Image VenusianArachnoid.png thumb 240px Venusian arachnoid In astrogeology , an arachnoid is a large structure of unknown origin, and they have been found only on the surface of the planet Venus . Arachnoids get their name from their resemblance to spider web s. They appear as wiktionary concentric concentric ovals surrounded by a complex network of fracture s, and can span 200 kilometers. Over thirty arachnoids have been identified on Venus, so far. The arachnoid might be a strange relative to the volcano , but possibly different arachnoids are formed by different processes. ref name APOD This article contains text from the Astronomy Picture of the Day http antwrp.gsfc.nasa.gov apod ap980120.html . As a work of the United States Federal Government, it is in the public domain. ref See also Astrogeology Chaos terrain Geysers on Mars Rille References reflist External links http antwrp.gsfc.nasa.gov apod ap980120.html Astronomy Picture of the Day Venus This article incorporates text from a public domain NASA website. Category Surface features of Venus Category Planetary geology crater stub ca Aracnoide es Aracnoide fr Arachno de exog ologie it Aracnoide esogeologia pt Aracnoide astrogeologia fi Araknoidi astrogeologia uk zh ... more details
wiktionarypar arachnoidArachnoid may refer to Relating to arachnid s Arachnoid mater , a layer of the meninges, membranes that contain the central nervous system Arachnoidastrogeology , a geological structure found only on the planet Venus See also Arkanoid , an arcade game disambig ... more details
Infobox Anatomy Name Arachnoid trabeculae Image Arachnoid Trabeculae.png Caption The arachnoid trabeculae connecting the arachnoid and pial layers of the meninges The arachnoid trabeculae are delicate strands of connective tissue that loosely connect the two innermost layers of the meninges the arachnoid mater and the pia mater . ref http www.britannica.com EBchecked topic 31820 arachnoid trabeculae Arachnoid trabeculae . Encyclop dia Britannica. 2010. Encyclop dia Britannica Online. 09 Sep. 2010. ref They are found within the subarachnoid space where cerebrospinal fluid is also found. Embryologically, the trabeculae are the remnants of the common precursor that forms both the arachnoid and pial layers of the meninges. ref Farr, Gary, MD. http www.becomehealthynow.com article bodynervousadvanced 813 The Nervous System Advanced Version The Meninges , 24 Jun 2002. Retrieved 9 Sep 2010. ref See also Subarachnoid space Arachnoid mater Notes references Meninges Category Meninges ... more details
Infobox Anatomy Name PAGENAME Latin GraySubject 193 GrayPage 878 Image Gray769 en.svg Caption Diagrammatic representation of a section across the top of the skull, showing the membranes of the brain, etc. Arachnoid granulation label is at top right. Image2 Caption2 System MeshName MeshNumber Arachnoid granulations or arachnoid villi are small protrusions of the arachnoid brain arachnoid the thin second layer covering the brain through the dura mater the thick outer layer . They protrude into the venous sinuses of the brain, and allow cerebrospinal fluid CSF to exit the sub arachnoid space and enter the blood stream. Largest granulations lie along the superior sagittal sinus , a large venous space running from front to back along the centre of the head on the inside of the human skull skull . They are, however, present along other dural sinuses as well. Smaller granulations are called villi , large calcification calcified ones are referred to as pacchionian bodies. Function The arachnoid granulations act as one way valve s. Normally the pressure of the CSF is higher than that of the venous system , so CSF flows through the villi and granulations into the blood. If the pressure is reversed for some reason, fluid will not pass back into the subarachnoid space of the brain . The reason for this is not known. It has been suggested that the endothelial cell s of the venous sinus create vacuole s of CSF, which move through the cell and out into the blood. The importance of arachnoid granulations for the drainage of CSF is controversial. By some accounts, a large portion perhaps the majority of CSF is drained through lymphatics associated with extracranial segments of the cranial nerves. A large proportion of CSF is believed to leave the cranial vault through the axons of CN I olfactory nerve through their extension through the cribiform plate . Eponym Occasionally, they are referred to by their old name Pacchioni s granulations or pacchionian bodies , named after Italian a ... more details
Infobox disease Name Arachnoid cyst Image Arachnoid cyst.jpg Caption An MRI of a 25 year old woman with left frontotemporal arachnoid cyst. DiseasesDB 33219 ICD10 G93.0 ICD9 ICD9 348.0 ICDO OMIM 207790 MedlinePlus eMedicineSubj radio eMedicineTopic 48 MeshID D016080 Arachnoid cysts are cerebrospinal ... M, Tatagiba M. Cerebellopontine angle arachnoid cyst harbouring ectopic neuroglia , Pediatr Neurosurg ... brain and the cranial base or on the arachnoid membrane , one of the three membranes that cover the brain and the spinal cord . ref name ninds http www.ninds.nih.gov disorders arachnoid cysts arachnoid cysts.htm NINDS Arachnoid Cysts Information Page ref Arachnoid cysts are a congenital disorder , ref Gelabert Gonzalez M. Intracranial arachnoid cysts , Rev Neurol. , 2004 Dec 16 31 39 12 1161 6 .... ref name ninds Classification Arachnoid cysts can be found on the brain, or on the Vertebral column spine . Intracranial arachnoid cysts usually occur adjacent to the arachnoidal cistern. ref name joynt Arachnoid cyst. n.d. . Gale Encyclopedia of Neurological Disorders. Retrieved September 10, 2006, from Answers.com Web site http www.answers.com topic arachnoid cyst ref Spinal arachnoid cysts ... of a radiculopathy . ref name joynt Arachnoid cysts may also be classified as primary congenital or secondary ... Arachnoid Cysts in a kitten and a dog. J Vet Diagn Invest 2009. 21 5 707 710. Arachnoid cysts ... symptoms for this reason, diagnosis is often delayed. Signs and symptoms Patients with arachnoid ... in a study on affected children. ref Millichap JG. Temporal lobe arachnoid cyst attention deficit ... an arachnoid cyst. In a 2002 study involving 78 patients with a migraine or tension type headache, CT scans showed abnormalities in over a third of the patients, though arachnoid cysts only accounted ... 3 A 542 7. PMID 12244387 ref A study found 18 of patients with intracranial arachnoid cysts had non ... Cameron AD. Psychotic phenomena with migraine and an arachnoid cyst , Progress in Neurology and Psychiatry ... more details
File ShoemakerCenter.jpg thumb 300px The USGS Shoemaker Center for Astrogeology, located on the campus of the Flagstaff Science Center, is the home of the Astrogeology Science Center Image AstroEntrance.jpg thumb 300px Displays in the entryway of the USGS Shoemaker Center for Astrogeology, featuring Grover, a working model of the lunar rover s used to train astronauts in Flagstaff, Arizona Flagstaff, Arizona. The USGS Astrogeology Science Center has a rich history of participation in space exploration efforts and planetary mapping, Citation needed date May 2008 starting in 1963 when the Flagstaff Science Center was established by Eugene Merle Shoemaker Gene Shoemaker to provide lunar geologic mapping and assist in training astronauts destined for the Moon. ref name Rocky Moon 1993 cite web url http www.lpi.usra.edu publications books rockyMoon title To a Rocky Moon A Geologist s History of Lunar Exploration last Wilhelms first Don date 1993 ref Starting with Project Apollo, the Program has participated in processing and analyzing data from various missions to the planetary bodies in our ... 1190 The U.S. Geological Survey, Branch of Astrogeology A Chronology of Activities from Conception ... 2005 . ref The Early Days Eugene Merle Shoemaker Gene Shoemaker founded the Astrogeology Research ... them worldwide fame. This was just one of Gene s many great accomplishments. Starting in 1963, the Astrogeology ... Schmitt joined the Astrogeology team as a geologist at the Flagstaff Science Center in 1964, having ... missions in 1973 and 1974, and Schmitt would go to the Moon on the Apollo 17 mission. Astrogeology Today Today, the mission of the USGS Astrogeology Research Program is to establish and maintain ... public in support of terrestrial and planetary geoscientific studies. The USGS Astrogeology Research ... and characterization. Recent, ongoing, and upcoming space missions involving the USGS Astrogeology ... USGS Astrogeology Science Center http arizona.usgs.gov Flagstaff USGS Flagstaff Science ... more details
saved book title Venus subtitle cover image Venus globe.jpg cover color Black Venus Overview Venus Features Atmosphere of Venus Atmosphere Geology of Venus Geology Volcanism on Venus Volcanism Arachnoid astrogeology Arachnoid List of geological features on Venus Geological features on Venus List of coronae on Venus Coronae on Venus List of craters on Venus Craters on Venus List of montes on Venus Montes on Venus List of terrae on Venus Terrae on Venus List of quadrangles on Venus Quadrangles on Venus Exploration Observations and explorations of Venus Observations and explorations List of artificial objects on Venus Artificial objects on Venus Colonization of Venus Colonization Terraforming of Venus Terraforming Flyby & direct missions Venera Venera 1 Venera 2 Venera 3 Venera 4 Venera 5 Venera 6 Venera 7 Venera 8 Venera 9 Venera 10 Venera 11 Venera 12 Venera 13 Venera 14 Venera 15 Venera 16 Mariner program Mariner 2 Mariner 5 Mariner 10 Zond program Zond 1 Pioneer Venus project Vega program Vega 1 Vega 2 Galileo spacecraft Galileo Magellan spacecraft Magellan Cassini Huygens Venus Express MESSENGER Akatsuki spacecraft Akatsuki IKAROS Shin en spacecraft Shin en Proposed missions Venera D Venus In Situ Explorer Venus Entry Probe Cancelled missions TMK Manned Venus Flyby Miscellany Ashen light Cytherean Hesperus Neith hypothetical moon Neith Venus in fiction Venusians Category Wikipedia books on astronomy Venus ... more details
In medicine , leptomeninges literally thin meninges is a term used to refer to the pia mater and arachnoid mater , two of the membranes that surround the brain and the spinal cord. ref EMedicineDictionary leptomeninges ref The morphology of the brain in meningococcal meningitis is said to be covered by exudate of the surface of, and within the leptomeninges. Because the arachnoid is connected to the pia by cob web like strands, it is structurally continuous with the pia, hence the name pia arachnoid or leptomeninges. References reflist Meninges Category Meninges es Leptomeninge ... more details
dike s or graben s and arachnoidastrogeologyarachnoid s. A nova is formed when large quantities ... geological processes. Image VenusianArachnoid.png thumb right 240px ArachnoidastrogeologyArachnoid ... more details
Unreferenced stub auto yes date December 2009 Orphan date February 2009 Astrolithology is the field of astrogeology which focuses on the study of rocks and the conditions by which they form. See also Petrology Astrophysics Astronomy Astrology Astrogeology Europa moon Europa Mars Category Planetary geology Astronomy stub ... more details
Villus Latin language Latin shaggy hair , ref name tiscali cite web url http www.tiscali.co.uk reference encyclopaedia hutchinson m0035419.html title villus work tiscali.co.uk accessdate 2009 06 19 ref plural villi may refer to Intestinal villus , the most common meaning when not more precisely specified Chorionic villi , found on the surface of the outermost membrane the chorion of the fetus Arachnoid villi , located on the arachnoid membrane of the brain Villi may also refer to Le Villi , opera by Puccini References references no Tarmtott disambig ... more details
ACMF may refer to Allied Central Mediterranean Force , a force consisting of the US Fifth Army and the British Eighth Army during World War II. Adriamycin , Cyclophosphamide , Methotrexate , and 5 Fluorouracil , a chemotherapy regimen used in the treatment of breast cancer Arachnoid cyst Arachnoid Cysts of the Middle Fossa, the most common location where intracranial arachnoid cysts are found Adivasi Cobra Militant Force , a militant adivasi organization in Assam Antimatter catalyzed nuclear pulse propulsion Antimatter Antiproton Catalyzed Micro Fission Fusion , a future technology being developed for long distance space travel Two similarly named country music organizations use this acronym Austria n Country Music Federation Australian Country Music Foundation disambig ... more details
Dorsum plural Dorsa is a Latin word. In science, it could mean Dorsum anatomy , the upper side of an animal, or the Anatomical terms of location back in humans and similarly erect organisms. Dorsum astrogeology , a term used in astrogeology for a ridge Theta Capricorni , a star on the back of Capricornus the Goat ref http www.constellationsofwords.com stars Dorsum.html Constellations of Words Dorsum ref disambig References reflist de Dorsum lb Dorsum ... more details
Sulcus plural sulci is, in astrogeology, a long parallel groove on a planet or a moon. For example, Uruk Sulcus is a bright region of grooved terrain adjacent to Galileo Regio on Jupiter s moon Ganymede moon Ganymede . References reflist Category Geology geology stub ... more details
life, but rather chaotic terrain . See also Arachnoidastrogeology Arachnoids Areas of chaos terrain on Mars Astrogeology Martian spiders Rilles References references DEFAULTSORT Chaos Terrain ...Image Europa Chaos.jpg thumb right 300px Conamara Chaos on Europa Chaos terrain or chaotic terrain is an astrogeology astrogeological term used to denote planetary surface areas where features such as ridges, cracks, and plains appear jumbled and enmeshed with one another. Chaos terrain is a notable feature of the planet Mars and Jupiter s moon Europa moon Europa . In scientific nomenclature, chaos is used as a component of proper nouns e.g., Aureum Chaos on Mars . ref Robert Roy Britt, http www.space.com scienceastronomy 050425 mars chaos.html Chaos on Mars , Space.com ref Chaos terrain on Mars Main Martian chaos terrain gallery Image Margaritifer Sinus Map.JPG Map of Margaritifer Sinus quadrangle with major features labeled. Aureum Chaos is near the top of the map. Image Canyons and Mesas of Aureum Chaos in Oxia Palus.JPG Huge canyons in Aureum Chaos , as seen by THEMIS . Gullies are rare at this latitude. Image from Margaritifer Sinus quadrangle . Image Iani Chaos.JPG Iani Chaos , as seen by THEMIS . Sand from eroding mesas is covering brighter floor material. Click on image to see relationship of Iani Chaos to other local features. Image from Margaritifer Sinus quadrangle. Image Oxia Palus Map.JPG Quadrangle architecture Quadrangle map of Oxia Palus labeled with major features. This quadrangle contains many collapsed areas of Chaos and many outflow channels old river valleys . Image Erosion in Aram Chaos.JPG Erosion in Aram Chaos , as seen by THEMIS . Image in Oxia Palus quadrangle . Image Blocks in Aram.JPG Blocks in Aram showing possible source of water, as seen by THEMIS. Image in Oxia Palus quadrangle. Image Hydraotes Chaos.JPG Hydraotes Chaos , as seen by HiRISE. Click on image to seen channels and layers. Scale bar is 1000 meters long. Image in Oxia Palus quadrangle ... more details
the dura mater , the arachnoid mater , and the pia mater . The primary function of the meninges and of the cerebrospinal ... of the pia mater and arachnoid. The dura mater is a sac which envelops the arachnoid and has ... s. Diaphragma sellae , smallest infolding covers the pituitary gland and sella turcica . Arachnoid mater The middle element of the meninges is the arachnoid mater , so named because of its spider web like appearance. It provides a cushioning effect for the central nervous system . The arachnoid mater ... by flat cells also thought to be impermeable to fluid. The arachnoid does not follow the convolutions ..., particularly, a large number of fine filaments called arachnoid trabeculae pass from the arachnoid through the subarachnoid space to blend with the tissue of the pia mater. The arachnoid brain arachnoid .... Spaces The subarachnoid space is the space which normally exists between the arachnoid brain arachnoid and the pia mater , which is filled with cerebrospinal fluid . Normally, the dura mater is attached to the Human skull skull , or to the bones of the vertebral canal in the spinal cord . The arachnoid brain arachnoid is attached to the dura mater , while the pia mater is attached to the central nervous system tissue. When the dura mater and the arachnoid brain arachnoid separate through ... under the arachnoid it may occur spontaneously or as a result of trauma. A subdural hematoma is a hematoma collection of blood located in a separation of the arachnoid brain arachnoid from the dura mater . The small veins which connect the dura mater and the arachnoid brain arachnoid are torn, usually ... meninx . Mammals retain the dura mater, and the secondary meninx divides into the arachnoid mater arachnoid ... more details
for the psychedelic rock band SubArachnoid Space Infobox Anatomy Name Subarachnoid space Latin spatium subarachnoideum, cavum subarachnoideale GraySubject 193 GrayPage 876 Image Gray769 en.svg Caption Diagrammatic representation of a section across the top of the skull, showing the membranes of the brain, etc. Subarachnoid cavity visible at left. Image2 Gray770 en.svg Caption2 Diagrammatic transverse section of the medulla spinalis and its membranes. Subarachnoid cavity colored blue. System MeshName Subarachnoid Space MeshNumber A08.186.566.166.686 DorlandsPre s 16 DorlandsSuf 12746651 In the central nervous system , the subarachnoid cavity subarachnoid space is the interval between the arachnoid membrane and pia mater . It is occupied by spongy tissue consisting of trabecula e delicate connective tissue filaments that extend from the arachnoid mater and blend into the pia mater and intercommunicating channels in which the cerebrospinal fluid is contained. This cavity is small on the surface of the hemispheres of the brain . On the summit of each gyrus the pia mater and the arachnoid are in close contact, but in the Sulcus neuroanatomy sulci between the gyri, triangular spaces are left, in which the subarachnoid trabecular tissue is found. Whilst the pia mater closely follows the surface of the brain and dips into the sulci, the arachnoid bridges across them from gyrus to gyrus. At certain parts of the base of the brain, the arachnoid is separated from the pia mater by wide intervals, which communicate freely with each other and are named subarachnoid cistern in these the subarachnoid tissue is less abundant. The subarachnoid space is the location of the interface between the vascular tissue and the cerebrospinal fluid and is active in the blood brain barrier . The arachnoid mater continues down the spinal cord too, and the subarachnoid layer with it. It serves a similar function in the spinal cord as it does in the brain. See also Subarachnoid hemorrhage Epidural ... more details
wiktionarypar arachnid An arachnid is a member of a class of joint legged invertebrate animals. Arachnid may also refer to Arachnid Solitaire or Spider, a solitaire card game Arachnid or Bug Starship Troopers Bugs Starship Troopers , a member of a fictional alien race in Starship Troopers by Robert A. Heinlein See also Arachne disambiguation Arachnoid disambiguation disambig ... more details
Infobox Anatomy Name PAGENAME Latin spatium subdurale, cavum subdurale GraySubject 193 GrayPage 875 Image Gray769 en.svg Caption Diagrammatic representation of a section across the top of the skull, showing the membranes of the brain, etc. Subdural cavity visible at left. Image2 Gray770 en.svg Caption2 Diagrammatic transverse section of the medulla spinalis and its membranes. Subdural cavity is colored green, labeled at bottom and top right. System MeshName MeshNumber DorlandsPre s 16 DorlandsSuf 12746663 The subdural space or subdural cavity is an artificial space created by the separation of the arachnoid mater from the dura mater as the result of trauma, pathologic process, or the absence of cerebrospinal fluid as seen in a cadaver. In the cadaver , due to the absence of cerebrospinal fluid in the subarachnoid space , the arachnoid mater falls away from the dura mater. It may also be the site of trauma, such as a subdural hematoma , causing abnormal separation of dura and arachnoid mater. Hence, the subdural space is referred to as potential space potential or artificial space. See also Epidural space Subarachnoid space Meninges Subdural hematoma External links eMedicineDictionary subdural space cite journal author Haines D, Harkey H, al Mefty O title The subdural space a new look at an outdated concept journal Neurosurgery volume 32 issue 1 pages 111 20 year 1993 pmid 8421539 doi 10.1227 00006123 199301000 00017 MeshName Subdural space neuroscience stub Gray s meninges Category Nervous system Category Meninges ... more details
Infobox Brain Name PAGENAME Latin cisterna fossae lateralis cerebri GraySubject 193 GrayPage 877 Image Caption Image2 Caption2 IsPartOf Components Artery Vein BrainInfoType BrainInfoNumber MeshName MeshNumber DorlandsPre c 37 DorlandsSuf 12241855 The cistern of lateral cerebral fossa is formed in front of either temporal lobe by the arachnoid bridging across the lateral fissure . This cavity contains the middle cerebral artery . Gray s anatomy stub Meninges Category Meninges ... more details
Unreferenced date July 2009 Antonio Pacchioni 1665 1726 was an Italy Italian scientist and anatomist , who focused chiefly on the outermost meninges meningeal layer of the brain , the dura mater . Paccioni s granulations or pacchionian bodies , where the arachnoid layer protrudes through the dura, are named for him although they are now generally known as arachnoid granulations . Pacchioni was born in Reggio Emilia, Italy Reggio Emilia , where he would later attend university. He received his degree in medicine in 1688, and left for Rome in 1689. Persondata Metadata see Wikipedia Persondata . NAME Pacchioni, Antonio ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH 1665 PLACE OF BIRTH DATE OF DEATH 1726 PLACE OF DEATH DEFAULTSORT Pacchioni, Antonio Category Italian anatomists Category 1665 births Category 1726 deaths italy med bio stub pl Antonio Pacchioni ... more details
Infobox Brain Name Cisterna magna Latin cisterna cerebellomedullaris GraySubject 193 GrayPage 876 Image Gray768.png Caption Diagram showing the positions of the three principal cisterns in the brain. The cisterna magna is visible at the lower right. Image2 Caption2 System Ventricular system Ventricular BrainInfoType hier BrainInfoNumber 533 MeshName Cisterna Magna MeshNumber A08.186.566.166.686.351 The cisterna magna or cerebellomedullary cistern is one of three principal openings in the subarachnoid space between the arachnoid mater arachnoid and pia mater layers of the meninges surrounding the brain. The openings are collectively referred to as cistern neuroanatomy cistern s. The cisterna magna is located between the cerebellum and the dorsal surface of the medulla oblongata . Cerebrospinal fluid produced in the fourth ventricle drains into the cisterna magna via the lateral apertures and median aperture . The two other principal cisterns are the pontine cistern located between the pons and the medulla, and the interpeduncular cistern located between the cerebral peduncles. Cerebral spinal fluid can also be obtained by puncture of the cisterna magna cistern puncture . Meninges DEFAULTSORT Cisterna Magna Category Meninges sv Cisterna Magna Neuroscience stub ... more details
dome s in Venus s Alpha Regio File VenusianArachnoid.png thumb right ArachnoidastrogeologyArachnoid ... of dike geology dike s or graben s and arachnoidastrogeologyarachnoid s. A nova is formed when ... dune fields List of mountains on Venus Arachnoidastrogeology List of geological features ... telescopes. Interest in the astrogeology geological characteristics of Venus was stimulated by the refinement ... more details
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