| nodal point | One of two point's in a compound optical system so related that a ray directed toward the first point will appear to have passed through the second point parallel to its original direction. Synonym: axial point. (05 Mar 2000) |
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| subnasal point | The centre of the root of the anterior nasal spine. Synonym: apophysary point, apophysial point, spinal point. (05 Mar 2000) |
| Sudeck's critical point | Region in the colon between the supply of the sigmoid arteries and that of the superior rectal artery. (05 Mar 2000) |
| supra-auricular point | A craniometric point on the posterior root of the zygomatic process of the temporal bone directly above the auricular point. (05 Mar 2000) |
| supranasal point | <anatomy> The supraorbital point. Origin: NL, fr. Gr, the brow. Source: Websters Dictionary (01 Mar 1998) |
| supraorbital point | <anatomy> The supraorbital point. Origin: NL, fr. Gr, the brow. Source: Websters Dictionary (01 Mar 1998) |
| sylvian point | The nearest point on the skull to the lateral (sylvian) fissure, about 30 mm behind the zygomatic process of the frontal bone. (05 Mar 2000) |
| dew-point | <meteorology> The temperature at which dew begins to form. It varies with the humidity and temperature of the atmosphere. Source: Websters Dictionary (01 Mar 1998) |
| double-point threshold | The least degree of separation of two points applied to the body surface that permits of their being felt as two. (05 Mar 2000) |
| incident point | The point at which a light ray enters an optical system. (05 Mar 2000) |
| incisal point | The point located between the incisal edges of the lower central incisors; the graphic projection of the excursions of the incisal point in certain planes is generally used to illustrate the envelope of motion of mandibular movement. (05 Mar 2000) |
| isoelectric point | <biochemistry> The pH at which a protein carries no net charge. Below the isoelectric point proteins carry a net positive charge, above it a net negative charge. Due to a preponderance of weakly acid residues in almost all proteins, they are nearly all negatively charged at neutral pH. The isoelectric point is of significance in protein purification because it is the pH at which solubility is often minimal and at which mobility in an electrofocusing system is zero (and therefore the point at which the protein will accumulate). (18 Nov 1997) |
| isoionic point | The pH at which a zwitterion has an equal number of positive and negative charges; in water and in the absence of other solutes, this is the isoelectric point. (05 Mar 2000) |
| isosbestic point | <physics> In applied spectroscopy, a wavelength at which absorbance of two substances, one of which can be converted into the other, is the same. (05 Mar 2000) |
| occipital point | The most prominent posterior point on the occipital bone above the inion. (05 Mar 2000) |