point of fixation

point (point)

1. a small area or spot; the sharp end of an object.

2. to approach the surface, like the pus of an abscess, at a definite spot or place.

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point A  a radiographic, cephalometric landmark, determined on the lateral head film; it is the most retruded part of the curved bony outline from the anterior nasal spine to the crest of the maxillary alveolar process.

acupuncture point  acupoint.

point B  a radiographic cephalometric landmark, determined on the lateral head film; it is the most posterior midline point in the concavity between the infradentale and pogonium.

boiling point  the temperature at which a liquid will boil; at sea level, water boils at 100°C (212°F).

cardinal points 

1. the points on the different refracting media of the eye that determine the direction of the entering or emerging light rays.

2. four points within the pelvic inlet—the two sacroiliac articulations and the two iliopectineal eminences.

craniometric point  one of the established points of reference for measurement of the skull.

far point  the remotest point at which an object is clearly seen when the eye is at rest.

point of fixation 

1. the point on which the vision is fixed.

2. the point on the retina on which are focused the rays coming from an object directly regarded.

freezing point  the temperature at which a liquid begins to freeze; for water, 0°C, or 32°F.

isoelectric point  the pH of a solution at which a charged molecule does not migrate in an electric field.

jugal point  the point at the angle formed by the masseteric and maxillary edges of the zygomatic bone.

lacrimal point  the opening on the lacrimal papilla of an eyelid, near the medial angle of the eye, into which tears from the lacrimal lake drain to enter the lacrimal canaliculi.

McBurney point  a point of special tenderness in appendicitis, about one-third the distance between the right anterior superior iliac spine and the umbilicus.

McBurney point.

point of maximal impulse  the point on the chest where the impulse of the left ventricle is felt most strongly, normally in the fifth costal interspace inside the mammillary line. Abbreviated PMI.

melting point  (mp) the minimum temperature at which a solid begins to liquefy.

near point  the nearest point of clear vision, the absolute near p. being that for either eye alone with accommodation relaxed, and the relative near p. that for both eyes with the employment of accommodation.

nodal points  two points on the axis of an optical system situated so that a ray falling on one will produce a parallel ray emerging through the other.

pressure point 

1. a point that is particularly sensitive to pressure.

2. one of various locations on the body at which digital pressure may be applied for the control of hemorrhage.

Various pressure points used to control hemorrhage.

subnasal point  the central point at the base of the nasal spine.

trigger point  a spot on the body at which pressure or other stimulus gives rise to specific sensations or symptoms.

triple point  the temperature and pressure at which the solid, liquid, and gas phases of a substance are in equilibrium.

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point of fixation

n.

The point on the retina at which the light rays coming directly from an object are focused. Also called fixation point.