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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.
The blood–ocular barrier is a barrier created by endothelium of capillaries of the retina and iris, ciliary epithelium and retinal pigment epithelium. [1] It is a physical barrier between the local blood vessels and most parts of the eye itself, and stops many substances including drugs from traveling across it. [2]
The innermost is the retina, which gets its oxygenation from the blood vessels of the choroid (posteriorly) as well as the retinal vessels (anteriorly). The spaces of the eye are filled with the aqueous humour anteriorly, between the cornea and lens, and the vitreous body , a jelly-like substance, behind the lens, filling the entire posterior ...
The blood–brain barrier (BBB) is a highly selective semipermeable border of endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system, thus protecting the brain from harmful or unwanted substances in the blood. [1]
The central part of the retina where the light rays are focused after passing through the pupil and the lens is a circular area called the macula. The center of this circular area is the fovea . The fovea and a small area surrounding it are not supplied by the central retinal artery or its branches, but instead by the choroid .
The blood retinal barrier has two components: the retinal vascular endothelium and the retinal pigment epithelium. [2] Retinal blood vessels that are similar to cerebral blood vessels maintain the inner blood-ocular barrier. This physiological barrier comprises a single layer of non-fenestrated endothelial cells, which have tight junctions.
The ganglion cell axons form the optic nerve after they leave the eye. The optic disc represents the beginning of the optic nerve and is the point where the axons of retinal ganglion cells come together. The optic disc in a normal human eye carries 1–1.2 million afferent nerve fibers from the eye toward the brain.
[4] [5] Pericytes help in the maintainenance of homeostatic and hemostatic functions in the brain, where one of the organs is characterized with a higher pericyte coverage, and also sustain the blood–brain barrier. [6] These cells are also a key component of the neurovascular unit, which includes endothelial cells, astrocytes, and neurons.