Firefighting - wikipedia Firefighting Jump to : navigation , search Not to be confused with a firefight , which is a battle with firearms . Firefighters at a major fire involving an abandoned convent in Canada , 2006 Firefighting in Jyväskylä , Finland Firefighting is the act of attempting to prevent the spread of and extinguish significant unwanted fires in buildings , vehicles , woodlands , etc . A firefighter suppresses and extinguishes fires to protect lives , property and the environment . Firefighters may provide other services to their communities . Firefighters typically undergo a high degree of technical training . This involves both general firefighting techniques and developing specialist expertise in particular fire operations , such as aircraft firefighting and wildland firefighting In the U.S. the national level of certifications are called Firefighter I / II . One of the major hazards associated with firefighting operations is the toxic environment created by combustible materials . The four major risks are smoke , oxygen deficiency , elevated temperatures , and poisonous atmospheres . Additional hazards include falls and structural collapse that can exacerbate the problems entailed in a toxic environment . To combat some of these risks , firefighters carry self - contained breathing equipment . The first step in a firefighting operation is reconnaissance to search for the origin of the fire and to identify the specific risks . Fires can be extinguished by water , fuel or oxidant removal , or chemical flame inhibition . Contents ( hide ) 1 History 1.1 Historic tactics and tools 1.2 Ancient Rome 1.3 United Kingdom 1.4 United States 2 Firefighter duties 2.1 Firefighter skills 2.2 Specialized skills 2.3 Shift hours 2.4 Fire wardens 3 Hazards caused by fire 4 Reconnaissance and `` reading '' the fire 5 Science of extinguishment 6 Use of water 6.1 Open air fire 6.2 Closed volume fire 7 Asphyxiating a fire 8 Tactical ventilation or isolation of the fire 9 Categorizing fires in the US 10 See also 11 References 12 External links History ( edit ) Bulgarian firefighters in action , 1930s Ottawa Fire Department motor pump , Ottawa , Ontario , taken by the Topley Studio , May 1915 . The earliest known firefighters were in the city of Rome . In 60 A.D. , emperor Nero established a Corps of Vigils ( Vigiles ) to protect Rome after a disastrous fire . It consisted of 7,000 people equipped with buckets and axes , and they fought fires and served as police . Historic tactics and tools ( edit ) In the 4th century B.C. , an Alexandrian Greek named Ctesibius made a double force pump called a siphona . As water rose in the chamber , it compressed the air inside , which forced the water to eject in a steady stream through a pipe and nozzle . In the 16th century , syringes were also used as firefighting tools , the larger ones being mounted on wheels . Another traditional method that survived was the bucket brigade , involving two lines of people formed between the water source and the fire . Typically , men in one of the lines would pass along the full buckets of water toward the fire while in the other line women and children would pass back the empty buckets to be refilled . In the 17th century , ' fire engines ' were made , notably in Amsterdam . In 1721 , the English inventor Richard Newsham made a popular fire engine that was essentially a rectangular box on wheels filled using a bucket brigade to provide a reservoir while hand - powered pumps supplied sufficient water pressure to douse fires at a distance . Ancient Rome ( edit ) Ancient Rome did not have municipal firefighters . Instead , private individuals relied on their slaves or supporters to take action . They would not only form bucket brigades or attempt to smother smaller fires , but would also demolish or raze nearby buildings to slow the spread of the fire . However , there is no mention of fires being extinguished , rather they were contained and burned themselves out . Ancient Rome did not have an organized firefighting force until the Vigiles were formed in the reign of Augustus . United kingdom ( edit ) Prior to the Great Fire of London in 1666 , some parishes in the UK had begun to organize rudimentary firefighting . After the Great Fire , Nicholas Barbon introduced the first fire insurance . In order to reduce insurance costs , Barbon also formed his own fire brigade , and other companies followed suit . By the start of the 1800s , insured buildings were identified with a badge or mark indicating that they were eligible for a company 's firefighting services . Buildings not insured with a particular company were left by its firefighters to burn , unless they happened to be adjacent to an insured building , in which case it was often in the company 's interest to prevent the fire from spreading . In 1833 fire insurance companies in London merged to form The London Fire Company Establishment . Steam - powered apparatuses were first introduced in the 1850s , allowing a greater quantity of water to be directed onto a fire ; in the early 1930s they were superseded by versions powered by an internal combustion engine . In World War II the Auxiliary Fire Service , and later the National Fire Service , were established to supplement local fire services . At that time , there was no countrywide standard for firefighting terms , procedures , ranks , or equipment ( such as hose couplings ) . These were standardized after the war . United States ( edit ) In January 1608 , a fire destroyed many of the colonists ' provisions and lodgings in Jamestown , Virginia . Boston , New York City , and Philadelphia were all plagued by fires , and volunteer fire brigades formed soon after such disasters . In 1736 , Benjamin Franklin founded the Union Fire Company in Philadelphia , which became the standard for volunteer fire organizations . These firefighters had two critical tools : salvage bags and so - called bed keys . Salvage bags were used to quickly collect and save valuables , and bed keys were used to separate the wooden frame of a bed into pieces for safe and rapid removal from the fire . The first American attempt at fire insurance failed after a large fire in Charlestown , Massachusetts in 1736 . Later in 1740 , Benjamin Franklin organized the Philadelphia Contributionship to provide fire insurance , which was more successful . The Contributionship adopted `` fire marks '' to easily identify insured buildings . Firefighting started to become formalized with rules for providing buckets , ladders , and hooks , and with the formation of volunteer companies . A chain of command was also established . Firefighter duties ( edit ) Play media Aerial video of Firefighting A firefighter 's goals are to save lives , property , and the environment . A fire can rapidly spread and endanger many lives , but with modern firefighting techniques , catastrophe can often be avoided . To prevent fires from starting , a firefighter 's duties may include public education about fire safety and conducting fire inspections of locations to verify their adherence to local fire codes . Firefighter skills ( edit ) A firefighter doing a ladder slide , which is used to quickly escape from a window Firefighting requires skills in combating , extinguishing , and preventing fires , responding to emergency calls , operating and maintaining fire department equipment and quarters , and extensive training in performing firefighting and rescue activities . Firefighters must also have , or be able to acquire , knowledge of department organizations , operations , and procedures , and the district or city street system they will have to negotiate in order to perform their duties . They must meet minimum physical fitness standards and learn various firefighting and rescue duties within a reasonable period Examples are : Structural Firefighting Wildland Firefighting Specialized skills ( edit ) Specialized areas of fire operations may require subject - specific training . A hose team training to fight an aircraft fire aboard a US aircraft carrier , 2006 Examples are : Aircraft Firefighting Maritime Firefighting Aerial Firefighting Shift hours ( edit ) Firefighters typically follow a 24 - hour shift schedule , although some fire departments work eight or 12 hour shifts . Australian firefighters work a 10 / 14 shift , in which the day shift works ten hours and the night shift works 14 hours . Firefighting personnel are split up into alternating shifts . Usually , the 24 hour shifts are followed by two days off . The shift personnel arrive for roll call at a specified time , ready to complete a regular tour of duty . While on shift , the firefighter remains at the fire station unless relieved or assigned other duties . Fire Wardens ( edit ) A fire warden poster , circa 1940s . In fire fighting , there are also people designated as fire wardens , also known as the chief officer . Their duties vary , some may ensure evacuation of that part of the building for which they are responsible ; others may be responsible for fire control in a particular area , direct a crew in the suppression of forest fires , or function as fire patrolmen in a logging area . The chief officer is in charge of his firefighters during fires or emergencies , and he is expected to command and control the overall situation while effectively combating a fire or other emergency . Chief officers must be able to evaluate their firefighters , use sound judgement when deciding when it is time to withdraw firefighters from a fire , and react calmly in emergency situations . The chief officer must direct the activities of a fire department and supervise all firefighting activities . In addition , he must have extensive knowledge of the city , the location of streets , fire hydrants and fire alarm boxes , and the principal buildings . Also he must have knowledge of explosives , hazardous chemicals , and the combustion qualities of materials in buildings , homes , and industrial plants . In certain jurisdictions , civilians can get certified to be a Fire Warden , and some cities require certain types of buildings , such as high rises , to have a certain number of Fire Wardens . For example , the City of Houston , Texas , requires every tenant in a high - rise to have at least one Fire Warden for every 7500 sq. ft. occupied , and a minimum of two Fire Wardens per floor . In this example , their duties include investigating any fire alarms ( see if there really is a fire and if so , its nature ) , ensuring the fire department is contacted , directing the evacuation of the facility , activating or delaying activation of fire suppression equipment such as halon and sprinklers ( delayed in case of a false alarm ) , meeting the fire department and taking them to the location of the alarm or to the fire past any security or locked doors , and , if necessary , fighting the fire until the fire department arrives . Hazards caused by fire ( edit ) Structure fire in Grand Rapids , Michigan , US One of the major hazards associated with firefighting operations is the toxic environment created by combusting materials . The four major hazards are : Smoke , which is becoming increasingly dangerous due to the increased variety and amount of synthetic household materials . Oxygen deficient atmosphere , 21 % O is normal , 19.5 % O is considered oxygen deficient . Elevated temperatures Toxic atmospheres To deal with such hazards , firefighters carry a self - contained breathing apparatus ( SCBA ; an open - circuit positive pressure system ) to prevent smoke inhalation . These are not oxygen tanks ( oxygen as a powerful fire accelerant would represent a grave risk when combined with virtually anything combustible in the presence of fire ) but use compressed air in a similar manner to SCUBA diving gear . A firefighter 's SCBA usually hold 30 to 45 minutes of air , depending on the size of the tank and the rate of consumption during strenuous activities . While this gear helps to eliminate the risks , firefighters are still exposed to smoke , toxic dust and fumes that have contributed to firefighters being 14 % more likely to develop cancer . Obvious risks associated with the immense heat generated by a fire , even without direct contact with the flames ( direct flame impingement ) , such as conductive heat and radiant heat , can cause serious burns even from great distances . There are a number of comparably serious heat - related risks , such as burns from hot gases ( e.g. , air ) , steam , and hot and / or toxic smoke . Accordingly , firefighters are equipped with personal protective equipment ( PPE ) that includes fire - resistant clothing such as Nomex or polybenzimidazole fiber ( PBI ) and helmets that limit the transmission of heat towards the body . No PPE , however , can completely protect the user from the effects of all possible fire conditions . Heat can cause flammable liquid contained in tanks to explode violently , producing what is called a BLEVE ( boiling liquid expanding vapor explosion ) . Some chemical products such as ammonium nitrate fertilizers can also explode , potentially causing physical trauma from blast or shrapnel injuries . Sufficient heat causes human flesh to burn as fuel , or the water within to boil , leading to potentially severe medical problems . Depending on the heat of the fire , burns can occur in a fraction of a second . Main article : Burn Additional risks of fire are the obscuring of vision due to smoke , potentially causing a fall or disorientation ; becoming trapped in a fire ; and structural collapse . `` Three hours of fighting a fire stiffens arteries and impairs cardiac function in firefighters '' according to a new study by Bo Fernhall , a professor in the department of kinesiology and community health in the College of Applied Health Sciences , and Gavin Horn , director of research at the Illinois Fire Service Institute . The conditions ( observed in healthy male firefighters ) are `` also apparent found in weightlifters and endurance athletes ... '' Reconnaissance and `` reading '' the fire ( edit ) The first step in a firefighting operation is reconnaissance to search for the origin of the fire ( which may not be obvious for an indoor fire , especially if there are no witnesses ) , to identify any specific risks , and to detect possible casualties . An outdoor fire may not require reconnaissance , but a fire in a cellar or an underground car park with only a few centimeters of visibility may require long reconnaissance to identify the source of the fire . The `` reading '' of a fire is the analysis by firefighters of indications of thermal events such as flashover , backdraft or smoke explosion . It is performed during reconnaissance and fire suppression maneuvers . The main signs are : Hot zones , which can be detected with a gloved hand , for example by touching a door before opening it ; Soot on windows , which usually means that combustion is incomplete , and thus , a lack of air in the room ; Smoke pulsing in and out around a door frame , as if the fire were breathing , which usually also means a lack of air to support combustion . Spraying water on the ceiling in short pulses of a diffused spray ( e.g. , a cone with an opening angle of 60 ° ) can be undertaken to test the heat of smoke : If the temperature is moderate , the water falls down in drops with a sound like rain ; if the temperature is high , the water vaporizes with a hiss -- the sign of a potentially extremely dangerous impending flashover . Ideally , part of reconnaissance is consulting a plan for the building that provides information about structures , firefighter hazards , and in some cases the most appropriate strategies and tactics for fighting a fire in that context . Science of extinguishment ( edit ) See also : Fire Chemistry and Physical properties of wildfires A fire helicopter is used to fight a wildfire There are four elements needed to start and sustain a fire and / or flame . These are a reducing agent ( fuel ) , Heat , an oxidizing agent ( oxygen ) , and a chemical reaction . A fire can be extinguished by taking away any of the four components . The fuel is the substance being oxidized or burned in the combustion process . The most common fuels contain carbon along with combinations of hydrogen and oxygen . Heat is the energy component of a fire . When it comes into contact with a fuel , it provides the energy necessary for ignition , causes the continuous production and ignition of fuel vapors or gases so that the combustion reaction can continue , and causes the vaporization of solid and liquid fuels . The resulting self - sustained chemical chain reaction is complex and requires fuel , an oxidizer , and heat energy to come together in a very specific way . An oxidizing agent is a material or substance that will release gases , including oxygen , when the proper conditions exist . It is crucial to the sustainment of a flame or fire . Using water is one common method to extinguish a fire . Water extinguishes a fire by cooling , which removes heat because of water 's ability to absorb massive amounts of heat as it converts to water vapor . Without heat , the fuel can not keep the oxidizer from reducing the fuel in order to sustain the fire . Water also extinguishes a fire by smothering it . When water is heated to its boiling point , it converts to water vapor . When this conversion takes place , it dilutes the oxygen in the air above the fire , thus removing one of the elements that the fire requires to burn . This can also be done with foam . Another way to extinguish a fire is fuel removal . This can be accomplished by stopping the flow of liquid or gaseous fuel , by removing solid fuel in the path of a fire , or by allowing the fire to burn until all the fuel is consumed , at which point the fire will self - extinguish . One final extinguishing method is chemical flame inhibition . This can be accomplished by applying dry chemical or halogenated agents that interrupt the chemical chain reaction and stop flaming . This method is effective on gas and liquid fuel ; because , they must have flame to burn . Sound waves have been successfully used in a device fabricated by two George Mason University senior engineering students , Viet Tran and Seth Robertson , but the procedure is still awaiting a patent ( 2015 ) . Use of water ( edit ) USMC firefighters neutralize a fire during a training exercise A firefighting aircraft dumping water on a forest fire in South Africa . One common way to extinguish a fire is to spray it with water . The water has two roles : It vaporizes when it comes in contact with fire , and this vapor displaces the oxygen ( the volume of water vapor is 1,700 times greater than liquid water , at 1,000 ° F ( 538 ° C ) it expands over 4,000 times ) . This leaves the fire without enough of the combustive agent , and it dies out . The vaporization of water also absorbs heat ; it thereby cools the smoke , air , walls , and objects that could act as further fuel , and thus prevents one of the means by which fires grow , which is by `` jumping '' to nearby heat / fuel sources to start new fires , which then combine . Water extinguishment is thus a combination of `` asphyxia '' ( cutting off the oxygen supply ) and cooling . The flame itself is suppressed by asphyxia , but the cooling is the most important element in mastering a fire in a closed area . Water may be accessed from a pressurized fire hydrant , pumped from water sources such as lakes or rivers , delivered by tanker truck , or dropped from water bombers , which are aircraft adapted as tankers for fighting forest fires . An armored vehicle ( firefighting tank ) may be used where access to the area is difficult . Open air fire ( edit ) For outdoor fires , the seat of the fire is sprayed with a straight spray : the cooling effect immediately follows the `` asphyxia '' caused by vaporization and reduces the further amount of water required . A straight spray is used so the water arrives massively to the seat of the fire before it vaporizes . A strong spray may also have a mechanical effect ; it can disperse the combustible product and thus prevent the fire from starting again . Spray is always aimed at a surface or an object . For this reason , the strategy is sometimes called a two - dimensional or 2D attack . An outdoor fire is always fed with air , and the risk to people is limited as they can move away from it , except in the case of wildfires or bushfires where they risk being easily surrounded by the flames . It might , however , be necessary to protect specific objects like houses or gas tanks against infrared radiation , and thus to use a diffused spray between the fire and the object . Breathing apparatus is often required as there is still the risk of inhaling smoke or poisonous gases . Closed volume fire ( edit ) Iranian firefighters had to extinguish the fire at Bistoon Petrochemicals Powerhouse Until the 1970s , fires were usually attacked while they declined , using the same strategy as for open air fires . Now fires are attacked in their development phase because firefighters arrive sooner at the site of a fire and because of changes in building construction . The increasing use of thermal insulation confines the heat , and modern materials , especially polymers , produce much more heat than do traditional materials like wood , plaster , stone , and bricks . Under these conditions , there is a greater risk of backdraft and flashover . Directly spraying the seat of the fire in enclosed areas can have unfortunate consequences : the force of water pushes air in front of it , which supplies the fire with extra oxygen before the water . The most important issue is not combating the flames , but controlling the fire ; for example , cooling the smoke so that it can not spread and start fires further away , and endanger the lives of people , including the firefighters . When a fire spreads beyond the building of its origin and spreads throughout the neighborhood , it is called a `` conflagration . '' Today , a conflagration is a large fire that is beyond the capability of the fire service to contain . The volume of the fire must be cooled before its seat is attacked . This strategy , originally of Swedish origin ( Mats Rosander & Krister Giselsson ) , was adapted by London Fire Officer Paul Grimwood following a decade of operational use in the busy West End of London between 1984 and 1994 and termed the three - dimensional or 3D attack . Use of a diffuse spray was first proposed by Chief Lloyd Layman of the Parkersburg Fire Department , at the 1950 Fire Department Instructors Conference ( FDIC ) held in Memphis . Using Grimwood 's modified 3D attack strategy , the ceiling is first sprayed with short pulses of a diffuse spray . This cools the smoke which is then less likely to start a fire when it moves away . As gas cools it becomes denser ( Charles 's law ) ; thus , it also reduces the mobility of the smoke and avoids a `` backfire '' of water vapor . Also , the diffuse spray creates an inert `` water vapor sky '' , which prevents `` roll - over '' ( rolls of flames on the ceiling created by hot burning gases ) . Only short pulses of water need to be sprayed , otherwise the spraying modifies the equilibrium , and the gases mix instead of remaining stratified : the hot gases ( initially at the ceiling ) move around the room , and the temperature rises at the ground , which is dangerous for firefighters . An alternative is to cool all the atmosphere by spraying the whole atmosphere as if drawing letters in the air ( `` penciling '' ) . Modern methods for extinguishing an urban fire dictate the use of a massive initial water flow , e.g. 500 L / min for each fire hose . The aim is to absorb as much heat as possible at the beginning to stop the expansion of the fire and to reduce the smoke . If the flow is too low , the cooling is insufficient , and the steam that is produced can burn firefighters ( the drop of pressure is too small and the vapor is pushed back in their direction ) . Although it may seem paradoxical , the use of a strong flow with an efficient fire hose and an efficient strategy ( diffuse spray , small droplets ) requires a smaller amount of water . This is because once the temperature is lowered , only a limited amount of water is necessary to suppress the fire seat with a straight spray . For a living room of 50 m ( 60 sq yd ) , the required amount of water is estimated as 60 L ( 15 gal ) . French firefighters used an alternative method in the 1970s : spraying water on the hot walls to create a water vapor atmosphere and asphyxiate the fire . This method is no longer used because it turned out to be risky ; the pressure created pushed the hot gases and vapor towards the firefighters , causing severe burns , and pushed the hot gases into other rooms where they could start other fires . Asphyxiating a fire ( edit ) This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . ( August 2017 ) ( Learn how and when to remove this template message ) In some cases , the use of water is undesirable . This is because some chemical products react with water to produce poisonous gases , or they may even burn when they come into contact with water ( e.g. , sodium ) . Another problem is that some products float on water , such as hydrocarbons ( gasoline , oil , and alcohol , etc . ) ; a burning layer can then be spread by the fire . If a pressurized fuel tank is endangered by fire it is necessary to avoid heat shocks that may damage the tank if it is sprayed with cooling water ; the resulting decompression might produce a BLEVE ( boiling liquid expanding vapor explosion ) . Electrical fires can not be extinguished with water since the water could act as a conductor . In such cases , it is necessary to asphyxiate the fire . This can be done in a variety of ways . Chemical products which react with the fuel can be used to stop the combustion . A layer of water - based fire retardant foam can be applied by the fire hose in order to separate the oxygen in the air from the fuel . carbon dioxide , halon , or sodium bicarbonate can be used . In the case of very small fires and in the absence of other extinguishing agents , covering the flame with a fire blanket can eliminate oxygen flow to the fire . A simple and usually effective way to put out a fire in a stove - top pan is to put a lid on the pan and leave it there . Tactical ventilation or isolation of the fire ( edit ) One of the main risks of a fire is the smoke ; because , it carries heat and poisonous gases , and obscures vision . In the case of a fire in a closed location ( building ) , the following two different strategies may be used : isolation of the fire or ventilation . Paul Grimwood introduced the concept of tactical ventilation in the 1980s to encourage a better thought - out approach to this aspect of firefighting . Following work with Warrington Fire Research Consultants ( FRDG 6 / 94 ) his terminology and concepts were adopted officially by the UK fire services , and are now referred to throughout revised Home Office training manuals ( 1996 -- 97 ) . Grimwood 's original definition of his 1991 unified strategy stated that , `` tactical ventilation is either the venting , or containment ( isolation ) actions by on - scene firefighters , used to take control from the outset of a fire 's burning regime , in an effort to gain tactical advantage during interior structural firefighting operations . '' When properly used , ventilation improves life safety , fire extinguishment , and property conservation by ' pulling ' fire away from trapped occupants and objects . In most cases of structural firefighting , a 4x4 foot opening is cut into the roof directly over the fire room . This allows hot smoke and gases to escape through the opening , returning the conditions inside the room to normal . It is important to coordinate the ventilation with an interior fire attack since the opening of a ventilation hole supplies more air , and thus oxygen , to the fire . Ventilation may also `` limit fire spread by channeling fire toward nearby openings and allows fire fighters to safely attack the fire '' as well as limit smoke , heat , and water damage . Positive pressure ventilation ( PPV ) consists of using a fan to create excess pressure in a part of the building . This pressure pushes the smoke and heat out of the building , and thus facilitates rescue and fire fighting operations . It is necessary to have an exit for the smoke , to know the building layout well to predict where the smoke will go , and to ensure that the doors ensuring the ventilation remain open by wedging or propping them . The main risk of this method is that it may accelerate the fire , or even create a flash - over ; for example , if the smoke and the heat accumulate in a dead end . Hydraulic ventilation is the process of directing a stream of water from the inside of a structure out the window using a fog pattern . This will effectively pull smoke out of room . Smoke ejectors may also be used for this purpose . Categorizing fires in the US ( edit ) Main article : Multiple - alarm fire In the US , fires are sometimes categorized as `` one alarm '' , `` all hands '' , `` two alarm '' , `` three alarm '' ( or higher ) fires . There is no standard definition for what this means quantifiably ; though , it always refers to the level of response by the local authorities . In some cities , the numeric rating refers to the number of fire stations that have been summoned to the fire . In others , it reflects the number of `` dispatches '' requesting additional personnel and equipment . Alarms levels are generally used to define the tiers of the response as to what resources are to be used . For example , a structure fire response draws the following equipment : four engine / pumper companies , one truck / ladder / aerial / quint company , and one battalion chief unit . This is referred to as an Initial Alarm or Box Alarm . A working fire request ( for the same incident ) would call for air / light units and chief officers / fireground commanders ( if not provided in the original dispatch ) . This summarizes the response to a First Alarm fire . Second and subsequent alarms call for two engine companies and one truck company . The reason behind the `` Alarm '' designation is so the Incident Commander does not have to list each apparatus required . He can simply say , `` Give me a second alarm here '' , instead of `` Give me a truck company and two engine companies '' along with requesting where they should come from . Categorization of fires varies among fire departments . A single alarm for one department may be a second alarm for another . Response always depends on the size of the fire and the department . See also ( edit ) Glossary of firefighting -- list of firefighting terms and acronyms , with descriptions Glossary of firefighting equipment -- expansion of Glossary of firefighting Glossary of wildfire terms -- expansion of Glossary of firefighting Index of firefighting articles -- alphabetical list of firefighting articles List of fire departments Outline of firefighting -- structured list of firefighting topics , organized by subject area References ( edit ) ^ Jump up to : `` Firefighter '' . Retrieved 30 November 2016 . Jump up ^ `` Recruitment `` UK Fire Service Resources '' . Retrieved 30 November 2016 . Jump up ^ Safety , Government of Canada , Canadian Centre for Occupational Health and . `` Fire Fighter : OSH Answers '' . Retrieved 30 November 2016 . ^ Jump up to : International Fire Service Training Association . Fire Service Orientation and Indoctrination . Philadelphia : Board of Regents , 1984 . Print . Jump up ^ Dillon , Matthew ; Garland , Lynda ( 2005 ) . Ancient Rome : From the Early Republic to the Assassination of Julius Caesar . ISBN 9780415224581 . Jump up ^ `` History `` UK Fire Service Resources '' . Retrieved 30 November 2016 . ^ Jump up to : `` Fire History - A Historical Repository for the Fire Service of the United States of America '' . Fire History . Retrieved 21 February 2015 . Jump up ^ City of Fort Lauderdale ( April 2011 ) . `` Fire - Rescue - Special Operations Command '' . fortlauderdale.gov . Jump up ^ Tommy Tine ( January 2014 ) . `` City of Dallas : Dallas Fire - Rescue Department '' . City of Dallas . Jump up ^ Jobmonkey ( January 2014 ) . `` Firefighter Schedules and Work Life '' . jobmonkey.com . Jump up ^ `` Fire & Rescue NSW - Annual Report 2012 / 13 '' . Fire.nsw.gov.au . Missing or empty url = ( help ) ; access - date = requires url = ( help ) Jump up ^ `` 7 key duties of a fire warden '' . healthandsafetyhandbook.com.au . Retrieved 21 February 2015 . Jump up ^ Fire Warden Certification Classes - City of Houston - http://houstontx.gov/fire/HFMO/highrisecert.html Jump up ^ Essentials of Fire Fighting and Fire Department Operations 5th Edition . 2008 . Jump up ^ `` 3 heat - related threats to firefighters and how to fix them '' . FireRescue1 . Retrieved 2016 - 06 - 16 . ^ Jump up to : Thomson Delmar Learning . The Firefighter 's Handbook : Essentials of Fire Fighting and Emergency Response . Second Edition . Clifton Park , NY : Delmar Publishers , 2004 . Jump up ^ `` The Risks of Being a Fireman '' . work.chron.com . Retrieved 2016 - 06 - 16 . Jump up ^ `` Firefighting stiffens arteries , impairs heart function - News Bureau - University of Illinois '' . illinois.edu . Retrieved 21 February 2015 . ^ Jump up to : Hall , Richard . Essentials of Fire Fighting . Fourth Edition . Stillwater , OK : Fire Protection Publications , 1998 : Jump up ^ `` George Mason University Students Use Sound to Put Out Fire '' . Retrieved 30 November 2016 . Jump up ^ http://www.fireengineering.com/fire-prevention-protection.html Jump up ^ `` Firefighter Career Guide '' . FireTactics . Retrieved February 21 , 2015 . Jump up ^ Bernard Klaene . Structural Firefighting : Strategies and Tactics . Jones and Bartlett Publishers , 2007 . ISBN 0 - 7637 - 5168 - 5 , ISBN 978 - 0 - 7637 - 5168 - 5 Jump up ^ `` Washington DC Business News - Business , Money , Financial & Corporate News '' . NBC4 Washington . Archived from the original on 23 November 2007 . Retrieved 21 February 2015 . Jump up ^ `` Four - alarm fire on Avenue B '' . thevillager.com . Retrieved 21 February 2015 . External links ( edit ) Look up firefighting in Wiktionary , the free dictionary . Wikimedia Commons has media related to Firefighting . 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Question: the removal of temperature in fire fighting method is known as


Just When I Needed You Most - wikipedia Just When I Needed You Most Jump to : navigation , search `` Just When I Needed You Most '' Single by Randy VanWarmer from the album Warmer B - side `` Your Light '' Released February 1979 Format 7 '' ( 45 rpm ) Genre Pop rock , country rock , soft rock Length 3 : 58 Label Bearsville Songwriter ( s ) Randy VanWarmer , Tony Wilson Producer ( s ) Del Newman `` Just When I Needed You Most '' is the title of a 1979 hit single by the American singer - songwriter Randy VanWarmer . Contents ( hide ) 1 Background 2 Chart performance 2.1 Weekly charts 2.2 Year - end charts 3 Cover versions 4 See also 5 References 6 External links Background ( edit ) VanWarmer was inspired to write `` Just When I Needed You Most '' after his old car that he loved and used for years broke down on the way to work in Denver , Colorado and by a `` devastating '' breakup with a girlfriend : he wrote the song six months after that breakup co-writing it with Tony Wilson of the group Hot Chocolate two years before it became a hit . After recording `` Just When I Needed You Most '' for an album recorded for the UK division of Bearsville Records , VanWarmer then flew to the US to pressure Bearsville 's head office to promote the album which was duly remixed and released with `` Just When I Needed You Most '' as lead single although VanWarmer would recall that Bearsville evinced little enthusiasm for the track : `` Nobody thought my version was an especially good version of the song ( which ) a few other people were thinking of cutting ... Everybody just assumed mine was a demo for people to listen to who 'd ( then ) cut the definitive version '' . It has also been asserted that `` Your Light '' the flip was the original intended A-side of VanWarmer 's single . Released as a single in February 1979 , VanWarmer 's `` Just When I Needed You Most '' spent two weeks atop the US Billboard adult contemporary chart in May of that year and in June 1979 reached its peak position of No. 4 on the Billboard Hot 100 chart accruing an overall Top 40 tenure of 14 weeks and earning RIAA Gold record status . In addition , the track reached No. 71 on the Billboard country music chart . and in September 1979 made the Top 10 on the UK Singles Chart , peaking at No. 8 . VanWarmer attributed his single 's success to empathy for its heartbreak scenario : `` It 's happened to everyone . That emotion is universal ... I always hoped the record was n't wallowing in self - pity and it had some redeeming value , and I guess it does . '' VanWarmer also attributed his single 's success to the autoharp instrumental break between the second and third verses , performed by John Sebastian . Chart performance ( edit ) Weekly charts ( edit ) Chart ( 1979 ) Peak position Australia KMR 17 Canada RPM Top Singles 32 Canada RPM Adult Contemporary 5 UK 8 U.S. Billboard Hot 100 U.S. Billboard Adult Contemporary U.S. Billboard Country 71 U.S. Cash Box Top 100 5 Year - end charts ( edit ) Chart ( 1979 ) Rank Australia 94 Canada 192 UK 74 U.S. Billboard Hot 100 29 U.S. Cash Box 46 Cover versions ( edit ) The song 's co-writer Tony Wilson recorded `` Just When I Needed You Most '' for his 1979 album Catch One . Dolly Parton recorded a cover version of the song for her 1996 album , Treasures : this version , which like the VanWarmer original featured John Sebastian on autoharp , reached No. 62 on the Billboard country music chart . Other artists who either recorded or performed the song in concert include country music singers Tim McGraw , Donna Fargo , Skeeter Davis and Conway Twitty , R&B vocalist Millie Jackson , the German disco musician Peter Griffin , British glam rock band Smokie , reggae artists Barbara Jones , and Eddie Lovette , Filipino singer Pops Fernandez , Bob Dylan , Paul Butterfield , Billy Joe Royal , and the Spanish group Mocedades . In 2002 , the American - Taiwanese singer Will Pan released a bilingual English / Chinese version of the song . Dana Winner recorded `` Just When I Needed You Most '' for her 2011 album Unforgettable . Anne Nolan recorded `` Just When I Needed You Most '' for her 2013 debut solo album Just One Voice . A Finnish rendering of `` Just When I Needed You Most '' entitled `` Juuri Kun Tarvitsin Sua '' was recorded by ELF ( fi ) for their 1979 album Tarantella - Joe . Ingela `` Pling '' Forsman wrote lyrics in Swedish as När jag behövde dig mest , which was recorded by Swedish dansband Wizex on the 1980 album You Treated Me Wrong . A Spanish rendering entitled `` Necesitando Tu Amor '' was recorded by Mocedades for their 1982 album Amor De Hombre . An Austrian rendering entitled `` Ausg  ́ lacht '' was recorded by Wolfgang Ambros for his 2012 album 190352 . See also ( edit ) List of number - one adult contemporary singles of 1979 ( U.S. ) References ( edit ) ^ Jump up to : The Item , August 14 , 1988 , p. 41 Jump up ^ Klingman Daily Miner , July 20 , 1978 , p. 15 Jump up ^ The Evening Independent , August 24 , 1979 , p. 15 ^ Jump up to : Hyatt , Wesley ( 1999 ) . The Billboard Book of # 1 Adult Contemporary Hits ( Billboard Publications ) , pages 228 - 9 . Jump up ^ Whitburn , Joel ( 2004 ) . The Billboard Book of Top 40 Hits , 8th Edition ( Billboard Publications ) , page 657 . Jump up ^ Roberts , David ( 2006 ) . British Hit Singles & Albums ( 19th ed . ) . London : Guinness World Records Limited . p. 582 . ISBN 1 - 904994 - 10 - 5 . Jump up ^ `` Australian Chart Book '' . Austchartbook.com.au . Archived from the original on 2016 - 03 - 05 . Retrieved 2016 - 10 - 15 . Jump up ^ `` Randy Vanwarmer '' . officialcharts.com . Retrieved 10 October 2016 . Jump up ^ Joel Whitburn 's Top Pop Singles 1955 - 1990 - ISBN 0 - 89820 - 089 - X Jump up ^ Steffen Hung . `` Forum - Top 100 End of Year AMR Charts - 1980s ( ARIA Charts : Special Occasion Charts ) '' . Australian-charts.com . Archived from the original on 2014 - 10 - 06 . Retrieved 2016 - 10 - 15 . Jump up ^ `` Image : RPM Weekly - Library and Archives Canada '' . Bac-lac.gc.ca . Retrieved 2016 - 10 - 15 . Jump up ^ `` Top 100 Singles of 1979 '' ( PDF ) . Record Mirror . London : Spotlight Publications . January 5 , 1980 . p. 30 . Retrieved September 27 , 2016 . Jump up ^ `` Top 100 Hits of 1979 / Top 100 Songs of 1979 '' . Musicoutfitters.com . Retrieved 2016 - 10 - 15 . Jump up ^ `` Archived copy '' . Archived from the original on 2016 - 03 - 04 . Retrieved 2016 - 04 - 12 . Jump up ^ `` Will Pan - Just When I Needed You Most '' . YouTube . 2006 - 04 - 04 . Retrieved 2016 - 10 - 15 . Jump up ^ `` You treated me wrong Svensk mediedatabas '' . SMDB.kb.se . Retrieved 2016 - 10 - 15 . External links ( edit ) Single release info from discogs.com Lyrics of this song at MetroLyrics Retrieved from `` https://en.wikipedia.org/w/index.php?title=Just_When_I_Needed_You_Most&oldid=819767389 '' Categories : 1979 singles Bearsville Records singles Randy VanWarmer songs Dolly Parton songs Billboard Adult Contemporary number - one singles Songs written by Randy VanWarmer Pop ballads Torch songs Music videos directed by John Lloyd Miller Hidden categories : Articles with hAudio microformats Talk Contents About Wikipedia Norsk Svenska Edit links This page was last edited on 11 January 2018 , at 04 : 38 . 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Question: who is the original singer of just when i needed you most


Optic nerve - wikipedia Optic nerve Jump to : navigation , search For other uses , see Optic Nerve . Optic Nerve The left optic nerve and the optic tracts . Details Identifiers Latin nervus opticus MeSH D009900 NeuroNames 289 TA A14. 2.01. 006 A15. 2.04. 024 FMA 50863 Anatomical terms of neuroanatomy ( edit on Wikidata ) Cranial nerves CN 0 -- Terminal CN I -- Olfactory CN II -- Optic CN III -- Oculomotor CN IV -- Trochlear CN V -- Trigeminal CN VI -- Abducens CN VII -- Facial CN VIII -- Vestibulocochlear CN IX -- Glossopharyngeal CN X -- Vagus CN XI -- Accessory CN XII -- Hypoglossal Overview Table The optic nerve , also known as cranial nerve II , is a paired nerve that transmits visual information from the retina to the brain . In humans , the optic nerve is derived from optic stalks during the seventh week of development and is composed of retinal ganglion cell axons and glial cells ; it extends from the optic disc to the optic chiasma and continues as the optic tract to the lateral geniculate nucleus , pretectal nuclei , and superior colliculus . Contents ( hide ) 1 Structure 2 Function 3 Clinical significance 3.1 Disease 4 Regeneration 5 Additional images 6 See also 7 References 8 External links Structure ( edit ) The optic nerve is the second of twelve paired cranial nerves and is technically part of the central nervous system , rather than the peripheral nervous system because it is derived from an out - pouching of the diencephalon ( optic stalks ) during embryonic development . As a consequence , the fibers of the optic nerve are covered with myelin produced by oligodendrocytes , rather than Schwann cells of the peripheral nervous system , and are encased within the meninges . Peripheral neuropathies like Guillain -- Barré syndrome do not affect the optic nerve . However , most typically the optic nerve is grouped with the other eleven cranial nerves and considered to be part of the peripheral nervous system . Dissection of Optic Nerve from above showing parts . Courtesy Dr. John B. Selhorst The optic nerve is ensheathed in all three meningeal layers ( dura , arachnoid , and pia mater ) rather than the epineurium , perineurium , and endoneurium found in peripheral nerves . Fiber tracts of the mammalian central nervous system ( as opposed to the peripheral nervous system ) are incapable of regeneration , and , hence , optic nerve damage produces irreversible blindness . The fibres from the retina run along the optic nerve to nine primary visual nuclei in the brain , from which a major relay inputs into the primary visual cortex . A fundus photograph showing the back of the retina . The white circle is the beginning of the optical nerve . The optic nerve is composed of retinal ganglion cell axons and glial cells . Each human optic nerve contains between 770,000 and 1.7 million nerve fibers , which are axons of the retinal ganglion cells of one retina . In the fovea , which has high acuity , these ganglion cells connect to as few as 5 photoreceptor cells ; in other areas of retina , they connect to many thousand photoreceptors . The optic nerve leaves the orbit ( eye socket ) via the optic canal , running postero - medially towards the optic chiasm , where there is a partial decussation ( crossing ) of fibres from the temporal visual fields ( the nasal hemi - retina ) of both eyes . The proportion of decussating fibers varies between species , and is correlated with the degree of binocular vision enjoyed by a species . Most of the axons of the optic nerve terminate in the lateral geniculate nucleus from where information is relayed to the visual cortex , while other axons terminate in the pretectal nucleus and are involved in reflexive eye movements . Other axons terminate in the suprachiasmatic nucleus and are involved in regulating the sleep - wake cycle . Its diameter increases from about 1.6 mm within the eye to 3.5 mm in the orbit to 4.5 mm within the cranial space . The optic nerve component lengths are 1 mm in the globe , 24 mm in the orbit , 9 mm in the optic canal , and 16 mm in the cranial space before joining the optic chiasm . There , partial decussation occurs , and about 53 % of the fibers cross to form the optic tracts . Most of these fibres terminate in the lateral geniculate body . Based on this anatomy , the optic nerve may be divided in the four parts as indicated in the image at the top of this section ( this view is from above as if you were looking into the orbit after the top of the skull had been removed ) : 1 . the optic head ( which is where it begins in the eyeball ( globe ) with fibers from the retina ; 2 . orbital part ( which is the part within the orbit ) . 3 . intracanicular part ( which is the part within a bony canal known as the optic canal ) ; and , 4 . cranial part ( the part within the cranial cavity , which ends at the optic chiasm ) . From the lateral geniculate body , fibers of the optic radiation pass to the visual cortex in the occipital lobe of the brain . In more specific terms , fibers carrying information from the contralateral superior visual field traverse Meyer 's loop to terminate in the lingual gyrus below the calcarine fissure in the occipital lobe , and fibers carrying information from the contralateral inferior visual field terminate more superiorly , to the cuneus . Function ( edit ) The optic nerve transmits all visual information including brightness perception , color perception and contrast ( visual acuity ) . It also conducts the visual impulses that are responsible for two important neurological reflexes : the light reflex and the accommodation reflex . The light reflex refers to the constriction of both pupils that occurs when light is shone into either eye ; the accommodation reflex refers to the swelling of the lens of eye that occurs when one looks at a near object as in reading ( lens adjusts to near vision ) . The eye 's blind spot is a result of the absence of photoreceptors in the area of the retina where the optic nerve leaves the eye . Clinical significance ( edit ) Disease ( edit ) Main article : List of eye diseases and disorders Damage to the optic nerve typically causes permanent and potentially severe loss of vision , as well as an abnormal pupillary reflex , which is diagnostically important . The type of visual field loss will depend on which portions of the optic nerve were damaged . In general : Damage to the optic nerve anterior to the optic chiasm causes loss of vision in the eye on the same side as the damage . Damage at the optic chiasm typically causes loss of vision laterally in both visual fields ( bitemporal hemianopsia ) . It may occur with large pituitary tumors pituitary adenoma . ( see image on right of Paris seen with bitemporal hemianopsia ) Paris views showing vision with loss of both temporal visual fields Damage to the optic tract , which is behind ( posterior ) to the chiasm , causes loss of the entire visual field from the side opposite the damage ( so if the left optic tract is cut , there is a loss of vision from the entire right visual field ) . Injury to the optic nerve can be the result of congenital or inheritable problems like Leber 's Hereditary Optic Neuropathy , glaucoma , trauma , toxicity , inflammation , ischemia , infection ( very rarely ) , or compression from tumors or aneurysms . By far , the three most common injuries to the optic nerve are from glaucoma , optic neuritis ( especially in those younger than 50 years of age ) , and anterior ischemic optic neuropathy ( usually in those older than 50 ) . Glaucoma is a group of diseases involving loss of retinal ganglion cells causing optic neuropathy in a pattern of peripheral vision loss , initially sparing central vision . Glaucoma is associated with increased intraocular pressure that damages the optic nerve as it exits the eyeball . Although glaucoma does eventually damage the optic nerve , it is primarily a disease of eye not of the nerve . Optic neuritis is inflammation of the optic nerve . It is associated with a number of diseases , the most notable one being multiple sclerosis . The patient will likely experience varying vision loss and eye pain . The condition tends to be episodic . Anterior ischemic optic neuropathy is commonly known as `` stroke of the optic nerve '' and affects the optic nerve head . There is usually a sudden loss of blood supply and nutrients to the optic nerve head ( where the nerve exits the eyeball ) . Vision loss is typically sudden and most commonly occurs upon waking up in the morning . This condition is most common in diabetic patients 40 -- 70 years old . Optic nerve hypoplasia is the underdevelopment of the optic nerve resulting in little to no vision in the affected eye . Tumors , especially those of the pituitary gland , can put pressure on the optic nerve causing various forms of visual loss . Similarly , cerebral aneurysms ( swelling of blood vessels ) can also affect the nerve . Trauma can cause serious injury to the nerve . Direct optic nerve injury can occur from a penetrating injury to the orbit , but the nerve can also be injured by indirect trauma in which severe head impact or movement stretches or even tears the nerve Ophthalmologists and optometrists can detect and diagnose some optic nerve diseases but neuro - ophthalmologists are often best suited to diagnose and treat diseases of the optic nerve . The International Foundation for Optic Nerve Diseases ( IFOND ) sponsors research and provides information on a variety of optic nerve disorders . Regeneration ( edit ) Similar to other CNS tracts , the optic has very limited regenerative potential after injury . However , some new techniques are being developed to increase this potential . Additional images ( edit ) MRI scan of human eye showing optic nerve . The ophthalmic artery and its branches . ( optic nerve is yellow ) Superficial dissection of brain - stem . Lateral view . Dissection of brain - stem . Lateral view . Scheme showing central connections of the optic nerves and optic tracts . Nerves of the orbit . Seen from above . Nerves of the orbit , and the ciliary ganglion . Side view . The terminal portion of the optic nerve and its entrance into the eyeball , in horizontal section . Structures of the eye labeled This image shows another labeled view of the structures of the eye Optic nerve. Deep dissection. Inferior view . Optic nerve. Deep dissection. Inferior view . Optic nerve Optic nerve Human brain dura mater ( reflections ) Optic nerve Optic nerve Optic nerve Cerebrum. Inferior view. Deep dissection Cerebral peduncle , optic chasm , cerebral aqueduct . Inferior view . Deep dissection . See also ( edit ) Wikimedia Commons has media related to Optic nerve . This article uses anatomical terminology ; for an overview , see Anatomical terminology . Cranial nerve References ( edit ) ^ Jump up to : Vilensky , Joel ; Robertson , Wendy ; Suarez - Quian , Carlos ( 2015 ) . The Clinical Anatomy of the Cranial Nerves : The Nerves of `` On Olympus Towering Top '' . Ames , Iowa : Wiley - Blackwell . ISBN 978 - 1118492017 . ^ Jump up to : Selhorst , JB ; Chen , Y ( 2009 ) . `` The Optic Nerve '' . Seminars in Neurology . 29 : 29 -- 35 . Jump up ^ Jonas , Jost B. ; et al. ( May 1992 ) . `` Human optic nerve fiber count and optic disc size '' . Investigative Ophthalmology & Visual Science . 33 ( 6 ) . Jump up ^ Textbook of Veterinary Anatomy , 4th Edition . Dyce , Sack and Wensing Jump up ^ `` Glaucoma and Retinal Neurodegenerative Research Group '' . www.ucl.ac.uk . External links ( edit ) The optic nerve on MRI Stained brain slice images which include the `` optic % 20nerve '' at the BrainMaps project IFOND online case history -- Optic nerve analysis with both scanning laser polarimetry with variable corneal compensation ( GDx VCC ) and confocal scanning laser ophthalmoscopy ( HRT II - Heidelberg Retina Tomograph ) . Also includes actual fundus photos . Animations of extraocular cranial nerve and muscle function and damage ( University of Liverpool ) lesson3 at The Anatomy Lesson by Wesley Norman ( Georgetown University ) ( orbit4 ) cranialnerves at The Anatomy Lesson by Wesley Norman ( Georgetown University ) ( II ) Notes on Optic Nerve The cranial nerves terminal Nuclei Septal nuclei Course no significant branches olfactory Nuclei Anterior olfactory nucleus Course olfactory bulb olfactory tract optic Nuclei Lateral geniculate nucleus Course optic chiasm optic tract oculomotor Nuclei Oculomotor nucleus Edinger -- Westphal nucleus Branches superior parasympathetic root of ciliary ganglion / ciliary ganglion inferior trochlear Nucleus Branches no significant branches trigeminal Nuclei PSN Spinal trigeminal nucleus MN TMN Course trigeminal ganglion Branches ophthalmic maxillary mandibular abducens Nucleus Branches no significant branches facial near origin intermediate nerve geniculate inside facial canal greater petrosal pterygopalatine ganglion nerve to the stapedius chorda tympani lingual nerve submandibular ganglion at stylomastoid foramen posterior auricular suprahyoid digastric stylohyoid parotid plexus temporal zygomatic buccal mandibular cervical Nuclei Facial motor nucleus Solitary nucleus Superior salivary nucleus vestibulocochlear Nuclei Vestibular nuclei Cochlear nuclei cochlear nerve striae medullares lateral lemniscus vestibular Scarpa 's ganglion glossopharyngeal before jugular fossa ganglia superior inferior after jugular fossa tympanic tympanic plexus lesser petrosal otic ganglion stylopharyngeal branch pharyngeal branches tonsillar branches lingual branches carotid sinus Nuclei Nucleus ambiguus Inferior salivatory nucleus Solitary nucleus vagus before jugular fossa ganglia superior inferior after jugular fossa meningeal branch auricular branch neck pharyngeal branch pharyngeal plexus superior laryngeal external internal recurrent laryngeal ( inferior ) superior cervical cardiac thorax inferior cardiac pulmonary vagal trunks anterior posterior abdomen celiac renal hepatic anterior gastric posterior gastric Nuclei Nucleus ambiguus Dorsal nucleus of vagus nerve Solitary nucleus accessory Nuclei Nucleus ambiguus Spinal accessory nucleus cranial spinal hypoglossal Nucleus Branches lingual Optical illusions List of optical illusions Afterimage Barberpole Bezold Blivet Café wall Cornsweet Delboeuf Ebbinghaus Ehrenstein Flash lag Fraser spiral Grid Hering Jastrow Mach McCollough Müller - Lyer Necker Orbison Penrose stairs triangle Peripheral drift Poggendorff Ponzo Rubin Sander Schroeder Ternus Vertical -- horizontal White 's Wundt Zöllner Related Auditory Tactile Temporal Op art Ascending and Descending Waterfall GND : 4205981 - 1 NDL : 00571252 Retrieved from `` https://en.wikipedia.org/w/index.php?title=Optic_nerve&oldid=829495086 '' Categories : Optic nerve Visual system Cranial nerves Hidden categories : Pages with unresolved properties All articles with unsourced statements Articles with unsourced statements from March 2016 Wikipedia articles with GND identifiers Talk Contents About Wikipedia Azərbaycanca Bân - lâm - gú Български Bosanski Català Čeština Cymraeg Dansk Deutsch Eesti Ελληνικά Español Euskara فارسی Français Galego 한국어 Հայերեն हिन्दी Hrvatski Bahasa Indonesia Italiano עברית Қазақша Latina Lietuvių Magyar Nederlands 日本 語 Norsk Polski Português Română Русский Simple English Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska Татарча / tatarça తెలుగు ไทย Türkçe Українська 中文 37 more Edit links This page was last edited on 9 March 2018 , at 00 : 00 . 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Question: ganglion axons forming the optic nerve run to the