| essential phthisis bulbi | A softening of the eyeball (ophthalmomalacia) and reduction in size, not due to inflammation. (05 Mar 2000) |
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| tunica conjunctiva bulbi | The part of the conjunctiva covering the anterior surface of the sclera and the surface epithelium of the cornea. Synonym: tunica conjunctiva bulbi, conjunctival layer of bulb. (05 Mar 2000) |
| tunica fibrosa bulbi | The outer layer of the eyeball composed of the sclera and cornea. Synonym: tunica fibrosa bulbi, tunica externa oculi. (05 Mar 2000) |
| tunica interna bulbi | Light sensitive layer of the eye. In vertebrates, looking from outside, there are four major cell layers: (i) the outer neural retina, which contains neurons (ganglion cells, amacrine cells, bipolar cells) as well as blood vessels, (ii) the photoreceptor layer, a single layer of rods and cones, (iii) the pigmented retinal epithelium (PRE or RPE), (iv) the choroid, composed of connective tissue, fibroblasts and including a well vascularised layer, the chorio capillaris, underlying the basal lamina of the PRE. Behind the choroid is the sclera, a thick organ capsule. In molluscs (especially cephalopods such as the squid) the retina has the light sensitive cells as the outer layer with the neural and supporting tissues below. See: retinal rods, retinal cones, rhodopsin. (18 Nov 1997) |
| tunica vasculosa bulbi | The vascular, pigmentary, or middle coat of the eye, comprising the choroid, ciliary body, and iris. Synonym: tunica vasculosa bulbi, Haller's tunica vasculosa, tunica vasculosa oculi, uvea, uveal tract. (05 Mar 2000) |
| fascia bulbi | A condensation of connective tissue on the outer aspect of the sclera from which it is separated by a narrow cleftlike episcleral space; the sheath is attached to the sclera near the sclerocorneal junction and blends with the fascia of the extraocular muscles. Synonym: vagina bulbi, capsula bulbi, eye capsule, fascia bulbi, sheath of eyeball, Tenon's capsule, vagina oculi. (05 Mar 2000) |
| fascia muscularis musculorum bulbi | Muscular fascia; the part of the orbital fascia that envelops the extraocular muscles; it is thin posteriorly but becomes thicker where it is continuous with the bulbar sheath; the fascial sheaths of the four rectus muscles are connected by an intermuscular membrane. Synonym: fascia muscularis musculorum bulbi, fascia of extraocular muscles, muscular fascia of extraocular muscle. (05 Mar 2000) |
| ligamentum annulare bulbi | The network of fibres (pectinate ligaments) at the iridocorneal angle between the anterior chamber of the eye and the venous sinus of the sclera; it contains spaces between the fibres that are involved in drainage of the aqueous humor, and is composed of two portions: the corneoscleral part, the part attached to the sclera, and the uveal part, the part attached to the iris. Synonym: reticulum trabeculare sclerae, Gerlach's valvula, Hueck's ligament, ligamentum annulare bulbi, pectinate ligaments of iridocorneal angle, pillar of iris, trabecular meshwork, trabecular network, trabecular zone. (05 Mar 2000) |
| axis | <botany> A stem, commonly used for the main stem of a whole plant or of an inflorescence. (09 Oct 1997) |
| axis corpuscle | Axile corpuscle, the central portion of a tactile corpuscle. (05 Mar 2000) |
| axis, crystallographic | <microscopy> One of several imaginary lines assumed in describing the positions of the planes by which a crystal is bounded, the positions of the atoms in the structure of the crystal and the directions associated with vectorial and tensorial physical properties. (05 Aug 1998) |
| axis cylinder | An obsolete term for axon. (05 Mar 2000) |
| axis deviation | Deflection of the electrical axis of the heart to the right or left of the normal. See: left axis deviation, right axis deviation, axis. Synonym: axis shift. (05 Mar 2000) |
| axis fracture | <radiology> Incidence: 6% of cervical spine injuries, associated with atlas fractures in 8%, hyperflexion injury: odontoid fracture, type I avulsion of tip of odontoid (5-8%) difficult to detect, type II fracture through base of dens (54-67%) complication: nonunion, type III subdental injury (30-33%) prognosis: good, Differential diagnosis: os odontoideum, ossiculum terminale, hypoplasia/aplasia of dens, hyperextension injury: hangman's fracture (12 Dec 1998) |
| axis lentis | A line connecting the anterior and posterior poles of the lens of the eye. Synonym: axis lentis. (05 Mar 2000) |