tapetum


Also found in: Dictionary, Encyclopedia, Wikipedia.

tapetum

 [tah-pe´tum] (L.)
1. a covering structure or layer of cells.
2. a stratum in the human brain composed of fibers from the body and splenium of the corpus callosum sweeping around the lateral ventricle.
tapetum lu´cidum the iridescent epithelium of the choroid of animals that gives their eyes the property of shining in the dark.

ta·pe·tum

, pl.

ta·pe·ta

(tă-pē'tŭm, -tă), [TA]
1. In general, any membranous layer or covering.
2. neuroanatomy a thin sheet of fibers in the lateral wall of the temporal and occipital horns of the lateral ventricle, continuous with the corpus callosum. Synonym(s): Fielding membrane, membrana versicolor
3. A dense layer in the choroidea of the eye of many mammalian species, including the cat and dog but not humans, which forms a discrete or diffuse area of reflective cells, rodlets, and fibers; its strong light-reflecting properties cause the metallic hue and light-glow of such eyes in the dark.
[L. tapeta, a carpet]

tapetum

/ta·pe·tum/ (tah-pe´tum) pl. tape´ta   [L.]
1. a covering structure or layer of cells.
2. a stratum of fibers of the corpus callosum on the superolateral aspect of the occipital horn of the lateral ventricle.

tapetum

(tə-pē′təm)
n. pl. tape·ta (-tə)
Anatomy
a. A reflective membrane in the back of the eye of many animals that are active during low-light conditions.
b. A layer of fibers of the corpus callosum forming the roof of part of the lateral ventricle of the brain.

ta·pe′tal (-pēt′l) adj.

tapetum

1 a carpetlike layer or covering of tissue.
2 a thin sheet of fibers covering parts of the brain and continuous with the corpus callosum.
3 the reflective part of the choroid coat of the eye in many mammals.

ta·pe·tum

, pl. tapeta (tă-pē'tŭm, -tă) [TA]
1. In general, any membranous layer or covering.
2. [TA] neuroanatomy A thin sheet of fibers in the lateral wall of the temporal and occipital horns of the lateral ventricle, continuous with the corpus callosum.
[L. tapeta, a carpet]

tapetum

  1. a nutritive layer surrounding those cells which will become MICROSPORES. The tapetum is found in a wide range of vascular plants, from FERNS to ANGIOSPERMS. In the latter, a tapetal layer is found in the pollen sacs of the ANTHER.
  2. a layer of specialized reflective cells in the choroid of the EYE, especially noticeable in the eyes of cats.

Fielding,

George H., English anatomist, 1801-1871.
Fielding membrane - in neuroanatomy, a thin sheet of fibers in the lateral wall of the temporal and occipital horns of the lateral ventricle, continuous with the corpus callosum. Synonym(s): tapetum

tapetum

pl. tapeta [L.]
1. a covering structure or layer of cells.
2. a stratum in the human brain composed of fibers from the body and splenium of the corpus callosum sweeping around the lateral ventricle.

tapetum cellulosum
a type of tapetum lucidum made of cells called iridocytes, as found in carnivores.
choroidal tapetum
see tapetum lucidum (below).
tapetum fibrosum
a type of tapetum lucidum composed predominantly of organized bundles of collagen as found in ungulates.
tapetum lucidum
the iridescent reflecting tissue layer of the choroid of some species of animals that gives their eyes the property of shining in the dark. It is characteristic of nocturnal animals and allows incident light two opportunities to stimulate the retinal receptors. Called also choroidal tapetum.
References in periodicals archive ?
When the disc was entirely surrounded by tapetum, pigmented ring (partial or complete) was seen around the disc (German Shepherds-1, Old English Sheep Dog-2).
Visual streak or area centralis, area in tapetum where large retinal blood vessels were absent, situated laterally and somewhat dorsally from the disc was seen in three dogs.
It is interesting that abnormal phenomena in the tapetum of sterile plants were observed during metaphase period of the development of the wall of pollen sac.
However, in fertile plants, the middle layers gradually dissociated and were finally absorbed by the tapetum (Fig.
To date our knowledge is insufficient to provide plausible answers to why many plants produce orbicules and why they are absent in several evolutionary successful lineages, even when they are characterized by a parietal tapetum type (e.
The current study aims at (1) providing a summary of all data available on orbicule presence/absence in the flowering plants; (2) identifying patterns in the distribution data by mapping them on a recent angiosperm classification; (3) discussing correlations with tapetum types, pollination syndromes and other traits.
The tapetum showed visible signs of degeneration between the late microspore stage (Fig.
Initial differences noted were a greater disorganization of the cytoplasmic organelles in both the cells of the tapetum and parietal layer (Fig.
Records of tapetum type in monocotyledons and some "primitive" dicotyledons, both new and from the literature, are given in Table I.
The secretory tapetum is composed of cells usually with large nuclei [ILLUSTRATION FOR FIGURES 1, 64, 67 OMITTED], and it stains dark due to the cytoplasmic contents of lipids, proteins, and sporopollenin precursors [ILLUSTRATION FOR FIGURES 4, 5, 38, 42, 45, 47-50, 54, 62, 63, 65, 66 OMITTED].
Exine (Ex) and Intine (In) are formed in this stage (fig 2 E) and tapetum in this plant is plasmodial type.
parietal, glandular, or cellular non-syncytial) tapetum and the amoeboid (a.