focal
121focal adhesions — Areas of close apposition, and thus presumably anchorage points, of the plasma membrane of a fibroblast (for example) to the substratum over which it is moving. Usually 1 x 0.2 m m with the long axis parallel to the direction of movement; always… …
122focal plane — Optics. 1. a plane through a focal point and normal to the axis of a lens, mirror, or other optical system. Cf. principal plane. 2. the transverse plane in a telescope where the real image of a distant view is in focus. [1890 95] * * * …
123focal point — 1. Also called principal focus. Optics. either of two points on the axis of a mirror, lens, or other optical system, one point being such that rays diverging from it are deviated parallel to the axis upon refraction or reflection by the system… …
124focal length — noun The distance at which something (e.g. a lens, mirror etc.) is in focus; in air it is the distance along the optical axis from a principal plane of the lens to one of the lenss focal points …
125focal distance — (of the eye) the distance between the lens and the point behind the lens at which light from a distant object is focused. In a normally sighted person the point of focus is on the retina, but in myopia (short sightedness) the focus is in front of …
126focal adhesion — a specialized area of the plasma membrane, characterized by clusters of integrins that transduce transmembrane signals and link actin filaments of the cytoskeleton to the extracellular matrix. Called also focal contact …
127focal interval — the distance from the anterior to the posterior focal point; called also Sturm i …
128focal length — (f) The distance from the lens to the principal focus is a primary descriptive parameter for the lens, when considering a thin simple lens. Focal length determines image size at a given lens to subject distance …
