Cone cells are somewhat shorter than rods, but wider and tapered, and are much less numerous than rods in most parts of the retina, but greatly outnumber rods in the fovea.Structurally, cone cells have a cone-like shape at one end where a pigment filters incoming light, giving them their different response curves.They are typically 40–50 µm long, and their diameter varies from 0.5 …

In vertebrates, activation of a photoreceptor cell is a hyperpolarization (inhibition) of the cell. When they are not being stimulated, such as in the dark, rod cells and cone cells depolarize and release a neurotransmitter spontaneously. This neurotransmitter hyperpolarizes the bipolar cell.Bipolar cells exist between photoreceptors and ganglion cells and act to transmit signals …

Rod and cone photoreceptors are found on the outermost layer of the retina; they both have the same basic structure.Closest to the visual field (and farthest from the brain) is the axon terminal, which releases a neurotransmitter called glutamate to bipolar cells.Farther back is the cell body, which contains the cell's organelles.Farther back still is the inner segment, a specialized part …

Axon guidance (also called axon pathfinding) is a subfield of neural development concerning the process by which neurons send out axons to reach their correct targets. Axons often follow very precise paths in the nervous system, and how they manage to find their way so accurately is an area of ongoing research.

A crusher is a machine designed to reduce large rocks into smaller rocks, gravel, sand or rock dust.. Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials (as in rock ore), so that pieces of different composition can be differentiated.

A viewing cone is thus defined by a locus (a closed line) in this coordinate system as indicated by the rectangle and the ellipse in fig. 4. If a viewing cone is specified by four directions only (e.g. in the horizontal and the vertical plane), it does not become clear if it is the rectangle or the elliptical cone according to fig. 4.

A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts).In these devices, one shaft is typically attached to an engine or other power unit (the driving member), while the other shaft (the driven member) …

A tweeter or treble speaker is a special type of loudspeaker (usually dome, inverse dome or horn-type) that is designed to produce frequencies in the upper range of human hearing, typically high frequencies from 3kHz up to 20kHz but often exceeding that range.The name is derived from the high pitched sounds made by some birds (tweets), especially in contrast to the low woofs made …

The Southern Cone (Spanish: Cono Sur, Portuguese: Cone Sul) is a geographical and cultural subregion composed of the southernmost areas of South America, mostly south of the Tropic of Capricorn.Traditionally, it covers Argentina, Chile, and Uruguay, bounded on the west by the Pacific Ocean and on the east by the Atlantic Ocean.In terms of social, economic and political …

pl. apices The tip; the point furthest from the point of attachment. aphananthous (of flowers) Inconspicuous or unshowy, as opposed to phaneranthous or showy. aphlebia pl. aphlebiae Imperfect or irregular leaf endings commonly found on ferns and fossils of ferns from the Carboniferous Period. aphyllous Leafless; having no leaves. apical At or on the apex of a …