disk
[disk]a circular or rounded flat plate; often spelled disc in names of anatomic structures.
articular disk a pad of fibrocartilage or dense fibrous tissue present in some synovial joints.
Bowman's disk one of the flat plates making up a striated muscle fiber.
choked disk papilledema.
ciliary disk pars plana.
embryonic disk (germ disk) (germinal disk) a flattened round bilaminar plate of cells in the blastocyst of a mammal, where the first traces of the embryo are seen; called also embryonic or germinal area.
herniated disk see herniated disk.
intervertebral disk the layer of fibrocartilage between the bodies of adjoining vertebrae; see also herniated disk.
intra-articular d's articular disk.
Merkel's d's small cup-shaped tactile receptors in the skin that are particularly sensitive to continuous pressure.
optic disk the intraocular part of the optic nerve formed by fibers converging from the retina and appearing as a pink to white disk in the retina; there are no sensory receptors in the region and hence no response to stimuli. Called also blind spot.
ruptured disk herniated disk.
slipped disk popular term for herniated disk.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
disc
(disk), [TA]1. A round, flat plate; any approximately flat circular structure.
2. Synonym(s): lamella (2)
3. In dentistry, a circular piece of thin paper or other material, coated with an abrasive substance, used for cutting and polishing teeth and fillings.
Synonym(s): disk [TA]
Farlex Partner Medical Dictionary © Farlex 2012
disc
(dĭsk)n. & v.
Variant of disk.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
disc
Anatomy(1) Disk.
(2) Discus.
Orthopaedics
Disc.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
disc
Fibrocartilaginous material between spinal vertebrae which provides a cushion-like support against shockMcGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
disc
(disk)1. A round, flat plate; any approximately flat circular structure.
2. dentistry A circular piece of thin paper or other material, coated with an abrasive substance, used for cutting and polishing teeth and fillings.
3. microbiology A plate coated with an antibiotic to measure susceptibility and resistance.
4. The optic nerve head as viewed during ophthalmoscopy.
[L. discus; G. diskos, a quoit, disc]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
disc
ordisk
that part of the receptacle surrounding the plant ovary which is fleshy and sometimes nectar-secreting.Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
disc
1. A flat, circular, coin-shaped structure. 2. In anatomy, the intervertebral disc.
Airy's disc Owing to the wave nature of light, the image of a point source consists of a diffraction pattern. If light passes through a circular aperture, the diffraction pattern will appear as a bright central disc, called Airy's disc, surrounded by concentric light and dark rings. Airy's disc receives about 87% of the luminous flux, the next concentric ring about 8%, and the next 3%. The radius of Airy's disc equals
choked d . See papilloedema.
cupped disc An enlarged and deepened excavation of the physiological cup. It may be physiological, or due to glaucoma (glaucomatous cup), or following atrophy of the optic nerve (as in papilloedema).
diffraction disc See Airy's disc.
Maxwell disc A rotating disc onto which differently coloured discs which are radially slit can be fitted together to overlap and divide the surface into sectors of different colours. It may be used to investigate colour mixture.
morning glory disc A congenital, usually unilateral, anomaly of the optic disc. It may be due to a failure of the embryonic fissure such that the optic disc and some peripapillary tissue prolapse posteriorly. The optic disc is abnormally large and a white-grey tuft of glial tissue covers its centre. The annular zone surrounding the disc has irregular areas of pigmentation and depigmentation. The optic disc thus resembles a morning glory flower. Patients present with reduced visual acuity and strabismus and, in about one-third of patients, retinal detachment.
optic disc Region of the fundus of the eye corresponding to the optic nerve head. It can be seen with the ophthalmoscope as a pinkish-yellow area with usually a whitish depression called the physiological cup. The optic disc has an area of about 2.7 mm2, a horizontal width of about 1.75 mm and a vertical height of about 1.9 mm. The optic disc is the anatomical correlate of the physiological blind spot. It is greatly affected in glaucoma, papillitis, Leber's hereditary optic atrophy. Syn. optic nerve head; optic papilla (this is not strictly correct because the disc is not elevated above the surrounding retina). See glaucomatous cup; optic disc drusen; neuroretinal rim; papilloedema; Swann's syndrome.
pinhole disc (ph) A blank disc with a small aperture (2 mm diameter or less) mounted in a trial lens rim. It is used to reduce the size of the blur circle in an ametropic eye. In this condition vision will improve giving an indication of the final visual acuity that will be obtained with corrective lenses. If no improvement occurs, the eye is amblyopic. This procedure is called the pinhole test.
Scheiner's disc An opaque disc in which there are two pinholes separated by a distance less than the pupil diameter. It is used to measure the dioptric changes during accommodation or to detect the type of ametropia (Fig. D6). See Scheiner's experiment.
situs inversus of the disc A congenital, usually bilateral condition in which the retinal vessels course nasally from the disc instead of temporally. It is often associated with congenital scleral crescent and myopic astigmatism.
stenopaeic disc 1. A pinhole disc. 2. A blank disc with a slit used in detecting and measuring the astigmatism of the eye (Fig. D7). Syn. stenopaeic slit. Note: also spelt stenopeic or stenopaic. See kinescope; stenopaeic spectacles.
tilted disc A congenital, bilateral condition in which the optic nerves insert obliquely into the globe. It is often associated with congenital scleral crescent and myopic astigmatism. The only sign is a bitemporal visual field defect (often upper temporal).
Airy's disc Owing to the wave nature of light, the image of a point source consists of a diffraction pattern. If light passes through a circular aperture, the diffraction pattern will appear as a bright central disc, called Airy's disc, surrounded by concentric light and dark rings. Airy's disc receives about 87% of the luminous flux, the next concentric ring about 8%, and the next 3%. The radius of Airy's disc equals
1.22λ f/d
where d is the radius of the entrance pupil of the optical system of focal length f and λ the wavelength of the light used. In the eye, with a pupil of 4 mm diameter and λ = 507 nm, the diameter of Airy's disc is about 5 mm, which corresponds to a visual angle of about one minute of arc (Fig. D5). Syn. diffraction disc. See Rayleigh criterion; point-spread function; limit of resolution.choked d . See papilloedema.
cupped disc An enlarged and deepened excavation of the physiological cup. It may be physiological, or due to glaucoma (glaucomatous cup), or following atrophy of the optic nerve (as in papilloedema).
diffraction disc See Airy's disc.
Maxwell disc A rotating disc onto which differently coloured discs which are radially slit can be fitted together to overlap and divide the surface into sectors of different colours. It may be used to investigate colour mixture.
morning glory disc A congenital, usually unilateral, anomaly of the optic disc. It may be due to a failure of the embryonic fissure such that the optic disc and some peripapillary tissue prolapse posteriorly. The optic disc is abnormally large and a white-grey tuft of glial tissue covers its centre. The annular zone surrounding the disc has irregular areas of pigmentation and depigmentation. The optic disc thus resembles a morning glory flower. Patients present with reduced visual acuity and strabismus and, in about one-third of patients, retinal detachment.
optic disc Region of the fundus of the eye corresponding to the optic nerve head. It can be seen with the ophthalmoscope as a pinkish-yellow area with usually a whitish depression called the physiological cup. The optic disc has an area of about 2.7 mm2, a horizontal width of about 1.75 mm and a vertical height of about 1.9 mm. The optic disc is the anatomical correlate of the physiological blind spot. It is greatly affected in glaucoma, papillitis, Leber's hereditary optic atrophy. Syn. optic nerve head; optic papilla (this is not strictly correct because the disc is not elevated above the surrounding retina). See glaucomatous cup; optic disc drusen; neuroretinal rim; papilloedema; Swann's syndrome.
pinhole disc (ph) A blank disc with a small aperture (2 mm diameter or less) mounted in a trial lens rim. It is used to reduce the size of the blur circle in an ametropic eye. In this condition vision will improve giving an indication of the final visual acuity that will be obtained with corrective lenses. If no improvement occurs, the eye is amblyopic. This procedure is called the pinhole test.
Scheiner's disc An opaque disc in which there are two pinholes separated by a distance less than the pupil diameter. It is used to measure the dioptric changes during accommodation or to detect the type of ametropia (Fig. D6). See Scheiner's experiment.
situs inversus of the disc A congenital, usually bilateral condition in which the retinal vessels course nasally from the disc instead of temporally. It is often associated with congenital scleral crescent and myopic astigmatism.
stenopaeic disc 1. A pinhole disc. 2. A blank disc with a slit used in detecting and measuring the astigmatism of the eye (Fig. D7). Syn. stenopaeic slit. Note: also spelt stenopeic or stenopaic. See kinescope; stenopaeic spectacles.
tilted disc A congenital, bilateral condition in which the optic nerves insert obliquely into the globe. It is often associated with congenital scleral crescent and myopic astigmatism. The only sign is a bitemporal visual field defect (often upper temporal).
)
Fig. D5 Point spread function of the intensity of the diffraction pattern from a circular aperture. Airy's disc is represented by the central disc (AA), the radius of which is equal to 1.22 λf′/d, the radius of the next concentric light ring () is equal to 2.23 λf′/d. The light intensity is maximum in the middle of Airy's disc, it is equal to 1
)
Fig. D6 Images of a distant object formed on the retina of an unaccommodated emmetrope (clear, single image), a hyperope and a myope (blurred, double images) looking through a Scheiner's disc
)
Fig. D7 Stenopaeic slit
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
disc
, disk (disk)dentistry a circular piece of thin paper or other material, coated with an abrasive substance, used for cutting and polishing teeth and fillings.
[L. discus; G. diskos, a quoit, disc]
Medical Dictionary for the Dental Professions © Farlex 2012
Patient discussion about disc
Q. Is degenerative disc disease and arthritis the same thing? My husband was recently in a auto accident at work. They did a CT Scan of his head and neck. The doctor said that the CT Scan found that he has arthritis in his neck. After receiving the report ourselves to take to another doctor it reads: "There is minimal early degenerative disc disease with osteophyte formation predominately at C5-6. " My husband never had a problem with his neck before the accident
A. I was suffering from pain for 2 years and undergoing numerous test for causes when a trip to a neurologist for migraines gave me an answer. FINALLY! This was in July of this year so I am still learning and finding out about fibromyalgia but I do know in the last couple of years there has been a greater acceptance BUT there are still a lot of doctors not being supportive (from experience and talking with others) and the public in general can be unaccepting b/c you look healthy, seem to be healthy and they can not understand why you are in pain that "can't be explained!" I encourage suffers of fibro to find support within their peers! it really helps to talk to people that understand! That's what brought me to this site to start with and I am so glad I found it!
Q. What alternatives are there for DDD.De generative Disc Disease? I can't sit upright for long periods of time, at times the symptoms are worse and then days and weeks where I feel fine. When I lean into my right legit alleviates it a little but it is excruciating when I shift weight. I also have to sleep with a pillow between my legs and have to shift frequently.I have a lot of strength in my legs and back. But if I stuck in my stomach more and curve my like doing a crunch. the pain is fine.
A. Degenerative disc disease can often be successfully treated without surgery. One or a combination of treatments such as Physical therapy, chiropractic manipulative therapy (CMT), osteopathic manipulation, anti-inflammatory medications such as nonsteroidal anti-inflammatory drugs, chiropractic treatments, Traction (orthopedics), or spinal injections often provide adequate relief of these troubling symptoms.
The option of surgery may be recommended if the conservative treatment options do not provide relief within 2 to 3 months. If leg or back pain limits normal activity, if there is weakness or numbness in the legs, if it is difficult to walk or stand, or if medication or physical therapy are ineffective, surgery may be necessary. You should dicucss this with an orthopedic surgeon.
The option of surgery may be recommended if the conservative treatment options do not provide relief within 2 to 3 months. If leg or back pain limits normal activity, if there is weakness or numbness in the legs, if it is difficult to walk or stand, or if medication or physical therapy are ineffective, surgery may be necessary. You should dicucss this with an orthopedic surgeon.
Q. what does c4-5 mild central disk bulging impinging upon cervical cord without spinal stenosis or distortion of the cord . mild righ neural foraminal narrowing from uncovertebral joint hypertropy mean
A. Well this basically means there is a very small narrowing of the cervical (your neck area) spinal canal (where the spinal cord is), however the narrowing does not cause any damage to the spinal cord, therefore probably does not cause any major symptoms involving the nerves. The c4-5 bulging part refers to the part in between the two cervical vertebras c4 and c5, in which the disc (a part in the spinal cord) is sliding a bit side-ways, but again, it does not seem to be causing any trouble.
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