell surfaces such as Cell_junction, cell junctions or indirect interaction, where cells attach to surrounding extracellular matrix (ECM), a gel-like structure containing molecules released by cells into spaces between them. Cells adhesion occurs from the interactions between cell adhesion molecules, cell-adhesion molecules (CAMs), transmembrane proteins located on the cell surface. Cell adhesion links cells in different ways and can be involved in signal transduction for cells to detect and respond to changes in the surroundings. Other cellular processes regulated by cell adhesion include cell migration and tissue development in multicellular organisms. Alterations in cell adhesion can disrupt important cellular processes and lead to a variety of diseases, including cancer and arthrit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Point Mutation
A point mutation is a genetic mutation where a single nucleotide base is changed, inserted or deleted from a DNA or RNA sequence of an organism's genome. Point mutations have a variety of effects on the downstream protein product—consequences that are moderately predictable based upon the specifics of the mutation. These consequences can range from no effect (e.g. Synonymous substitution, synonymous mutations) to deleterious effects (e.g. frameshift mutations), with regard to protein production, composition, and function. Causes Point mutations usually take place during DNA replication. DNA replication occurs when one double-stranded DNA molecule creates two single strands of DNA, each of which is a template for the creation of the complementary strand. A single point mutation can change the whole DNA sequence. Changing one purine or pyrimidine may change the amino acid that the nucleotides code for. Point mutations may arise from spontaneous mutations that occur during DNA re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Growth
Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a device used to convert chemical energy to electrical energy * Prison cell, a room used to hold people in prisons Cell may also refer to: Arts, entertainment, and media Fictional entities * Cell (comics), a Marvel comic book character * Cell (Dragon Ball), Cell (''Dragon Ball''), a character in the manga series ''Dragon Ball'' Literature * Cell (novel), ''Cell'' (novel), a 2006 horror novel by Stephen King * "Cells", poem, about a hungover soldier in gaol, by Rudyard Kipling *The Cell (play), ''The Cell'' (play), an Australian play by Robert Wales Music * Cell (music), a small rhythmic and melodic design that can be isolated, or can make up one part of a thematic context * Cell (American band) * Cell (Japanese band) * Cell (album), ''Cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Stress
Shear stress (often denoted by , Greek alphabet, Greek: tau) is the component of stress (physics), stress coplanar with a material cross section. It arises from the shear force, the component of force vector parallel to the material cross section. ''Normal stress'', on the other hand, arises from the force vector component perpendicular to the material cross section on which it acts. General shear stress The formula to calculate average shear stress or force per unit area is: \tau = ,where is the force applied and is the cross-sectional area. The area involved corresponds to the material face (geometry), face parallel to the applied force vector, i.e., with surface normal vector perpendicular to the force. Other forms Wall shear stress Wall shear stress expresses the retarding force (per unit area) from a wall in the layers of a fluid flowing next to the wall. It is defined as:\tau_w := \mu\left.\frac\_,where is the dynamic viscosity, is the flow velocity, and is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gliosis
Gliosis is a nonspecific reactive change of glial cells in response to damage to the central nervous system (CNS). In most cases, gliosis involves the proliferation or hypertrophy of several different types of glial cells, including astrocytes, microglia, and oligodendrocytes. In its most extreme form, the proliferation associated with gliosis leads to the formation of a glial scar. The process of gliosis involves a series of cellular and molecular events that occur over several days. Typically, the first response to injury is the migration of macrophages and local microglia to the injury site. This process, which constitutes a form of gliosis known as microgliosis, begins within hours of the initial CNS injury. Later, after 3–5 days, oligodendrocyte precursor cells are also recruited to the site and may contribute to remyelination. The final component of gliosis is astrogliosis, the proliferation of surrounding astrocytes, which are the main constituents of the glial sca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
