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Ciliary Arteries
The ciliary arteries are divisible into three groups, the long posterior, short posterior, and the anterior. * The short posterior ciliary arteries from six to twelve in number, arise from the ophthalmic artery as it crosses the optic nerve. * The long posterior ciliary arteries, two for each eye, pierce the posterior part of the sclera at some little distance from the optic nerve. * The anterior ciliary arteries The anterior ciliary arteries are seven small arteries in each eye-socket that supply the conjunctiva, sclera and the recti muscles. They are derived from the muscular branches of the ophthalmic artery. Course The anterior ciliary arteries are ... are derived from the muscular branches of the ophthalmic artery. Additional images File:Gray514.png, The ophthalmic artery and its branches File:Gray878.png, Iris, front view. File:Gray880.png, The terminal portion of the optic nerve and its entrance into the eyeball, in horizontal section. References Arteries of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short Posterior Ciliary Arteries
The short posterior ciliary arteries, around twenty in number, arise from the medial posterior ciliary artery and lateral posterior ciliary artery, which are branches of the ophthalmic artery as it crosses the optic nerve. Course and target They pass forward around the optic nerve to the posterior part of the eyeball, pierce the sclera around the entrance of the optic nerve, and supply the choroid (up to the equator of the eye) and ciliary processes. Some branches of the short posterior ciliary arteries also supply the optic disc via an anastomotic ring, the circle of Zinn-Haller or ''circle of Zinn'', which is associated with the fibrous extension of the ocular tendons (common tendinous ring (also annulus of Zinn)). Additional images File:Gray880.png, The terminal portion of the optic nerve and its entrance into the eyeball, in horizontal section See also * Long posterior ciliary arteries *Anterior ciliary arteries The anterior ciliary arteries are seven small arteries in ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmic Artery
The ophthalmic artery (OA) is an artery of the head. It is the first branch of the internal carotid artery distal to the cavernous sinus. Branches of the ophthalmic artery supply all the structures in the orbit around the eye, as well as some structures in the nose, face, and meninges. Occlusion of the ophthalmic artery or its branches can produce sight-threatening conditions. Structure The ophthalmic artery emerges from the internal carotid artery. This is usually just after the internal carotid artery emerges from the cavernous sinus. In some cases, the ophthalmic artery branches just before the internal carotid exits the cavernous sinus. The ophthalmic artery emerges along the medial side of the anterior clinoid process. It runs anteriorly, passing through the optic canal inferolaterally to the optic nerve. It can also pass superiorly to the optic nerve in a minority of cases. In the posterior third of the cone of the orbit, the ophthalmic artery turns sharply and medially t ... [...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 system, 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 area, 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 per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long Posterior Ciliary Arteries
The long posterior ciliary arteries are arteries of the head arising, together with the other ciliary arteries, from the ophthalmic artery. There are two in each eye. Course They pierce the posterior part of the sclera at some little distance from the optic nerve, and run forward, along either side of the eyeball, between the sclera and choroid, to the ciliary muscle, where they divide into two branches. These form an arterial circle, the circulus arteriosus major, around the circumference of the iris, from which numerous converging branches run, in the substance of the iris, to its pupillary margin, where they form a second (incomplete) arterial circle, the circulus arteriosus minor. Target The long posterior ciliary arteries supply the iris, ciliary body and choroid. See also * Short posterior ciliary arteries The short posterior ciliary arteries, around twenty in number, arise from the medial posterior ciliary artery and lateral posterior ciliary artery, which are branches ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anterior Ciliary Arteries
The anterior ciliary arteries are seven small arteries in each eye-socket that supply the conjunctiva, sclera and the recti muscles. They are derived from the muscular branches of the ophthalmic artery. Course The anterior ciliary arteries are branches of the ophthalmic artery and run to the front of the eyeball in company with the extraocular muscles. They form a vascular zone beneath the conjunctiva, and then pierce the sclera a short distance from the cornea and end in the circulus arteriosus major. Three of the four rectus muscles; the superior, inferior and medial, are supplied by two ciliary arteries each, while the lateral rectus Lateral is a geometric term of location which may refer to: Healthcare * Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral co ... only receives one branch. References Arteries of the head and neck {{circul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
