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Superior Ophthalmic Vein
The superior ophthalmic vein is a vein of the orbit that drains venous blood from structures of the upper orbit. It is fromed by the union of the angular vein, and supraorbital vein. It passes backwards within the orbit alongside the ophthalmic artery, then exits the orbit through the superior orbital fissure to drain into the cavernous sinus. The superior ophthalmic vein can be a path for the spread of infection from the danger triangle of the face to the cavernous sinus and the pterygoid plexus. It may also be affected by an arteriovenous fistula of the cavernous sinus. Structure The superior ophthalmic vein - together with the inferior ophthalmic vein - represents the principal drainage system of the orbit (with the superior ophthalmic vein being the larger of the two). The superior ophthalmic vein drains venous blood from structures of the upper orbit. The superior ophthalmic vein is the largest and the most consistently present vein of the orbit. It usually measures 2-10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angular Vein
The angular vein is a vein of the face. It is the upper part of the facial vein, above its junction with the superior labial vein. It is formed by the junction of the supratrochlear vein and supraorbital vein, and joins with the superior labial vein. It drains the medial canthus, and parts of the nose and the upper lip. It can be a route of spread of infection from the danger triangle of the face to the cavernous sinus. Structure The angular vein is the upper part of the facial vein, above its junction with the superior labial vein. It it anastomoses with the supratrochlear vein, and the supraorbital vein. Its connection with the supraorbital vein forms the superior ophthalmic vein that drains through the orbit. This also connects it with the inferior ophthalmic vein and the cavernous sinus. These do not have valves. The angular vein itself may not contain valves. It receives the lateral nasal veins from the ala of the nose, and the inferior palpebral vein. The an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optic Nerve
In neuroanatomy, the optic nerve, also known as the second cranial nerve, cranial nerve II, or simply CN II, is a paired cranial 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. Structure The optic nerve has been classified as the second of twelve paired cranial nerves, but it 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embolization
Embolization refers to the passage and lodging of an embolus within the bloodstream. It may be of natural origin ( pathological), in which sense it is also called embolism, for example a pulmonary embolism; or it may be artificially induced ( therapeutic), as a hemostatic treatment for bleeding or as a treatment for some types of cancer by deliberately blocking blood vessels to starve the tumor cells. In the cancer management application, the embolus, besides blocking the blood supply to the tumor, also often includes an ingredient to attack the tumor chemically or with irradiation. When it bears a chemotherapy drug, the process is called chemoembolization. Transcatheter arterial chemoembolization (TACE) is the usual form. When the embolus bears a radiopharmaceutical for unsealed source radiotherapy, the process is called radioembolization or selective internal radiation therapy (SIRT). Uses Embolization involves the selective occlusion of blood vessels by purpos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exophthalmos
Exophthalmos (also called exophthalmus, exophthalmia, proptosis, or exorbitism) is a bulging of the eye anteriorly out of the orbit. Exophthalmos can be either bilateral (as is often seen in Graves' disease) or unilateral (as is often seen in an orbital tumor). Complete or partial dislocation from the orbit is also possible from trauma or swelling of surrounding tissue resulting from trauma. In the case of Graves' disease, the displacement of the eye results from abnormal connective tissue deposition in the orbit and extraocular muscles, which can be visualized by CT or MRI. If left untreated, exophthalmos can cause the eyelids to fail to close during sleep, leading to corneal dryness and damage. Another possible complication is a form of redness or irritation called superior limbic keratoconjunctivitis, in which the area above the cornea becomes inflamed as a result of increased friction when blinking. The process that is causing the displacement of the eye may also compre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Churchill Livingstone
Churchill Livingstone is an academic publisher. It was formed in 1971 from the merger of Longman's medical list, E & S Livingstone (Edinburgh, Scotland) and J & A Churchill (London, England) and was owned by Pearson PLC, Pearson. Harcourt (publisher), Harcourt acquired Churchill Livingstone in 1997. It is now integrated as an imprint (trade name), imprint in Elsevier's health science division after Elsevier acquired Harcourt in 2001. In the past it published a number of classic medical texts, including Sir William Osler's textbook ''The Principles and Practice of Medicine, Gray's Anatomy,'' and ''Margaret Myles, Myles' Textbook for Midwives.'' In the 1980s, in addition to new texts in all areas of clinical medicine, it published an extensive list of medical and nursing textbooks in low-cost editions for low-income countries supported by the UK-funded Educational Low Priced Book Scheme (ELBS). [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavernous Sinus Thrombosis
The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica. Structure The cavernous sinus is one of the dural venous sinuses of the head. It is a network of veins that sit in a cavity. It sits on both sides of the sphenoidal bone and pituitary gland, approximately 1 × 2 cm in size in an adult. The carotid siphon of the internal carotid artery, and cranial nerves III, IV, V (branches V1 and V2) and VI all pass through this blood filled space. Both sides of cavernous sinus is connected to each other via intercavernous sinuses. The cavernous sinus lies in between the inner and outer layers of dura mater. Nearby structures * Above: optic tract, optic chiasma, internal carotid artery. * Inferiorly: foramen lacerum, and the junction of the body and greater wing of sphenoid bone. * Medially: pituit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Rectus Muscle
The medial rectus muscle is a muscle in the orbit near the eye. It is one of the extraocular muscles. It originates from the common tendinous ring, and inserts into the anteromedial surface of the eye. It is supplied by the inferior division of the oculomotor nerve (III). It rotates the eye medially (adduction). Structure The medial rectus muscle shares an origin with several other extrinsic eye muscles, the common tendinous ring. It inserts into the anteromedial surface of the eye. This insertion has a width of around 11 mm. Nerve supply The medial rectus muscle is supplied by the inferior division of the oculomotor nerve (III). A branch of it enters the muscle around two fifths along its length. It usually divides into 2 smaller branches, occasionally 3. These further subdivide, becoming smaller down the length of the muscle until they become imperceptible to standard staining around 17 mm from the insertion of the muscle. Relations The insertion of the medial re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Oblique Muscle
The superior oblique muscle, or obliquus oculi superior, is a fusiform muscle originating in the upper, medial side of the orbit (i.e. from beside the nose) which abducts, depresses and internally rotates the eye. It is the only extraocular muscle innervated by the trochlear nerve (the fourth cranial nerve). Structure The superior oblique muscle loops through a pulley-like structure (the trochlea of superior oblique) and inserts into the sclera on the posterotemporal surface of the eyeball. It is the pulley system that gives superior oblique its actions, causing depression of the eyeball despite being inserted on the superior surface. The superior oblique arises immediately above the margin of the optic foramen, superior and medial to the origin of the superior rectus, and, passing forward, ends in a rounded tendon, which plays in a fibrocartilaginous ring or pulley attached to the trochlear fossa of the frontal bone. The contiguous surfaces of the tendon and ring are lined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vorticose Veins
The vorticose veins, referred to clinically as the vortex veins, are veins that drain the choroid The choroid, also known as the choroidea or choroid coat, is a part of the uvea, the vascular layer of the eye, and contains connective tissues, and lies between the retina and the sclera. The human choroid is thickest at the far extreme rea ... of the eye. There are usually 4-5 vorticose veins in each eye, with at least one vorticose vein per each quadrant of the eye. Vorticose veins drain into the superior ophthalmic vein, and inferior ophthalmic vein. Vorticose veins are an important ophthalmoscopic landmark. Anatomy Course and relations Vorticose veins exit the eyeball 6 mm posterior to its equator. Fate Upper vortex veins empty into the superior ophthalmic vein, and lower vortex veins empty into the inferior ophthalmic vein. Variation The number of vorticose veins is known to vary from 4 to 8, with about 65% of the normal population having 4 or 5 with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Retinal Vein
The central retinal vein (retinal vein) is a vein that drains the retina of the eye. It travels backwards through the centre of the optic nerve accompanied by the central retinal artery before exiting the optic nerve together with the central retinal artery to drain into either the superior ophthalmic vein or the cavernous sinus. Structure Origin The central retinal vein is formed by the convergence of veins that drain retinal tissue. The central retinal vein originates within the eyeball, emerging from the eyball already as a single unified vein. Course The central retinal vein runs through the centre of the optic nerve (alongside the central retinal artery) surrounded by a fibrous connective tissue envelope. It leaves the optic nerve 10 mm from the eyeball along with the central retinal artery, also exiting the meningeal envelope of the optic nerve. Fate The central retinal vein drains into either the superior ophthalmic vein or the cavernous sinus. Variatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrimal Vein
The term Lacrimal or lachrymal, may refer to: Anatomy * Lacrimal apparatus * Lacrimal artery * Lacrimal bone * Lacrimal canaliculi (singular: canaliculus), also known as ''Lacrimal ducts'' * Lacrimal fossa (other) * Lacrimal fluid, see Tears * Lacrimal gland * Lacrimal groove, also known as ''Lacrimal sulcus'' * Lacrimal hamulus * Lacrimal lake * Lacrimal nerve * Lacrimal papilla * Lacrimal punctum * Lacrimal sac * Lacrimal secretion, see Tears * Lacrimal tubercle * Nasolacrimal duct The nasolacrimal duct (also called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity. The duct begins in the eye socket between the maxillary and lacrimal bones, from where it passes downwards and backwards. T ... Typography * A type of stroke ending See also * Lacrima (other) {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Ethmoidal Vein
The superior ophthalmic vein is a vein of the orbit that drains venous blood from structures of the upper orbit. It is fromed by the union of the angular vein, and supraorbital vein. It passes backwards within the orbit alongside the ophthalmic artery, then exits the orbit through the superior orbital fissure to drain into the cavernous sinus. The superior ophthalmic vein can be a path for the spread of infection from the danger triangle of the face to the cavernous sinus and the pterygoid plexus. It may also be affected by an arteriovenous fistula of the cavernous sinus. Structure The superior ophthalmic vein - together with the inferior ophthalmic vein - represents the principal drainage system of the orbit (with the superior ophthalmic vein being the larger of the two). The superior ophthalmic vein drains venous blood from structures of the upper orbit. The superior ophthalmic vein is the largest and the most consistently present vein of the orbit. It usually measures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
