| choroid | <anatomy> Middle layer of the vertebrate eye, between retina and sclera. Well vascularised and also pigmented to throw light back onto the retina (the tapetum is an irridescent layer in the choroid of some eyes). Not to be confused with the choroid plexus, a highly vascularised region of the roof of the ventricles of the vertebrate brain that secretes cerebrospinal fluid. (18 Nov 1997) |
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| choroid branches | The choroid branches: ramus choroidei posteriores laterales, lateral posterior choroid branches of posterior cerebral artery distributed to the choroid plexus of the lateral ventricle; ramus choroidei posteriores mediales, medial posterior choroid branches of posterior cerebral artery distributed to the choroid plexus of the third ventricle; ramus choroidei ventriculi lateralis, lateral ventricle choroid branch of anterior choroid artery distributed to the plexus of the lateral ventricle; ramus choroidei ventriculi tertii, third ventricle choroid branch of anterior choroid artery to the third ventricle; ramus choroidei ventriculi quarti, fourth ventricle choroid branch of posterior inferior cerebellar artery. Synonym: rami choroidei. (05 Mar 2000) |
| choroid diseases | Disorders of the choroid including hereditary choroidal diseases, neoplasms, and other abnormalities of the vascular layer of the uvea. (12 Dec 1998) |
| choroid fissure | In the embryo, the temporary gap in the ventral margin of the developing optic cup. Synonym: choroid fissure, choroid fissure, choroidal fissure. (05 Mar 2000) |
| choroid glomus | A marked enlargement of the choroid plexus of the lateral ventricle at the junction of the central part with the inferior horn. Synonym: glomus choroideum, choroid skein. (05 Mar 2000) |
| choroid haemorrhage | Haemorrhage from the vessels of the choroid. (12 Dec 1998) |
| choroid neoplasms | Tumours of the choroid; most common intraocular tumours are malignant melanomas of the choroid. These usually occur after puberty and increase in incidence with advancing age. Most malignant melanomas of the uveal tract develop from benign melanomas (nevi). (12 Dec 1998) |
| choroid plexus | <radiology> Formed by the invagination of ependyma into ventricles CP of lateral and third ventricles are continuous, extends posteriorly to temporal horn, 3rd and two lateral ventricles continuous at interventricular foramen CP of fourth ventricle is seperate, shape of a T, vertical limb extends from near Magendie's foramen to the fastigium, horizontal limbs project into cerebellopontine angle cisterns the glomus is a localised enlargement of CP, found at the posterior part of the floor of the ventricle (12 Dec 1998) |
| choroid plexus neoplasms | Neoplasms of the choroid plexus, blood vessels of the pia mater that project into the brain ventricles. (12 Dec 1998) |
| choroid plexus of fourth ventricle | One of two vascular fringes of pia mater projecting on either side from the lower part of the roof of the fourth cerebral ventricle. Synonym: plexus choroideus ventriculi quarti. (05 Mar 2000) |
| choroid plexus of lateral ventricle | The vascular fringe that projects from the choroidal fissure into each lateral ventricle. Synonym: plexus choroideus ventriculi lateralis. (05 Mar 2000) |
| choroid plexus of third ventricle | The double row of vascular projections from the undersurface of the tela choroidea where it roofs over the third ventricle. Synonym: plexus choroideus ventriculi tertii. (05 Mar 2000) |
| choroid plexus papilloma | <radiology> Isodense or hyperdense enhancing mass, location: usually atrium of lateral ventricle, age: usually less than 10 yrs, complications: non-obstructive hydrocephalus (12 Dec 1998) |
| choroid skein | A marked enlargement of the choroid plexus of the lateral ventricle at the junction of the central part with the inferior horn. Synonym: glomus choroideum, choroid skein. (05 Mar 2000) |
| choroid tela of fourth ventricle | The sheet of pia mater covering the lower part of the ependymal roof of the fourth ventricle. Synonym: tela choroidea ventriculi quarti, tela choroidea inferior. (05 Mar 2000) |
| basal lamina of choroid | The transparent, nearly structureless inner layer of the choroid in contact with the pigmented layer of the retina. Synonym: basal lamina of choroid, basal layer of choroid, Bruch's membrane, Henle's membrane, lamina vitrea, vitreous lamella, vitreous membrane. (05 Mar 2000) |
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| basal layer of choroid | The transparent, nearly structureless inner layer of the choroid in contact with the pigmented layer of the retina. Synonym: basal lamina of choroid, basal layer of choroid, Bruch's membrane, Henle's membrane, lamina vitrea, vitreous lamella, vitreous membrane. (05 Mar 2000) |
| vascular lamina of choroid | <anatomy> The outer portion of the choroid of the eye containing the largest blood vessels. Synonym: lamina vasculosa choroideae, Haller's vascular tissue, uvaeformis, vascular layer of choroid coat of eye, vascular layer. (05 Mar 2000) |
| vascular layer of choroid coat of eye | <anatomy> The outer portion of the choroid of the eye containing the largest blood vessels. Synonym: lamina vasculosa choroideae, Haller's vascular tissue, uvaeformis, vascular layer of choroid coat of eye, vascular layer. (05 Mar 2000) |
| gyrate atrophy of choroid and retina | A slowly progressive atrophy of the choriocapillaris, pigmentary epithelium, and sensory retina, with irregular confluent atrophic areas and an associated ornithinuria; autosomal recessive inheritance; due to a deficiency of ornithine d-aminotransferase. (05 Mar 2000) |
| coloboma of choroid | A congenital defect of the choroid and retinal pigment epithelium exposing the sclera; the defect is usually situated below the optic disk in the region of foetal fissure. (05 Mar 2000) |
| plexus of choroid artery | <anatomy, artery> An autonomic plexus accompanying the artery of the same name, derived from the internal carotid plexus. Synonym: plexus arteriae choroideae. (05 Mar 2000) |
| superior choroid vein | <anatomy, vein> A tortuous vein that follows the choroid plexus of the lateral ventricle and unites with the superior thalamostriate vein and the anterior vein of the transparent septum to form the internal cerebral vein. Synonym: vena choroidea superior. (05 Mar 2000) |
| inferior choroid vein | <anatomy, vein> A small vein draining the lower part of the choroid plexus of the lateral ventricle into the basal vein. Synonym: vena choroidea inferior. (05 Mar 2000) |
| epithelial choroid layer | The layer of modified ependymal cells that forms the inner layer of the tela choroidea, facing the ventricle. Synonym: lamina epithelialis, epithelial choroid layer, lamina choroidea epithelialis, lamina choroidea. (05 Mar 2000) |