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Vortex Veins
The vorticose veins, referred to clinically as the vortex veins, are veins that drain the choroid 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. Structure 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 The inferior ophthalmic vein is a vein of the orbit that - together with the superior ophthalmic vein - represents the principal drainage system of the orbit. It begins from a venous network in the front of the orbit, then passes backwards throug .... 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 at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 formed 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 forms/represents a connection between facial veins, and intracranial veins. It is valveles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Ophthalmic Vein
The inferior ophthalmic vein is a vein of the orbit that - together with the superior ophthalmic vein - represents the principal drainage system of the orbit. It begins from a venous network in the front of the orbit, then passes backwards through the lower orbit. It drains several structures of the orbit. It may end by splitting into two branches, one draining into the pterygoid venous plexus and the other ultimately (i.e. directly or indirectly) into the cavernous sinus. Structure The inferior ophthalmic vein - together with the superior ophthalmic vein - represents the principal drainage system of the orbit. It forms/represents a connection between facial veins, and intracranial veins. It is valveless. Origin The inferior ophthalmic vein originates from a venous network at the anterior part of the floor and anterior part of the medial wall of the orbit. Course The inferior ophthalmic vein passes posterior-ward through the inferior orbit upon the inferior rectus muscle. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short Posterior Ciliary Arteries
The short posterior ciliary arteries are a number of branches of the ophthalmic artery. They pass forward with the optic nerve to reach the eyeball, piercing the sclera around the entry of the optic nerve into the eyeball. Anatomy The number of short posterior ciliary arteries varies between individuals; one or more short posterior ciliary arteries initially branch off the ophthalmic artery, subsequently dividing to form up to 20 short posterior ciliary arteries. Origin The short posterior ciliary arteries branch off the ophthalmic artery as it crosses the optic nerve medially. Course and relations About 7 short posterior ciliary arteries accompany the optic nerve, passing anterior-ward to reach the posterior part of the eyeball, where they divide into 15-20 branches and pierce the sclera around the entrance of the optic nerve. Distribution The short posterior ciliary arteries contribute arterial supply to the choroid, ciliary processes, optic disc, the outer retina, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choroid
The choroid, also known as the choroidea or choroid coat, is a part of the uvea, the vascular layer of the eye. It contains connective tissues, and lies between the retina and the sclera. The human choroid is thickest at the far extreme rear of the eye (at 0.2 mm), while in the outlying areas it narrows to 0.1 mm. The choroid provides oxygen and nourishment to the outer layers of the retina. Along with the ciliary body and iris, the choroid forms the uveal tract. The structure of the choroid is generally divided into four layers (classified in order of furthest away from the retina to closest): *Haller's layer – outermost layer of the choroid consisting of larger diameter blood vessels; * Sattler's layer – layer of medium diameter blood vessels; * Choriocapillaris – layer of capillaries; and * Bruch's membrane (synonyms: Lamina basalis, Complexus basalis, Lamina vitra) – innermost layer of the choroid. Blood supply There are two circulations of the eye: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 formed 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 forms/represents a connection between facial veins, and intracranial veins. It is valveles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
