| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 1,515,433,378 visitors served. |
|
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
macula |
Also found in: Dictionary/thesaurus, Encyclopedia, Wikipedia | 0.06 sec. |
|
macula /mac·u·la/ (mak´u-lah) pl. ma´culae [L.] 1. a stain, spot, or thickening; in anatomy, an area distinguishable by color or otherwise from its surroundings. Often used alone to refer to the macula retinae. 2. m. lutea. 3. macule. 4. a corneal scar, appreciated as a gray spot.mac´ularmac´ulate acoustic maculae maculae acusticae. ma´culae acus´ticae the macula sacculi and macula utriculi considered together. macula adhe´rens desmosome. ma´culae atro´phicae white scarlike patches formed on the skin by atrophy. ma´culae ceru´leae faint grayish blue spots sometimes found peripheral to the axilla or groin in pediculosis. cerebral macula tache cérébrale. ma´culae cribro´sae three perforated areas (inferior, medial, and superior) on the vestibular wall through which branches of the vestibulocochlear nerve pass to the saccule, utricle, and semicircular canals. macula den´sa a zone of heavily nucleated cells in the distal renal tubule. macula fla´va laryn´gis a yellow nodule at one end of a vocal cord. macula lu´tea , macula lu´tea re´tinae, macula re´tinae an irregular yellowish depression on the retina, lateral to and slightly below the optic disk. macula sac´culi a thickening on the wall of the saccule where the epithelium contains hair cells that are stimulated by linear acceleration and deceleration and by gravity. macula utri´culi a thickening in the wall of the utricle where the epithelium contains hair cells that are stimulated by linear acceleration and deceleration and by gravity.
Macula The central part of the retina where the rods and cones are densest. Mentioned in: Eye Examination
macula a small pigmented area or a spot that appears separate or different in color from the surrounding tissue. macula (ma·kyu·l n a region within the retina of the eye; is responsible for clear and defined vision. Macular degeneration is the leading cause of loss of vision in elderly populations. Smoking, hypertension, aging, and atherosclerosis are implicated in macular degeneration.
macula pl. maculae [L.] 1. a stain, spot, or thickening; 2. an area distinguishable by color or otherwise from its surroundings. Often used alone to refer to the macula retinae. 3. a macule: a discolored spot on the skin that is not raised above the surface. 4. a corneal scar that can be seen without special optical aids; presenting as a gray spot intermediate between a nebula and a leukoma. 5. macula lutea. macula acusticae terminations of the vestibulocochlear nerve in the utricle and saccule. macula adherens see desmosome. macula atrophica a white atrophic patch on the skin. macula corneae a circumscribed opacity of the cornea. macula cribrosa a perforated spot or area; one of three perforated areas (inferior, medial and superior) in the wall of the vestibule of the ear through which branches of the vestibulocochlear nerve pass to the saccule, utricle and semicircular canals. macula densa a zone of heavily nucleated cells in the distal renal tubule. macula folliculi the point on the surface of a vesicular ovarian follicle where rupture occurs; follicular stigma. macula germinativa germinal area; the part of the conceptus where the embryo is formed. inner ear macula sensory receptor areas in the walls of the utriculus and sacculus which monitor the position of the head relative to gravity; see also macula sacculi, macula utriculi (below). macula lutea an irregular yellowish depression on the retina, lateral to and slightly below the optic disk. Called also macula retinae. macula retinae see macula lutea (above). macula sacculi a thickening on the wall of the saccule where the epithelium contains hair cells that receive and transmit vestibular impulses. macula utriculi
a thickening in the wall of the utricle where the epithelium contains hair cells that are stimulated by linear acceleration and deceleration and by gravity. fovea
centralis A small area of the retina of approximately 1.5 mm in diameter situated within the macula lutea. At the fovea centralis, the retina is the thinnest as there are no supporting fibres of Mueller, no ganglion cells and no bipolar cells. These cells are shifted to the edge of the depression. The fovea centralis contains mainly cone cells, each one being connected to only one ganglion cell and thus contributing to the highest visual acuity of the retina. The visual field represented by the fovea centralis is equal to about 5º (Fig. F9). Syn. foveal pit; macula (term often used by clinicians). See central visual acuity; retinal image; macula lutea. macula lutea An oval area of the retina 3-5 mm in diameter, with the foveal depression at its centre, slightly below the level of the optic disc and temporal to it (its centre lies 3.5 mm from the edge of the disc). The side wall of the depression slopes gradually towards the centre where the fovea centralis is located and where the best photopic visual acuity is obtained. Around the fovea, the ganglion cells are much more numerous than elsewhere, being arranged in five to seven layers. The outer molecular layer is also thicker than elsewhere and forms the outer fibre layer of Henle and there is a progressive disappearance of rods so that at the foveola only cones are found. The area of the macula lutea is impregnated by a yellow pigment (macular pigment) in the inner layers and for that reason is often called the yellow spot. Syn. area centralis (although that area is considered to be slightly larger, about 5.5 mm in diameter); punctum luteum. See blue field entoptoscope; fovea centralis; macular pigment. How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
|
| Medical browser | ? | ? Full browser | |||
|---|---|---|---|---|---|
macula lutea macula retinae macula sacculi macula solaris macula utriculi maculae Maculae ceruleae maculae cribrosae macular macular amyloidosis macular area macular cyst macular degeneration macular dystrophy macular edema |
| ||||
| Medical Dictionary |
| Free Tools: |
For surfers:
Browser extension |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup | Partner with us |
|---|