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in man and vertebrates, cone-shaped photoreceptors of the eye that function in the perception of daylight and provide color vision. They are located, together with the rods, in the outer layer of the retina.

The cones are made up of an external segment, an internal segment, a connective fiber, a nucleus-containing portion, and an internal fiber that ends in a thickening in which a synaptic juncture is established with the bipolar and horizontal nerve cells of the retina. The ultrastructure of the cone indicates that the external segment is a derivative of cilia. It is constructed of numerous membranous disks containing visual pigment. The internal segment contains mitochondria and a fat drop. In many vertebrates the internal segment also contains a contractile element called the myoid. The external and internal segments are joined by a delicate structure that consists of nine pairs of double threads distributed along the periphery; the central pair of threads, characteristic of movable cilia, is absent.

Cones predominate over rods in the retinas of diurnal animals (for example, the suslik has only rods). In man, cones predominate at the center of the retina and rods predominate along the edges. The central depression, or fovea, contains only cones.


References in periodicals archive ?
Located around the corner from Hot Spot in Defence, it's a small, almost congested, two-storey cafe with a wooden interior, a 'Nutella fountain', and a baking station rolling out cones live in one corner.
This is to add texture to the overall look, and they help keep the cones steady and in place.
Sabesan and colleagues discerned this color vision strategy by stimulating 273 individual cones in the eyes of two men.
M2 EQUITYBITES-September 30, 2016-Joy Cone Acquires BoDeans Baking, Mexican Ice Cream Cone Maker Altesa
The King Cone Choc Brownie, chocolate and fudge-flavoured ice cream wrapped in an American Style wafer cone.
Three generations of Oregon's Cone family carved a business empire out of Lane County's forests, starting in the late 1800s.
For people with damaged eyesight repairing the cones is most important because it would restore day-time color vision.
The researchers asserted that this shows some hope for stem cell therapy that could regenerate damaged cones in people, especially in the cone-rich regions of the retina that provide daytime/colour vision.
Stable Micro Systems, leading designer and manufacturer of texture analysis equipment, has introduced new testing possibilities for ice cream cone manufacturers.
Brian O'Mara, Vice President of Marketing for Baskin-Robbins, said, "The miniature dessert trend continues to grow and gain popularity across the country, and our new Mini Cones certainly fit right in," said.
Then we continued this for every other coloured cones until we had a complete collection of every coloured cone which made up my golf course.