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Vitreous Membrane
The vitreous membrane (or hyaloid membrane or vitreous cortex) is a layer of collagen separating the vitreous humour from the rest of the eye. At least two parts have been identified anatomically. The posterior hyaloid membrane separates the rear of the vitreous from the retina. It is a false anatomical membrane. The anterior hyaloid membrane separates the front of the vitreous from the lens (anatomy), lens. Andres Bernal, Jean-Marie Parel, Fabrice MannsEvidence for posterior zonular fiber attachment on the anterior hyaloid membrane "Investigative Ophthalmology and Visual Science" 2006, 47, 4708-4713. Bernal et al. describe it "as a delicate structure in the form of a thin layer that runs from the pars plana to the posterior lens, where it shares its attachment with the posterior zonule via Weigert's ligament, also known as Egger's line". References External links Image at ivy-rose.co.uk Human eye anatomy {{eye-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Eye
The human eye is a sensory organ in the visual system that reacts to light, visible light allowing eyesight. Other functions include maintaining the circadian rhythm, and Balance (ability), keeping balance. The eye can be considered as a living optics, optical device. It is approximately spherical in shape, with its outer layers, such as the outermost, white part of the eye (the sclera) and one of its inner layers (the pigmented choroid) keeping the eye essentially stray light, light tight except on the eye's optic axis. In order, along the optic axis, the optical components consist of a first lens (the cornea, cornea—the clear part of the eye) that accounts for most of the optical power of the eye and accomplishes most of the Focus (optics), focusing of light from the outside world; then an aperture (the pupil) in a Diaphragm (optics), diaphragm (the Iris (anatomy), iris—the coloured part of the eye) that controls the amount of light entering the interior of the eye; then an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyaloid
A hyaline substance is one with a glassy appearance. The word is derived from , and . Histopathology Hyaline cartilage is named after its glassy appearance on fresh gross pathology. On light microscopy of H&E stained slides, the extracellular matrix of hyaline cartilage looks homogeneously pink, and the term "hyaline" is used to describe similarly homogeneously pink material besides the cartilage. Hyaline material is usually acellular and proteinaceous. For example, arterial hyaline is seen in aging, high blood pressure, diabetes mellitus and in association with some drugs (e.g. calcineurin inhibitors). It is bright pink with PAS staining. Ichthyology and entomology In ichthyology and entomology, ''hyaline'' denotes a colorless, transparent substance, such as unpigmented fins of fishes or clear insect wings. Resh, Vincent H. and R. T. Cardé, Eds. Encyclopedia of Insects, Elsevier 2003. Botany In botany, ''hyaline'' refers to thin and translucent plant parts, such as the marg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collagen
Collagen () is the main structural protein in the extracellular matrix of the connective tissues of many animals. It is the most abundant protein in mammals, making up 25% to 35% of protein content. Amino acids are bound together to form a triple helix of elongated fibril known as a collagen helix. It is mostly found in cartilage, bones, tendons, ligaments, and skin. Vitamin C is vital for collagen synthesis. Depending on the degree of biomineralization, mineralization, collagen tissues may be rigid (bone) or compliant (tendon) or have a gradient from rigid to compliant (cartilage). Collagen is also abundant in corneas, blood vessels, the Gut (anatomy), gut, intervertebral discs, and the dentin in teeth. In muscle tissue, it serves as a major component of the endomysium. Collagen constitutes 1% to 2% of muscle tissue and 6% by weight of skeletal muscle. The fibroblast is the most common cell creating collagen in animals. Gelatin, which is used in food and industry, is collagen t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitreous Humour
The vitreous body (''vitreous'' meaning "glass-like"; , ) is the clear gel that fills the space between the lens and the retina of the eyeball (the vitreous chamber) in humans and other vertebrates. It is often referred to as the vitreous humor (also spelled humour), from Latin meaning liquid, or simply "the vitreous". Vitreous fluid or "liquid vitreous" is the liquid component of the vitreous gel, found after a vitreous detachment. It is not to be confused with the aqueous humor, the other fluid in the eye that is found between the cornea and lens. Structure The vitreous humor is a transparent, colorless, gelatinous mass that fills the space in the eye between the lens and the retina. It is surrounded by a layer of collagen called the vitreous membrane (or hyaloid membrane or vitreous cortex) separating it from the rest of the eye. It makes up four-fifths of the volume of the eyeball. The vitreous humour is fluid-like near the centre, and gel-like near the edges. The vit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retina
The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional image of the visual world on the retina, which then processes that image within the retina and sends nerve impulses along the optic nerve to the visual cortex to create visual perception. The retina serves a function which is in many ways analogous to that of the photographic film, film or image sensor in a camera. The neural retina consists of several layers of neurons interconnected by Chemical synapse, synapses and is supported by an outer layer of pigmented epithelial cells. The primary light-sensing cells in the retina are the photoreceptor cells, which are of two types: rod cell, rods and cone cell, cones. Rods function mainly in dim light and provide monochromatic vision. Cones function in well-lit conditions and are responsible fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lens (anatomy)
The lens, or crystalline lens, is a Transparency and translucency, transparent Biconvex lens, biconvex structure in most land vertebrate eyes. Relatively long, thin fiber cells make up the majority of the lens. These cells vary in architecture and are arranged in concentric layers. New layers of cells are recruited from a thin epithelium at the front of the lens, just below the basement membrane surrounding the lens. As a result the vertebrate lens grows throughout life. The surrounding lens membrane referred to as the lens capsule also grows in a systematic way, ensuring the lens maintains an optically suitable shape in concert with the underlying fiber cells. Thousands of suspensory ligaments are embedded into the capsule at its largest diameter which suspend the lens within the eye. Most of these lens structures are derived from the epithelium of the embryo before birth. Along with the cornea, aqueous humour, aqueous, and vitreous humours, the lens Refraction, refracts light, Fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pars Plana
The ''pars plana'' (also known as ''orbicularis ciliaris'' ) (Latin: flat portion) is part of the ciliary body in the uvea (or vascular tunic, the middle layer of the three layers that comprise the eye). It is about 4 mm long, located near the junction of the iris and sclera, and is scalloped in appearance. The ''pars plana'' may not have a function in the post-fetal A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic stage, the fetal stage of development takes place. Prenatal development is a ... period, making this a good site of entry for ophthalmic surgery of the posterior segment of eyeball; this surgery is known as pars plana vitrectomy. References Human eye anatomy {{Eye-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Zonule
Posterior may refer to: * Posterior (anatomy), the end of an organism opposite to anterior ** Buttocks, as a euphemism * Posterior horn (other) * Posterior probability The posterior probability is a type of conditional probability that results from updating the prior probability with information summarized by the likelihood via an application of Bayes' rule. From an epistemological perspective, the posteri ..., the conditional probability that is assigned when the relevant evidence is taken into account * Posterior tense, a relative future tense {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
