Sunday, March 31, 2019
Orbids of the Skull
Orbids of the SkullSarah Ferreira1.INTRODUCTIONThe mountain chains of a gentlemans gentleman skull is the space in which the optic and its appendages argon located. The two stadiums in the mankinds skull are conical holes that absolveds into the midline of the introduce and point jeopardize into the head. Each orbit includes an summit, quad rings and a base. The functions of these orbits is firstly to keep the pump safe from whatever mechanical brand and fosterly to supply an first appearance for the optic warmness(that transports visual discipline from the eyes retina to the vision centers in the brain through electrical impulses) to the brain. A thorough understanding of the mannikin of the orbits of the human skull is very important to any doctor in sight to comprehend any dis golf-clubs that patients might experience that are related to the eye socket itself, as soundly as to understand the surgical management of this area in the human skull.2.The orbit of the skull2.1The general location of the orbits in the human skullThe orbit in the human skull lies preliminary to the temporary endo automobilep ( squint-eyedly) and antecedent to the middle cranial infernal region (medi all in ally). Its similarly situated topping to the upper jaw raisery air sinus, askance to the emaciated space as surface as below the anterior cranial perdition.2.2The spurt of the orbit of the skullThe shape of the orbit in the human skull looks like a pyramid that has four distinctive sides ( circumvents), but as one moves freighter, it becomes three sided( toward the eyeshade). The most skunk portion of the pyramid molded orbit is the vizor (of the orbit) and its positioned at the craniofacial junction. ( The apex is in any case where the optic furnish (that contains the central retina vein, ophthalmic artery, symphathetic face and optic nerve) opens into the hinder(prenominal) per centum of the orbit and it forms the tip of this pyramid shaped cavity or structure.)2.3The pearls of the orbit of the skull and their arise classification in that respect are seven tog up up that make up the orbit videlicet the1)The Maxillary organise(that is withal categorize an minute bone)2)The orbital plate of the window dressing bone(that is as well classified as an irregular bone)3)The malar bone bone(that is as well classified as a flat bone)4)The Ethmoidal bone(that is alike classified as an irregular bone)5)The Lac strandal bone(that is likewise classified as a flat bone)6) The Palative bone (that is in any case classified as an irregular bone)7) The Sphenoid bone (that is also classified as an irregular bone)All of the preceding(prenominal) mentioned bones also form part of the human skull. The orbit also contains tornados and fossae where various crosscurrent vessels and nerves pass through.2.4The walls of the orbitThe orbit as mentioned earlier comprise of four sides or walls. The facial and cranial bon es that forms the structure of the orbits also forms these four walls. The walls of the orbit of the skull are as follows1)The superior wall/ detonator2)The lateral wall3)The inferior wall/ decorate4)The medial wall.3Introduction to the bones of the orbit and the orbital walls that they formThe superior edge and most of the jacket of the orbit are formed by the frontal bones of the orbital plate. The inferomedial borderline and the floor of the orbit is also formed by the upper jawbone bone. The anterior part of the lateral wall and the inferolateral margin of the orbit is also formed by the jugal bone bone. Much of the medial wall of the orbit is also formed by the lateral push-down store of the ethmoid bone. on that point are also a number of ways in which the os sphenoidale bone bone bone contributes to the structure of the orbit Firstly, the lateral wall bed to the Zygomatic bone is constituted by the greater extension service of the sphenoid bone and jiffyly the posterior margin of the roof (or superior wall) is formed by the lesser aviate of the sphenoid bone.Thirdly the optic canal (that provide a passage for the optic canal and the optic nerve into the orbital space) which is in the apex of the orbit, is also framed by the roots of the lesser move of the sphenoid bone.( Thisroots of the lesser wing also connects it to the body of the sphenoid bone.)The medial wall of the orbit( that is between the frontal cognitive process of the maxilla and the lateral mass of the ethmoid is completed by the small, curved , lacrimal bone. The posterior tip off of the floor or inferior wall is completed by the orbital process of the palatine bone that is insinuated behind the maxilla and underneath the ethmoid bone.3.1The superior wall or roofThe lesser wing of the sphenoid bone constitutes/forms the posterior margin of the superior wall and also surrounds the optic canal( that ac as a channel for the optic nerve and ophthalmic artery). Thus the opt ic canal is situated posteriorly in the wing of the sphenoid bone that is smaller i.e. the lesser wing and this canal also communicates with the middle cranial fossa. (A fossa is a hollow or a shallow depression.)The superior margin of the bony cavity that contains the human globe are formed by the orbital plate of the frontal bone and this bone forms nigh everything of the superior wall of the orbit except the posterior extremity of the superior wall. This specific part (the posterior extremity) is formed by the lesser wing of the sphenoid bone. The superior orbital snap is also situated posteriorly between the greater wing of the sphenoid bone and the lesser wing of the sphenoid bone. (This fissure also communicates with the middle cranial fossa and also provides a passage for the frontal nerve, lacrimal nerve, oculomotor nerve, trochlear nerve, abducent nerve, nasociliary nerve and lastly the superior ophthalmic vein). A fossa for the lacrimal gland is made by the roof that ri ses laterally above the level of the rim of the orbit.The superior orbitals margins contour is laterally sharp and medially round. The supraorbital nonch also leads from the orbit onto the face at the point of transition. On the frontal bones maxilla process, a small trochlear fossa that is in the anterior medial tilt of the orbit gives an attachment to the trochlea.3.2The Medial wallThe medial wall consists of 4 bones namely the sphenoid bone, ethmoid bone, lacrimal bone and upper jaw bone. Thus the frontal process of the maxilla largely constitutes the medial margin of the orbit. The shorter maxillary process of the frontal bone are also met by the rising of the frontal process of the maxilla. The maxilla itself contributes little more than the rim to the medial orbital wall.The lacrimal bone, that has an irregular shape, articulates vertically with the frontal process of the maxilla within the orbit. The lacrimal sacs fossa are framed or formed by both of these bones.The bony nasolacrimal canal is also endless with the fossa which also hold up into the inferior nasal meatus below( that is the gap(space) covered by the inferior nasal concha.Posteriorly the fossa is bounded by a vertical ridge (that is named the lacrimal crest) and from this the orbital surface of the lacrimal bone increases posteriorly to meet the lateral mass of the ethmoid bone.The upper part of the nasal cavity are separated from the orbit by the lateral mass of the ethmoid bone.The lateral mass of the ethmoid is pneumatized extensively by the ethmoid air cells and in many skulls this gives the medial wall the appearance or likeness of an unviolated honeycomb.The thinnest part of the wall is the lamina papyracea which means a storey as thin as paperThe frontoethmoidal suture is where the medial wall and the roof of the orbit mets. Across this boundary, the ethmoid air cells of the lateral mass extend upward into the overlying frontal bone.The anterior and posterior ethmoidal forami na open out of the orbit along the suture line into canals that pass horizontally between adjacent air cells. The first leads onto the upper surface of the cribriform plate, the second into the posterior ethmoidal and sphenoid air sinuses.3.3The Lateral wallThe Zygomatic bone forms the lateral margin and wall of the orbit and the greater wing of the sphenoid bone, completes this lateral wallThe greater wing of the sphenoid also does non articulate with the lesser wing of the sphenoid or the maxilla bone and because of this there is two gaps posteriorly.The first gap is the superior orbital fissure that is located between the lateral wall and the superior wall and the secondgap is the inferior orbital fissure that located between the floor( also called the inferior wall ) and the lateral wall. These 2 fissures converge in the apex of the orbit of the skull that is just lateral to he optic canal.The inferior orbital fissure is roughly in line with the zygomatico-orbital foramen that opens in the orbital surface of the zygomatic bone.hThis Zygomatic orbital foramen can be doubled or multiple or it may be so hidden as to be virtually missed by the human eye.3.4The floor or inferior wallThe maxilla(medially) and the Zygomatic bone(laterally) forms the inferior margin of the orbit that is also named the floor. The floor is also the shortest of all the orbits walls)The whole of the orbit floor is also virtually formed by the maxilla bone and the Zygomatic bone.The maxilla bone constitutes almost all of the surface of the floor except the extreme lateral angle.The roof of the maxillary air sinus is also formed by the bone of the floor that is very thin.The floor is completed in front of the apex by the small orbital process of the palatine bone.The inferior orbital fissure is left by the prominent infraorbital groove and this prominent infraorbital groove runs straight off forward on the surface of the maxilla.This groove (halfway across the floor of the orbit) b ecomes continuous with the infraorbital canal( thus the infraorbital groove (and canal) is located in the inferior wall of the orbit and in the maxillas orbital plate and it transfer the demarcation vessels and the infraorbital nerve) , which eventually ends in the infraorbital foramen ( on the anterior surface of the maxilla below the orbital margin.4The neurovascular portals in the orbits walls and in the apex( few of them ( the nerves and arteries that go through passages in the orbit and apex) are discussed below.)4.1The apexFrom the middle cranial fossa the optic canal opens directly into the apex of the orbit. The ophthalmic branch of the internal carotid artery as well as the optic nerve(thats covered by all meningeal layers) goes through the optic canal. Between the orbit and the middle cranial fossa the main pass is the superior orbital fissure.4.2The Medial wallThe anterior and posterior ethmoidal branches of the nasociliary nerve are transmitted by the anterior and pos terior ethmoidel foramina. Corresponding branches of the ophthalmic artery and veins draining to the superior ophthalmic vein also accompanies them.4.3The RoofThe supraorbital nerve and vessels are transmitted by the supraorbital notch( or foramen) onto the forehead. The supraorbital nerve is the larger extension of the frontal nerve and the artery is from the ophthalmic artery.4.4FloorThe infraorbital and zygomatic nerves and vessels are transferred by the inferior orbital fissure.The infraorbital nerve and vessels are carried from the inferior orbital fissure to the infra orbital foramen(through this foramen they appear onto the face) , by the infraorbital canal and the infraorbital groove.4.5Lateral wallThe zygomatic orbital foramen transmits the zygomatic vessels and the zygomatic nerves into the zygomaric bone( this receives beyond the lateral end of the inferior orbital fissure)The Zygomatoc facial foramen is the passageway through which the zygomatico facial nerve and vessel appear on to the head. It may happen that there are two foramens rather than one and this is not unusual. The zygomaticotemporal foramen is also the passageway through which the zygomaticotemporal nerve and vessels emerge into the temporal fossa.Picture of the orbits5Possible clinical application in RadiographyIn Radiography(orbital Radiogrpahy) injury to they eye or trauma to the eye are detected by orbital x rays. ( orbital x-rays are x-ray images of the left and the right way eye sockets in the human skull. It also includes the frontal sinuses and maxillary sinuses). athletic fieldal x-rays are also used to detect changes in the structure of the eye, which may lead to various diseases, as well as to detect contrary bodies in the eye that a opthalmoscope( thats an instrument that detect international bodies in the eye) cannot spotIn the Radiography department there is discharge to be patients who have ruptures and diseases of the orbitals. Some of the fractures encountered could be a fracture of the zygomatic arch, displacement of the zygomatico-frontal suture, infraorbital fractures, etc. It will be expected of every serve Radiographer to grow orbital x-ray images of these patients orbitals. To be able to do this a Radiographer must be familiar with complex anatomy of the orbits in the skull and it associated mild tissue . For example if a patients thats been in a car accident has fractured his orbitals and this resulted in a fracture of the zygomatic arch, because it would be expected of a radiographer to write out where this zygomatic arch is located in order to use up an orbital x-ray image of that area. A Radiographer must also have sufficient get it onledge to be able take an orbital x ray image in the correct angle or to discern when to take several x-rays (from different angles) in order to show the fracture to the zygomatic arch more clearly.It may happen in serious emergency cases that the Radiographer must firstly look for any damag e on the patients face(before he/she can take an x-ray) , and if this radiographer doesnt get by where the facial bones or orbital bones is located then it wouldnt help taking an image of the wrong facial bone, because that would be of no usage to the doctors seeing the orbital x-rays, because they want to see the fracture in order to make a diagnosis. A doctor may also ask a radiographer if she can see anything abnormal on the x-ray and then again this radiographer must be able to nominate the bones and the location of the fractures. Thus it is very important for a radiographer to know where the orbitals lie and of what bones it consists.6CONCLUSIONFrom the above mentioned research I conclude that it is very necessary for a radiographer to know the orbits of the eye in order to take valuable x-ray orbital images of this area. The orbitals of the human skull is also of utmost greatness , because of the fact that it contains the eye, ( a vital organ that is used in almost every ac tivity of a human being ex. from reading the report to crossing the street) and thus patients that has any damage to this area need to be helped swiftly before a minor orbital injury could proceed to a life threatening injury and results in the patient losing his eye. A Radiographer also pays an important role in helping these patients and must know the anatomy of the orbits in order to supply the doctors with the needed medical information that would help doctors to make a diagnosis.REFERENCESThogarapalli, N. s.a. The human eye what and importance . http//www.odec.ca/projects/2006/thog6n2/importance.html Retrieved on the second of April 2014Scott, O. 2010. Zygomatic Arch and Orbital Fractures. http//www.patient.co.uk/doctor/Zygomatic-Arch-and-Orbital-Fractures.htm Retrieved on the 2nd of April 2014Siwek, D.F. 2009. The orbit http//skullanatomy.info/Individ%20Spaces/Orbit/Orbit.htm Retrieved on the 2nd of April 2014Farlex. s.a. The Free dictionary orbital cavity http//www.thefreedi ctionary.com/orbital+cavity Retrieved on the 2nd of April 2014Thiagarajan, Balasubramanian Thiagarajan, B. 2013. http//entscholar.com/article/anatomy-of-orbit/ Retrieved on the 2nd of April 2014Balasubramanian, T. s.a. http//www.drtbalu.com/orbit_ana.html Retrieved on the 2nd of April 2014Quizlet, 2014. Anatomy test 3 http//quizlet.com/7795054/anatomy-test-3-flash-cards/ Retrieved on the 2nd of April 2014ORahilly,R., Muller,F. , Carpenter, S. Swenson, R. 2008. Basic human anatomy the orbit. https//www.dartmouth.edu/humananatomy/part_8/chapter_45.html Retrieved on the 01st of AprilPetruzelli, G.J. 2013. Orbit Anatomy http//emedicine.medscape.com/article/835021-overview Retrieved on the 01st of April 2014Orbits. s.a. https//www.boundless.com/physiology/the-skeletal-system/skull/orbits/ Retrieved on the 01st of April 2014Snell, R.S. 2011. Clinically anatomy by regions http//books.google.co.za/books?id=vb4AcUL4CE0Cpg=PA553lpg=PA553dq=orbital+opening+lies+anteriorly.+About+one+sixth+of +the+eye+is+exposedsource=blots=fJHbn-cfItsig=HzlJmwJuIL1FfloCdW5BUw75e_8hl=ensa=Xei=uvE7U4boOZSqhQernYGgBwved=0CCkQ6AEwAQv=onepageq=orbital%20opening%20lies%20anteriorly.%20About%20one%20sixth%20of%20the%20eye%20is%20exposedf=falseRetrieved on the 01st April 20141
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