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Orbital Blowout Fracture
An orbital blowout fracture is a traumatic deformity of the orbital floor or medial wall that typically results from the impact of a blunt object larger than the orbit (anatomy), orbital aperture, or eye socket. Most commonly this results in a herniation of orbital contents through the orbital fractures. The proximity of maxillary and ethmoidal sinus increases the susceptibility of the floor and medial wall for the orbital blowout fracture in these anatomical sites. Most commonly, the inferior orbital wall, or the floor, is likely to collapse, because the bones of the roof and lateral walls are robust. Although the bone forming the medial wall is the thinnest, it is buttressed by the bone separating the ethmoidal air cells. The comparatively thin bone of the floor of the orbit and roof of the maxillary sinus has no support and so the inferior wall collapses mostly. Therefore, medial wall blowout fractures are the second-most common, and superior wall, or roof and lateral wall, blowou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit (anatomy)
In anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ..., the orbit is the Body cavity, cavity or socket/hole of the skull in which the eye and Accessory visual structures, its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is about , of which the eye occupies . The orbital contents comprise the eye, the Orbital fascia, orbital and retrobulbar fascia, extraocular muscles, cranial nerves optic nerve, II, oculomotor nerve, III, trochlear nerve, IV, trigeminal nerve, V, and abducens nerve, VI, blood vessels, fat, the lacrimal gland with its Lacrimal sac, sac and nasolacrimal duct, duct, the eyelids, Medial palpebral ligament, medial and Lateral palpebral raphe, lateral palpebr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Rectus
The inferior rectus muscle is a muscle in the orbit near the eye. It is one of the four recti muscles in the group of extraocular muscles. It originates from the common tendinous ring, and inserts into the anteroinferior surface of the eye. It depresses the eye (downwards). Structure The inferior rectus muscle originates from the common tendinous ring (annulus of Zinn). It inserts into the anteroinferior surface of the eye. This insertion has a width of around 10.5 mm. It is around 7 mm from the corneal limbus. Blood supply The inferior rectus muscle is supplied by an inferior muscular branch of the ophthalmic artery. It may also be supplied by a branch of the infraorbital artery. It is drained by the corresponding veins: the inferior muscular branch of the ophthalmic vein, and sometimes a branch of the infraorbital vein. Nerve supply The inferior rectus muscle is supplied by the inferior division of the oculomotor nerve (III). Development The inferior rectus muscle de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endoscopy
An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are inserted directly into the organ. There are many types of endoscopies. Depending on the site in the body and type of procedure, an endoscopy may be performed by a doctor or a surgeon. During the procedure, a patient may be fully conscious or anaesthesia, anaesthetised. Most often, the term ''endoscopy'' is used to refer to an examination of the upper part of the human gastrointestinal tract, gastrointestinal tract, known as an esophagogastroduodenoscopy. Similar instruments are called borescopes for nonmedical use. History Adolf Kussmaul was fascinated by sword swallowers who would insert a sword down their throat without gagging. This drew inspiration to insert a hollow tube for observation; the next problem to solve was how to shine light th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ciliary Muscle
The ciliary muscle is an intrinsic muscle of the eye formed as a ring of smooth muscleSchachar, Ronald A. (2012). "Anatomy and Physiology." (Chapter 4) . in the eye's middle layer, the uvea ( vascular layer). It controls accommodation for viewing objects at varying distances and regulates the flow of aqueous humor into Schlemm's canal. It also changes the shape of the lens within the eye but not the size of the pupil which is carried out by the sphincter pupillae muscle and dilator pupillae. The ciliary muscle, pupillary sphincter muscle and pupillary dilator muscle sometimes are called intrinsic ocular muscles or intraocular muscles. Structure Development The ciliary muscle develops from mesenchyme within the choroid and is considered a cranial neural crest derivative. Nerve supply The ciliary muscle receives parasympathetic fibers from the short ciliary nerves that arise from the ciliary ganglion. The parasympathetic postganglionic fibers are part of cranial n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjunctiva
In the anatomy of the eye, the conjunctiva (: conjunctivae) is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium and stratified cuboidal epithelium (depending on the zone). The conjunctiva is highly Angiogenesis, vascularised, with many microvessels easily accessible for imaging studies. Structure The conjunctiva is typically divided into three parts: Blood supply Blood to the bulbar conjunctiva is primarily derived from the ophthalmic artery. The blood supply to the palpebral conjunctiva (the eyelid) is derived from the external carotid artery. However, the circulations of the bulbar conjunctiva and palpebral conjunctiva are linked, so both bulbar conjunctival and palpebral conjunctival vessels are supplied by both the ophthalmic artery and the external carotid artery, to varying extents. Nerve supply Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyethylene
Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging (plastic bags, plastic films, geomembranes and containers including bottles, cups, jars, etc.). , over 100 million tonnes of polyethylene resins are being produced annually, accounting for 34% of the total plastics market. Many kinds of polyethylene are known, with most having the chemical formula (C2H4)''n''. PE is usually a mixture of similar polymers of ethylene, with various values of ''n''. It can be ''low-density'' or ''high-density'' and many variations thereof. Its properties can be modified further by crosslinking or copolymerization. All forms are nontoxic as well as chemically resilient, contributing to polyethylene's popularity as a multi-use plastic. However, polyethylene's chemical resilience also makes it a long-lived and decomposition-resistant pollutant when disposed of improperly. Being a h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium
Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in sea water, aqua regia, and chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791 and was named by Martin Heinrich Klaproth after the Titans of Greek mythology. The element occurs within a number of minerals, principally rutile and ilmenite, which are widely distributed in the Earth's crust and lithosphere; it is found in almost all living things, as well as bodies of water, rocks, and soils. The metal is extracted from its principal mineral ores by the Kroll and Hunter processes. The most common compound, titanium dioxide (TiO2), is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride (TiCl4), a component of smoke screens and cata ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extraocular Muscles
The extraocular muscles, or extrinsic ocular muscles, are the seven extrinsic muscles of the eye in human eye, humans and other animals. Six of the extraocular muscles, the four recti muscles, and the superior oblique muscle, superior and inferior oblique muscles, control Eye movement, movement of the eye. The other muscle, the Levator palpebrae superioris muscle, levator palpebrae superioris, controls eyelid elevation and depression, elevation. The actions of the six muscles responsible for eye movement depend on the position of the eye at the time of muscle contraction. The ciliary muscle, pupillary sphincter muscle and pupillary dilator muscle sometimes are called intrinsic ocular muscles or intraocular muscles. Structure Since only a small part of the eye called the Fovea centralis, fovea provides sharp vision, the eye must move to follow a target. Eye movements must be precise and fast. This is seen in scenarios like reading, where the reader must shift gaze constantly. Alt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaze (physiology)
The term gaze is frequently used in physiology to describe coordinated motion of the eyes and neck. The lateral gaze is controlled by the paramedian pontine reticular formation (PPRF). The vertical gaze is controlled by the rostral interstitial nucleus of medial longitudinal fasciculus and the interstitial nucleus of Cajal. Nerves and muscles The three nerves that control the extraocular muscles are the oculomotor, trochlear nerve, trochlear, and abducens nerves, which are the third, fourth, and sixth cranial nerves. the abducens nerve is responsible for abducting the eye, which it controls through contraction of the lateral rectus muscle. The trochlear nerve controls the superior oblique muscle to rotate the eye along its axis in the orbit medially, which is called intorsion, and is a component of focusing the eyes on an object close to the face. The oculomotor nerve controls all the other extraocular muscles, as well as a muscle of the upper eyelid. Conjugate gaze The ''conjugat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxillary Sinus
The pyramid-shaped maxillary sinus (or antrum of Nathaniel Highmore (surgeon), Highmore) is the largest of the paranasal sinuses, located in the maxilla. It drains into the middle meatus of the noseHuman Anatomy, Jacobs, Elsevier, 2008, page 209-210 through the semilunar hiatus. It is located to the side of the nasal cavity, and below the orbit. Structure It is the largest air sinus in the body. It has a mean volume of about 10 ml. It is situated within the body of the maxilla, but may extend into its Maxilla, zygomatic and Maxilla, alveolar processes when large. It is pyramid-shaped, with the apex at the maxillary zygomatic process, and the base represented by the lateral nasal wall. It has three recesses: an alveolar recess pointed inferiorly, bounded by the alveolar process of the maxilla; a zygomatic recess pointed laterally, bounded by the zygomatic bone; and an infraorbital recess pointed superiorly, bounded by the inferior Orbital surface of the body of the maxilla, orbita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiograph
Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical ("diagnostic" radiography and "therapeutic radiography") and industrial radiography. Similar techniques are used in airport security, (where "body scanners" generally use backscatter X-ray). To create an image in conventional radiography, a beam of X-rays is produced by an X-ray generator and it is projected towards the object. A certain amount of the X-rays or other radiation are absorbed by the object, dependent on the object's density and structural composition. The X-rays that pass through the object are captured behind the object by a detector (either photographic film or a digital detector). The generation of flat two-dimensional images by this technique is called projectional radiography. In computed tomography (CT scanning), an X-ray source and its associated de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
